140mm travel fork too tall for dirt jumping?

Lee,

I really dig your website and all the solid advice and especially all the good pump track action.

I recently built up a new dirt jumping bike with an azonic steel head frame which has classic dirt jumping geometry. I got a great deal on a new fox vanilla rlc 32 fork.

This bike rides great on trails and really soaks up bigger drops. I haven’t gotten a chance to jump it yet since there is still lots of snow around as Flagstaff Arizona is at 7000ft. Is such a tall fork going to be a problem dirt jumping?

BRAAAAP

Jay Holt
Flagstaff, Arizona

Hey Jay,

140 millimeters are about 40 millimeters more than that bike is designed for. Compared to stock, your bike is much slacker, and it’s bottom bracket is much higher. I can see how that might feel good on trail and off hucks.

As far as dirt jumping goes, there are two concerns:

1. Too-high bars. With that fork on that bike, you should run a low stem and bars.

2. Excessive squishiness. The plushness you love on trails will make your fork collapse under the heavy Gs of dirt jumping. Your bike will jump better if you tune the fork to resist the pump.

Your FOX VANILLA RLC 32 is very tunable. Here are a few options:

– Max your low speed compression. That’s the ring on top of your right fork leg. That will make your bike feel a bit less plush but more stable.

– Try a stiffer spring. That will give you more control and pop — you’d be amazed at how heavily you load your bike when you dirt jump.

– Jump with the fork locked out. The knob on the bottom of the right leg adjusts the lockout threshold, so the fork can be moderately responsive or fully stiff. I know people who jump locked out, but I like my fork to feel the same all the time.

Good luck, and have fun!

— Lee

Related: Bad idea: Long travel fork on trail hardtail