[eicca]

You don't mean zero compression damping right? As in no compression damper? Cause that's not going to work too well.

I mean no resistance of any kind to the compression stroke of the shock. Smooth as butter.

 

[Jayem]

I and many I know find compression damping to be utterly stupid. The point of suspension is to absorb the terrain and keep traction.

Yeah, that's basically complexly wrong. That may just be due to the poor suspension stuff that you've been on, but that is in no way accurate. Proper compression damping helps to maintain the chassis stability while maintaining grip. A lot of mtb suspension has been crap, due to overly restrictive high speed valves for fatties or the worst case scenario that makes for a jackhammer when you add compression damping, or not using proper circuits, etc., but custom tuners do it right a lot of the time and the OEM stuff is slowly getting there. The point of suspension is not to absorb the terrain, it's to maintain control and grip. Attenuating bumps is necessary to maintain grip, but chassis control is also necessary for the same. Chassis control is going to come through good low speed damping. You don't want the front end to dive with every impact, g-out and braking event. That will upset your traction all the same.

You may not understand that even with a setting of "zero", you still have compression damping, usually both low speed and high speed. If your fork is getting harsh when you dial it up, it's likely just the OEM damping. If all you've ever ridden is this, you tend to assume that's how it must be for everything, that if you increase the compression damping, it gets harsher.

If you think control is improved by having the chassis move around all over the place...I just don't know what to say, that's pretty much opposite of any suspension theory.

 

[jeremy3220]

I mean no resistance of any kind to the compression stroke of the shock.

Yeah not possible. Not unless they start making 600 psi shocks.

 

[eicca]

Yeah, that's basically complexly wrong. That may just be due to the poor suspension stuff that you've been on, but that is in no way accurate. Proper compression damping helps to maintain the chassis stability while maintaining grip. A lot of mtb suspension has been crap, due to overly restrictive high speed valves for fatties or the worst case scenario that makes for a jackhammer when you add compression damping, or not using proper circuits, etc., but custom tuners do it right a lot of the time and the OEM stuff is slowly getting there. The point of suspension is not to absorb the terrain, it's to maintain control and grip. Attenuating bumps is necessary to maintain grip, but chassis control is also necessary for the same. Chassis control is going to come through good low speed damping. You don't want the front end to dive with every impact, g-out and braking event. That will upset your traction all the same.

You may not understand that even with a setting of "zero", you still have compression damping, usually both low speed and high speed. If your fork is getting harsh when you dial it up, it's likely just the OEM damping. If all you've ever ridden is this, you tend to assume that's how it must be for everything, that if you increase the compression damping, it gets harsher.

If you think control is improved by having the chassis move around all over the place...I just don't know what to say, that's pretty much opposite of any suspension theory.

With my springs tuned properly it doesn't dive with every slight impact or movement. It stays very stable while the suspension is totally free to move and erase the chatter. I've been on a lot of different bikes and never felt as much grip or control as I do on my Canfield with the "extremely very light" compression tune that DVO made for me. Wide open, all the time, and I'm faster and more controlled than ever, with none of the arm pump or limb cramping I used to get on other bikes/shocks/forks even with those wide open.

Chris Canfield's philosophy is the same, which I think is why I like his suspension design so much with as little compression damping as possible.

 

[PhillipJ]

What about chassis movement when standing and hammering? Use better technique. That's what I do.

This would make heaps of sense if compression damping was all about controlling pedal induced movement.

Having experimented with removing almost all compression damping from a fork I'll say that for me at least I'd rather ride a jackhammer orifice damper than suspension with no compression damping.

 

[eicca]

This would make heaps of sense if compression damping was all about controlling pedal induced movement.

Having experimented with removing almost all compression damping from a fork I'll say that for me at least I'd rather ride a jackhammer orifice damper than suspension with no compression damping.

I mean, everybody has their style. I just can't fathom it and I haven't had any problems with my wide-open setup.

 

[Suns_PSD]

I mean no resistance of any kind to the compression stroke of the shock. Smooth as butter.

The reality is 'no damping' at all as you call it is actually not to far from what is considered normal damping, such is the limitations of those dials.
If you actually rode 'no damping' you'd fly over your bars after the first bump on your pogo stick suspension.

Sent from my KYOCERA-E6920 using Tapatalk

 

[eicca]

Well, of course, I assumed that specifying "compression" damping meant we'd understand that I do still like (need) a properly-adjusted rebound damper.

