100mm forks on 80mm frame

Slimtim

Ok, this is my first on the MTB board so please be kind.

I have a 1999 Litespeed Ocoee frame that I am building up. The problem is that i need to choose some forks. Siince 1999 technology has come a long way and many of the ones I like are only in 100mm form.

I have looked at the geometry of the current Ocoee and it is basically the same as mine (only 0.5 degree difference in head and seat angle) and it will take a 80-100mm fork.

Can I assume that my frame is equally adaptable (Litespeed's website recommends 80mm forks for pre-2003 frames).

Does 20mm make that much difference? If so, could I compensate by running more sag?

Thank you for your thoughts.

nicklouse

travel\is not the issue the fork axle to crown height is.

have a look at this.

http://www.bikeradar.com/forum/viewtopic.php?t=12559057

Slimtim

Nick

Thanks for the quick reply - I feel I am now REALLY in unfamiliar territory!

I had a look at the axle to crown lengths and a Rockshok SID 80mm travel for example is 445mm. The Fox Float 100RLs are said to be 470mm (is the approx 23mm difference due to the obvious difference in travel?).

Why is axle to crown so important?

Tim

nicklouse

every inch in fork length changes the head angle by 1 degree. if you start with a taller fork the slacker the angle is to start with and the more sag you need to run to give a good feel to the steering as you see on the tora, reba comparison there is a difference in total fork length of one mm which is less than the difference in travel.

so you need to find out what the old fork length is and get something similar.

Slimtim

OK, I understand all that but the frame was sold separate to the forks (I actually bought just the frame) and Litespeed recommends an 80mm travel fork (they don't state an axle to crown length). The range of axle to crown lengths in 80mm forks is wide - at least as wide as the difference in the same measurement if you compared 80mm and 100mm travel forks.

Tim

ride_whenever

you could space down some 100mm ones, not exactly difficult.

nicklouse

Ok change of track.

what forks is it that you like.

and contact litespeed about the recomended axle to crown distance.

tbmincey

I am also looking to replace a vanilla 125r with something more suitable to my 1999 Ocoee. I sent the frame back to chattanooga to have the headtube cups and seatpost sleeve replace (litespeed has since gone to SS cups from AL). While talking with jason, he looked up the 99 Ocoee a found that the geometry designed around a 454mm uncompressed fork length.