mtb vs. mx suspension

[scottvelez]

Been watching some MX videos lately and I have to ask - why do most of us set up our suspension to rebound so FAST? I mean, watch the MX bikes and notice how slow the rebound is.
100 foot long jumps, 15 feet in the air and the bikes bottom out then rebound sssssssssssssssssssssssssssslooooooooooooowly.

Push down on your front fork and watch how fast it returns. Do the same with a MX bike. Why the difference? Both bikes are usd on rough dirt trails, we both have to deal with traction issues, small bumps and big jumps... so why the difference?

[ronald55555]

most of us dont do jumps nearly as big as MX, so we dont need the rebound to be as slow, and keep it fast for bumps.

[scottvelez]

The other thing I noticed, is they tend to bottom out over little five-to-seven foot jumps. If you watch in slow motion, it looks like they go through the full suspension range. Full travel.

Here is my take on it. They don't use BIG springs to prevent bottoming, but simply tune the suspension by adjusting the compression and dampening circuits with the goal of using as much of the suspension travel as possible at all times... tweaking the compression dampening to prevent harsh bottoming.
Why pay for 14" of travel, if you have it so stiff, you only ever use 3" of it? Kind of makes sense. I think I need to rework the way I tune my bike.

[hampstead bandit]

weight balance on an MX bike, MX fork is totally different to MTB?

also the weight of the bikes are so different

i run my rebound pretty slow (firm springs, 10wt oil) both ends for free riding

[Slamigo]

Originally posted by scottv
The other thing I noticed, is they tend to bottom out over little five-to-seven foot jumps. If you watch in slow motion, it looks like they go through the full suspension range. Full travel.

Here is my take on it. They don't use BIG springs to prevent bottoming, but simply tune the suspension by adjusting the compression and dampening circuits with the goal of using as much of the suspension travel as possible at all times... tweaking the compression dampening to prevent harsh bottoming.
Why pay for 14" of travel, if you have it so stiff, you only ever use 3" of it? Kind of makes sense. I think I need to rework the way I tune my bike.

Exactly. You want to use all of your travel. The ideal situation is to have the lightest springs possible for your weight/riding style. Then use the end compression to stop the shock from bottoming out. In a fork, you always try to use the lightest springs that you can get away with, and use oil volume/density to get good compression at the end of the stroke. This way, your bike will soak up all the little hits that slow you down and still be able to handle some drops. BTW, if all you do is big hucks, you have to go the stiff spring AND good end-stroke compression route BUT your small hit sensitivity will be crap and you won't be as fast on downhills. But most people want a smooth fast ride and usually only do drops to nice trannies.

[ryan]

Motocross riders don't have to pedal through their 14 inches of suspension.

[hampstead bandit]

Motocross riders don't have to pedal through their 14 inches of suspension.

yeah they are like 2 totally different vehicles in terms of weight, balance, dynamics, acceleration and deacceleration

they look pretty similar (minus engine and gas tank) these days..make it confusing?

[oryx_ryder]

if the rear shock on a bike were that slow, the bike would bob like a ho every time you pedal:thepimp:

[RAcErX336]

Heres the thing, and I know this becasue I have raced MX for nearly 10 years now.

When you jump an MX bike, if you don't give the bike gas on the landing, the rear suspension rebounds waay faster than if you load the suspension by blipping the throttle as you land.

THis is especially true if you case the landing alittle bit. Just by gassing the bike you make the rear tire stick to the ground and could possible save yourself from eating shit.

So really ther is no way to safely keep a MTB from rebounding so fast, you can slow the rebound down a bunch. But then it will pack like crazy and want to swap sideways on braking bumps and rock gardens.

THe only way I can think it would be possible is with some sort of suspension design or mechinism.

- Andrew

[WBC]

Racer is right. The setup on my mx bike is also set slower, but just pushing down on my shox, it's not a real big difference.

It's all about weight placement, torque interference, etc. Also, MX bikes have compression settings that tend to sink into landings, like how an Avalanche shock or SPV shock does. The settings are a lot more sensitive to...well...I guess you could call it valve placement.

With the suspension spring weight setup, mx bikes are setup kinda like how one would setup a 5thE vs a Fox. The compression damping actually works and won't explode if used to it's full potential, so they're able to setup with more sag. Nothing advanced there.

We could never setup our mountainbikes like our mx bikes, they're two completely different beasts with different physics.

[IFO]

i run my fork/shock as slow as possible without it having a problem of "packing up"...

i dont like suspension to rebound so fast it pogo's...but then again im not a super-fast DH racer either...

for those guys i can see have a faster rebound setting...

[DangerousDean]

i try to make my suspension on my bike as slow as possible, without it packing up, or feeling dead...but you can never really get it that slow like a mx bike
on my quad, the suspension is SUPER slow though :)

[corey@nsmb.com]

Hey Dean,

Post some pics of the Quad!

[DangerousDean]

Anything for mully

http://www.pbase.com/image/22141468

http://www.pbase.com/image/22141471

[corey@nsmb.com]

SWEET.

Lucky you, that must be a blast to ride!

[IFO]

Jesus... that beast looks like alot of fun....:eek:

round here there isnt enuf places to ride one thou...:(

[DangerousDean]

haha so fun, kinda cold to ride in the winter... but still fun

:) if i lived in bc i dont think i would have one though :(