There's nothing wrong with 34mm, stanchion diameter isn't everything when building a stiff fork. Feels like we're in a bit of an arms race to use bigger...
There's nothing wrong with 34mm, stanchion diameter isn't everything when building a stiff fork.
Feels like we're in a bit of an arms race to use bigger and bigger stanchions. I'm guilty of it... Went from a 36 to a 38 when my favourite fork chassis is a 35mm lyrik... And my gravel/xc bike has a 35mm pike lol.
Look at the Mattoc down there at 34mm that is as stiff as a 36 and plenty burly enough for more than just down country.
You know Ive always been curious about this. Unsure how it could be tested in a controlled way, but Ive always wondered how much stiffer are...
You know Ive always been curious about this. Unsure how it could be tested in a controlled way, but Ive always wondered how much stiffer are forks by increasing stanchion size? Or is it placebo? Going for a well built 34mm to a 35mm to a 36. Should the focus be on the stanchion size or the actual construction of the lowers to make the most difference?
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is
Stiffness = E*(pi/64)*(OD^4 - ID^4).
Because the diameters are scaled to the 4th power, small increases in stanchion size can yield huge stiffness increases.
Crown stiffness quickly becomes a limiting factor though. That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork.
There are some other things that affect fork performance too. For example, a less stiff fork will be more susceptible to bushing bind when ridden in rough terrain.
I hope they get short down to at least Deore level. There is a need for good quality, afordable, short cranks. Sram has listed his SX...
I hope they get short down to at least Deore level. There is a need for good quality, afordable, short cranks. Sram has listed his SX chainset in 155mm but Im yet to find it for sale anywhere
Echoing this in case Raceface is looking. Love my Aeffect R's in 165 and since they're strong 7050 al and lifetime warranty pretty much the only thing that would get me to buy more would be a 150 or 155 option 😉
There's nothing wrong with 34mm, stanchion diameter isn't everything when building a stiff fork. Feels like we're in a bit of an arms race to use bigger...
There's nothing wrong with 34mm, stanchion diameter isn't everything when building a stiff fork.
Feels like we're in a bit of an arms race to use bigger and bigger stanchions. I'm guilty of it... Went from a 36 to a 38 when my favourite fork chassis is a 35mm lyrik... And my gravel/xc bike has a 35mm pike lol.
Look at the Mattoc down there at 34mm that is as stiff as a 36 and plenty burly enough for more than just down country.
100%. I just got a mattoc for my new “XC” bike (last gen stumpy short travel… quotes around XC because I’m 6’6” 225lbs so it’s XC for me). I was super worried it would be a noodle, but I’m blown away by how stiff it feels and how well it works. I honestly don’t think I could tell a difference between it and a 36 blindfolded. Might even work better. And I thought the fox 34 was a wet noodle. Flex alone doesn’t bother me that much, but I’ve found flexy forks tend to bind up and feel harsh, which does bother me. This has none of that. Not sure what magic they used but it is a great reminder that the whole system matters, not just stanchion diameter.
Can add 14psi in a km (deflation much quicker) into a gravel tyre, would be slower for an xc tyre.
At that rate, probably only plausible for xc marathon/stage racing which can have sustained road or fire road sections interspersed with difficult-for-an-xc-bike singletrack.
i remember seeing something like that years ago for fatbikes, maybe a decade ago? don't know if it ever went anywhere production wise.
There's nothing wrong with 34mm, stanchion diameter isn't everything when building a stiff fork. Feels like we're in a bit of an arms race to use bigger...
There's nothing wrong with 34mm, stanchion diameter isn't everything when building a stiff fork.
Feels like we're in a bit of an arms race to use bigger and bigger stanchions. I'm guilty of it... Went from a 36 to a 38 when my favourite fork chassis is a 35mm lyrik... And my gravel/xc bike has a 35mm pike lol.
Look at the Mattoc down there at 34mm that is as stiff as a 36 and plenty burly enough for more than just down country.
