So the question is, are they using inertia dampers like countershox, which seem to work in MX in a well documented way, or are they actual TMDs? If you tuned a TMD to the tyre bounce frequency, it might really improve rear braking (think the scf-scf-scf as you brake on the edge of locking on a rough surface). My suspicion is a resized countershox
Have u tried to ride e-bike downhill compared to regular bike, u will be much faster and overshoot jumps (without pedal assist) , so adding weight around BB definitely make sence, especially when minimal pedaling required
slowmo goods from world champs. (besides trying to dissect the bikes, it's nuts how they'll just huck into that boulder on the steeps, significantly nose case and just carry on like it was a small bump)
The most terrifying part is the horrendous rear end kick out they nearly all had every run just after rock garden huck.
Also, just after the rock garden itself, when they dodge or bunny hop the rock against the tree into the fire road: do we think they are casing the rock on purpose to slow down? There's plenty of footage in practice of people clearing it easily enough, so either race pace they were too fast/loose/tired to full clear it, or they actually use it as braking point.
this stuff is rad, I love it. I’m all about it. I prefer the feel of my heavy eeb to my light pedal bike, I’d love to send vibrations into a ball of silly putty in my downtube. Are there active mass dampers?
I was looking at reviews of their Moto version, and it all seems pretty positive, though I've not found any cutaways or proper engineering explanations of how it works other than that graph on the insta. Various people doing timed runs and being noticeably faster with it
I was looking at reviews of their Moto version, and it all seems pretty positive, though I've not found any cutaways or proper engineering explanations of...
I was looking at reviews of their Moto version, and it all seems pretty positive, though I've not found any cutaways or proper engineering explanations of how it works other than that graph on the insta. Various people doing timed runs and being noticeably faster with it
you can make some educated guesses based on how Rimpact are designing theirs
I was looking at reviews of their Moto version, and it all seems pretty positive, though I've not found any cutaways or proper engineering explanations of...
I was looking at reviews of their Moto version, and it all seems pretty positive, though I've not found any cutaways or proper engineering explanations of how it works other than that graph on the insta. Various people doing timed runs and being noticeably faster with it
I've found the exact springs that the rimpact one uses in my local hardware store, so that alone is making me think that rimpact is only in the early stages of their R&D. Or maybe it just happens to be the right spring rate, I dunno. You could probably calculate the spring stiffness with the damped oscillator model pretty easily, however if 20-26 Hz is your aim, the spring would need to be way stiffer than the one they use.
Even the countershox one can't be very complicated. There can't be any seals to introduce friction so the damping is probably done with elastomers or a viscous fluid. The mass only affects the amplitude of the vibration damping, so more mass -> bigger effect
So I need an inserts, o Chain, added weight and mass dampers to be fast now? 🤣In all seriousness I get why they are doing this...
So I need an inserts, o Chain, added weight and mass dampers to be fast now? 🤣
In all seriousness I get why they are doing this at the to level but seems crazy the amount of stuff we are adding to bikes now.
A rider doesn’t, “need” any of this to ride. Just depends how much comfort and ride feel you want. Like someone could ride a hard tail, single pivot or 6 bar.
To me, It’s a hobby sport for us, it’s a hobby to tune my bike better.
I've found the exact springs that the rimpact one uses in my local hardware store, so that alone is making me think that rimpact is only...
I've found the exact springs that the rimpact one uses in my local hardware store, so that alone is making me think that rimpact is only in the early stages of their R&D. Or maybe it just happens to be the right spring rate, I dunno. You could probably calculate the spring stiffness with the damped oscillator model pretty easily, however if 20-26 Hz is your aim, the spring would need to be way stiffer than the one they use.
Even the countershox one can't be very complicated. There can't be any seals to introduce friction so the damping is probably done with elastomers or a viscous fluid. The mass only affects the amplitude of the vibration damping, so more mass -> bigger effect
If you used a mass of 0.5kg or just over a pound (which seems pretty heavy to be sticking to your bike/inside the steerer) a rate of 7.9N/mm would give you 20Hz. Thats similar to a fork spring (eg a "green" ohlins spring or 45lb/in) so pretty easy to find in that range
I've found the exact springs that the rimpact one uses in my local hardware store, so that alone is making me think that rimpact is only...
