Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers as opposed to 26ers.
Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers...
Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers as opposed to 26ers.
They are also expensive. Maybe not so much compared to xtr or x01 but considering manufacturers would have to use a completely different frame design to hit most price points it’s unlikely they’ll become mass market until they are cheaper or the demand is high enough for them that they’ll cheapen builds elsewhere.
I don't know much about the differences between Pinion and Effigear, but I always wondered why so many gearbox mountain bikes seem to be going with...
I don't know much about the differences between Pinion and Effigear, but I always wondered why so many gearbox mountain bikes seem to be going with Pinion. The high pivot Effigear design seems superior to me. But even a lot of the high pivot designs choose a Pinion with an idler over an Effigear with an offset output shaft. There must be some drawbacks I'm not aware of?
Sorry, I missed this.
I was in contact with Effigear guys a few years back. I was told that in their case, you need to have the relative motion of the output shaft faster than the relative motion of the input shaft to release the shift mechanism to shift in one of the two ways (only one, not both). I forgot if it was shifting to an easier gear or a harder gear though.
Now, in practice that means they used a hub with no freewheel on it and a taught chain/belt, so the rear wheel 'powered' the gearbox. That meant that you let off the pedals and the rear wheel released the shifting mechanism. If you used a standard hub (with a freewheel), you had to backpedal a bit to release it, which is cumbersome to say the least.
That second point meant a suspension design that didn't use a concentric single pivot design wasn't possible or practical. That and their use of the housings meant a very specific frame design. A Pinion is much more interchangeable with a classic derailleur design, you maybe have to move a few pivots (like you have to with an e-bike - I'm really surprised the pinion electric strategy is their gearbox with an inhub motor as opposed to a modified casing with a motor attached to the output shaft, that would be so simple and practical, but i digress).
Now, I was asking the effigear guys what's up regarding the above points on their new design on Instagram yesterday and the reply was 'you can choose whatever you want' hub wise and 'the shifting mechanism is the same'. So either they updated that or it will be a cumbersome thing. I'm betting on the first given that Cavaliere also now has non-concentric designs as well.
As for gears, Effigear is sticking to their 490 %, Pinion is in the lead here with 600 % and their option of 9, 12 or 18 gears as opposed to the 9 of the Effigear.
Ideally I'd have a Pinion with all the clunk down low then and extended casing with an output gear higher up to facilitate high pivots with little maintenance (as opposed to using a jackshaft and two chains).
EDIT: maybe one additional point as a benefit of all gearboxes, it's much easier to get equal steps between gears because you can vary the modulo of the gears to get the desired gear ratio, where the modulo for the cassette-chain drivetrain is fixed at 0,5 inches.
Looks like DVO have a progressive coil coming. Seems to say prorate on one part and then have one spring rate and a dash next to it. Plus it looks like some of the coils are closer together
Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers...
Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers as opposed to 26ers.
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn parts, cross-chaining, poor lube and poor cleaning practises than they would from a gearbox!
New bike from specialized With some top riders and guerilla marketing strategy. #statusmtb on IG.
Can tell it’s a specialized from the heat tube/down tube junction, linkage, stays, and everyone on IG has Butcher tires.
Looks to be a dedicated mullet setup.
Would be pretty great if Specialized made a play against the YT/Canyon with a B2C sub-2000 all-arounder with solid geo and some profit line to local bike shops thru an upgrade catalog like KTM PowerParts, plus some type of optional service contracts/vouchers.
yep the old status was a free ride weapon back in the day, bring back the Big Hit!!!
I had one of those enduro evo's with the 180mm boxxers, Sort of before it's time in a way. If it was 1260mm wheelbase, mullet, 12 speed with dropper people would be losing their shit.
Kenda's launching a new Aaron Gwin signature tire, the Pinner Pro. (BikeRadar over in the UK with the 12:01 a.m. post--I'm guessing the US outlets will be out of embargo in a couple hours? Link) I hope somebody does a back-to-back test of Gwin's Onza tire and his Kenda tire now.
yep the old status was a free ride weapon back in the day, bring back the Big Hit!!!
I had one of those enduro evo's with...
yep the old status was a free ride weapon back in the day, bring back the Big Hit!!!
I had one of those enduro evo's with the 180mm boxxers, Sort of before it's time in a way. If it was 1260mm wheelbase, mullet, 12 speed with dropper people would be losing their shit.
I always really liked those. In 2002, I bought my first real bike - a brand new Norco VPS Shore with the super dialed 2002 Monster T. That bike was a little heavier and the geo more outdated, but was part of the same thread of pedal-able dual crown aggressive trail bikes.
I podiumed some races on that bike - from weird, fringe freeride races to downhill to even a short course XC race. I was 14 and also a gym rat then, but I haven’t had a bike that well rounded since my 2015 Patrol.
Even though I worked in shops for a long time and loved fancy boutique bikes I used to buy - and built many miles of unsanctioned extreme trails...as a new father, I’m really looking forward to capable and fun bikes under $2000 that are approachable to the masses, and get more people out to public trail centers.
High-end, fringe, weird is ok for some - but there’s a lot higher likelihood my kid(s) will also enjoy the sport if it’s accessible and they have peers that are into it, too.
Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers...
Because they are heavy and draggy. But they could have huge benefits for high pivot bikes. And high pivot bikes could have huge benefits for 29ers as opposed to 26ers.
