I’m just about to start building a bike around a frame that is designed for a 6″ fork, but can take bigger (head tube angle is 68.5) . Would it make much of a difference if I ran a 5″ fork instead?? Pikes seem to be a popular choice for the frame which are 5.5″

Is there much difference in total fork lengths between companies, say fox fork are longer than rockshox etc?

You will almost certainly be killed by death in an enormous fireball, so probbly best not to really.

I don’t think it’ll matter at all. I mean, the frame’ll be designed around a 6″ fork, but owt an inch or so either side of that’s not going to muck up the handling to any significant degree.

Do it, but wear a flameproof suit.

Is there much difference in total fork lengths between companies, say fox fork are longer than rockshox etc?

Fox come up a bit shorter but not a significant amount…my Fox forks at 140mm travel are only 3mm longer than my RS Revs at 130mm travel iirc

I’ve just set up for PA for the Winter with 90mm forks…rides fine.

My hardtail is 100 mm and I have run it with 80-140 [different forks] and it is fine.

Good words from Elfinsafety.

I had a friend who rode a 80mm fork on a 100mm travel frame – One evening he spontaneously combusted 😯

The only reason we could come up with was down grading of fork……you have been warned. 😉

Damm and there was me worrying about a massive boulder falling from the sky!

What i’m curious about is the change in handling by altering the head angle.

you WILL be raped by zombie roadkill should you ever ride it at night.

Until very recently I was running my Stumpy FSR 120mm with an F100 fork. It was fine, although BB height was a slight issue. It played on my mind more than anything, and when a suitably priced F120 came up, I bought it.

handling does not alter as much as you think as you get greater sag in higher travel u-turn so I turn it down

The shorter fork ( taking into account the axle to crown) will steepen the head angle making the bike turn quicker and feel a little less stable, also when lent over in a corner it will be less stable. Unless you go hugely under length wise with the forks it should’nt be an issue, you’ll feel the difference most when decending steep stuff where the fork are compressed more due to the weight transfer further steepening the headangle.

The shorter fork ( taking into account the axle to crown) will steepen the head angle making the bike turn quicker and feel a little less stable, also when lent over in a corner it will be less stable.

It’ll be no less stable that the longer fork would be slightly further through it’s travel though. I.e. you probably won’t notice.

Until it gave you cancer, obviously.

Like I said it shouldn’t be an issue, but a shorter fork will result in slightly quicker handling.

A 6″ travel fork with 25% sag which is 1.5″ would have 4.5″ of stantion showing.
A 5″ trvael fork with 25% sag which is 1.25″ would have 3.75″ of stantion showing.

Therefore the 5″ travel fork would be shorter (taking into account the axle to crown)and acts of god, fire balls, boulders, rabid sheep e.t.c 😉

My commuter (modern hardcore-ish Marin frame) has a really short mid 90s steel p2 fork on, it’s a bit whippy but i’m not dead. Yet.

from the glass half full perspective, the seat tube angle will be steeper, possibly giving you a better position for pedalling and climbing *

*other contributory factors may apply :-).

oh god, won’t somebody think of the children!

What frame is it? Some frames are more prone to combustion than others and there are some ‘experts’ on here that can advise if your frame is one of those.

If you compare A-C lengths of different forks with the same nominal travel you will see there is a wide variance. You can get 6″ers about the same length as some 5″ers.

You can get 6″ers about the same length as some 5″ers.

I bet you say that to all the girls 😉

Fork too long = snap front off frame
Fork too short = nothing (and/or Legionnaires’ Disease)