Elastomers Are Back? SRAM Patents 'ButterCups For Shocks'

Sep 8, 2023 at 9:03
by Seb Stott  
photo

We always keep an eye out for patent documents that might reveal what the bike industry has in store for the years ahead. But in this case, patent purveyor Jessie-May Morgan over at Bikerumor got the scoop on a very juicy patent from SRAM.

photo
Elastomers (526 & 528 ) isolate the frame mounting part (314) from the shock eyelet (500).

The patent document, which you can read for yourself here, describes shock eyelet mounts that contain elastomers (rubber springs) in-between the shock and the frame. These elastomers could perform a similar function to the ButterCups already seen in the latest generation of RockShox forks. That is to say, their function is to absorb the very low-amplitude but high-frequency vibrations caused by small stones and washboard surfaces.

These small undulations usually don't provide enough force to overcome the static friction resulting from all the tight seals found in mountain bike forks and shocks (especially air-sprung varieties). As a result, MTB suspension (air suspension in particular) does a poor job of reacting to these subtle variations in force coming from the ground, but because the vibrations are high-frequency and continuous, they can contribute to rider fatigue and joint pain.

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Here you can see the elastomer mount in the compressed position (left) and extended position (right). Elastomers (526 & 528 ) on either side of the frame-connecting part (502) provide resistance in both directions.

As well as reacting to small vibrations which the air shock couldn't, they might allow the suspension to start compressing slightly earlier after the tire hits a bump. This initial bump response can have an outsized effect on harshness and contact patch load variation (and hence grip).

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The ButterCups in a RockShox fork.

I explained in a previous article why I think ButterCups only offer a modest benefit in RockShox forks, mostly because the bump force still has to overcome the friction between the upper and lower fork legs before the ButterCups can compress at all. So, they can only be effective for bump forces large enough to overcome the friction in the fork chassis, but not large enough to overcome the friction in the spring and damper. However, this isn't the case with the shock elastomers described here. They work in series with the whole shock, not just the air spring, so only the (minimal) friction in the suspension linkage has to be overcome before they can start doing their thing.

Also, because the rear wheel moves by as much as three millimeters for every millimeter the shock compresses, the effect of such elastomers would be amplified. If they can compress by as much as 4 mm (as the fork ButterCups claim to), this could translate to as much as 12 mm of movement at the rear axle. Additionally, because the elastomers can be accessed more easily in this design than in a fork, it may be possible for the end user to swap out elastomers of different hardness to match their weight or preference.

photo
In this diagram, the frame mounting threads (316) sit parallel to the regular shock eyelet, so the eye-to-eye length could be unaffected, but the overall length is considerably greater.

The elastomers could be fitted to either end of the shock (or both) and are housed in such a way that the overall length of the shock would be increased, but the eye-to-eye length could be nominally the same. Because the elastomers act as a spring in series with the shock, they would increase the travel and decrease the spring rate slightly, even during slow, sustained movement.

photo
An example of how the elastomer-equipped shock might fit on a bike.

It's not clear at this point whether this concept could be retrofitted to existing shocks, but it looks like the elastomer frame mounts could be affixed to existing shock eyelets. If nothing else, it's possible that shocks could benefit from different damping tunes to complement the effect of the elastomers. They would increase the overall length and travel of the shock, so it seems likely that they wouldn't be compatible with every frame. Of course, it may not see production at all, but we'll keep an eye out for strange-looking shocks in the wild.




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Member since Dec 29, 2014
305 articles

134 Comments
  • 121 1
 I also see on that last diagram they have come up with a design where the cables DON'T go through the headset. Revolutionary idea right there, hopefully that will catch on.
  • 22 10
 Man this is low-hanging fruit humor now
  • 16 0
 36 spoke wheels are apparently making a comeback, too!
  • 8 1
 @VtVolk: I'm actually not totally against a 36 spoke rear wheel for strict DH usage
  • 9 0
 The external fork steerer will simplify maintenance for the home mechanic who hates threading the steerer through the headtube (and loses it somewhere halfway).
  • 39 1
 Sounds like someone should patent an elastomer inside of a lower headset cup to be even better than Buttercups. Headshock anyone?
  • 37 0
 we're stuck in an endless loop of innovation
  • 13 0
 @mior: why stop with shocks??