You know Ive always been curious about this. Unsure how it could be tested in a controlled way, but Ive always wondered how much stiffer are...
You know Ive always been curious about this. Unsure how it could be tested in a controlled way, but Ive always wondered how much stiffer are forks by increasing stanchion size? Or is it placebo? Going for a well built 34mm to a 35mm to a 36. Should the focus be on the stanchion size or the actual construction of the lowers to make the most difference?
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is Stiffness = E*(pi/64)*(OD^4 - ID^4).Because the diameters...
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is
Stiffness = E*(pi/64)*(OD^4 - ID^4).
Because the diameters are scaled to the 4th power, small increases in stanchion size can yield huge stiffness increases.
Crown stiffness quickly becomes a limiting factor though. That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork.
There are some other things that affect fork performance too. For example, a less stiff fork will be more susceptible to bushing bind when ridden in rough terrain.
"That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork."
35mm dual crown fork 🤮 I always casually browse the used bike listings for DH bikes I don't really need.. After seeing this pic in the G Out Project, anything with an oldschool boxxer is immediatley ruled out unless the bike is a screaming deal.
Hey all, just got this shiny new thing in the mail to test. Rimpact's press release is linked here, along with some of my first impressions before bolting it on the old bike. Obviously it looks a lot like an Ochain, but Rimpact says their device is designed to address a different mechanism of suspension interference. Innovation! Let me know what you think: https://www.vitalmtb.com/forums/hub/rimpact-chain-damper
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.But steerers...
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.
But steerers are flexy, crowns are flexy, and axle interfaces are flexy. If you put some effort into locking the two tubes together then they work together and will flex together, and this also massively increases stiffness. The keyed axle of the Mattoc or a 20mm axle with four pinchbolts like the old 36, the bulky crown like a lyrik, all help to make the most of their tube stiffness. The flexy modern 36 with its slim crown and arch and shitty little axle make for a comparative noodle.
It would be cool to see tests. Both for bending stiffness and torsional stiffness. Torsional stiffness affects the feel the most in my opinion, and that's where you get the most advantage from the crown/axle/arch rather than the stanchions.
Was thinking the same thing. Go to your local hardware store and start picking up different sizes of PVC pipe and try to bend them. Skinny PVC will bend like licorice, whereas the big pipes will break before they bend. Diameter makes a really, really big difference.
My first mental example was the difference between a 2x4 and a 2x6 when used in a floor or wall (huge, immediately noticeable difference), and that difference is amplified when we're talking about a hollow circular tube instead of a solid piece of lumber. TLDR: stanchion size matters, especially for simple fore/aft braking and bump flex.
Also, shoutout to the Manitou Hexbolt axle patent. Must be expired by now, and if Fox is making a 36mm stanchion XC fork with crazy 3D-printed Ai-powered crowns and arches, they could save a whole bunch of weight and gain a whole bunch of stiffness by putting a Hexlock axle on there. They just have to admit that Manitou had a good idea some 20-odd years ago.
You know Ive always been curious about this. Unsure how it could be tested in a controlled way, but Ive always wondered how much stiffer are...
You know Ive always been curious about this. Unsure how it could be tested in a controlled way, but Ive always wondered how much stiffer are forks by increasing stanchion size? Or is it placebo? Going for a well built 34mm to a 35mm to a 36. Should the focus be on the stanchion size or the actual construction of the lowers to make the most difference?
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is Stiffness = E*(pi/64)*(OD^4 - ID^4).Because the diameters...
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is
Stiffness = E*(pi/64)*(OD^4 - ID^4).
Because the diameters are scaled to the 4th power, small increases in stanchion size can yield huge stiffness increases.
Crown stiffness quickly becomes a limiting factor though. That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork.
There are some other things that affect fork performance too. For example, a less stiff fork will be more susceptible to bushing bind when ridden in rough terrain.
"That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork." 35mm dual crown fork 🤮 I always casually browse the used...