 

[233946]

With my springs tuned properly it doesn't dive with every slight impact or movement. It stays very stable while the suspension is totally free to move and erase the chatter. I've been on a lot of different bikes and never felt as much grip or control as I do on my Canfield with the "extremely very light" compression tune that DVO made for me. Wide open, all the time, and I'm faster and more controlled than ever, with none of the arm pump or limb cramping I used to get on other bikes/shocks/forks even with those wide open.

Chris Canfield's philosophy is the same, which I think is why I like his suspension design so much with as little compression damping as possible.

The light compression tune you have, still has significant compression dampening. Outside of tuning the shim stack, the only other adjustment for compression is the 3 position low speed lever which has only a mild effect, as DVO relies on the stack for almost the entire compression tune. Having no compression would result in constant bottoming, even without jumps.

 

[eicca]

The light compression tune you have, still has significant compression dampening. Outside of tuning the shim stack, the only other adjustment for compression is the 3 position low speed lever which has only a mild effect, as DVO relies on the stack for almost the entire compression tune. Having no compression would result in constant bottoming, even without jumps.

I'm almost certain it doesn't though, not in a "significant" degree at all. I can feel the compression damping even in Fox or RockShox forks when they're "wide open." There's a tangible resistance in the compression stroke of the fork and it's terrible. Underneath me those forks get really harsh over chatter and don't hold traction as well as my DVO components. That's why I went with DVO. I can't feel any resistance in the floor test, the chatter is completely erased and I have loads more grip because my dampers aren't resisting the fork's compression motion. Of course, they still have rebound damping.

Besides, doesn't the inherent nature of a properly-configured spring prevent bottoming from happening? A very linear coil might bottom out with no damping, or an air spring with way too large a volume for the rider weight. I can set mine up like that if I want, but between the OTT on the fork and the volume spacer flexibility on the shock, I've got just the right amount of progression and tons of top-stroke sensitivity. If I pick my bike up and drop it, it doesn't bounce when it lands. If I add any compression damping, it does.

It's entirely possible to run without any compression damping. Chris Canfield likes it that way, and he's a certified suspension genius.

 

[Gman086]

There is nothing magical about the CBF, it is just another four bar. They tune it to have a relatively flat antisquat slope, so it isn't as sensitive to sag as some designs, but there are tradeoffs. First, 100% antisquat does not mean that pedaling forces have no impact on traction, it means that the chain compensates for the rider's weight transfer. 0% is pedaling independent with no chain growth or shrinkage. It is not done because the compromises are too large (we used to see under 50% in downhill bikes). By keeping antisquat at approximately 100% through the travel range, Canfield has a higher level of pedal kickback on large bumps than designs that aim for antisquat that drops after the sag point. Here is a good article about antisquat and the tradeoffs:
Again, there is no free lunch, it is choosing the tradeoffs. A 4bar is a 4bar is a 4bar no matter what it is called and they all follow the same laws of physics.
/QUOTE]

So... in your previous post you're quick to point out the importance of chainstay length... CBF's parallel link suspension allows for the shortest chainstays of all without the need of gimmicks like "Super Boost". The Riot has 16.3" chainstays (on standard 142 width hubs I might add) yet CBF is "just another four bar"??? Then you go on to post anti-squat graphs for their most "trail oriented" bike ever and decide CBF has a bunch of pedal kickback? As an owner of a CBros Balance, I really REALLY appreciate the laughs...

Have FUN!

G MAN

 

[233946]

I'm almost certain it doesn't though, not in a "significant" degree at all. I can feel the compression damping even in Fox or RockShox forks when they're "wide open." There's a tangible resistance in the compression stroke of the fork and it's terrible. Underneath me those forks get really harsh over chatter and don't hold traction as well as my DVO components. That's why I went with DVO. I can't feel any resistance in the floor test, the chatter is completely erased and I have loads more grip because my dampers aren't resisting the fork's compression motion. Of course, they still have rebound damping.

Besides, doesn't the inherent nature of a properly-configured spring prevent bottoming from happening? A very linear coil might bottom out with no damping, or an air spring with way too large a volume for the rider weight. I can set mine up like that if I want, but between the OTT on the fork and the volume spacer flexibility on the shock, I've got just the right amount of progression and tons of top-stroke sensitivity. If I pick my bike up and drop it, it doesn't bounce when it lands. If I add any compression damping, it does.

It's entirely possible to run without any compression damping. Chris Canfield likes it that way, and he's a certified suspension genius.

