Increasing front fork travel effects.

[big_peaches]

I'm contemplating upgrading my forks on my lapierre x control, i know in the end i will fall for some Fox RLC....but i have a genuine question. other then head angle change what would be the realworld effects of going from 120mm to 140mm travel.... surely 20mm would not hurt too much. I consider my self aggressive XC or Trail rider. i'm not a Downhiller or a XC race wippet but would love an extra 20 up front.

any one had any experience ?


I currently have RS 335 Recon Solo air.

Edited by big_peaches on Friday 29th October 00:28

[Shinysideup]

I have upped the travel front and rear on a few my bikes with no probs.
Going up 20mm travel will raise the Bottom bracket height by a very small amount and will slacken the head tube angle slightly.

If you still have a warranty running it might be worth contacting the manufacturer to see if they have guidelines/limits on the maximum axle to crown length of fork that you can use without throwing the geometry too far out or over stressing the headtube junction etc.

(imo - it should be fine)

Edited by Shinysideup on Friday 29th October 07:26

[a11y_m]

Shinysideup said:

If you still have a warranty running it might be worth contacting the manufacturer to see if they have guidelines/limits on the maximum axle to crown length of fork that you can use without throwing the geometry too far out or over stressing the headtube junction etc.

It'll be worth signing up on www.lapierreownersclub.com and asking on there for a definative answer about the effect on warranty, etc.


The figure I always see mentioned is that every 20mm increase in fork travel (or overall fork length) slackens the head angle by approx 1.0 degrees.

Slacker head angle =
- more stability going downhill
- less twitchy
- slower steering

I increased the travel on my 29er from 80mm to 100mm with no ill effects. Initially it put the front end too high (and hence too little weight over the front tyre) but I removed a few spacers from under the stem and it's great now.

Also, I just swapped frames from a hardtail with a 69.5deg head angle (with 130mm fork) to a 68.0 (with 140mm fork). Only ridden it once but the steering is weird - very slow at turning in, almost as if I need to put steering input in sooner. I'll be lowering the front end by removing stem spacers and fitting a shorter stem to hopefully improve this, but overall I like the greater stability on the downs!

[Pablo16v]

Having just had a quick look at fork axle to crown measurements it appears that the difference between 120mm Recons and 140mm Fox 32 RLC is only 12mm. 499mm for the Recons versus 510.9mm for the Fox. 12mm is not going to make that much of a difference to the front end.

[Dr S LB]

a11y_m said:

I just swapped frames from a hardtail with a 69.5deg head angle (with 130mm fork) to a 68.0 (with 140mm fork). Only ridden it once but the steering is weird - very slow at turning in, almost as if I need to put steering input in sooner. I'll be lowering the front end by removing stem spacers and fitting a shorter stem to hopefully improve this, but overall I like the greater stability on the downs!

You could also try a wider bar with more backsweep.