Fork travel vs frame

xtreem

Does it matters the fork travel depending of the frame. I have a Courage frame and I don't know what's the maximum travel of the fork that I can install on it. By the way I can't find my frame for information on the internet nowhere. I'll give you a picture in a few days because I'm writing from internet cafe. Thanks.

dave_s

Yes it matters what travel your frame can take because putting too much travel on the front will mess up the handling.
If you're replacing forks because they're damaged, then fit ones with similar amount of travel.
If you want more travel then you definitely need to refer to the manufacturer to find out max recommended travel for your frame

dave_hill

Dave is right, but the length of travel isn't the important thing - it's the axle-to-crown length of the forks that causes the issues.

You need to measure the distance from the centre of the front axle to the top of the fork crown, just under the bottom headset race. The forks which you buy to replace your old ones need to be within about 10mm of this measurement either way. Any more than 10mm and you will start to notice a difference in handling.

If you go too long, the front end will wander or "flop" about when climbing, but the bike will be stable at high speed. The bottom bracket will also be lifted, raising the centre of gravity.

If you go too short, the head angle will steepen. The steering will become twitchy and you may experience a loss of traction at the back wheel when climbing.

bluefoam

I upgraded my fork from a 100mm to 120mm & you do notice the difference going up hills, but I got a fork with ETA, which allows the fork to drop down for climbing.

dave_s

I'd agree with Dave_Hill on that about axle to crown measurement.
I switched forks on my Heckler a while ago from 05 Marzocchi 150mm 66s to Fox 36 Van R forks which have 10mm more travel than the 66s.
The main thing that allowed this while retaining handling was the fact that these first issue 66s had quick a long axle to crown measurement.
So despite my Fox forks having 10mm more travel, the overall front end height was actually lowered by a few millimetres when I did the swop.

Usually the threads asking about max fork travel though are when people are thinking of upping the travel on their forks.
I think Nicklouse knows alot about the head angle effects of this type of thing but anyone who's added say 25mm to the fork travel will tell you it makes a big difference to handling.
I did exactly that on my Heckler when I originally got the 66s and had to get a lower rise stem and mid-rise bars to compensate along with removing spacers from under the stem

supersonic

For every 20-25mm the fork gets longer, the head angle (and seat tube angle) slackens by a degree. Bottom bracket also raises. This effects handling and weight distribution.

Anonymous

my bike has a deliberate function whihc means i can adjust my head and seat angles on the fly, i can steepen for climbs and slacken for descents, i think i get about 5 degrees of diference and even a small amount is very noticeable.

supersonic

Ah, the ol' bio-onion!

RS Uturn gives me 45mm of adjustment, and two degrees change.

andy-mchugh

il back sheepsteeth there, i own a edison an it does make a big difference!

brooklyn66

Hi,
I searched around but didn't find anything. What's the maximum travel fork I can put on a Orange Hitman without screwing up its geometry?
I can expect problem with the headtube with Marzo 66 rc2x ?

supersonic

100-130mm is I believe the travel range Orange specify.

brooklyn66

I can expect problem with on the frame with 66rc2 ?

supersonic

If it is longer than 130mm, very likely.