"That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork."
35mm dual crown fork 🤮 I always casually browse the used bike listings for DH bikes I don't really need.. After seeing this pic in the G Out Project, anything with an oldschool boxxer is immediatley ruled out unless the bike is a screaming deal.
Agree, everything goes out the window when talking DH forks. The torsional stiffness of the 35mm boxxer feels great due to the double crown and 20mm axle and wider set stanchions, but the bending stiffness is arse and it really affects the plushness and steering. They feel a bit shit compared to 38s or 40s when you've put a big old curve in the stanchions in a g-out and totally misaligned the sliding surfaces in the bushings, and wildly fucked with your offset.
I had some old boxxers on my Tues and being very long travel and very progressive in the rear it was happy to get right through the first half of its stroke, if you landed rear wheel first or just happened to load up the rear while the front was still near full extension, the fork would just refuse to move. I would have killed for a 40 on that bike.
Other than the cable ports the front triangle looks literally identical. Credit to taprider on the NSMB forums. Apparently my LBS has them in stock, built, and hidden in the back, but I haven't been down to look.
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.But steerers...
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.
But steerers are flexy, crowns are flexy, and axle interfaces are flexy. If you put some effort into locking the two tubes together then they work together and will flex together, and this also massively increases stiffness. The keyed axle of the Mattoc or a 20mm axle with four pinchbolts like the old 36, the bulky crown like a lyrik, all help to make the most of their tube stiffness. The flexy modern 36 with its slim crown and arch and shitty little axle make for a comparative noodle.
It would be cool to see tests. Both for bending stiffness and torsional stiffness. Torsional stiffness affects the feel the most in my opinion, and that's where you get the most advantage from the crown/axle/arch rather than the stanchions.
Was thinking the same thing. Go to your local hardware store and start picking up different sizes of PVC pipe and try to bend them. Skinny...
Was thinking the same thing. Go to your local hardware store and start picking up different sizes of PVC pipe and try to bend them. Skinny PVC will bend like licorice, whereas the big pipes will break before they bend. Diameter makes a really, really big difference.
My first mental example was the difference between a 2x4 and a 2x6 when used in a floor or wall (huge, immediately noticeable difference), and that difference is amplified when we're talking about a hollow circular tube instead of a solid piece of lumber. TLDR: stanchion size matters, especially for simple fore/aft braking and bump flex.
Also, shoutout to the Manitou Hexbolt axle patent. Must be expired by now, and if Fox is making a 36mm stanchion XC fork with crazy 3D-printed Ai-powered crowns and arches, they could save a whole bunch of weight and gain a whole bunch of stiffness by putting a Hexlock axle on there. They just have to admit that Manitou had a good idea some 20-odd years ago.
The biggest problem with hexloc was consumers complete inability to understand how to remove their axle despite being demonstrated live and in front of their face several times. I can't see a company like Fox adopting it because even though it provides superior stiffness at the same weight, customers are too stupid to make it work.
Source: the utter misery of selling bikes that came stock with hexloc axles.
The biggest problem with hexloc was consumers complete inability to understand how to remove their axle despite being demonstrated live and in front of their face...
The biggest problem with hexloc was consumers complete inability to understand how to remove their axle despite being demonstrated live and in front of their face several times. I can't see a company like Fox adopting it because even though it provides superior stiffness at the same weight, customers are too stupid to make it work.
Source: the utter misery of selling bikes that came stock with hexloc axles.
Are you talking about the old five-bolt versions on their downhill, freeride, and dirt jump forks, or the new fancy free-spinning QR lever version that came on newer trail forks? I feel like there's some middle ground solution between the two, but I take your point that the QR version was confusing (I agree!) and most XC or trail bike customers don't want a 3 or 5-bolt front axle. I trust that someone somewhere can figure out how to make a keyed axle interface easy to use.
