Hopefully blatant inter-forum copy and paste isn’t bad forum etiquette – I’ve posted the same question in Retrobike. More opinions is better, surely. We shall see…

I have a GT Tequesta (modified to take disc brakes) which I believe was made in 1998. According to an advert from 1998 featuring exactly this bike it came with either a “11.8 CrMo w/Bolegna Cut” or a “Rockshox Indy C”, which I believe (based on a little Googling) had 60mm travel.

What length (axle to crown) forks can I get away with on this bike? I’ve currently got some rigid steel On One forks which work but aren’t very nice (a bit rough & heavy) – I think they’re 420mm – and I’ve just got hold of a pair of Project 2s which appear to be 440mm – should I try it with these or will it handle dreadfully / explode?

I did have a slightly shorter Mosso aluminium one on it at one point which felt great but I decided I didn’t trust it when I saw how much it was flexing when braking. I suspect something around 410mm would be ideal, but what? Steel options seem very limited.

It would be great to find some kind of definitive guide to what length rigid forks are equivalent to what travel suspension forks but I’ve failed to do so so far.

We’ll 440mm is 80mm corrected, so 420mm would seem right for 60mm, but at the end if the day it is what you feel is right that matters.

I’ve always gone by …..

410mm AtoC 60 to 70mm travel
420mm AtoC 80mm travel
440mm AtoC 100mm travel

These are lengths for rigid forks.

I have a similar aged Kona originally speced with 65mm forks. I found 420mm AtoC Cromotos a good fit replacing the original forks.

I found 440mm forks too tall for my 99 Hei Hei.

I would stick with 420mm for ease as they come up more often than the 410s especially with a disc mount.

In summary, then, using a 440mm fork probably won’t destroy my bike but might feel… what? A bit weird? But wouldn’t destroy my head tube?