Pushing down on the handlebars or bouncing on the bike tells you nothing about the amount of high speed compression, you simply cannot push fast enough to do anything but feel the amount of low speed compression and friction in any design. Your statement that Chris Canfield doesn't like any compression dampening is an incorrect understanding of what Chris may have said. There is no such thing as a damper with no compression dampening. You must have at least a single compression shim in a damper, without it, the oil would flow virtually unrestricted on rebound, as the shim also acts as a check valve to prevent oil from flowing unimpeded back through the piston on rebound. The piston also has limited flow and even with a very light shim stack will provide some high speed dampening.

DVO forks, despite your belief, use plenty of high speed dampening. I have spend significant time playing with and tuning the stacks in both the Emerald and Diamonds. If you like, I can provide a spreadsheet with the stacks (the midvalve in the Diamond also has a significant impact on the high speed dampening). The difference between the DVO and Rockshox and some Fox forks, is the DVO doesn't run into a flow wall because the piston has inadequate flow. They also use a coil negative and larger bath volumes which help to reduce breakaway friction, which can cause some forks to feel harsh.

Finally, in regard to your question about a spring preventing bottoming, the answer is no. A spring is used to set ride height and the rate used to help control the amount of energy to bottom, but an unrestricted spring will bottom extremely easily. A spring and damper function as a system, the damper controls the spring movement (dissipates energy, as a spring merely holds energy). To a certain extent you exchange spring rate and dampening to control bottoming, but only to a certain extent.

I strongly encourage you to read Race Tech's Motorcycle Suspension Bible, which spends a great deal of time discussing the entire system, how it works, and the tradeoffs.

 

[233946]

So... in your previous post you're quick to point out the importance of chainstay length... CBF's parallel link suspension allows for the shortest chainstays of all without the need of gimmicks like "Super Boost". The Riot has 16.3" chainstays (on standard 142 width hubs I might add) yet CBF is "just another four bar"??? Then you go on to post anti-squat graphs for their most "trail oriented" bike ever and decide CBF has a bunch of pedal kickback? As an owner of a CBros Balance, I really REALLY appreciate the laughs...

Have FUN!

G MAN

You are conflating two concepts. Chainstay length effects balance on a bike, but has nothing to do with whether a bike is a four bar and the fundamental physics that govern all suspension designs. Canfield emphasis short stays, but there are plenty of variations of four bar that allow for them (Knolly comes to mind). It doesn't matter the chainstay length, it is independent of the tradeoffs that come with antisquat and pedal kickback. The more antisquat you have, the more kickback, period, because antisquat is dependent on chain tension. Canfield chooses to have a more linear antisquat, including deeper in the travel, which results in more pedal kickback further in the travel than some other implementations. There is nothing wrong with that, it is purposeful decision made at the design phase, but again, there is nothing magical about the CBF design, just as there is nothing magical about the KS Link, VPP, DW-Link, or FSR, they are all just four bars with different marketing terms.

Finally, as you seem to feel I picked the wrong bike to show the high kickback with Canfield's chosen tuning, here is the antisquat and pedal kickback for the Balance. As you can seek, because it has a flat antisquat curve, it has more pedal kickback deeper in the travel than bikes that have a decreasing antisquat. Again, there is nothing wrong with this, as with all designs, this was a tradeoff chosen by the brothers when designing the bike, as all designers balance antisquat/brake jack, leverage curves, shock turning, geometry, and frame stiffness.

Marketing sells, not physics. Nobody gets market share by admitting that their design works the same as everyone else's and that it is implementation that makes it feel different. So to sell bikes, the designers carve out very minor variations of the same design that have no functional difference, patent their very minor variation, and claim that it is proprietary and therefore better. Again, talented designers bring a lot to the table, it is their knowledge and the design of the entire package (suspension, geometry, frame stiffness) that make the bike, not the minor differences in their variation of a four bar design.

 

[eicca]

You're saying the rebound damper itself will have some effect on compression because the oil has to flow through it to get back to the rebound control. I get that, and it's easy to test. If I crank my rebound damping to max I can also feel increased resistance in the compression stroke.

I'm still not convinced that the compression side of the damper is an essential part of bottom-out prevention. That's what spring rate and frame progression are for. I can make my fork/shock bottom super easy or not at all with the same amount of sag, entirely by tweaking the spring rates, with no change in the damper. Odds are, if your spring can't do the majority of bottom-out prevention, something in the setup is way off. I guarantee you my compression dampers aren't doing jack squat in their wide-open state to prevent me bottoming out my bike.