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn...
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn parts, cross-chaining, poor lube and poor cleaning practises than they would from a gearbox!
I ride a hardtail with a Pinion gearbox and I really can't feel any drag from the drivetrain.
if it were a road bike on smooth roads, sure you would feel it.
Also 600% is way too much range for general mtb usage. I rarely use 1st gear and never get above 9/10 on the trail. only when going for it on a flat road do I reach 12. Next time I'd save the 200g and go with 9 speed.
Looks like DVO have a progressive coil coming. Seems to say prorate on one part and then have one spring rate and a dash next to...
Looks like DVO have a progressive coil coming. Seems to say prorate on one part and then have one spring rate and a dash next to it. Plus it looks like some of the coils are closer together
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn...
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn parts, cross-chaining, poor lube and poor cleaning practises than they would from a gearbox!
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency of 0,99 and each gear pair also has an efficiency of 0,99 (in the case of steel gears, which we have with Pinion). It's generalisation, but still. In a Pinion gearbox, the driven branch will have at least 6 bearings and 2 gear pairs doing the transmissioning of power from the pedals to the chain. Take away two bearings to substitute the bottom bracket of a classic derailleur transmission and you have 4 bearings and two gear pairs, giving you an efficiency of 0,99^6 = 94 %. So by design, the Pinion will lose _at least_ 6 % compared to the classical transmission because of the components a cassette-derailleur transmission doesn't have. You win some of that back with a straighter chain in the case of the Pinion, while a dirty and worn drivetrain is neither here nor there, it's more or less equal for both sides (okay, you could argue this issue is exacerbated with a worn chain, buy maybe the bendiness is actually improved with wear).
The kicker? With a P1.12 gearbox besides the powered branch I mentioned you also spin additional 5 gear pairs (it's a 3x4 layout, a two stage gearbox) where at least one of those two needs to be bearinged. They are not powered, so power losses will be smaller than on the driven branch, but the losses are still present.
Now, I do believe Pinion is relatively okay, I wouldn't be surprised if a Pinion is less lossy on it's own than say a DH casing, half empty aggro tread tyre is.
An additional remark, gearboxes being heavy I think came out of Rohloff internal gear hubs, where planetary drives are used. These use at least 3 planet gears which means, by definition, at least 6 bearing pair contacts (with each planet interfacing with the sun and the ring gear). And 3 bearings. The more planets you have, the more losses you have. So a Rohloff will be on the back foot from the start. And it could be the reason gearboxes are though to be draggy.
I ride a hardtail with a Pinion gearbox and I really can't feel any drag from the drivetrain.
if it were a road bike on smooth...
I ride a hardtail with a Pinion gearbox and I really can't feel any drag from the drivetrain.
if it were a road bike on smooth roads, sure you would feel it.
Also 600% is way too much range for general mtb usage. I rarely use 1st gear and never get above 9/10 on the trail. only when going for it on a flat road do I reach 12. Next time I'd save the 200g and go with 9 speed.
Sorry for the double post, but it's the Vital way... (I usually join these on other platforms).
What kind of tyre do you ride? Aiming at my previous post here.
Regarding the range, Pinion's P1.9 gearboxes have either 568 % of range (XR model) or 364 % (CR model). The latter is useless of course (this is essentially a 11-40 cassette, when even a 10-42 is not enough). The 568 % miiiight be a bit much, 520 % probably would be enough, I feel very well covered with the 500 % of Eagle range. Looking at the P1.9XR, the jumps are 24 %. Going to 20 % jumps in 9 gears gives you a range of 430 % which is not really enough and people already like to moan about the jumps in the cassettes we have now (case in point, Shimano 12sp 10-45 Rhythm cassette). So P1.12 with the 17,7 % jump between gears isn't that wrong. 600 % is too much range? A 16 % between gears would get you to 500 % of range, so just a little change between gears causes such a big change overall. So you're not profiting THAT much (2 percentage points) but keeping everything else the same. So you're saving 200 g to get much larger jumps between gears or get a really pitiful range of them. I'm taking the 200g.
Plus, the product has to cover a large variety of use cases. We have climbs where a 30-50 combo on a 29er is a must for a vast majority of people, yet on a slight downhill it's easy to spin up to 30-10 combo. On the same ride. And I'm well aware (from the ton of '11-36 and a single ring is enough, otherwise just walk or get fitter' comments on the internet) that people live in flatter areas. But then they could provide a custom gearing service. And that would get expensive really fast
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency...
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency of 0,99 and each gear pair also has an efficiency of 0,99 (in the case of steel gears, which we have with Pinion). It's generalisation, but still. In a Pinion gearbox, the driven branch will have at least 6 bearings and 2 gear pairs doing the transmissioning of power from the pedals to the chain. Take away two bearings to substitute the bottom bracket of a classic derailleur transmission and you have 4 bearings and two gear pairs, giving you an efficiency of 0,99^6 = 94 %. So by design, the Pinion will lose _at least_ 6 % compared to the classical transmission because of the components a cassette-derailleur transmission doesn't have. You win some of that back with a straighter chain in the case of the Pinion, while a dirty and worn drivetrain is neither here nor there, it's more or less equal for both sides (okay, you could argue this issue is exacerbated with a worn chain, buy maybe the bendiness is actually improved with wear).