Buttercups between bar and stem...
post and seat rails.
pedal body and spindles
  • 53 0
 I have an idea for buttercups between your hands and the cold, hard handlebars. Like a cylindrical rubber thing that slips over and damps vibrations before it gets to your body. And some of my “Butterhands” are going to have another kind of material inside for different frequencies of vibration. Headed to the patent office now with a sketch my 4 year old did.
  • 14 0
 Cannondale did a lot of super innovative stuff back in the day, they just went way too Cannondale on the design and introduction in the market and Cannondale'd everything up.
  • 41 0
 @ReformedRoadie: buttercup between your ass and the seat. Secured by butt plug.

elASStomer? Buttholecup?
  • 12 0
 @nfontanella: Sram Butterhole lube required for installation.
  • 1 0
 @ReformedRoadie: thadd be an interesting concept bike honestly
  • 9 0
 @ReformedRoadie: Welcome back Girvin Flexstem
  • 5 0
 @nfontanella: You, sir, have a job waiting for you in the SRAM marketing department.
  • 2 0
 Yeah but what about an elastomer in an integrated headset to prevent cable rattle?
  • 5 0
 @ReformedRoadie: besides the pedals all of these things exist in some way or another.
  • 1 0
 @lowkeyokeydokey: I miss those days
  • 10 0
 @ReformedRoadie: I have a 20-year-old specialized cyclocross handlebar with this exact thing. It seemed heavy and dumb at the time so I took it off. Now Im heavy and dumb so who got the last laugh?
  • 2 0
 While we are at it, we could just invent something called hiking shoes and be done with it!
  • 1 0
 @mior: until SRAM patents it, and give it some cool name, does it really exist?
  • 1 0
 Isnt specialized basically doing that with their latest gravel bike?
  • 1 0
 Quick, Bell-Bottom patenting coming your way!
  • 2 0
 @mior: "besides the pedals all of these things exist in some way or another."