Accidentally I've noticed a photo in this article where Dario Lillo is appararently racing on a prototype Fox 34 (?) fork with completely new lowers. Pinkbike...
I tried to find some more close-up pics for spotting e.g. a Serial Number (which, in case of Fox could tell us hell a lot of more info
) but haven't found anything yet. (Sorry, if this has been already posted, tried to double-check but I haven't found any info which were posted earlier here)
Wait this is that fork crown that fox patented where the air chamber extends inside the hollowed crown. Patent app link below.
Accidentally I've noticed a photo in this article where Dario Lillo is appararently racing on a prototype Fox 34 (?) fork with completely new lowers. Pinkbike...
I tried to find some more close-up pics for spotting e.g. a Serial Number (which, in case of Fox could tell us hell a lot of more info
) but haven't found anything yet. (Sorry, if this has been already posted, tried to double-check but I haven't found any info which were posted earlier here)
so the new Element is now a flex-pivot, interesting. Seems to be the trend lately with xc/dc bikes
Crab-country bikes
Edit: looks like the flex is built into the chain stay, which looks to slim out right where the pivot on the current one is. I think most of the rest flex in the seat stay, no?
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.But steerers...
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.
But steerers are flexy, crowns are flexy, and axle interfaces are flexy. If you put some effort into locking the two tubes together then they work together and will flex together, and this also massively increases stiffness. The keyed axle of the Mattoc or a 20mm axle with four pinchbolts like the old 36, the bulky crown like a lyrik, all help to make the most of their tube stiffness. The flexy modern 36 with its slim crown and arch and shitty little axle make for a comparative noodle.
It would be cool to see tests. Both for bending stiffness and torsional stiffness. Torsional stiffness affects the feel the most in my opinion, and that's where you get the most advantage from the crown/axle/arch rather than the stanchions.
Upside down forks disagree on torsional stiffness being a benefit... Users of them mostly say it is not a problem. Darren Murphy put it in a good way - how much torque do you actually put on a fork?
Crab-country bikes Edit: looks like the flex is built into the chain stay, which looks to slim out right where the pivot on the current one is...
Crab-country bikes
Edit: looks like the flex is built into the chain stay, which looks to slim out right where the pivot on the current one is. I think most of the rest flex in the seat stay, no?
That's right. They are trying the same approach as Cannondale's "FlexPivot" by encouraging crab-link design feel without the bearings. Most other flex pivot bikes have equal amount of flex throughout the rear triangle.
Accidentally I've noticed a photo in this article where Dario Lillo is appararently racing on a prototype Fox 34 (?) fork with completely new lowers. Pinkbike...
I tried to find some more close-up pics for spotting e.g. a Serial Number (which, in case of Fox could tell us hell a lot of more info
) but haven't found anything yet. (Sorry, if this has been already posted, tried to double-check but I haven't found any info which were posted earlier here)
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is Stiffness = E*(pi/64)*(OD^4 - ID^4).Because the diameters...
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is
Stiffness = E*(pi/64)*(OD^4 - ID^4).
Because the diameters are scaled to the 4th power, small increases in stanchion size can yield huge stiffness increases.
Crown stiffness quickly becomes a limiting factor though. That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork.
There are some other things that affect fork performance too. For example, a less stiff fork will be more susceptible to bushing bind when ridden in rough terrain.
"That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork." 35mm dual crown fork 🤮 I always casually browse the used...
"That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork."
35mm dual crown fork 🤮 I always casually browse the used bike listings for DH bikes I don't really need.. After seeing this pic in the G Out Project, anything with an oldschool boxxer is immediatley ruled out unless the bike is a screaming deal.
Agree, everything goes out the window when talking DH forks. The torsional stiffness of the 35mm boxxer feels great due to the double crown and 20mm...
Agree, everything goes out the window when talking DH forks. The torsional stiffness of the 35mm boxxer feels great due to the double crown and 20mm axle and wider set stanchions, but the bending stiffness is arse and it really affects the plushness and steering. They feel a bit shit compared to 38s or 40s when you've put a big old curve in the stanchions in a g-out and totally misaligned the sliding surfaces in the bushings, and wildly fucked with your offset.