The kicker? With a P1.12 gearbox besides the powered branch I mentioned you also spin additional 5 gear pairs (it's a 3x4 layout, a two stage gearbox) where at least one of those two needs to be bearinged. They are not powered, so power losses will be smaller than on the driven branch, but the losses are still present.
Now, I do believe Pinion is relatively okay, I wouldn't be surprised if a Pinion is less lossy on it's own than say a DH casing, half empty aggro tread tyre is.
An additional remark, gearboxes being heavy I think came out of Rohloff internal gear hubs, where planetary drives are used. These use at least 3 planet gears which means, by definition, at least 6 bearing pair contacts (with each planet interfacing with the sun and the ring gear). And 3 bearings. The more planets you have, the more losses you have. So a Rohloff will be on the back foot from the start. And it could be the reason gearboxes are though to be draggy.
what about the two jockey wheels & bearings in a derailleur?
What I think is they don't do much because the chain is relatively slack (tensioned only by the derailleur cage in fact). That means any articulation and rotation will take up relatively small amounts of energy (or power) since the friction losses will be reduced.
That same fact is why I think idler pulleys also sometimes maybe feel draggy (I haven't had the chance to ride a bike with one yet, so going off Internet banter here) and most certainly are noisy - idler pulleys are invariably small.
Story time. With the classical drivetrain layout your chain is taught, how much depending on the power output, from the last tooth in contact with the cassette to the first tooth in contact with the chainring. As soon as you get to the second tooth (on either side), the amount of force applied to the chain lowers because of elasticity of both the sprocket and the chain (and a bit due to geometry of the forces acting on the system and all). Ballparking here, but I'd say somewhere around 5 to 10 teeth in all your tension in the chain is gone (depending on the sprocket size of course, it's probably 2 teeth for a 10T sprocket and up to 10 on a 50T sprocket). A similar story happens with threads in bolts and nuts, almost 90 % of the load is carried by the first three threads, then it all tapers off.
How does that all connect together? Your chain losses come from the rotation of the links. The bigger the chainring/sprocket, the less each link rotates when it wraps around the sprocket. Plus in a classical drivetrain the chain only unwraps once (coming off the cassette) and wraps (wrapping around the front chainring) once when it is taught, therefore producing any meaningful loss in the system from friction. All other movement of the chain is in a relatively slack condition and has much lower losses.
The idler? It adds a whole another unwrapping and rewrapping of the chain in the powered state and I think the chain is taught all around it because it's essentially pulled from both sides. Add the fact that idlers are small, increasing the angle of rotation in the links and you get more losses, more noise from all the tension, etc.
I hope I made it clear enough, if anything is not clear I can easily try to explain it again
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn...
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn parts, cross-chaining, poor lube and poor cleaning practises than they would from a gearbox!
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency...
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency of 0,99 and each gear pair also has an efficiency of 0,99 (in the case of steel gears, which we have with Pinion). It's generalisation, but still. In a Pinion gearbox, the driven branch will have at least 6 bearings and 2 gear pairs doing the transmissioning of power from the pedals to the chain. Take away two bearings to substitute the bottom bracket of a classic derailleur transmission and you have 4 bearings and two gear pairs, giving you an efficiency of 0,99^6 = 94 %. So by design, the Pinion will lose _at least_ 6 % compared to the classical transmission because of the components a cassette-derailleur transmission doesn't have. You win some of that back with a straighter chain in the case of the Pinion, while a dirty and worn drivetrain is neither here nor there, it's more or less equal for both sides (okay, you could argue this issue is exacerbated with a worn chain, buy maybe the bendiness is actually improved with wear).
The kicker? With a P1.12 gearbox besides the powered branch I mentioned you also spin additional 5 gear pairs (it's a 3x4 layout, a two stage gearbox) where at least one of those two needs to be bearinged. They are not powered, so power losses will be smaller than on the driven branch, but the losses are still present.
Now, I do believe Pinion is relatively okay, I wouldn't be surprised if a Pinion is less lossy on it's own than say a DH casing, half empty aggro tread tyre is.
An additional remark, gearboxes being heavy I think came out of Rohloff internal gear hubs, where planetary drives are used. These use at least 3 planet gears which means, by definition, at least 6 bearing pair contacts (with each planet interfacing with the sun and the ring gear). And 3 bearings. The more planets you have, the more losses you have. So a Rohloff will be on the back foot from the start. And it could be the reason gearboxes are though to be draggy.
Yeah you're pretty spot on at 94% efficiency, thats consistent with the average measured power losses I've seen recorded for the pinion. If you compare it to the data from zerofrictioncycling.com, who have the best drivetrain data I have seen -
Factor in the vast differences in contamination resistance or absorption, differing levels of
chain and drive train maintenance, and real world differences between chains can easily be
10w+. There are cyclists using –unbeknownst to them – a poor performing lubricant and
with average attention to maintenance who will literally be running a 15 to 20w loss chain at
250w load, vs cycling buddies on a top performing lubricant with good maintenance sitting
anywhere between around 5 to 8w loss.
You can get bang on equal loss in power between the 2 (250w x .94 - 5w (for a good lube) = 230, 250w-20w (for a poor drivetrain) = 230!)
What I think is they don't do much because the chain is relatively slack (tensioned only by the derailleur cage in fact). That means any articulation...
