Fox Float 120 RL 120mm to 140mm modification - possible?

coursemyhorse

Hi all,

I have a Specialized Stumpjumper FSR 2007 with Fox Float 120 RL forks. I have read of a few people online claiming that these forks can have the internal spacer removed to make the 120mm travel become 140mm. I checked the Fox online manuals and guides, and it states that this is in fact a supported method of extending the travel and it goes on to give full instructions on removing the internal spacer which results in extended travel up to 130mm. Note, 130mm, not 140mm. Why do people say that they are possible to extend to 140mm? Is it that people are incorrectly measuring them? Are Fox wrong? Do people do something else to get it to 140mm?

Finally, what do you think about running them on my bike with the increased travel? I read on a forum somewhere amongst my searching, of someone that ran 140mm shocks on his 2007 Stumpjumper and loved it. I'm aware the Geometry would change slightly, but his argument was that it raised the bottom bracket ever so slightly and made for a more aggressive bike for what he wanted it for.

nicklouse

http://www.mojo.co.uk/faq.html#question3

ask Mojo but

Float and F-Series forks can be dropped in travel but not increased in travel from their supplied configuration

The Rookie

Lengthening the travel at the front of your older stumpy actually puts the geo closer to the latest trail bikes, it is as you say a common and effective mode, besides if it's only a spacer you can always put it back!

coursemyhorse

Hi Nick thanks. I have emailed Mojo already because there is actually an added complication - well possibly anyway. The previous owner had the Forks serviced by Mojo before (2010) and one of the things he said they did was to fit new Stanchions. My question to them was asking whether the same like for like stanchions would have been fitted, or if it was possible that any slightly different ones (newer?) were fitted and would this affect any potential setup such as travel length.

If you scroll to the bottom of this guide for these forks below, you can see it clearly shows that the fork can be modified upto 130mm and specifically states not beyond. However, as I say, I see a lot of people online on forums saying they become 140mm if you take the spacer out....hmm.

http://www.foxracingshox.com/fox_tech_c ... _120rl.htm

coursemyhorse

The Beginner wrote:

Lengthening the travel at the front of your older stumpy actually puts the geo closer to the latest trail bikes, it is as you say a common and effective mode, besides if it's only a spacer you can always put it back!

Yes indeed, this is what I was trying to say but you said it better. It kind of brings it inline more with more modern day full suss trail bikes with slightly slacker head angle. I'm sure the change even right up to 140mm would only be slight on the actual handling.

One thing that is making me slightly concerned, is that one forum post I read where someone had tried this it didn't work out so well. He got a metallic clunking when the shocks bottomed out their travel. Admittedly, this was on a slightly different fork and/or year. I recall it being a 2008 fork. I think I read that from 2008 onwards they stopped using a spacer and instead just a lock pin on its own? Someone then suggested the cartidge or damper internally would be destroying itself running it like that each time it made the whack sound. So....dunno.

coursemyhorse

After a little bit more reading of various threads on other forums. It seems basically that Fox are wrong. lol. More specifically, the diagrams and instructions they provide for doing it are all correct, it's just that the internal spacer is not 10mm as stated, it's 20mm. So you just take them apart, take the spacer out and reassemble giving 140mm. One guy did it and then measured his stanchions after and they were 145mm showing (so probably 140mm actual travel) and he too was expecting only 130mm. Perhaps some OEM 120 RL's were spec'd on certain bikes with a 10mm spacer, but all the people I find online that have done it claim it to be 20mm and hence you gain 140mm.

EDIT: Unless it's a UK/US thing or different parts of the world get different specs.

Anyway, I will wait to see what MOJO say as well...

pofadder

I did exactly this - I have the same bike - 2007 Stumpjumper FSR Comp.

If you look at the top-end bikes in the 2007 Stumpjumper range, the top-end ones all have 140mm of travel - it's just the bottom end of the range that's limited to 120mm. The frames are identical (except of course the carbon one).
So the frame can definitely take it.

My Fox Float 120 RL had two 10mm spacers, removing these takes the fork up to 140mm. The exposed bit was more like 150mm on mine, with 140mm actual travel.

I did this after reading the thread on MTBR - they have loads of details on it. Someone on there commented that these are rebranded and travel-limited 140mm forks done specially, for Specialized. Dunno about that tho..

The extra 20mm of travel is definitely noticable (in a good way!), and I didn't have bottom-out clunking at all.
Only negative is that since these forks are a bit flexy already, increasing the travel makes you notice the flex a bit more.

I later had Mojo do a FIT and Kashima upgrade on this fork, and its still going happily ever after....

coursemyhorse

pofadder wrote:

I did exactly this - I have the same bike - 2007 Stumpjumper FSR Comp.

If you look at the top-end bikes in the 2007 Stumpjumper range, the top-end ones all have 140mm of travel - it's just the bottom end of the range that's limited to 120mm. The frames are identical (except of course the carbon one).

So the frame can definitely take it.