I had some old boxxers on my Tues and being very long travel and very progressive in the rear it was happy to get right through the first half of its stroke, if you landed rear wheel first or just happened to load up the rear while the front was still near full extension, the fork would just refuse to move. I would have killed for a 40 on that bike.
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of extra flex might even be desirable on the way up the hill. What really turned me off on the old Boxxer was the amount of listings where people specifically mentioned that they had rebuilt it recently, or it had new seals, ect.. So apparently the extra flex comes at a cost for reliability too. Also lots of bike comparisons mention that you have to run the old Boxxer extra firm to avoid bottoming/wallowy feeling. The new Boxxer or an Ohlins sounds pretty Goldilocks though as 40's can be kinda tankish sometimes... Rant Over, lol.
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of...
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of extra flex might even be desirable on the way up the hill. What really turned me off on the old Boxxer was the amount of listings where people specifically mentioned that they had rebuilt it recently, or it had new seals, ect.. So apparently the extra flex comes at a cost for reliability too. Also lots of bike comparisons mention that you have to run the old Boxxer extra firm to avoid bottoming/wallowy feeling. The new Boxxer or an Ohlins sounds pretty Goldilocks though as 40's can be kinda tankish sometimes... Rant Over, lol.
I’ve owned nearly every generation of Boxxer between 2004 and 2020. They’re perfectly fine for reliability.
Have you ever even owned one, or are you just shitting on it because you saw a photo online? BTW, if you blow up that G-Out photo and hold up a ruler, it’s nowhere near as deflected as it looks. The number plate and decals are an optical illusion.
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of...
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of extra flex might even be desirable on the way up the hill. What really turned me off on the old Boxxer was the amount of listings where people specifically mentioned that they had rebuilt it recently, or it had new seals, ect.. So apparently the extra flex comes at a cost for reliability too. Also lots of bike comparisons mention that you have to run the old Boxxer extra firm to avoid bottoming/wallowy feeling. The new Boxxer or an Ohlins sounds pretty Goldilocks though as 40's can be kinda tankish sometimes... Rant Over, lol.
If I was selling a bike I'd say "XXXXXX" was rebuilt as a way to indicate it's as good as new, perceivably. Could be BS but I don't think it's related to reliability.
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of...
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of extra flex might even be desirable on the way up the hill. What really turned me off on the old Boxxer was the amount of listings where people specifically mentioned that they had rebuilt it recently, or it had new seals, ect.. So apparently the extra flex comes at a cost for reliability too. Also lots of bike comparisons mention that you have to run the old Boxxer extra firm to avoid bottoming/wallowy feeling. The new Boxxer or an Ohlins sounds pretty Goldilocks though as 40's can be kinda tankish sometimes... Rant Over, lol.
If I was selling a bike I'd say "XXXXXX" was rebuilt as a way to indicate it's as good as new, perceivably. Could be BS but...
If I was selling a bike I'd say "XXXXXX" was rebuilt as a way to indicate it's as good as new, perceivably. Could be BS but I don't think it's related to reliability.
Just reminds me too much of my MX days where every ad for a Kawasaki, or Suzuki two stroke mentions a recent top end, and or bottom end/clutch and that's out of necessity because they really are garbage compared to Honda/Yamaha.
Browse some listings for DH forks. I guarantee you'll see more more people mentioning they just rebuilt their Boxxer VS 40's.
i never posted it here but the slowmo vid from MSA below has some fantastic examples of bikes/forks flexing, especially in the slab section with slow-but-big curb-like hits on the front wheel. rocks start around 4 mins i think. sometimes the forks flex, sometimes the frames do. energy has to go somewhere (and yes, i know everyone wants the fork to absorb the energy through its operation).