Shoes. If you haven't tried them yet, I recommend them highly
  • 4 0
 @gabriel-mission9: getting elastomers surgically implanted in my feet soon
  • 6 0
 In the interest of minimizing unsprung mass, it would be ideal if we could find a way to place the compliant rubber devices as close to the ground as possible.
  • 1 0
 thudbuster ftw!
  • 1 0
 @lowkeyokeydokey: The biggest thing they Cannnondale'd up was a motorcycle, to the point where it basically ran them out of business and they had to sell off what was left to Dorel.
  • 2 0
 you're getting far to complicated here. I just patented an idea for an infinitely long pneumatic cylinder that wraps around an infinitely long carbon fibre or metal carrier. These two components are attached to a transverse central cylinder that rotates and when combined with the longitudinal cylinders via thin rods of any tensile material, provides a renewable traction surface. Because the cylinders are filled with another patent of mine called ArNO, the amount of elasticity is also infinitely variable via something I'm called a ArNO Mass-Turbator due to the turbulent flow that allows the infinite variability. I hope it will catch on. My savings depends on it
  • 2 0
 @golefty: smart isnt allowed on pinkbike
  • 1 0
 @mior: sorry,.... it won't happen again
  • 1 0
 @mior: Onza used elastomer in place of springs for their clipless pedal mechanism. Not the same, but still in a pedal.
  • 1 0
 @yonderboy: i know my old stuff
  • 12 0
 Anyone else have doubts these pucks do anything?
  • 5 13
flag 541freeride (Sep 8, 2023 at 10:30) (Below Threshold)
 Ride it and you'll feel the difference. I got it in my Zeb fork and I feel less fatigued after a long day riding.
  • 28 0
 If only there was some other way to put rubber between the rider and the ground to dampen vibrations.
  • 13 0
 @Trailsoup: You could even make this adjustable via air pressure and later also add elastomers inside ...
  • 12 0
 Put the Charger 3 and new air spring with Buttercups in my '21 Zeb and can confidently say I did not notice any difference at all. Expensive worthless upgrade.
  • 8 0
 Decoupling elastomers for vibration isolation are not a new concept in the world of engineering and their functional benefits are well documented and understood. For example, they are used to isolate a car's engine from its chassis, in aircraft interiors, realistically anywhere there is a reason to reduce noise, vibration, and harshness.
  • 3 1
 @jbadger1977: I don't feel any difference pedaling and riding flatter trails. But bike park and long downhills are where it becomes noticable.
  • 2 0
 @Segamethod: And on race cars all that spongy junk is thrown away for rigid mounts and maximum stiffness where it counts...
Exactly what size is item 510 and what screw size is 518? Looks flexy
  • 7 0
 To be honest, even if it doesn't dampen anything, it should offset the torque caused by the trunnion mounts.
  • 1 3
 @vr6ix: pretty hard to compare a mountainbike to a race car. The don't have a whole lot in common.
  • 1 0
 @jomacba: Before I read the whole thing that's what I thought these were for. I thought it weird for SRAM to be taking that on care of the frame manufacturers, but it was an interesting thought.
  • 1 0
 @jbadger1977: might be due to the charger 3 being, well, not great
  • 11 0
 Proflex 2.0… just need Onza to update the HO pedal now
  • 7 0
 gonna bring back panaracer smoke/darts and blue and purple ano everything
  • 3 0
 @mior: Gotta admit...I've wondered how a Dart/smoke with a solid tubeless casing and quality rubber would ride.
  • 3 0
 @mior: I used to love the Smoke tire. There were some trails where those tires hooked up so well I felt like I was riding on rails.
  • 2 0
 @ReformedRoadie: they would probably work great but no one would admit it because they don't look like a Minion clone. Bring back the Velociraptors back too.
  • 1 0
 @Sscottt: Kinda like how that new(ish) Tioga tire with no center knobs that gets great reviews has never had any traction in the market.
  • 1 0
 @jonemyers: Rail trails? Ah, yes, I've heard of those.
  • 1 0
 @ReformedRoadie:
www.panaracerusa.com/products/smoke-dart-classic-folding-mtb-tires-1
folding, not tubeless. surprised they still make them. these and rider T1's are the only vintage style tires still available
  • 2 0
 Every time some old timer mentions Onza pedals, my shins start to ache. The random ejections once the elastomers started to fade were brutal. The crazy thing was, for one brief shining moment in the life of each set of elastomers, they were really good pedals.
  • 1 0
 Those were my first clipless pedals. Loved the temperature dependent release rate!
  • 9 0
 Sounds complicated. I want
  • 3 0
 I'm holding-out for the wireless battery-powered option myself
  • 9 0
 Why do you fill me up, butter cup, just to let me down?
  • 3 0
 Was reading through the comments to see if someone already took this. dang it !
  • 6 0
 I'd really like to go back to school to do some testing on this 3 phase damper: Tire, buttercup, shock. Even your tire is two-phase if you have inserts.
  • 6 0
 Yes, this - I already have elastomers between the ground and frame - TIRES. And as noted, with inserts they're two-phase. If I was running the tires at 100psi, maybe another elastomer might have some effect. But at 22psi I have a hard time imagining what sort of bump I would or could cancel out with another elastomer in the system.
  • 4 0
 Fasst handlebars work similarly but put the elastomer in the handlebars themselves. Do i believe they work? Absolutely. Will I ever be able to prove it? Not likely.
  • 3 0
 The shock mounts in cars often have an elastomer that allows for a bit of movement as well. I wonder if this less rigid mounting could alleviate some of the problems that shocks have with side loading?
  • 3 4
 And then the performance cars don’t.

Do you want a Toyota Camry on the trails, or a Mclaren 720S ?

Same thing with engine mounts. Companies even use hydraulic fluid filled engine mounts.