Case and point, we took the compression damper cartridge out of my uncle's fork to troubleshoot the lockout, and the curve and bottom out resistance of the spring felt totally unchanged. It just felt way better and more sensitive. Wasn't any easier to bottom out in testing. Maybe it might have bottomed out slightly easier on actual rides, but an air spring tweak would fix that no problem.

Also I absolutely CAN feel the difference in the high speed damping adjustments in the floor test. My Diamond on max high speed damping feels like the stock tune Diamonds at about 30%.

Chris Canfield's words are "I'm on the side of open compression damping. Take your compression and turn it all the way off. Both of them, all the way off. Get your spring rate right and you're fine. If you need a little help, buy a better bike. Rebound is personal choice."
Chris Canfield of Suspension Formulas - The Inside Line Podcast at time 1:17:00.

And also motorcycle/automotive suspension principles don't translate to MTB beyond how shim stacks work. The similarities end at wheels moving up and down. They really can't be compared.

Saying there's "no functional difference" between Horst, VPP, DW-Link, CBF, etc is preposterous. "Minor differences" in four bar design are called millimeters between pivot points. Not entirely separate implementations. No Horst-link bike out there right now rides anything like a CBF bike. It's a preference thing, but they are definitely not just marketing ploys.

 

[233946]

You're saying the rebound damper itself will have some effect on compression because the oil has to flow through it to get back to the rebound control. I get that, and it's easy to test. If I crank my rebound damping to max I can also feel increased resistance in the compression stroke.

I'm still not convinced that the compression side of the damper is an essential part of bottom-out prevention. That's what spring rate and frame progression are for. I can make my fork/shock bottom super easy or not at all with the same amount of sag, entirely by tweaking the spring rates, with no change in the damper. Odds are, if your spring can't do the majority of bottom-out prevention, something in the setup is way off. I guarantee you my compression dampers aren't doing jack squat in their wide-open state to prevent me bottoming out my bike.

Case and point, we took the compression damper cartridge out of my uncle's fork to troubleshoot the lockout, and the curve and bottom out resistance of the spring felt totally unchanged. It just felt way better and more sensitive. Wasn't any easier to bottom out in testing. Maybe it might have bottomed out slightly easier on actual rides, but an air spring tweak would fix that no problem.

Also I absolutely CAN feel the difference in the high speed damping adjustments in the floor test. My Diamond on max high speed damping feels like the stock tune Diamonds at about 30%.

Chris Canfield's words are "I'm on the side of open compression damping. Take your compression and turn it all the way off. Both of them, all the way off. Get your spring rate right and you're fine. If you need a little help, buy a better bike. Rebound is personal choice."
Chris Canfield of Suspension Formulas - The Inside Line Podcast at time 1:17:00.

And also motorcycle/automotive suspension principles don't translate to MTB beyond how shim stacks work. The similarities end at wheels moving up and down. They really can't be compared.

I have explained it as well as I can. It appears you are more interested in believing that your conclusions are correct than expending your knowledge. You are taking Chris Canfield's comment and misinterpreting it to fit your beliefs. He says "open compression" not "no compression". Similarly, "[t]ake your compression and turn it all the way off" is a reference to low speed compression adjustments on shocks and forks as few have high speed. Even with those that do, backing the compression adjuster all the way out does not eliminate compression, merely lightens it.

It is great your like your Canfield, they make nice bikes, but there is no magic in their design or tuning. Chris is one of dozens of talented engineers that design bikes.

 

[eicca]

I'm believing my conclusions are correct based on years and years of training and suspension setup while working for pro shops, and feedback from customers that found new life and better performance in their bikes thanks to my work. Are we all deluded? Could be. But I'm definitely not making my adjustment decisions based on motorcycles because the two are not the same.

I'd highly recommend you don't rely on that motorcycle book to tell you how to set up your mountain bike. You're probably missing out on a lot of its potential.

The bottom line is compression damping alone is not at all necessary for a mountain bike to function properly. Spring rate and kinematics are, and with those set right, zero compression damping is totally reasonably and can result in far better traction and control.

 

[233946]

Again, you take a statement and twist it around. I never advocated making adjustment decisions based off of motorcycles. I suggested you read the book as it discusses suspension design and tuning and specifically recommended it so you would be able to understand there is no such thing as a shock or fork with no compression dampening. Again you seem more interested in validating your beliefs than taking a look at where they may be correct and where they may be incorrect. The fundamentals of design and turning are same regardless of the vehicle, all that changes are the ratios of weight transfer, sprung v. unsprung weight, and shaft speeds.