Please buy my DH fork that's been ridden super hard and never serviced. The oil seals don't leak because there's not enough oil left in the lowers to properly lubricate the bushings.
If you can deflect a 35mm Boxxer to the point it's truly an issue, I'll be the first one to cheer for you on the WC circuit or at Rampage.
Apparently I struck a nerve. Good news is there are plenty of DH bikes with old Boxxers, and enduro bikes with 21'-23' X2's for you guys to pony up to, since they are such awesome products.
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.But steerers...
The bending stiffness of a tube increases to the fourth power with respect to diameter... Ie bigger tubes are way fucking stiffer than smaller tubes.
But steerers are flexy, crowns are flexy, and axle interfaces are flexy. If you put some effort into locking the two tubes together then they work together and will flex together, and this also massively increases stiffness. The keyed axle of the Mattoc or a 20mm axle with four pinchbolts like the old 36, the bulky crown like a lyrik, all help to make the most of their tube stiffness. The flexy modern 36 with its slim crown and arch and shitty little axle make for a comparative noodle.
It would be cool to see tests. Both for bending stiffness and torsional stiffness. Torsional stiffness affects the feel the most in my opinion, and that's where you get the most advantage from the crown/axle/arch rather than the stanchions.
Upside down forks disagree on torsional stiffness being a benefit... Users of them mostly say it is not a problem. Darren Murphy put it in a...
Upside down forks disagree on torsional stiffness being a benefit... Users of them mostly say it is not a problem. Darren Murphy put it in a good way - how much torque do you actually put on a fork?
I'm happy to agree that a complete lack of torsional stiffness is something that some people enjoy. I assume that they also like flexy frames like Pole or Yeti or that old intense tracer that would spit you out of corners in random directions, but if you were delicate they'd track around bumps rather than over them.
Couldn't imagine anything worse myself. There's compliance which helps a tire grip in a corner, and there's compliance which spits you off your line. USD forks or fox 34s are the latter.
Theyre not open bath forks. Theres just a few mils splashing around in there. Unless he means "blow a damper" from flexing a fork. The majority of the oil is in the damper. Its not an issue. In your defense your theory isnt as confusing as "blow a trani" , NTTAWWT
Please buy my DH fork that's been ridden super hard and never serviced. The oil seals don't leak because there's not enough oil left in the...
Please buy my DH fork that's been ridden super hard and never serviced. The oil seals don't leak because there's not enough oil left in the lowers to properly lubricate the bushings.
If you can deflect a 35mm Boxxer to the point it's truly an issue, I'll be the first one to cheer for you on the WC circuit or at Rampage.
Just reminds me too much of my MX days where every ad for a Kawasaki, or Suzuki two stroke mentions a recent top end, and or...
Just reminds me too much of my MX days where every ad for a Kawasaki, or Suzuki two stroke mentions a recent top end, and or bottom end/clutch and that's out of necessity because they really are garbage compared to Honda/Yamaha.
Browse some listings for DH forks. I guarantee you'll see more more people mentioning they just rebuilt their Boxxer VS 40's.
I like how you interprete that as boxxer needing more care than fox 40, when both have comparable service intervals. Let's turn it around, what if most 40 owners cannot be bothered to service their gear? Because you know, Kashima is self lubricating 🙄
It’s been nearly 10 years since I covered it in school, but IIRC the bending stiffness of a tube is
Stiffness = E*(pi/64)*(OD^4 - ID^4).
Because the diameters are scaled to the 4th power, small increases in stanchion size can yield huge stiffness increases.
Crown stiffness quickly becomes a limiting factor though. That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork.
There are some other things that affect fork performance too. For example, a less stiff fork will be more susceptible to bushing bind when ridden in rough terrain.