Aircraft use solid mounts, no rubber anywhere.
  • 4 0
 @Yourworstnightmare: And performance cars have worse NVH issues. On a bike, NVH translates to loud bikes, extra fatigue and arm pump
  • 2 0
 @Yourworstnightmare: Depends on the aircraft (AS350 B2 and B3’s for example have plenty of elastomers) but your point still stands. In certain places if NVH isn’t a concern then there are advantages for a direct connection
  • 2 0
 @Yourworstnightmare: POV you don't know what engine mounts are
  • 2 0
 @Yourworstnightmare: The Mclaren 720S uses rubber bushings in the suspension, just like a Camry.
  • 2 0
 @Yourworstnightmare: i guess my ignorance shows then, ive never driven, owned or worked on a mclaren. Only normal regular people cars.

as to your question, i think id rather have the camry if we're comparing cars to bikes. I cant afford a 10,000 dollar bike anymore than i can afford a 100,000 dollar car. Even if i could, it wouldnt be a smart use of my money. what i would like is a bike that works everyday, does what its supposed to, without having to spend tons of time and money on it. I dont need hypercar performance, or the highest end bike, because im not a race car driver, or a pro mountain biker. Just a regular dude.
  • 1 0
 exista something like this
FixShox
dhsign.it/en/18-fixshox-revo
  • 2 0
 @Yourworstnightmare: How about I want a trophy truck on the trails.

McLaren isn't getting too far on my local rides.
  • 7 0
 I really wish someone would go through the effort of blind testing buttercups.
  • 2 0
 @mtmc99: I quick dyno run from any of the suspension shops would easily be able to objectively show the difference. All these other ones are just kind of anecdotal and opinion. Even from that article he says "Clearly, when it comes to suspension I'm just not that discerning." Even working in the suspension industry, the ride engineers were kind of a joke to the manufacturing and design engineers.
  • 1 0
 @slovenian6474: yeah that would do the trick as well I suppose. It seems like the claims would be easy to confirm or refute and yet there hasnt been anything conclusive
  • 4 0
 Whole lotta back patting going on, down at the SRAM offices for “inventing” strut mounts.
  • 2 1
 the "endless loop" of innovation is kinda lame and a layman's take. Maybe separate preconceptions of "elastomers" until you've ridden it? Suspension is pretty good and SRAM is pushing in avenues no other manufacturer is (for MTB anyway). Buttercups aren't groundbreaking but they at the very least its a performance gain (even if it is small).
  • 5 0
 broooooooo.... new idea........ since buttercups are so good why dont we remove the air shaft and just fill it with buttercups.....
  • 1 0
 @mior: yeah, exactly, subtlety of a jackhammer. lol
  • 1 0
 @mior: I got destroyed in the comments for making the same joke about tire inserts
  • 1 1
 @fewnofrwgijn: tire inserts rule.
tbf, high end elastomer forks arent that bad. my 99 manitou sx carbon has a real damper and actually isnt too terrible, certainly not as plush as coil or as poppy as air though
  • 1 0
 One thing I have learned over the years is that no matter what innovation RS will come up with, it does not really change much in practice and their products are still a little bit worse than the best. They however used to be relatively cheap, durable and worked just OK. But currently they added more "innovations" and risen the prices.
  • 2 0
 Help my Buttercups are frozen and not able to completely remove trail buzz, when will RS bring out the winter version, answer at the same time as the winter fluid for the Reverb!!!!!
  • 2 0
 Below 7degC you just replace them for the winter version. Otherwise, they'll just work as well as what you'd have had if you wouldn't use these cups. I'm more interested in how this will increase the durability of the shock.
  • 3 1
 Anyone else see these as another recurring revenue grab for wear and tear parts? I'm sure there's minor benefit, but current suspension is already pretty incredible without these.
  • 1 0
 Hooray for adding hysteresis! Between the tires and CuppyCups, it's a wonder the shock is going to have any part in helping you maintain traction. CushCore partly came about to get the suspension moving sooner when the tire compresses, more closely linking the shock to the trail. Now SRAM wants to separate the trail from the shock, going the exact other way.
  • 2 0
 Has anyone with a buttercup fork had to replace one yet? Curious about the lifespan. I imagine once they blow out the fork/ shock would have quite the rattle
  • 1 0
 Sooo... could they make this an aftermarket upgrade, at least for certain frames? I feel like if the bike's hardware allows it, it could be put in between any rear shock and its mounting hardware.
  • 1 0
 Bike industry patents are getting more laughable by the day. I wonder how any of these are even granted. Using first semester mechanical engineering knowledge is not patent worthy.
  • 1 0
 They just have to be new and unique ideas... it's not the patent office's job to care if they're good ones
  • 1 0
 @AndrewHornor: I never said it was a bad idea. Its quite good actually. Elastomers have been used to dampen and compensate for small alignment errors forever, making this not patent worthy.
Claw couplings are the prime example for this.
  • 1 0
 @endoplasmicreticulum: Fair, sorry for the misinterpretation.
  • 3 0
 I've never seen so much hype around bits of rubber.
  • 11 0
 You've never seen a Trojan ad then
  • 3 0
 Im rolling with Butterbutts and Butternuts - for some saddle cushioning.
  • 1 0
 An external elastomer which does not separate the forces between different seals makes no sense at all. Your tire does a better job at that
  • 3 1
 Do they call them Buttercups because they “suck it up”?
  • 3 0
 Golf clap, but with side-eye.
  • 1 1
 What's the difference between this and something like the bottom out bumper in a Float X? Would this prevent a harsh top out as well?
  • 3 0
 The bottom out bumper would only factor in for bottom out events. These would provide the initial bit of travel anytime your shock is at rest before the forces break the stiction in the shock (and I guess some amount during normal use)
  • 5 0
 These elastomers are meant to compress at the very beginning of the travel, before the shock has overcome its initial breakaway (which is higher than for a coil shock because the air seals have to be tight and snug), so should make a shock more sensitive to small trail chatter. (Until it's cold outside when they will just become very rigid)
The bottom out bumper in a Fox shock is on the other end of the scale, providing extra cushioning when you have used all the travel of the shock and would experience a hard bottom out.
  • 2 0
 It's literally the opposite of a bottom out bumper. It comes into play on forces too small to even start moving the shock.
  • 2 0
 @rarerider: I see. That makes more sense.
  • 2 0
 They could possibly call it a silent block
  • 2 0
 Everything old is new again
  • 1 1
 or perhaps everything new is old again.


