First time suspension tuning...

Iain C
Iain C Posts: 464
edited July 2008 in MTB workshop & tech
6 months in now and with confidence up I am starting to push my bike (07 Fuel EX7) a lot harder and starting to see what it can really do. I rode the Follow the Dog at Cannock yesterday (twice...in that heat...I was knackered!) and as I have not been there for a while and sped up a lot in the meantime, I noticed a couple of funny things happening with my suspension. I am wondering if I can tune it out without affecting the rest of my riding, whether it's normal/to be expected, or whether perhaps the bike just needs a service. For 99% of the time the bike rides fine, nice and plush, and there are no oil leaks anywhere from what I can see. I think I understand the basics of suspension...but I'm loathed to start fiddling with anything until I understand what I am trying to achieve. I also hear about "spiking" and other terms, but I don't what they mean or if that's what I am experiencing. The two issues are these...

-Big ringing it down "chainslap alley" or whatever it's called, the nice downhill that runs alongside Birches Valley Road...the bike was fine for most of it, then every so often if I hit a really rough section it felt as if I was suddenly riding across corrugated steel with no suspension at all. I could hear the chain slapping like mad (clue in the name perhaps?) , and the wheels would be really struggling for grip, especially if I was braking. If I can make this better then great, or I am I just asking the impossible of the bike?

-If I did a short sharp descent followed by a rapid rise/jump/bump and I was either lazy or promoted it by just sitting down rather than being in the attack position, there would be a sharp bump right at the point of maximum g, as the bike hit the bottom of the dip and went from descending to climbing. I thought that this was the suspension bottoming out, but from what I could see from the wipe marks on the forks and the O-ring on the rear shock, I still had some travel to go. It only did it once or twice when the bike was really loaded up. Any thoughts?

Comments

  • supersonic
    supersonic Posts: 82,708
    what fork and shock, and what settings?
  • Iain C
    Iain C Posts: 464
    Shock...Fox Float RPL

    Fork...Rockshox Recon 351 Air

    Settings...erm, more or less as it came out of the shop! Fork, compression fully open, it turned the opposite way to locked out, rebound, not sure, I think somewhere in the middle (it's on the bottom of the fork leg). Rear shock would have been in the open position (mine has one lever, up for locked, down and left as you look at it from the saddle is open, down and right is propedal.) Rebound dial is definitely in the middle of it's range.

    Air was set up for my weight, although not checked since new, sag looks about right from what I can see. Marks showed I still had a bit of travel left yesterday, however Coed y Brenin 2 weeks previously had used it all a couple of times but it's much more gnarly in places.