Compression damping on Suntour SF-XCM-DA fork?

LaurenceGough
LaurenceGough Posts: 218
edited October 2007 in MTB workshop & tech
Hey guys,

Another question on my Mongoose's front forks.

Compression damping, I know what it is basically and I know my forks lack the adjustment. I would like the damping to be less on compression so it would be a smoother ride over bumps. I still have tons of pre-load left for if I ever want to do jumps at a later date.

Is there some kind of mod I can do or something internal?

http://www.srsuntour-cycling.com/index. ... &tnid=1631

Thanks!
Specialized Stumpjumper FSR Elite 2010
Mongoose Tyax Elite 2007
Carrera Limited Edition TDF

Full suspension - King of the forest!

If anyone rides in Sulham Wood give me a shout :).

Comments

  • supersonic
    supersonic Posts: 82,708
    The only way you could adjust it would be to change the oil for something lighter. But the cartridge may solely be a rebound circuit with a simple bypass valve. TBH I think you are expecting a little too much from the fork! Some forks the price of your whole bike do not have compression damping adjustment! The smoothness will not be the same as a top end fork as the seals, bushes and materials will not be of the same standard or tolerance. However this is sitill a great fork for a bike of this price.

    You could contact the importer for details of the damper if you want to try and mod it, but I am sure they will tell you to leave it well alone!
  • Well I suppose your right. I think those forks are a rip off price though mate... Lighter oil that sounds good...

    What side is slowing down the compression most then I guess you can't change the spring so it would be the right hydraulic side?

    Is there oil in both anyway?
    Specialized Stumpjumper FSR Elite 2010
    Mongoose Tyax Elite 2007
    Carrera Limited Edition TDF

    Full suspension - King of the forest!

    If anyone rides in Sulham Wood give me a shout :).
  • supersonic
    supersonic Posts: 82,708
    The oil is in the damping side. It could be a sealed cartridge, in which you wouldnt (and shouldnt) crack it open as its not designed to be user servicable. I don't think what you are experiencing is an over damped fork, but merely stiction. You could try backing the rebound off and see what happens.
  • But I love rebound damping, it's what makes the fork/bike stand out from the others in the same level... Adds a better ride quality also. ATM I have it set all the way minus half a turn...

    Why would it change compression damping anyway or stiction for that matter?

    Thanks mate.
    Specialized Stumpjumper FSR Elite 2010
    Mongoose Tyax Elite 2007
    Carrera Limited Edition TDF

    Full suspension - King of the forest!

    If anyone rides in Sulham Wood give me a shout :).
  • supersonic
    supersonic Posts: 82,708
    I'm not saying turn it off - but experiment, like before. What can happen is that the fork starts to pack doown over bumps if its too high. This can feel as if its slowing down in action, as the fork has not fully extended for the next hit.

    It only offers a better ride if set correctly for your riding. Too much is as bad as too little.
  • Yeah I understand about this pack down problem. I have a good mechanical understanding of the suspension system. The thing is I don't go over more than 1 curb height bump every 5 secs... At the most it's just pot holes in the road or the smaller curbs. There the ones that are annoying me. It's to late I'm already over the bump shaken up before the shock compresses.

    Because of the stiction it may seem like having a faster rebound rate would be better but I don't think that matters when your actually riding...
    Specialized Stumpjumper FSR Elite 2010
    Mongoose Tyax Elite 2007
    Carrera Limited Edition TDF

    Full suspension - King of the forest!

    If anyone rides in Sulham Wood give me a shout :).
  • supersonic
    supersonic Posts: 82,708
    A fork will not absorb everything, some will get through. Especially a 50 quid fork! There is not much yiou can do unless you buy a more tunable fork.
  • :( Okay then mate. Bah.
    Specialized Stumpjumper FSR Elite 2010
    Mongoose Tyax Elite 2007
    Carrera Limited Edition TDF

    Full suspension - King of the forest!

    If anyone rides in Sulham Wood give me a shout :).
  • supersonic
    supersonic Posts: 82,708
    Lol. Compared to the other suntours, this is one of the better ones, and is streets ahead of most RSTs and the basic RS dart. But as you move up to the Tora, you get a compression based lockout too, then the Motion Control. More money does buy more adjustability. A fork like yours wsa unheard of for the price of your whole bike just 10 years ago, and to see one on a sub 300 bike is astonishing!