"Vu ja'de- Somehow none of this has ever hapend before"

George Carlin
  • 2 0
 Ngl, my old coil/ elastomer fork wasn't half bad.
  • 1 0
 How long until someone comes out with elastonomer shock mounting bushings with 5mm of travel to compete?
  • 1 0
 This is the smart take. Could easily build rubber bushings with sleeves that would fit existing eyelets for way less expense and hassle , if you wanted to go that way.
  • 2 0
 It's just to alleviate trunnion miss aligned frames.
  • 1 0
 I see they are also patenting radial spokes lacing for disc brake wheels. This must require some really trick carbon layups
  • 1 0
 That bike on the last picture makes for an interesting leverage curve.
  • 1 0
 I can't believe they could patent something like that.
  • 4 0
 I'm patenting the word "patent". You owe me One-Hundred-Biiilllllllion-Dollars.
  • 3 0
 @jbuzzinco: Technically, that would be a trade mark. FYI, I've trade marked "technically (TM).
  • 1 0
 Does it come with a hairdryer for winter riding?
  • 1 0
 Should be called Fruit Cake cups
  • 2 0
 Margarine-al gains
  • 1 0
 I think the buttercup itself needs a negative spring lol
  • 2 2
 Oh look...more bullshit from SRAM. Who would've guessed?
  • 1 0
 Oh, but than everyone else tries to copy, Who would've guessed.
  • 1 0
 its actually a good idea. Motor vehicle suspension has rubber bushes to dampen NVH
  • 1 0
 I'll be your Buttercup
  • 1 0
 buttercup pivot hardware
  • 1 0
 WHAT THE, WHAT?!!!!
  • 1 0
 Wireless brakes.
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