Echoing this in case Raceface is looking. Love my Aeffect R's in 165 and since they're strong 7050 al and lifetime warranty pretty much the only thing that would get me to buy more would be a 150 or 155 option 😉
100%. I just got a mattoc for my new “XC” bike (last gen stumpy short travel… quotes around XC because I’m 6’6” 225lbs so it’s XC for me). I was super worried it would be a noodle, but I’m blown away by how stiff it feels and how well it works. I honestly don’t think I could tell a difference between it and a 36 blindfolded. Might even work better. And I thought the fox 34 was a wet noodle. Flex alone doesn’t bother me that much, but I’ve found flexy forks tend to bind up and feel harsh, which does bother me. This has none of that. Not sure what magic they used but it is a great reminder that the whole system matters, not just stanchion diameter.
i remember seeing something like that years ago for fatbikes, maybe a decade ago? don't know if it ever went anywhere production wise.
"That’s why a 38mm single crown works like crap compared to a 35mm dual crown fork."
35mm dual crown fork 🤮 I always casually browse the used bike listings for DH bikes I don't really need.. After seeing this pic in the G Out Project, anything with an oldschool boxxer is immediatley ruled out unless the bike is a screaming deal.
Hey all, just got this shiny new thing in the mail to test. Rimpact's press release is linked here, along with some of my first impressions before bolting it on the old bike. Obviously it looks a lot like an Ochain, but Rimpact says their device is designed to address a different mechanism of suspension interference. Innovation! Let me know what you think: https://www.vitalmtb.com/forums/hub/rimpact-chain-damper
Was thinking the same thing. Go to your local hardware store and start picking up different sizes of PVC pipe and try to bend them. Skinny PVC will bend like licorice, whereas the big pipes will break before they bend. Diameter makes a really, really big difference.
My first mental example was the difference between a 2x4 and a 2x6 when used in a floor or wall (huge, immediately noticeable difference), and that difference is amplified when we're talking about a hollow circular tube instead of a solid piece of lumber. TLDR: stanchion size matters, especially for simple fore/aft braking and bump flex.
Also, shoutout to the Manitou Hexbolt axle patent. Must be expired by now, and if Fox is making a 36mm stanchion XC fork with crazy 3D-printed Ai-powered crowns and arches, they could save a whole bunch of weight and gain a whole bunch of stiffness by putting a Hexlock axle on there. They just have to admit that Manitou had a good idea some 20-odd years ago.
Agree, everything goes out the window when talking DH forks. The torsional stiffness of the 35mm boxxer feels great due to the double crown and 20mm axle and wider set stanchions, but the bending stiffness is arse and it really affects the plushness and steering. They feel a bit shit compared to 38s or 40s when you've put a big old curve in the stanchions in a g-out and totally misaligned the sliding surfaces in the bushings, and wildly fucked with your offset.
I had some old boxxers on my Tues and being very long travel and very progressive in the rear it was happy to get right through the first half of its stroke, if you landed rear wheel first or just happened to load up the rear while the front was still near full extension, the fork would just refuse to move. I would have killed for a 40 on that bike.
Other than the cable ports the front triangle looks literally identical. Credit to taprider on the NSMB forums. Apparently my LBS has them in stock, built, and hidden in the back, but I haven't been down to look.
The biggest problem with hexloc was consumers complete inability to understand how to remove their axle despite being demonstrated live and in front of their face several times. I can't see a company like Fox adopting it because even though it provides superior stiffness at the same weight, customers are too stupid to make it work.
Source: the utter misery of selling bikes that came stock with hexloc axles.
Are you talking about the old five-bolt versions on their downhill, freeride, and dirt jump forks, or the new fancy free-spinning QR lever version that came on newer trail forks? I feel like there's some middle ground solution between the two, but I take your point that the QR version was confusing (I agree!) and most XC or trail bike customers don't want a 3 or 5-bolt front axle. I trust that someone somewhere can figure out how to make a keyed axle interface easy to use.
so the new Element is now a flex-pivot, interesting. Seems to be the trend lately with xc/dc bikes
Wait this is that fork crown that fox patented where the air chamber extends inside the hollowed crown. Patent app link below.
https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/117183…
Definitely looks like there is some kind of toob in that crown from the pictures, could be an additional air chamber
Crab-country bikes
Edit: looks like the flex is built into the chain stay, which looks to slim out right where the pivot on the current one is. I think most of the rest flex in the seat stay, no?