What I think is they don't do much because the chain is relatively slack (tensioned only by the derailleur cage in fact). That means any articulation and rotation will take up relatively small amounts of energy (or power) since the friction losses will be reduced.
That same fact is why I think idler pulleys also sometimes maybe feel draggy (I haven't had the chance to ride a bike with one yet, so going off Internet banter here) and most certainly are noisy - idler pulleys are invariably small.
Story time. With the classical drivetrain layout your chain is taught, how much depending on the power output, from the last tooth in contact with the cassette to the first tooth in contact with the chainring. As soon as you get to the second tooth (on either side), the amount of force applied to the chain lowers because of elasticity of both the sprocket and the chain (and a bit due to geometry of the forces acting on the system and all). Ballparking here, but I'd say somewhere around 5 to 10 teeth in all your tension in the chain is gone (depending on the sprocket size of course, it's probably 2 teeth for a 10T sprocket and up to 10 on a 50T sprocket). A similar story happens with threads in bolts and nuts, almost 90 % of the load is carried by the first three threads, then it all tapers off.
How does that all connect together? Your chain losses come from the rotation of the links. The bigger the chainring/sprocket, the less each link rotates when it wraps around the sprocket. Plus in a classical drivetrain the chain only unwraps once (coming off the cassette) and wraps (wrapping around the front chainring) once when it is taught, therefore producing any meaningful loss in the system from friction. All other movement of the chain is in a relatively slack condition and has much lower losses.
The idler? It adds a whole another unwrapping and rewrapping of the chain in the powered state and I think the chain is taught all around it because it's essentially pulled from both sides. Add the fact that idlers are small, increasing the angle of rotation in the links and you get more losses, more noise from all the tension, etc.
I hope I made it clear enough, if anything is not clear I can easily try to explain it again
*I am not an engineer and have no actual knowledge of these sorts of things*
This is an interesting point brought up with idler pulleys - they definitely do not follow 'efficiency guidelines' like track cyclists do, where they make a gear ratio with the largest possible chainring + sprocket to minimize chain articulation.
That being said, it is the articulation of the chain that seems to matter more than the size of the ring. Would an idler like the prototype Norco Aurum (where it sat only a bit above the chainring) be inherently more efficient than the Aurum HSP since the chain articulates less, no matter the pulley size?
All that being said, why are companies using such small pulley wheels for idler bikes? I would like to think it's not a weight thing since an idler is going to add weight anyway - what's the difference in adding 200 vs 210 grams? Though that is enough to dissuade some. Is it an availability thing? Maybe no one is making 50 tooth pie plates for idler bikes for some reason? Is this the Illuminati?!?!?
Status is definitely interesting, I’m sure it will sell well but the sub $2000 references above are way off. In those photos, it has the same exact spec as the sj evo comp which is $3700.
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn...
The drag complaint is funny because I would bet that at least 50% of people with derailleur bikes are experiencing more power loss dues to worn parts, cross-chaining, poor lube and poor cleaning practises than they would from a gearbox!
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency...
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency of 0,99 and each gear pair also has an efficiency of 0,99 (in the case of steel gears, which we have with Pinion). It's generalisation, but still. In a Pinion gearbox, the driven branch will have at least 6 bearings and 2 gear pairs doing the transmissioning of power from the pedals to the chain. Take away two bearings to substitute the bottom bracket of a classic derailleur transmission and you have 4 bearings and two gear pairs, giving you an efficiency of 0,99^6 = 94 %. So by design, the Pinion will lose _at least_ 6 % compared to the classical transmission because of the components a cassette-derailleur transmission doesn't have. You win some of that back with a straighter chain in the case of the Pinion, while a dirty and worn drivetrain is neither here nor there, it's more or less equal for both sides (okay, you could argue this issue is exacerbated with a worn chain, buy maybe the bendiness is actually improved with wear).
The kicker? With a P1.12 gearbox besides the powered branch I mentioned you also spin additional 5 gear pairs (it's a 3x4 layout, a two stage gearbox) where at least one of those two needs to be bearinged. They are not powered, so power losses will be smaller than on the driven branch, but the losses are still present.
Now, I do believe Pinion is relatively okay, I wouldn't be surprised if a Pinion is less lossy on it's own than say a DH casing, half empty aggro tread tyre is.
An additional remark, gearboxes being heavy I think came out of Rohloff internal gear hubs, where planetary drives are used. These use at least 3 planet gears which means, by definition, at least 6 bearing pair contacts (with each planet interfacing with the sun and the ring gear). And 3 bearings. The more planets you have, the more losses you have. So a Rohloff will be on the back foot from the start. And it could be the reason gearboxes are though to be draggy.
Yeah you're pretty spot on at 94% efficiency, thats consistent with the average measured power losses I've seen recorded for the pinion. If you compare it...
Yeah you're pretty spot on at 94% efficiency, thats consistent with the average measured power losses I've seen recorded for the pinion. If you compare it to the data from zerofrictioncycling.com, who have the best drivetrain data I have seen -
Factor in the vast differences in contamination resistance or absorption, differing levels of
chain and drive train maintenance, and real world differences between chains can easily be
10w+. There are cyclists using –unbeknownst to them – a poor performing lubricant and
with average attention to maintenance who will literally be running a 15 to 20w loss chain at
250w load, vs cycling buddies on a top performing lubricant with good maintenance sitting
anywhere between around 5 to 8w loss.