I've found the exact springs that the rimpact one uses in my local hardware store, so that alone is making me think that rimpact is only in the early stages of their R&D. Or maybe it just happens to be the right spring rate, I dunno. You could probably calculate the spring stiffness with the damped oscillator model pretty easily, however if 20-26 Hz is your aim, the spring would need to be way stiffer than the one they use.
Even the countershox one can't be very complicated. There can't be any seals to introduce friction so the damping is probably done with elastomers or a viscous fluid. The mass only affects the amplitude of the vibration damping, so more mass -> bigger effect
If you used a mass of 0.5kg or just over a pound (which seems pretty heavy to be sticking to your bike/inside the steerer) a rate...
If you used a mass of 0.5kg or just over a pound (which seems pretty heavy to be sticking to your bike/inside the steerer) a rate of 7.9N/mm would give you 20Hz. Thats similar to a fork spring (eg a "green" ohlins spring or 45lb/in) so pretty easy to find in that range
I'm not convinced the countershox is a traditional TMD. What it seems to do is respond to a shock input with a delay that feeds back an opposing force (now of course the setup will lead to a specific resonant frequency, but I don't think they've tuned it that way). If anyone wants to buy one and ship it to the UK, I'd love to pop it on a shaker table to measure the frequency response, whack it with a modal hammer to see the shock response, then of course get out the hacksaw!
seems applicable (sort of). why not just put ebike batteries in one to isolate the weight : )
Thats a pretty good comparison! The live view of the forces is possibly the most relevant, and shows why some kind of damping is important for grip - even though the highest forces are on the undamped pack (which in respect to tyres you might think means more grip) the lows are actually negative, ie unweighted which means no grip!
I had to zoom in to check the scales on both plots were the same. Also side note - increasing force on the tyres doesn't have a linear increase in grip, so simply adding more weight (eg shifting all your weight forward to the front tyre) gives proportionally less grip than the amount of weight distribution change. Therefore consistent and even loading of the tyres can potentially have far more available grip and why TMD's are an interesting technology
Serious stupid question - can you use this on a hardtail?
No reason why not - it would just need to be tuned differently. The main reason you don't see it more yet is people are still getting their heads around it and haven't figured out the best places to use them. They might not take off, but the only way to find out is if people try it!
Countershox are actually already selling those dampers, and surprisingly they aren't crazy expensive. They must be new to the industry lol.
They're an honest company. The tech isn't expensive at all.
As @TheSuspensionLabNZ noted, you could McGyver one with an Ohlins green spring, a 600g mass and a tube and some rubber for vibrations, forget a mountain bracket just zip tie that sucker on.
Charging $500 just means someone else will move in and undercut you and make you look like an idiot and lose all sales.
They're an honest company. The tech isn't expensive at all. As @TheSuspensionLabNZ noted, you could McGyver one with an Ohlins green spring, a 600g mass and a...
They're an honest company. The tech isn't expensive at all.
As @TheSuspensionLabNZ noted, you could McGyver one with an Ohlins green spring, a 600g mass and a tube and some rubber for vibrations, forget a mountain bracket just zip tie that sucker on.
Charging $500 just means someone else will move in and undercut you and make you look like an idiot and lose all sales.
There's a lot more to the CounterShox than going to a hardware store and picking up parts. Think about the millions of combinations of springs and weights, rattle noises, fork mounts, ect. I suspect there's more going on with their product than springs and weights.
I've tried it on a motocross bike and DH bike and was really surprised/happy with the results. I think the price isn't for everyone and the added weight isn't for everyone. I bought them because I'm interested in trying new parts, but it's going to be hard to ride without them now.
Yeah fine tuning the exact spring rates, mass and travel for the device would be pretty time consuming - get it wrong and you would make things worse or make a noisy shaker device that yeets itself off the bike if you hit just the right size bump....
I rigged up a janky device from bits around the shop that seemed to be in the right range and bolted it to a wheel this morning - will get some video of it in action later today
They're an honest company. The tech isn't expensive at all. As @TheSuspensionLabNZ noted, you could McGyver one with an Ohlins green spring, a 600g mass and a...
They're an honest company. The tech isn't expensive at all.
As @TheSuspensionLabNZ noted, you could McGyver one with an Ohlins green spring, a 600g mass and a tube and some rubber for vibrations, forget a mountain bracket just zip tie that sucker on.
Charging $500 just means someone else will move in and undercut you and make you look like an idiot and lose all sales.
