SB 95 120mm to 140mm Fork Mod
I've put about 250 miles on my 95 so far this year - all has been great but I'm curious to change my fork to 140mm, mostly because when it is time to head downhill, I like to push it as hard as i can and am assuming I could benefit from another 20.
My primary concern is the 1/2"-ish of added height I'll have on the front end (stem / handlebar). I have my stem slammed down quite a ways already and like the body position and stance for climbing.
Who has went from 120 to 140 and what did you think about the change?
Last edited by KGAmoto; 03-11-2014 at 04:44 PM.
I switched to 140 after about a year on my 95.
It was a noticeable difference for me for the first couple of rides. But, after getting used to it, I'm a big fan of how it rides with the 140. Eventually, I ended up shortening my stem down to 50 (from 90 stock, then 70, then 50) as well. Now, with the bigger 140mm Pike, short stem, and beefy tires, it's riding like a beast.
Did the added height to the bars / stem take a while to get used to? That's my biggest concern; mostly because the frame is right not the cusp of being too big - not sure I want to be any more upright.
What tires are you running / size?
Not too much, personally. I definitely did notice the difference for the first few climbs, but it's not anything that is nagging at me now, and I don't feel any more upright.
Originally Posted by KGAmoto
Right now, I've got 2.4 Ardent up front, and am trying the new 29 2.3 Minion in the back. Really like beefiness of the Minion actually... I've got lots of rocks around here to knock around.
KGA, when you extend the fork to 140 you'll want to consider making some minor cockpit adjustments to keep things ideal ...
- lower the tip of the saddle slightly. Compensates for the slight raise you get from the fork.
- rotate the h-bars slightly forward. Compensates for the slight change of angle. More an issue for people with flat-top grips like the Ergons though than others.
- possibly saddle forward on the rails a bit too. I found about 1 cm was right. Compensates for the slacker ST pulling the saddle further behind the pedals.
- changing where headset spacers are relative to the stem + headset top cap, and/or flip the stem. Compensates for changed h-bar height.
- psi will be very different in the fork at 140 vs 120, which also affects your rebound setting at least
- you may find you want to slightly alter the setup on the rear shock too, for optimal tune, but it won't be a big change. For me it varied 5-10 psi at most because of fork induced geometry change.
I'm *very* picky about my bike setup. Can you tell?
I've run the fox fork on my 95a at 120, 140, and 130 (using a 10mm spacer I got from JensonUSA) and 130 was a super-duper overall setting, but I have over 2000 miles on the bike at 140.
Last last autumn I sold the fox and upgraded (?) to a Pike...150. It's marginally taller than the fox was at 140, not even 10mm I think, but taller. Sadly I haven't had trail conditions to really tune it out since the fork was put on, but I am am optimistic.
I have done 20+ mile non-trail rides on the bike (working on my legs, and the cockpit setup, and tuning the shocks in as much as I can) and I think the overall bike setup for me is solid, now I just need time to finish tuning the suspension on trail.
All of Bear's tips are right on the money, do all of the above when I use the slack setting on my Prime which is 1 degree slacker, take his advice and I doubt you'll have any issues. Not sure what type stem you have zero degree or if it has a rise, if it's a rise stem, as Bear said just flip it to drop the bars back down close to where they were with the 120mm height, if it's a zero, buy a rise and flip it.
Thanks for the detail; those were the elements I figured would need to happen. I'm pretty picky too and have slightly changed almost all of those quite a bit to get this (fairly new) 95 figured out and fitting really well.
Originally Posted by bear
I'm mentioned this a million times, but I'm on the very bottom end of fitting a Large, so I have it as compact as possible (but on the contrary I usually have a Medium maxed way out for more room - 'can't win). But that's my worry - I already have my stem flipped down (10 degree) with a 7mm spacer underneath it to equal the same as a 0 degree stem. Given that, I still have 7mm to work with and would probably go to a 3mm spacer, but that just strikes me as a pretty odd setup. If I had a Medium it wouldn't be so extreme.
And I already have the seat pushed quite a ways forward - I have about 1cm left of forward movement already.
I need to do an oil change anyway and will do it myself, so I might just try it and see how it is once the higher-elevation stuff opens up (rockier stuff). Right now I'm just cranking out mild XC stuff, so the 120 isn't a big deal.
