Can I combine parts from Fox 100 and 120 forks?

[yuley95]

Ok smart people, here's my question - I have a Fox 32 F100 RL from 2010 with QR dropouts and a 1 1/8 steerer. I want to get 15mm dropout (my wheels will convert).

Is it possible to buy a Fox 32 120mm RLC with 15mm lowers and a tapered steerer and make it work? (There is one for sale).

I need to use my steerer tube ( because my head tube is straight 1 1/8) which means using the entire uppers from the 100mm fork.

I believe, at the least, I can just swap the lowers and keep the rest of my old fork leaving me with an F100 RL with a straight steerer and 15mm dropouts.

I would, though, like to think that I might be able to use the lowers, spring and damper from the 120 fork together with my current uppers - that would leave me with a fork that has 120mm travel, rebound/lockout/compression damping and 15mm dropouts. Will those parts work together?

Final question. If that does work, will it also mean I will be left with a second fork that has a tapered steerer, 100mm travel, rebound/lockout and 9mm QR dropouts?

I hope all that makes sense.

I really predicate any insight.

Cheer,
Yuley

 

[merc-blue]

Possibly.
Swapping lowers will be fine.

Putting the 15mm lower and RLC damper in your fork will also be OK.

doing the complete swap maybe an issue, you would need to measure the piston size of both float plungers,
Fox have 3 piston sizes 1.111 inch, 1.089 inch and 1.079 inch. the 100mm fork will be 1.111 inch but the 120mm probably 1.089.
You could swap the pistons on the plungers but the 1 1/8th steerer fork is going to have thinner walls nobody would ever recommend running them at above 100mm.

Also there can be an issue with running short travel forks on longer travel due to Fox having 2 bushing height options.

 

[yuley95]

Thanks Merc-blue. So by the sound of it your are saying I could create a straight steerer, 100mm RLC with 15mm dropouts - is that right?.

I could certainly live with that and forego the extra 20mm travel.

Theoretically I could then put together a 120mm fork with the 9mm dropouts and RL damper as well?

Thanks again.

 

[ACNRS]

it is certainly possible to do the swap exactly as you have said, and what merc said is true but i have run 100mm fox for at 120mm and had no trouble from it. it is possible to have a 120mm travel RL qr fork but you must not change the spring damper (LH side damper) as that controls the height and are only changable from 120 to 100 but not from 100 to 120 unless it was origionaly 120.
The bushing height does not present an issue going between a fox F100 and F120 fork

 

[yuley95]

it is certainly possible to do the swap exactly as you have said, and what merc said is true but i have run 100mm fox for at 120mm and had no trouble from it. it is possible to have a 120mm travel RL qr fork but you must not change the spring damper (LH side damper) as that controls the height and are only changable from 120 to 100 but not from 100 to 120 unless it was origionaly 120.
The bushing height does not present an issue going between a fox F100 and F120 fork

So basically, if I keep the springs in their original uppers/stanchions I'm good? Dampers and lowers are interchangeable though...

 

[ACNRS]

So basically, if I keep the springs in their original uppers/stanchions I'm good? Dampers and lowers are interchangeable though...

yea pretty much!

 

[Gripo]

What is the easiest way to swap lowers....assuming that the two forks involved are compatible ie. 9mm lowers for 15mm lowers on a F120...

I've read elsewhere that if you let all the air out, then turn the forks upside down for an hour or so to let the oil drain into the uppers, undo the foot nuts.....its then a simple swap over.

So no need for a total messy disassembly?

 

[0psi]

Sounds like it would work but if you are going to go to all that effort why wouldn't you spend an extra 10 mins giving it a clean and putting some fresh oil in there?

 

[ACNRS]

if your goign to take the lowers off you might as well change the oil.. forks will run better and no harm in fresh oil and doesnt make it much messier

 

[Gripo]

Both forks were fresh so no need for an o/haul....

But the LBS did the swap in 10mins and because I'd stood the forks upside down over night there was not a drop of oil spilled, just a bit of greasy love on the lowers for the bushings and some again on the seals.

Too easy.