You can get bang on equal loss in power between the 2 (250w x .94 - 5w (for a good lube) = 230, 250w-20w (for a poor drivetrain) = 230!)
And I agree, I think most peoples perception of Gearboxes comes from Rohloff hubs!
Strangely enough, Rohloff hubs are MORE efficient than Pinion, and even more efficient than a 1x11 drivetrain when you're in the lowest gear and have the most severe offset chainline. Of course a 2x11 is the most efficient of them all since you can maintain a straighter chainline.
What I think is they don't do much because the chain is relatively slack (tensioned only by the derailleur cage in fact). That means any articulation...
What I think is they don't do much because the chain is relatively slack (tensioned only by the derailleur cage in fact). That means any articulation and rotation will take up relatively small amounts of energy (or power) since the friction losses will be reduced.
That same fact is why I think idler pulleys also sometimes maybe feel draggy (I haven't had the chance to ride a bike with one yet, so going off Internet banter here) and most certainly are noisy - idler pulleys are invariably small.
Story time. With the classical drivetrain layout your chain is taught, how much depending on the power output, from the last tooth in contact with the cassette to the first tooth in contact with the chainring. As soon as you get to the second tooth (on either side), the amount of force applied to the chain lowers because of elasticity of both the sprocket and the chain (and a bit due to geometry of the forces acting on the system and all). Ballparking here, but I'd say somewhere around 5 to 10 teeth in all your tension in the chain is gone (depending on the sprocket size of course, it's probably 2 teeth for a 10T sprocket and up to 10 on a 50T sprocket). A similar story happens with threads in bolts and nuts, almost 90 % of the load is carried by the first three threads, then it all tapers off.
How does that all connect together? Your chain losses come from the rotation of the links. The bigger the chainring/sprocket, the less each link rotates when it wraps around the sprocket. Plus in a classical drivetrain the chain only unwraps once (coming off the cassette) and wraps (wrapping around the front chainring) once when it is taught, therefore producing any meaningful loss in the system from friction. All other movement of the chain is in a relatively slack condition and has much lower losses.
The idler? It adds a whole another unwrapping and rewrapping of the chain in the powered state and I think the chain is taught all around it because it's essentially pulled from both sides. Add the fact that idlers are small, increasing the angle of rotation in the links and you get more losses, more noise from all the tension, etc.
I hope I made it clear enough, if anything is not clear I can easily try to explain it again
[i]*I am not an engineer and have no actual knowledge of these sorts of things*[/i]
This is an interesting point brought up with idler pulleys -...
*I am not an engineer and have no actual knowledge of these sorts of things*
This is an interesting point brought up with idler pulleys - they definitely do not follow 'efficiency guidelines' like track cyclists do, where they make a gear ratio with the largest possible chainring + sprocket to minimize chain articulation.
That being said, it is the articulation of the chain that seems to matter more than the size of the ring. Would an idler like the prototype Norco Aurum (where it sat only a bit above the chainring) be inherently more efficient than the Aurum HSP since the chain articulates less, no matter the pulley size?
All that being said, why are companies using such small pulley wheels for idler bikes? I would like to think it's not a weight thing since an idler is going to add weight anyway - what's the difference in adding 200 vs 210 grams? Though that is enough to dissuade some. Is it an availability thing? Maybe no one is making 50 tooth pie plates for idler bikes for some reason? Is this the Illuminati?!?!?
I think it's a packaging issue. A small idler is very compact and relatively easy to implement.
As for the two Norcos, I think you're aiming at the wrapping angle, not articulation. The wrapping angle doesn't matter, the link will rotate the same once it's starting to wrap around a chainring regardless of how it wraps. It's only where it unwraps that the wrapping angle defines. The link rotation is the same for a given number of teeth regardless of the wrapping angle.
The number of teeth of a chainring define the radius around which the chain wraps and that defines how much each link has to rotate in regards to the neighbour. This is also connected to the polygon effect that is exhibited on small chainrings (and is supposedly the reason Sram went 10-42 for their 1x11 drivetrain as opposed to a 9T smallest sprocket they were testing in development - supposedly the variation in speed could be felt through the pedals?). The less teeth you have, the tighter the angle between two sides of a polygon and the more the links have to rotate.
This is all thinking out loud without any numbers, calculations or tests to back it up, but to me it's sound logic. I could be wrong.
As for the idlers, it has to be a packaging/practicality issue. But I would try out a mule with a layshaft. You are limited to how low you can position the main pivot then, since you can bring a small idler much closer than a layshaft with a 32T sprocket (on the output side), but with clever packaging (overlapping primary and secondary sprockets and using a pair of 22T sprockets for the first stage) it might be possible to get relatively close. It would be heavier and more complex to package, so there's a question if the packaging and weight headaches are worth the marginal gains in efficiency and noise, but you can't know unless you try
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency...
I wrote this in the morning but it somehow got lost... Anywho.
