150mm Fork on a Stumpjumper FSR Comp?

C

cgjeff

· Registered

Joined Jun 8, 2011

·

145 Posts

Discussion starter · #1 · Dec 1, 2011

Only show this user

Considering a fork upgrade/replacement on my 2010 Stumpjumper FSR Comp and concerned going from the stock 130mm (Fox Float 32 RL) to a 150mm setup will mess with geometry to much? Been riding more aggressive stuff lately and could use a little more travel.

Any words of wisdom on the 2011 Marzocchi 44 RC3 Ti fork for this application?

Thanks

 

his dudeness

· Registered

Joined May 9, 2007

·

1,879 Posts

#2 · Dec 1, 2011

Only show this user

Suspension companies should list the axle to crown heights of their forks on their websites. I'd say if the difference in height isn't too bad then consider it.

One thing to consider though is that the added height will not only make your head tube angle more slack but it will also raise your bottom bracket height. Throwing on a monster truck sized fork could make your Stumpy ride like doo doo.

And FYI- your 2010 Stumpy came with a 140mm fork. The 2010 and 2011 Stumpies were 140mm front and rear. A 10mm of difference in travel height would slacken the head angle about half a degree. BUT definitely check up on the axle to crown height of the fork you have and the fork you're looking at.

 

D

darkest_fugue

· Registered

Joined Sep 25, 2007

·

1,745 Posts

#3 · Dec 1, 2011

Only show this user

the 2011 comp had a 140mm fork which i ride at 150mm, its nice go for it, the 2010 stumpy comp had a 130mm fox fork, i think you could take the spacer out and have it at 140mm, the rest of the 2010 stumpy range had a 140mm fork

 

C

cgjeff

· Registered

Joined Jun 8, 2011

·

145 Posts

Discussion starter · #4 · Dec 1, 2011

Only show this user

Good information and DF is correct, the 2010 Comp was setup as 130mm with all other Stumpies in the line at 140mm. Considering the frame geometry is identical across the 2010 line, obviously going to a 140mm fork should present no concerns. Best I can tell, the Marzocchi 44 RC3 (150mm fork) axle to crown is 10.6 mm taller than a Fox 140mm fork...thus resulting in half a degree adjustment in the head angle.

Well, technically I would see a full degree adjustment over what I am running now going from 130mm to 150mm.

Does anyone have experience with the Marz 44 RC3 vs a Float RL that they care to share some feedback on? I read a spot in MBA that they saw some great improvements between these two shocks in testing on a Stumpy.

 

C

checocc

· Registered

Joined Sep 15, 2005

·

296 Posts

#5 · Dec 1, 2011

Only show this user

I put a 150 revelation uturn air TA fork on mine about a year ago, and after this time and a couple of races I defenitely think that handling performance has been afected, the higher BB means less confidence in curves and turns, the thing that helps me is the adjustable travel of the fork, that i use around the 135mm when at races, or twisty technical singletrack.
Maybe the way to go is getting a nice 140mm fork or be able to get the shock that comes in the SJ EVO that is a tad shorter(lowering the BB) I think the newer SJ models have that shock length also. That would be my next move.

 

C

cgjeff

· Registered

Joined Jun 8, 2011

·

145 Posts

Discussion starter · #6 · Dec 6, 2011

Only show this user

Thanks for all the advice!! Did go ahead and order the 2011 Marzocchi 44RC3 Ti fork today in 150mm. It is internally adjustable down to 130 if it does not feel right, but I have a feeling it will be good with the type of riding we have been doing.

 

M

MisterNice

· Mister Nice

Joined Jun 27, 2012

·

3 Posts

#7 · Jun 27, 2012

Only show this user

I know this is resurrecting a long dormant thread but google brought me here...

cgjeff - how did you get on with the RC3? I'm thinking of making a similar change.

 

C

cgjeff

· Registered

Joined Jun 8, 2011

·

145 Posts

Discussion starter · #8 · Jun 27, 2012

Only show this user

MisterNice....

The RC3 is working out great, especially with the type of riding we are doing more and more. It took a couple rides to get the settings to feel right, but with a little patience (and some good online info)... I think it's pretty close. Definitely more plush than the Float fork with more adjustments. Bottom line, I am very happy that I made the change. I know my son is as well since he ended up with my old Fox fork on his bike... lol.

Jeff

 

M

MisterNice

· Mister Nice

Joined Jun 27, 2012

·

3 Posts

#9 · Jun 27, 2012

Only show this user

That's really useful to know it's worked out well. My riding buddy on an enduro keeps leading me into rock gardens at speed and I'm having trouble keeping up! The RC3 gets great write-ups but I was wary of jacking the front end up too much. Is it still good on technical climbs?

Mrs Nice has put in a claim for my fox if I go ahead with the replacement...

 

C

cgjeff

· Registered

Joined Jun 8, 2011

·

145 Posts

Discussion starter · #10 · Jun 27, 2012

Only show this user

To be honest, climbing has suffered a little due to the raised front end, but that could just be the fact that I am getting older and don't really like climbing that much... lol. Based on specs alone, the RC3 at 150mm is 20mm longer than the fork it replaced on my bike. The overall measurement from crown to axle is more like 12-13mm due to the design differences between the two forks (the crown on the RC3 is designed more compact). So, I gained the extra 20mm in travel, without actually affecting the bike by as much... if that makes sense?

 

M

MisterNice

· Mister Nice

Joined Jun 27, 2012

·

3 Posts

#11 · Jun 27, 2012

Only show this user

that does make sense - I'd been figuring the effective increase would be less than 20mm. Cheers

 

J

jsph_custer

· Registered

Joined Feb 2, 2016

·

44 Posts

#12 · Mar 9, 2016

Only show this user

Sorry to resurrect the dead here, but I wanted to add my 2 cents for those still looking into this topic.
I just upgraded the fork on my 2008 Specialized Stumpjumper FSR Comp from a 120mm FOX RL to a RockShox Sektor Gold RL Dual Position Coil fork. It is a 150mm fork that is adjustable to 120mm with a switch. It's super sweet. The total fork length from axle to crown on the RockShox is just under 3 inches taller than the FOX. That sounds like a lot, but I don't really notice it when riding. The 120mm mode makes it almost identical in length to the stock FOX fork, so no change in geometry for climbs. Going downhill is much better. I feel a lot more confident in steep, rocky descents and the handling feels almost the same. I wouldn't say it's gotten worse; quite the opposite in my opinion. I have yet to really test it out over time and multiple trails though.
My only concern is the integrity of the steering tube on the frame. The rake is bigger, so there's more force on the steering tube. The bike, though, is designed for a person that weighs as much as 300 lbs. I only weight 200 lbs, which is still heavy for a bike, but much lower than the max weight for the stock bike. So, aside from the age of the frame, possible stress and so forth, I don't have any real concern for the frame.
I know Specialized doesn't condone increasing travel more than 10% or whatever their stupid number is, but that makes no sense. They should specify an axle to crown length, and that value should increase/decrease as rider weight decreases/increases. The main point is force on the frame. So rider weight is the biggest factor, IMO.
So, if anyone is thinking about upgrading their front end to increase the travel of their older stumpy, I say go for it! I'm stoked I did. Plus, I had forgotten how nice and plush coils are. And the Sektor Gold RL isn't much heavier than my old FOX RL.