There's a lot more to the CounterShox than going to a hardware store and picking up parts. Think about the millions of combinations of springs and...
There's a lot more to the CounterShox than going to a hardware store and picking up parts. Think about the millions of combinations of springs and weights, rattle noises, fork mounts, ect. I suspect there's more going on with their product than springs and weights.
I've tried it on a motocross bike and DH bike and was really surprised/happy with the results. I think the price isn't for everyone and the added weight isn't for everyone. I bought them because I'm interested in trying new parts, but it's going to be hard to ride without them now.
Oh I absolutely agree. I'm not trying to say countershox haven't invested the time and made a good product.
But you also have to realize with it on the market, you can cut one open, copy it, and undercut them enormously if they're charging a lot for them.
The product itself is simple and easy to copy. The research and development is the hard part, but since they've done it for you...
Serious stupid question - can you use this on a hardtail?
Why has it taken so long for mass dampers to turn up in DH and why now? What changed?
So the question is, are they using inertia dampers like countershox, which seem to work in MX in a well documented way, or are they actual TMDs? If you tuned a TMD to the tyre bounce frequency, it might really improve rear braking (think the scf-scf-scf as you brake on the edge of locking on a rough surface). My suspicion is a resized countershox
Have u tried to ride e-bike downhill compared to regular bike, u will be much faster and overshoot jumps (without pedal assist) , so adding weight around BB definitely make sence, especially when minimal pedaling required
slowmo goods from world champs. (besides trying to dissect the bikes, it's nuts how they'll just huck into that boulder on the steeps, significantly nose case and just carry on like it was a small bump)
In case you gotta get one now that Loris won with one: https://www.ebay.com/itm/276399279077?_nkw=shakeweight&epid=691408230&itmmeta=01J6MRQARF45ST3X141R9KRBV8&hash=item405aae4be5:g:Z9oAAOSwyvlmA0GA&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKmnoczB3F1w%2Fp3fWedv1W5o1epmijHpeiInZmT2IlFq8UuXXSSQYBjwT2fHvtSIez1aE7BEAQ3dGuvINESZo1J7cqsw6VGEoWdGOvZWHs7sL2HPVa5MUdQ9QgDx0ynirx8u5w5KE65%2FC0fljAcwZZzzKY7%2F04GfT2cXWLA5gTuNKB5meZZdZhnU05DUBtuoS56yIhdbPtF8NBMvZOEGZscjMWamPE4NZMA54cZGKWgs%2BVOa1Swy8F2igCnr%2Bim3Ohrz51ziG1ILTNFk%2F9seg%2BPdzhwvqUxDCTiXC7c9CxgZAA%3D%3D%7Ctkp%3ABFBMqqzdmLVk
I didn’t see it on the outside of a bike in the broadcast, was it hidden somewhere?
The most terrifying part is the horrendous rear end kick out they nearly all had every run just after rock garden huck.
Also, just after the rock garden itself, when they dodge or bunny hop the rock against the tree into the fire road: do we think they are casing the rock on purpose to slow down? There's plenty of footage in practice of people clearing it easily enough, so either race pace they were too fast/loose/tired to full clear it, or they actually use it as braking point.
nah that's french onion dip stash bro
They just call it onion dip there.
this stuff is rad, I love it. I’m all about it. I prefer the feel of my heavy eeb to my light pedal bike, I’d love to send vibrations into a ball of silly putty in my downtube. Are there active mass dampers?
Countershox started a new account last night called Countersycle. Lots of good info and pics of their tmd.
https://www.instagram.com/countersycle?igsh=MXkwd3h3NTJ4YWhsOQ==
I was looking at reviews of their Moto version, and it all seems pretty positive, though I've not found any cutaways or proper engineering explanations of how it works other than that graph on the insta. Various people doing timed runs and being noticeably faster with it
you can make some educated guesses based on how Rimpact are designing theirs
https://www.rimpactmtb.com/post/rimpact-tuned-mass-damper-development-b…
I've found the exact springs that the rimpact one uses in my local hardware store, so that alone is making me think that rimpact is only in the early stages of their R&D. Or maybe it just happens to be the right spring rate, I dunno. You could probably calculate the spring stiffness with the damped oscillator model pretty easily, however if 20-26 Hz is your aim, the spring would need to be way stiffer than the one they use.