My Fox Float 120 RL had two 10mm spacers, removing these takes the fork up to 140mm.

I did this after reading the thread on MTBR - that has loads of details on it.

I didn't notice any negatives in terms of handling. The extra 20mm of travel is definitely noticable, and I didn't have bottom-out at all.

One negative is that since these forks are a bit flexy already, increasing the travel makes you notice the flex a bit more.

Pofadder, thanks that's a great help. I thought the same about the frames. I will wonder off to find the thread over there but when I searched I could not find it. Yeah I know what you mean about the flexy forks. A compromise, but worth it I reckon.
My forks were last serviced in summer of 2010 so I guess they are due. I would like to give them a service AND change the setup at the same time. What do you reckon the total cost would be for me to do this and do I need a headset press to remove headset to remove the forks? Never removed forks before but I'm an ok home mechanic and pick things up quick.
You are down the road from where I work as well.

pofadder

whoops - I've edited my last post since you quoted...

That MTBR thread was an old one, I think the title was something off topic. I'll see if I can find it....

It was a bit expensive. I think it was around £400 for the Kashima upgrade + FIT damper upgrade + service.
But on the plus-side - you effectively get back a brand new fork. (for about half what a proper brand new one would be!)

The Kashima upgrade however is overrated I think, so you could save some money by not doing it (about half cheaper).

Its very easy to take the forks off - you don't need to remove the headset (so no headset press needed - they are expensive things).
Basically - Remove the wheel, remove the front brake from the fork leg, remove top-cap bolt and top-cap, remove stem, and that's it really - the fork just slides out. You might want to lay down the bike on its side to make it easier (that is if you don't have a workstand)

pofadder

Here's some info from MTBR - but its more about the rear shock than the fork, still good info....

http://forums.mtbr.com/specialized/moun ... 501-2.html

I can't find the thread on the fork :-(

coursemyhorse

Ok thanks pofadder. As for my comment above about the previous owner getting the original stanchions replaced, does this affect anything to do with these mods? Sorry I am not too clued up on front suspension internals yet. What I meant in terms of costs, were how much does it cost to service your shocks yourself and is it doable? Basically just new oil and seals and a clean right?

pofadder

no probs.

I reckon you should be OK with those new stanchions.
The spacer that you'll want to remove is in the air-side leg, so shouldn't have been affected.

Yep servicing yourself is definitely cheaper, definitely do-able. Haha, I mean servicing the fork yourself.

Seals are about £10-20, oil is cheap (£1.50 for those little sachets that go on the seals or about £15 for a large can of oil), and you don't always need to replace the seals.
It takes about 30mins to do a basic service, is very easy, and is very messy.

Servicing the rear shock on the Stumpy is not a prob either, but it takes a bit longer to remove the shock from the frame.

Oil spill on carpet almost gauranteed!

coursemyhorse

Sweet. I will start reading up on fork servicing and do this over the winter sometime. Only other thing I could do with, is some new decals for the forks as they have worn off and started to peal. Best place for cheap Fox decals that are decent? Ebay? Cheers

pofadder

Yep - ebay or mojo should have some

coursemyhorse

Hey there. I just measured the current amount of stanchion I have showing incase i already have it set to 140mm by the previous owner. Just a thought as they seem really plush forks as it is to be honest for supposedly 120mm. Anyway, I measued about 138mm showing. So that sounds like its probably set at stock 120mm? Ta

pofadder

Howdy,

18mm is a lot of extra - could be that it is set at 130mm travel?
You can double-check this easily - if you let out all the air out of the fork, and then compress it fully. Measure up to where it goes, and that's how much travel it has at the moment.

coursemyhorse

I just measured it by letting all the air out as best I could. The actual total amount of stancion showing between the top of the lower and the crown using a digital vernier caliper, is 136.1mm. It bottoms out (or stops travelling) 6.8mm before the crown. i.e. You can still see stanchion for 6.8mm before it hits the crown as it internally hits the stops obviously. So 136.1mm - 6.8mm = 129.3mm.
So it currently has 129.3mm of travel. Hmm. Is that right? Maybe the previous owner took out one of the spacers? You said there were 2 x 10mm in yours? I guess since the service manual does say not to run them at more than 130mm he might have followed that. I'm not sure why it says that though. I guess the only way to find out is to strip it down.

coursemyhorse

I just went out there again and pumped it back up and it now shows total travel as just over 120mm :?
Bah. Dunno now.

Will give it a service over winter and have a butchers inside. It's probably I've unsettled it or not got a decent enough shock to put enough air back in to fully extend it back out to where it was.

pofadder

hmmm, interesting - I would guess that the previous owner took it up to 130mm most likely...but then you wouldn't only get 120mm when its pumped back up.

Mine had the 2 10mm spacers in (Looking at MTBR some seem to have 1x20mm as well).

The best bet is to open it when you service it to see how many spacers are in there. I experimented with 130mm and 140mm on mine - I liked it at 140mm more, as you can run it with 40mm of sag and still get decent travel.