The way I was taught in college is that each bearing has an efficiency of 0,99 and each gear pair also has an efficiency of 0,99 (in the case of steel gears, which we have with Pinion). It's generalisation, but still. In a Pinion gearbox, the driven branch will have at least 6 bearings and 2 gear pairs doing the transmissioning of power from the pedals to the chain. Take away two bearings to substitute the bottom bracket of a classic derailleur transmission and you have 4 bearings and two gear pairs, giving you an efficiency of 0,99^6 = 94 %. So by design, the Pinion will lose _at least_ 6 % compared to the classical transmission because of the components a cassette-derailleur transmission doesn't have. You win some of that back with a straighter chain in the case of the Pinion, while a dirty and worn drivetrain is neither here nor there, it's more or less equal for both sides (okay, you could argue this issue is exacerbated with a worn chain, buy maybe the bendiness is actually improved with wear).
The kicker? With a P1.12 gearbox besides the powered branch I mentioned you also spin additional 5 gear pairs (it's a 3x4 layout, a two stage gearbox) where at least one of those two needs to be bearinged. They are not powered, so power losses will be smaller than on the driven branch, but the losses are still present.
Now, I do believe Pinion is relatively okay, I wouldn't be surprised if a Pinion is less lossy on it's own than say a DH casing, half empty aggro tread tyre is.
An additional remark, gearboxes being heavy I think came out of Rohloff internal gear hubs, where planetary drives are used. These use at least 3 planet gears which means, by definition, at least 6 bearing pair contacts (with each planet interfacing with the sun and the ring gear). And 3 bearings. The more planets you have, the more losses you have. So a Rohloff will be on the back foot from the start. And it could be the reason gearboxes are though to be draggy.
Yeah you're pretty spot on at 94% efficiency, thats consistent with the average measured power losses I've seen recorded for the pinion. If you compare it...
Yeah you're pretty spot on at 94% efficiency, thats consistent with the average measured power losses I've seen recorded for the pinion. If you compare it to the data from zerofrictioncycling.com, who have the best drivetrain data I have seen -
Factor in the vast differences in contamination resistance or absorption, differing levels of
chain and drive train maintenance, and real world differences between chains can easily be
10w+. There are cyclists using –unbeknownst to them – a poor performing lubricant and
with average attention to maintenance who will literally be running a 15 to 20w loss chain at
250w load, vs cycling buddies on a top performing lubricant with good maintenance sitting
anywhere between around 5 to 8w loss.
You can get bang on equal loss in power between the 2 (250w x .94 - 5w (for a good lube) = 230, 250w-20w (for a poor drivetrain) = 230!)
Strangely enough, Rohloff hubs are MORE efficient than Pinion, and even more efficient than a 1x11 drivetrain when you're in the lowest gear and have the...
Strangely enough, Rohloff hubs are MORE efficient than Pinion, and even more efficient than a 1x11 drivetrain when you're in the lowest gear and have the most severe offset chainline. Of course a 2x11 is the most efficient of them all since you can maintain a straighter chainline.
Well this is completely unexpected. I would really like some more details about the test (not much were given) and a possible explanation for this.
There is a possible mistake there though, it's said a faster moving chain (Pinion) is less efficient than the slower mowing chain (Rohloff). I'd say it should be the other way around, a faster moving chain transfers the same power with less chain tension, meaning less force in the chain, which I think should be beneficial for efficiency. Again, I could be wrong though.
I'd really like an explanation for those numbers though.
Status is definitely interesting, I’m sure it will sell well but the sub $2000 references above are way off. In those photos, it has the same...
Status is definitely interesting, I’m sure it will sell well but the sub $2000 references above are way off. In those photos, it has the same exact spec as the sj evo comp which is $3700.
As the first poster to make a “Sub-2000” reference...
I was not stating the build as pictured would be sub-2000, but rather that I think another good geometry full suspension bike that has builds starting under 2000 (in the spirit of the original Status) would be a good product position for a big company like Specialized to target. I also expanded and stated that a lower overhead sales model might help that position.
Status is definitely interesting, I’m sure it will sell well but the sub $2000 references above are way off. In those photos, it has the same...
Status is definitely interesting, I’m sure it will sell well but the sub $2000 references above are way off. In those photos, it has the same exact spec as the sj evo comp which is $3700.
As the first poster to make a “Sub-2000” reference...
I was not stating the build as pictured would be sub-2000, but rather that I think another...
As the first poster to make a “Sub-2000” reference...
I was not stating the build as pictured would be sub-2000, but rather that I think another good geometry full suspension bike that has builds starting under 2000 (in the spirit of the original Status) would be a good product position for a big company like Specialized to target. I also expanded and stated that a lower overhead sales model might help that position.
I feel like this is where Giant tried to go with the Stance, except they missed out on the whole 'good geometry' thing
I was in contact with Effigear guys a few years back. I was told that in their case, you need to have the relative motion of the output shaft faster than the relative motion of the input shaft to release the shift mechanism to shift in one of the two ways (only one, not both). I forgot if it was shifting to an easier gear or a harder gear though.
Now, in practice that means they used a hub with no freewheel on it and a taught chain/belt, so the rear wheel 'powered' the gearbox. That meant that you let off the pedals and the rear wheel released the shifting mechanism. If you used a standard hub (with a freewheel), you had to backpedal a bit to release it, which is cumbersome to say the least.
That second point meant a suspension design that didn't use a concentric single pivot design wasn't possible or practical. That and their use of the housings meant a very specific frame design. A Pinion is much more interchangeable with a classic derailleur design, you maybe have to move a few pivots (like you have to with an e-bike - I'm really surprised the pinion electric strategy is their gearbox with an inhub motor as opposed to a modified casing with a motor attached to the output shaft, that would be so simple and practical, but i digress).