Upside down forks disagree on torsional stiffness being a benefit... Users of them mostly say it is not a problem. Darren Murphy put it in a good way - how much torque do you actually put on a fork?
That's right. They are trying the same approach as Cannondale's "FlexPivot" by encouraging crab-link design feel without the bearings. Most other flex pivot bikes have equal amount of flex throughout the rear triangle.
Fox.
Creates larger air chamber.
Fills it with grease.
Benefits negated.
I used to do a lot of Downduro riding on my Glory, and that's what I would do on a new DHer, so a bit of extra flex might even be desirable on the way up the hill. What really turned me off on the old Boxxer was the amount of listings where people specifically mentioned that they had rebuilt it recently, or it had new seals, ect.. So apparently the extra flex comes at a cost for reliability too. Also lots of bike comparisons mention that you have to run the old Boxxer extra firm to avoid bottoming/wallowy feeling. The new Boxxer or an Ohlins sounds pretty Goldilocks though as 40's can be kinda tankish sometimes... Rant Over, lol.
I’ve owned nearly every generation of Boxxer between 2004 and 2020. They’re perfectly fine for reliability.
Have you ever even owned one, or are you just shitting on it because you saw a photo online? BTW, if you blow up that G-Out photo and hold up a ruler, it’s nowhere near as deflected as it looks. The number plate and decals are an optical illusion.
If I was selling a bike I'd say "XXXXXX" was rebuilt as a way to indicate it's as good as new, perceivably. Could be BS but I don't think it's related to reliability.
Just reminds me too much of my MX days where every ad for a Kawasaki, or Suzuki two stroke mentions a recent top end, and or bottom end/clutch and that's out of necessity because they really are garbage compared to Honda/Yamaha.
Browse some listings for DH forks. I guarantee you'll see more more people mentioning they just rebuilt their Boxxer VS 40's.
i never posted it here but the slowmo vid from MSA below has some fantastic examples of bikes/forks flexing, especially in the slab section with slow-but-big curb-like hits on the front wheel. rocks start around 4 mins i think. sometimes the forks flex, sometimes the frames do. energy has to go somewhere (and yes, i know everyone wants the fork to absorb the energy through its operation).
Please buy my DH fork that's been ridden super hard and never serviced. The oil seals don't leak because there's not enough oil left in the lowers to properly lubricate the bushings.
If you can deflect a 35mm Boxxer to the point it's truly an issue, I'll be the first one to cheer for you on the WC circuit or at Rampage.
Apparently I struck a nerve. Good news is there are plenty of DH bikes with old Boxxers, and enduro bikes with 21'-23' X2's for you guys to pony up to, since they are such awesome products.
I'm happy to agree that a complete lack of torsional stiffness is something that some people enjoy. I assume that they also like flexy frames like Pole or Yeti or that old intense tracer that would spit you out of corners in random directions, but if you were delicate they'd track around bumps rather than over them.
Couldn't imagine anything worse myself. There's compliance which helps a tire grip in a corner, and there's compliance which spits you off your line. USD forks or fox 34s are the latter.
Theyre not open bath forks. Theres just a few mils splashing around in there. Unless he means "blow a damper" from flexing a fork. The majority of the oil is in the damper. Its not an issue. In your defense your theory isnt as confusing as "blow a trani" , NTTAWWT
Been MIA for a minute, dunno if it has been brought up but apparently there is a RM slayer test mule floating aboot.
So many "heavy hitters" around these forums lol.
I like how you interprete that as boxxer needing more care than fox 40, when both have comparable service intervals. Let's turn it around, what if most 40 owners cannot be bothered to service their gear? Because you know, Kashima is self lubricating 🙄
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