Even the countershox one can't be very complicated. There can't be any seals to introduce friction so the damping is probably done with elastomers or a viscous fluid. The mass only affects the amplitude of the vibration damping, so more mass -> bigger effect
So I need an inserts, o Chain, added weight and mass dampers to be fast now? 🤣
In all seriousness I get why they are doing this at the to level but seems crazy the amount of stuff we are adding to bikes now.
A rider doesn’t, “need” any of this to ride. Just depends how much comfort and ride feel you want. Like someone could ride a hard tail, single pivot or 6 bar.
To me, It’s a hobby sport for us, it’s a hobby to tune my bike better.
Photo from Rimpact R&d
If you used a mass of 0.5kg or just over a pound (which seems pretty heavy to be sticking to your bike/inside the steerer) a rate of 7.9N/mm would give you 20Hz. Thats similar to a fork spring (eg a "green" ohlins spring or 45lb/in) so pretty easy to find in that range
https://nz.rs-online.com/web/c/fasteners-fixings/clips-springs/compression-springs/?pn=1&sortBy=Spring+Rate&sortType=DESC&applied-dimensions=4294518355,4294518319,4294518339,4294513782,4294518323,4294513778,4294518342,4294518304
and a nice online calculator to use so people can go nuts!
https://www.omnicalculator.com/physics/natural-frequency
I'm not convinced the countershox is a traditional TMD. What it seems to do is respond to a shock input with a delay that feeds back an opposing force (now of course the setup will lead to a specific resonant frequency, but I don't think they've tuned it that way). If anyone wants to buy one and ship it to the UK, I'd love to pop it on a shaker table to measure the frequency response, whack it with a modal hammer to see the shock response, then of course get out the hacksaw!
seems applicable (sort of). why not just put ebike batteries in one to isolate the weight : )
Maybe someday someone will throw enough money at this that we can have the Bose bus seat version of a mass damper.
Thats a pretty good comparison! The live view of the forces is possibly the most relevant, and shows why some kind of damping is important for grip - even though the highest forces are on the undamped pack (which in respect to tyres you might think means more grip) the lows are actually negative, ie unweighted which means no grip!
I had to zoom in to check the scales on both plots were the same. Also side note - increasing force on the tyres doesn't have a linear increase in grip, so simply adding more weight (eg shifting all your weight forward to the front tyre) gives proportionally less grip than the amount of weight distribution change. Therefore consistent and even loading of the tyres can potentially have far more available grip and why TMD's are an interesting technology
I wondered about how heavy the mass needed to be and also about the amplitude of the movement. I found some answers and formulas here:
https://euphonics.org/9-4-3-the-tuned-mass-damper/
Countershox are actually already selling those dampers, and surprisingly they aren't crazy expensive. They must be new to the industry lol.
No reason why not - it would just need to be tuned differently. The main reason you don't see it more yet is people are still getting their heads around it and haven't figured out the best places to use them. They might not take off, but the only way to find out is if people try it!
They're an honest company. The tech isn't expensive at all.
As @TheSuspensionLabNZ noted, you could McGyver one with an Ohlins green spring, a 600g mass and a tube and some rubber for vibrations, forget a mountain bracket just zip tie that sucker on.
Charging $500 just means someone else will move in and undercut you and make you look like an idiot and lose all sales.
There's a lot more to the CounterShox than going to a hardware store and picking up parts. Think about the millions of combinations of springs and weights, rattle noises, fork mounts, ect. I suspect there's more going on with their product than springs and weights.
I've tried it on a motocross bike and DH bike and was really surprised/happy with the results. I think the price isn't for everyone and the added weight isn't for everyone. I bought them because I'm interested in trying new parts, but it's going to be hard to ride without them now.
Yeah fine tuning the exact spring rates, mass and travel for the device would be pretty time consuming - get it wrong and you would make things worse or make a noisy shaker device that yeets itself off the bike if you hit just the right size bump....
I rigged up a janky device from bits around the shop that seemed to be in the right range and bolted it to a wheel this morning - will get some video of it in action later today
Oh I absolutely agree. I'm not trying to say countershox haven't invested the time and made a good product.
But you also have to realize with it on the market, you can cut one open, copy it, and undercut them enormously if they're charging a lot for them.
The product itself is simple and easy to copy. The research and development is the hard part, but since they've done it for you...
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