Thanks for the info.
why not split the difference and go 130? I have a Pike on my 95a and I reduced it to 130mm from 140mm. I feel like this is the fit for this bike. I am 5'8 and ride a medium so I am on the shorter end of the spectrum for a medium and I appreciate that 130mm stand over height is a little lower. I don't feel that dropping the Pike 130mm really gives up anything on the descents, once I added another token to firm up the stroke. 140 is nice but I really didn't feel that much of an advantage over 130mm.
Well I'm 5'9" and on a Large that's why I'm hesitant to do this to begin with (the way I have it setup makes the fit really good for my style, but I don't have much room to spare).
Originally Posted by Jake_kth
I've thought about 130, but I'm bottoming the hell out of my fork at 120 (I run a fairly low pressure to give me the small-bump-resistance I want), so I really want to go 140 or leave it if that makes sense. But the height it will add is what is making me uncertain, until I can locate a Medium frame.
How much do you weight KGA?
I'm about 210-220 and never had what I'd call a problem with bottom out of the fork vs supple ride (on the Fox) regardless of travel setting, just adjusted for proper sag uniquely for each setting.
Haven't had enough time on the Pike yet to have an opinion.
It's worth trying at 140 though because that'll give the fork more air volume and probably require less psi for the same sag % ... but if you're not liking the small-bump behavior you may want to change the lower bath oil with something more slippery instead of running the fork too low in psi.
I'm 170. I'm running 60psi in the fork; if I bump it up to where it should be technically (closer to 70), it feels really rigid bombing through rough stuff downhill.
Originally Posted by bear
My last bike I messed with the fork quite a bit which made it a lot better - I plan to go to 140, increase the oil volume beyond their recommended specs (for bottoming resistance and the ability to running lower pressure), plus I'll probably add oil under the air cap to take up airspace too. But I need to dig into it more and become more familiar with the internals of this fork.
Man, don't pay attention to "manual psi" - measure sag to find the right setting.
I think with my fork @ 120 I ran maybe 70 psi and i'm way heavier than you.
I think the only place you should play with minor oil additions to affect progression should be the air spring, fyi. There's probably also a practical limit.
If you have a '13 model year fork then it's also possible you may want to look into the damper rework from Fox, from what's been shared the '14 and later had much better support without losing out on travel use or small bump. I was going to send my fork in for that, before I ended up moving to a Pike.
I always pay attention to PSI over sag. i go by feel (but I DO loosely monitor my shock sag to make sure I'm fairly close to 20-30ish percent). Now with my motorcycle, you can't do that, and sag measurements are crucial within the millimeter (shock only - sag does not apply to forks). But I've always preferred watching my air pressure and going by feel and feedback.
Originally Posted by bear
Checking with Fox is a good idea; they've always been very cool to work with - I'll give them a call and see what exactly those updates do from the 13 to 14 setup.
If you have a '13 model year fork then it's also possible you may want to look into the damper rework from Fox, from what's been shared the '14 and later had much better support without losing out on travel use or small bump. I was going to send my fork in for that, before I ended up moving to a Pike.[/QUOTE]
How you can tell the 2013 model from the 2014?
KGA, Fox got to the point with complaints from the '13 MY damper that they were rebuilding forks for 50$ with the '14 damper. This included oil and seals. Not counting shipping this was a hell of a deal considering oil and seals probably account for 30$ for most consumers in the USA.
You're also literally the first person I've encountered that favors book-psi over measured-sag on a bike. Who knew. *whatever* - what works for you works for you and that's what is important in the end.
FIKO, I'm pretty sure you need to check serial numbers, I don't know that externally there's anything obvious. Search around and you'll find a lot of discussion about the issue. For the record I'm pretty sure it only relates to the Float 34 CTD FIT w/Kashima. I'm pretty sure it affected 29/26 forks equivalently. The non-FIT fork has a whole other set of issues IMO.
He never said "book PSI" he said he goes by feel and pays attention to what PSI that is, and it's exactly the same way I setup a fork, because unless you fully kit up and then put the bike to balance and really assume the attack position to put enough weight on the fork, like you do while riding, you will always have a fork that is too soft so you can get "proper" SAG.
Originally Posted by bear
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