[jaysen]

I've got a 2005 Specialized P2 (completely stock) and as I continued to ride more and more, testing others bikes out and feeling for myself, I am starting to realize my front fork doesn't feel as tight/stiff - what gives ?

This might be a dumb question so forgive me... is there something I can do to stiffen the bounce. I noticed on my last ride, while traveling uphill mainly, my front tire was lifting quite a bit.

According to bikepedia, the standard forks that came on the bike are Marzocchi Dirt Jam Pro, 100mm. Can these (or all) forks be adjusted to stiffen the bounce ?

Thanks in advance - learning everyday !

 

[mtnbiker72]

The right (drive side) leg has a schrader valve under the top cap, you can add up to 65psi in it to stiffen up the fork. You can also turn the knob on the left leg to increase spring preload.

 

[AZ]

delete

 

[gmcttr]

I found a 2006 manual with setup instructions toward the end. Hopefully it will be helpful.

http://manualer.happymtb.org/marzocchi/2006-dirt-jam-pro.pdf

 

[jaysen]

gmcttr,

Wow, thanks man - Especially if does help me out! If not, thanks anyway for the effort.

 

[9.8m/s/s]

I'll go out on a limb and say that some bounce might not be a bad thing. Forks are made to move up and down as you ride along the trail- many beginners (and not so beginners) stiffen there equipment up until they only use a small percentage of whats available during a normal ride. Best advice I recieved is that on the hardest hit of the day (rock, drop, roller transition, etc) you should bottom out. Just once, but use it. You payed for it.

If you want to get a better picture, push the rubber bumper on your fork all the way to the lowers. Sit on your bike with all your weight, and get off without bouncing. Now measure how much of your travel you've used. It should be in the 15-25% range. Any stiffer and it will not conform to the terrain you're rolling over as well and will create friction.

Think of it as keeping your body mass in a straight line, with the bike conforming to the features of the trail so you don't have to.

Also, many bike shops set up there bikes waaaayyyy to hard, because they have no idea who will be coming in (heavier individuals) and don't want to keep adjusting.

 

[trailville]

I noticed on my last ride, while traveling uphill mainly, my front tire was lifting quite a bit.

This is most likely due to a combination of your climbing technique and your bike setup. A P2 is essentially a dirtjump bike, so the geometry is designed for that purpose, not riding uphill on trails. You can compensate for this by shifting your weight forward while climbing, but a DJ bike is never going to climb as well as an XC bike.

 

[Bikinfoolferlife]

Like trailville says, if your front wheel is lifting it's not necessarily your fork as much as your position on the bike created by your technique and the bar/stem combo. A slightly longer stem may do the trick, or weighting the front of the bike differently. If you're getting a lot of bob from excessive upper body motion, different fork setup (or a different fork) might be the way to go as well.