A question on suspenion forks

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A question on suspenion forks

Postby Mr888 » Fri Jul 06, 2007 10:41 pm

Hi Guys

This question is for the MTB riders.

After purchasing a 2nd hand mountain bike, I've noticed that on the front forks there are 3 knobs. I'm sure that they are used for adjusting the movement of the suspension thing, but what do they each do and how do I set it correctly?

There is a knob on top of each (arm of) fork, and one on the underside of the right arm.

Thanks
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by BNA » Fri Jul 06, 2007 10:51 pm

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Postby Kalgrm » Fri Jul 06, 2007 10:51 pm

We're going to need a lot more info - all forks are different. Can you post make, model and photos?

Cheers,
Graeme
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Postby MountGower » Sat Jul 07, 2007 12:27 pm

It's
Last edited by MountGower on Tue Feb 15, 2011 1:10 pm, edited 1 time in total.
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Postby Mulger bill » Sat Jul 07, 2007 6:20 pm

Depends on the fork Mr 888, can we get a brand and model.

Quite possible you've got preload, and compression and rebound damping. Red knobs are generally compression damping and blue for rebound, but that's not set in stone :roll:

Shaun
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Postby Mr888 » Sat Jul 07, 2007 6:54 pm

I think you guys are on to something...

The fork in question is a Manitou XVert TPC

The left knob says = Compression Damping +-
The right knob says = Spring preload +-
The bottom knob under says = Rebound +-

What are they for and what happens if I turn the knobs towards the + or - ?

I've googled their web site but t doesn't explain anything

Thanks Again
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Postby Kalgrm » Sat Jul 07, 2007 7:19 pm

Okay, let's have a crack at it.

Compression damping controls how quickly the forks compress. The higher the damping, the slower the forks compress when you hit a bump. High compression damping will mean you get lifted up when you hit a bump, medium (correct) compression damping will let the wheel come up without lifting you. If you set it too low, you'll nose-dive every time you hit the brakes and you'll feel like the bike is running in syrup.

Spring preload allows you to set the amount of sag in the forks for your weight. The recommended amount of sag is about 1/4 of the travel of the fork, so in your case, about 25mm. You set that by putting a cable tie around the stanchion (the shiny inner tube) and sitting on the bike. When you get off, there should be about an inch of travel showing between the bottom of the stanchion and the cable tie.

Rebound is rebound damping. Essentially, you want this to be set so that the forks don't extend fast enough to buck you off but not so slowly that they don't have time to fully extend before you hit the next bump. Again, the higher the damping, the slower the extension after compression will be. I set mine so that when I stand over the bike and push down, the wheel stays on the ground as I pull the bar up again.

Basically, you don't want a pogo stick on the front of your bike. The damping allows you to control how quickly the springs extend and contract - increasing the damping slows the motion of the fork. The preload sets the fork for your weight.

Don't be afraid to experiment - everybody likes their bike slightly different from the next person. Play - it's hard to kill the forks with these adjustments! It's your bike, so adjust it to suit the way you ride.

Cheers,
Graeme

Edit: Found this article after posting. Have a look, it explains things pretty well.
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Postby Mr888 » Sat Jul 07, 2007 8:31 pm

Wow! Thanks Graeme. I think you've explained it very well.

I'll be playing around with the settings tomorrow now that I know what I'm doing

Cheers
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