 

[eicca]

You literally told me to study a motorcycle suspension book. What's the point, other than to use that knowledge to tune a bike? Not going to work. Tuning a motorcycle and car is nowhere near like tuning a bicycle, other than they all have springs and dampers. That should be extremely obvious.

I agree that there's no such thing as a fork or shock without some degree of compression damping. But the fact is it's not a crucial necessity as you suggest, and when used wrong (which most people do) it only hurts performance. The other fact is is my setup has almost none of it, so little that it's completely undetectable and has next to zero impact on the motion of my bike, and it's the best setup I've ever ridden. Which, as you imply, should be impossible.

 

[Gman086]

Again, talented designers bring a lot to the table, it is their knowledge and the design of the entire package (suspension, geometry, frame stiffness) that make the bike, not the minor differences in their variation of a four bar design.

THAT was my ENTIRE POINT for bringing up the chainstays... it is the IMPLEMENTATION of the suspension design to the overall bike design, not just the "4 bar" that you were lumping everything into... saying CBF is just another 4 bar?! The straight rate you show in the graph is also very well calculated for (and rather easily I might add) with a low compression shock tune (that eicca refers to) again making this suspension superior to many I have ridden over the last 25 years. I guess most just won't get it until they actually ride it. Same goes for Yeti. Those two don't have "cult followings" just because of their kewl headbadges... I can assure you! The overwhelming positive reviews also reflect that but to each their own.

Have FUN!

G (have not used a climb switch in years) MAN

 

[233946]

That's why I'm currently such a CBF fanboy. They aim for 100% anti-squat at all points in the travel, and they do this by keeping the chain perpendicular to the axle path, which effectively means that pedaling forces have no impact on traction and that deep compressions don't make the bike stall. In my experience the hype is real.

Which got me thinking: you can put a single pivot in the right spot to keep the chain perpendicular, super easy. Horst links can also be tuned to keep the chain perpendicular. I believe Norco's newest Sight and Optic are tuned that way. But both of those instances are missing something, either the high traction or the alive feeling. It must have something to do with the combination of leverage ratios and axle path and that stuff. I don't know. CBF still wins it all for me. But it seems like DW-Link does the job too.

The final answer is a test ride, of course...

So... in your previous post you're quick to point out the importance of chainstay length... CBF's parallel link suspension allows for the shortest chainstays of all without the need of gimmicks like "Super Boost". The Riot has 16.3" chainstays (on standard 142 width hubs I might add) yet CBF is "just another four bar"??? Then you go on to post anti-squat graphs for their most "trail oriented" bike ever and decide CBF has a bunch of pedal kickback? As an owner of a CBros Balance, I really REALLY appreciate the laughs...

Have FUN!

G MAN

THAT was my ENTIRE POINT for bringing up the chainstays... it is the IMPLEMENTATIOUN of the suspension design to the overall bike design, not just the "4 bar" that you were lumping everything into saying CBF is just another 4 bar?! The straight rate you show in the graph is also very well caclulated for (and rather easily I might add) with a low compression shock tune (that eicca refers to) again making this suspension superior to many I have ridden over the last 25 years. I guess most just won't get it until they actually ride it. Same goes for Yeti. Those two don't have "cult followings" just because of their kewl headbadges... I can assure you! The overwhelming positive reviews also reflect that but to each their own.

Have FUN!

G (have not used a climb switch in years) MAN

In my original post, I pointed out that chainstays have an effect on climbing, as they affect the balance point on the bike. I also addressed Eicca's incorrect post which I have quoted above again: i.e. 100% antisquat does not mean "that pedaling forces have no impact on traction and deep compressions don't make the bike stall." You then complained that my post regarding the high level of kickback associated with the tradeoffs that Canfield chooses was incorrect because it was their most "trail oriented" bike (ignoring it shows the both a Canfield and Revel, both Canfield designs) and implied that your Balance doesn't have high kickback. When I posted the actual kinematics of the Balance, you then abandon that line of arguement and took the new position that the high level of kickback "is also very well calculated".

What you have never addressed is the original issue: What is different about the CBF than any other four bar? The answer is nothing, it is just another variation of a four bar with some fancy marketing. If you would like to present some evidence that demonstrates that CBF has repealed the laws of physics and their design somehow avoids the direct tradeoffs of antisquat/brake jack/pedal kickback, I (and I am sure others) would love to see it as they will have found the holy grail. At this point all we have is you claiming "this suspension is superior" and eicca who lacks even the basic understanding of antisquat and compression dampening, claiming he is suspension tuner.