Now, I was asking the effigear guys what's up regarding the above points on their new design on Instagram yesterday and the reply was 'you can choose whatever you want' hub wise and 'the shifting mechanism is the same'. So either they updated that or it will be a cumbersome thing. I'm betting on the first given that Cavaliere also now has non-concentric designs as well.
As for gears, Effigear is sticking to their 490 %, Pinion is in the lead here with 600 % and their option of 9, 12 or 18 gears as opposed to the 9 of the Effigear.
Ideally I'd have a Pinion with all the clunk down low then and extended casing with an output gear higher up to facilitate high pivots with little maintenance (as opposed to using a jackshaft and two chains).
EDIT: maybe one additional point as a benefit of all gearboxes, it's much easier to get equal steps between gears because you can vary the modulo of the gears to get the desired gear ratio, where the modulo for the cassette-chain drivetrain is fixed at 0,5 inches.
Can tell it’s a specialized from the heat tube/down tube junction, linkage, stays, and everyone on IG has Butcher tires.
Looks to be a dedicated mullet setup.
Would be pretty great if Specialized made a play against the YT/Canyon with a B2C sub-2000 all-arounder with solid geo and some profit line to local bike shops thru an upgrade catalog like KTM PowerParts, plus some type of optional service contracts/vouchers.
The name fits...
I had one of those enduro evo's with the 180mm boxxers, Sort of before it's time in a way. If it was 1260mm wheelbase, mullet, 12 speed with dropper people would be losing their shit.
I podiumed some races on that bike - from weird, fringe freeride races to downhill to even a short course XC race. I was 14 and also a gym rat then, but I haven’t had a bike that well rounded since my 2015 Patrol.
Even though I worked in shops for a long time and loved fancy boutique bikes I used to buy - and built many miles of unsanctioned extreme trails...as a new father, I’m really looking forward to capable and fun bikes under $2000 that are approachable to the masses, and get more people out to public trail centers.
High-end, fringe, weird is ok for some - but there’s a lot higher likelihood my kid(s) will also enjoy the sport if it’s accessible and they have peers that are into it, too.
if it were a road bike on smooth roads, sure you would feel it.
Also 600% is way too much range for general mtb usage. I rarely use 1st gear and never get above 9/10 on the trail. only when going for it on a flat road do I reach 12. Next time I'd save the 200g and go with 9 speed.
The way I was taught in college is that each bearing has an efficiency of 0,99 and each gear pair also has an efficiency of 0,99 (in the case of steel gears, which we have with Pinion). It's generalisation, but still. In a Pinion gearbox, the driven branch will have at least 6 bearings and 2 gear pairs doing the transmissioning of power from the pedals to the chain. Take away two bearings to substitute the bottom bracket of a classic derailleur transmission and you have 4 bearings and two gear pairs, giving you an efficiency of 0,99^6 = 94 %. So by design, the Pinion will lose _at least_ 6 % compared to the classical transmission because of the components a cassette-derailleur transmission doesn't have. You win some of that back with a straighter chain in the case of the Pinion, while a dirty and worn drivetrain is neither here nor there, it's more or less equal for both sides (okay, you could argue this issue is exacerbated with a worn chain, buy maybe the bendiness is actually improved with wear).
The kicker? With a P1.12 gearbox besides the powered branch I mentioned you also spin additional 5 gear pairs (it's a 3x4 layout, a two stage gearbox) where at least one of those two needs to be bearinged. They are not powered, so power losses will be smaller than on the driven branch, but the losses are still present.
Now, I do believe Pinion is relatively okay, I wouldn't be surprised if a Pinion is less lossy on it's own than say a DH casing, half empty aggro tread tyre is.
An additional remark, gearboxes being heavy I think came out of Rohloff internal gear hubs, where planetary drives are used. These use at least 3 planet gears which means, by definition, at least 6 bearing pair contacts (with each planet interfacing with the sun and the ring gear). And 3 bearings. The more planets you have, the more losses you have. So a Rohloff will be on the back foot from the start. And it could be the reason gearboxes are though to be draggy.
What kind of tyre do you ride? Aiming at my previous post here.
Regarding the range, Pinion's P1.9 gearboxes have either 568 % of range (XR model) or 364 % (CR model). The latter is useless of course (this is essentially a 11-40 cassette, when even a 10-42 is not enough). The 568 % miiiight be a bit much, 520 % probably would be enough, I feel very well covered with the 500 % of Eagle range. Looking at the P1.9XR, the jumps are 24 %. Going to 20 % jumps in 9 gears gives you a range of 430 % which is not really enough and people already like to moan about the jumps in the cassettes we have now (case in point, Shimano 12sp 10-45 Rhythm cassette). So P1.12 with the 17,7 % jump between gears isn't that wrong. 600 % is too much range? A 16 % between gears would get you to 500 % of range, so just a little change between gears causes such a big change overall. So you're not profiting THAT much (2 percentage points) but keeping everything else the same. So you're saving 200 g to get much larger jumps between gears or get a really pitiful range of them. I'm taking the 200g.
