Fox Factory 32 Set up

Viking2136
Viking2136 Posts: 116
edited November 2017 in MTB workshop & tech
Hi, I have recently changed from a Scott Scale hard tail to a Trek Top Fuel 9.9 Race Shop full sus XC bike. It has Fox Factory 32 Float, Step Cast, FIT4 2-position damper fitted on the front.

Since having it I've struggled with the suspension set up, I've use the Trek suspension calculator and inputted the model, my weight etc and the settings all come up quite hard. It recommends 85 Psi on the front and 165 PSI on the rear and mid settings for rebound on both.

I have now got the ride about right for bigger lumps and bumps and have the front down to 50 PSI but not quite using all the travel and the rear is at 100 PSI which again is not bottoming out so i think its about there.

Its the front that is being an issue, I have got the rebound to nearly the slowest settings (2 clicks out) but I still get juddering from the front end on small bumps and rough tracks which rattles back up through the bars, this definitely did not happen with my old Scott.

Like I said the big lumps are being soaked up OK but its the small stutters and little rattles that are coming back across the bars, tire pressures are about 23-25 PSI dependent on terrain (tubeless) so is good.

Any suggestions/experience of this?
Trek Top Fuel 9.9 - Fuji CX 1.1 - Trek Boone 7 Disc - Room for 1 more

Comments

  • The Rookie
    The Rookie Posts: 27,812
    What have you done with the compression damper at the front? Also too little damping will make it rattle as the air spring goes out of control.

    Also (anecdotally) Fox need some bedding in before they start to free up and suffer too much stuction, a simple lower service to make sure it has the right amount of lube may be beneficial.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Thanks for the tip.

    The compression damper (little blue dial in the middle of the RH leg)is set to soft (max) so ill bring that back to medium and see how it goes, I've also read a bit about Volume reducers and might check to see if dropping one out maybe the better option as well.

    If that fails ill get the oil checked.
    Trek Top Fuel 9.9 - Fuji CX 1.1 - Trek Boone 7 Disc - Room for 1 more
  • rockmonkeysc
    rockmonkeysc Posts: 14,774
    I'd always give a new fork a lower lube. They rarely have enough. Dry seals and bushes will cause harshness over small bumps.
    Soft compression damping is minimum damping not maximum.
    Slow rebound won't help either, the fork won't be able to recover between bumps so it gets stiffer. I set rebound by finding a bumpy corner (choppy, not big holes) keep going around it flat out and give it a click less rebound each time until you lose grip and then wind it back two clicks. You need rebound nice and quick for the best grip and damping performance.