Plus, the product has to cover a large variety of use cases. We have climbs where a 30-50 combo on a 29er is a must for a vast majority of people, yet on a slight downhill it's easy to spin up to 30-10 combo. On the same ride. And I'm well aware (from the ton of '11-36 and a single ring is enough, otherwise just walk or get fitter' comments on the internet) that people live in flatter areas. But then they could provide a custom gearing service. And that would get expensive really fast
That same fact is why I think idler pulleys also sometimes maybe feel draggy (I haven't had the chance to ride a bike with one yet, so going off Internet banter here) and most certainly are noisy - idler pulleys are invariably small.
Story time. With the classical drivetrain layout your chain is taught, how much depending on the power output, from the last tooth in contact with the cassette to the first tooth in contact with the chainring. As soon as you get to the second tooth (on either side), the amount of force applied to the chain lowers because of elasticity of both the sprocket and the chain (and a bit due to geometry of the forces acting on the system and all). Ballparking here, but I'd say somewhere around 5 to 10 teeth in all your tension in the chain is gone (depending on the sprocket size of course, it's probably 2 teeth for a 10T sprocket and up to 10 on a 50T sprocket). A similar story happens with threads in bolts and nuts, almost 90 % of the load is carried by the first three threads, then it all tapers off.
How does that all connect together? Your chain losses come from the rotation of the links. The bigger the chainring/sprocket, the less each link rotates when it wraps around the sprocket. Plus in a classical drivetrain the chain only unwraps once (coming off the cassette) and wraps (wrapping around the front chainring) once when it is taught, therefore producing any meaningful loss in the system from friction. All other movement of the chain is in a relatively slack condition and has much lower losses.
The idler? It adds a whole another unwrapping and rewrapping of the chain in the powered state and I think the chain is taught all around it because it's essentially pulled from both sides. Add the fact that idlers are small, increasing the angle of rotation in the links and you get more losses, more noise from all the tension, etc.
I hope I made it clear enough, if anything is not clear I can easily try to explain it again
Factor in the vast differences in contamination resistance or absorption, differing levels of
chain and drive train maintenance, and real world differences between chains can easily be
10w+. There are cyclists using –unbeknownst to them – a poor performing lubricant and
with average attention to maintenance who will literally be running a 15 to 20w loss chain at
250w load, vs cycling buddies on a top performing lubricant with good maintenance sitting
anywhere between around 5 to 8w loss.
You can get bang on equal loss in power between the 2 (250w x .94 - 5w (for a good lube) = 230, 250w-20w (for a poor drivetrain) = 230!)
Taken from here - https://zerofrictioncycling.com.au/wp-content/uploads/2019/05/Key-Learnings-from-Lubricant-Testing-Round-1.pdf
And I agree, I think most peoples perception of Gearboxes comes from Rohloff hubs!
This is an interesting point brought up with idler pulleys - they definitely do not follow 'efficiency guidelines' like track cyclists do, where they make a gear ratio with the largest possible chainring + sprocket to minimize chain articulation.
That being said, it is the articulation of the chain that seems to matter more than the size of the ring. Would an idler like the prototype Norco Aurum (where it sat only a bit above the chainring) be inherently more efficient than the Aurum HSP since the chain articulates less, no matter the pulley size?
All that being said, why are companies using such small pulley wheels for idler bikes? I would like to think it's not a weight thing since an idler is going to add weight anyway - what's the difference in adding 200 vs 210 grams? Though that is enough to dissuade some. Is it an availability thing? Maybe no one is making 50 tooth pie plates for idler bikes for some reason? Is this the Illuminati?!?!?
https://www.cyclingabout.com/speed-difference-testing-gearbox-systems/
As for the two Norcos, I think you're aiming at the wrapping angle, not articulation. The wrapping angle doesn't matter, the link will rotate the same once it's starting to wrap around a chainring regardless of how it wraps. It's only where it unwraps that the wrapping angle defines. The link rotation is the same for a given number of teeth regardless of the wrapping angle.
The number of teeth of a chainring define the radius around which the chain wraps and that defines how much each link has to rotate in regards to the neighbour. This is also connected to the polygon effect that is exhibited on small chainrings (and is supposedly the reason Sram went 10-42 for their 1x11 drivetrain as opposed to a 9T smallest sprocket they were testing in development - supposedly the variation in speed could be felt through the pedals?). The less teeth you have, the tighter the angle between two sides of a polygon and the more the links have to rotate.
This is all thinking out loud without any numbers, calculations or tests to back it up, but to me it's sound logic. I could be wrong.
As for the idlers, it has to be a packaging/practicality issue. But I would try out a mule with a layshaft. You are limited to how low you can position the main pivot then, since you can bring a small idler much closer than a layshaft with a 32T sprocket (on the output side), but with clever packaging (overlapping primary and secondary sprockets and using a pair of 22T sprockets for the first stage) it might be possible to get relatively close. It would be heavier and more complex to package, so there's a question if the packaging and weight headaches are worth the marginal gains in efficiency and noise, but you can't know unless you try
There is a possible mistake there though, it's said a faster moving chain (Pinion) is less efficient than the slower mowing chain (Rohloff). I'd say it should be the other way around, a faster moving chain transfers the same power with less chain tension, meaning less force in the chain, which I think should be beneficial for efficiency. Again, I could be wrong though.
I'd really like an explanation for those numbers though.
I was not stating the build as pictured would be sub-2000, but rather that I think another good geometry full suspension bike that has builds starting under 2000 (in the spirit of the original Status) would be a good product position for a big company like Specialized to target. I also expanded and stated that a lower overhead sales model might help that position.
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