2015 Stumpjumper FSR 650b Comp Evo

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2015 Stumpjumper FSR 650b Comp Evo
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flag jimbob007
Posted: May 20, 2016 at 3:28 Quote
Hi,

Anyone riding one of these?

Its the one with the 29er front end and the Spacer under the head tube, and the bad geometry!

Has anyone managed to modify/upgrade the bike so that it rides better and the geometry problems get improved or fixed?

I am talking about the head angle that is too steep, the BB height that is too low and causes constant pedal strikes when climbing or descending, and the slack seat tube angle that makes the bike wheelie on climbs so that you can't steer.
The large amount of layback on the dropper post doesn't help this, but even with the seat pushed as far forward as it can go, the bike still doesn't steer on steep climbs even when you are sitting right up on the nose of the saddle.
I have dropped the stem to the headtube and put the spacers on top, to try and lower the height up front.
Any lower than this and I am afraid the chances of going OTB on descents will be even worse.

The steep head angle with 150mm travel forks, means that when the forks compress on descents that head angle goes much much steeper (as it will on any bike), but because it is too steep to begin with if you catch an obstacle at the 'wrong' moment the bike does not roll over what's in front of you, the front wheel stops and you get launched OTB.

I broke my right hand in October going OTB, and now I have broken my left thumb and detatched the ligament going OTB again, I have a cast on my left hand for a month and then a splint and physio to follow.
(no biking for a long while now in any case)

I have owned and ridden many different brands of MTB since 1987, I have already been OTB on this bike more times than any other I have owned.

In order to try to reduce the pedal striking, I am running more air in the rear shock to try and raise the ride height.
Then I have to put more air in the forks as well, otherwise its not balanced and I go OTB again!
So I have to run higher air pressures than I would choose.

I realise that "back in the day" we all rode MTBs with really steep head angles, but back then we didn't have 150mm of travel or more on the forks, so the head angle wouldn't increase massively through fork compression.

This bike encourages me to ride rocky, technical stuff but then spits me off with no warning!
flag MSVF
Posted: May 24, 2016 at 3:51 Quote
Hi,

I'm surprised that you have so many problems with the 2015 SJ 650b. Yes i know it's kinda a Frankenstein Bike, but that's the Enduro 650b too and both bikes are great.

I have the 2015 SJ FSR Expert Carbon Evo in Size L, I'm 188cm tall. I have never experienced any problems regarding OTB - I was even surprised how stable the bike is with it's steep head angle. The only thing that I have changed is the stem (to 60mm) and handlebar (s-works dh 780mm).
But yes I agree, the BB is too low, but you get used to it. Bottom line for me is that I really like the bike.

Just guessing: Did you maybe pick the wrong frame size? Maybe a wider handlebar will help?

Best
flag jimbob007
Posted: May 25, 2016 at 14:14 Quote
Hi MSVF,

Thanks for the reply.

I am 170cm tall and my frame is a Medium.
It feels OK for size, I have ridden 6+ hours in a ride recently and not had any problem.

I didn't think about wider bars because the stock ones feel fine.

Maybe a shorter stem would help, its something I may try.

Cheers.
flag Allmost
Posted: May 26, 2016 at 13:40 Quote
Wow that's weird.

I've got a XL SJ comp 29'r and its a dream, (I'm 6'4 240ish)

One would think that the EVO would be the better bike for the steeps over the standard bike.

I will admit one issue with these bikes are they mask speed very well, So maybe you where cooking in to sections that should of been taken at a slower pace? I've been OTB once already and that was the case for me. (Basically trail dropped about a foot, then dived to the left. and my front tire didn't touch the ground until it was past the turn, then OTB into a stump.)

As far as the shock dive affecting the geo maybe you need to looking into increasing or decreasing your volume in the fork to get a handle on the dive? You may also need to look at your riding position? Maybe you need to be a bit further back in the bike?

I'm not trying to knock your skills, just thinking about your case.
flag jimbob007
Posted: May 31, 2016 at 11:45 Quote
Thanks for the reply Allmost.

The 29" Stumpies like yours are excelent and have had rave reviews everywhere, for many years.
The first 650bs from 2015 did not, and thats what I have unfortunately.

I hear what you are saying about my riding position, it seems that if I am going OTB way too much then I must be too far forward.
But this has never been an issue before, and I have ridden/owned many bikes from many different manufacturers, but this Stumpy has the most travel I have ever had, and it seems to be the most unpredictable bike I have ever owned as well!

The head angle on the 2004 26" FSR I still have in the shed is crazy-steep compared to what we ride now.
But with very little travel on the forks the head angle didn't change that much, and I suppose we weren't trying to ride the technical stuff we are trying to ride now either.

I don't know whether an angle-set headset would work on my stumpy, or whether that would lower the BB even more as well.
I don't know if an angle-set would be compatible, to try and slacken the head angle.

Cheers.
flag benripley
Posted: Jun 9, 2016 at 5:08 Quote
I have this bike and while I haven't experienced the same issues climbing the front felt very twitchy when descending. Either the front wheel would wash out (ie not weighted enough) or I would weight the front more with body position and would then feel like I might go OTB in techy terrain.

I'm 176cm tall and ride a medium.

I have recently done a couple of simple mods: a Kore Repute 50mm 0 rise stem and a 760mm wide 20mm rise Kore Mega handlebar. Under £100 all-in and keep enough weight over the front for climbing but makes descending much better. This enables me to have that bit more weight over the front to prevent washing out without moving forwards deliberately and pitching over the front.

I initially flipped the stock 60mm 6 deg rise stem but IMHO it's too long anyway, and with a 40mm rise bar (I measured it even though it's not quoted by Spesh) I was never going to get the front where I wanted it. Hence the zero rise stem and wider, lower bar.

I'm upgrading the fork soon also. Looking at a Pike or Lyrik 160mm. I noticed when looking at the Coastal Crew's 2025 SJ FSRs (the same model frame in carbon) that they were running Pikes with no lower headset spacer... This to me means that they were running 160mm forks; the extra 10mm travel offsetting the height of the spacer without changing the geo.

You could get a taller fork and keep the spacer, which would slacken your head angle and raise the BB, but my UK Spesh owner's book says 150mm max on the fork anyway. So while even I'd be breaking the rules (though I understand in the US you can be +/_ 10% on Stumpy fork travel and not get into trouble???) I would not be changing the overall axle to crown measurement too much.

The other thing I have found I need to do is really *ride* the bike. Take charge of it, bully it, and and it's way fast. The NSMB review http://nsmb.com/stumpjumper-fsr-comp-evo-650b-reviewed/ effectively stated this and it does work. So while it's tempting to blame the geo; we all rode bikes steeper than this not too long back and they were fine as they were 'normal'. This bike may not be the slackest nowadays but it ain't bad, and it sure is quick if you work at it.

That said I see a transition Patrol in my future...
flag jimbob007
Posted: Jun 15, 2016 at 7:22 Quote
Thanks for the reply Ben.

So, a zero rise stem and flatter bar has helped you? Thats cool.
I was worried that fitting the same to mine would improve the climbing, but make the likelyhood of going OTB
on descents worse!

Maybe an even shorter stem would help to move my weight back a bit more.... I don't know.

I can't fit a slack-set to this bike because it has a fully integrated headset, so there are no 'cups' to play around with, which is a bit of a blow.

My busted thumb is still busted and will take a few more weeks to heal before I can ride anyway.
I am missing a good chunk of the summer which is gutting.

I will take a look at bars and stems.

Cheers,
Jim
flag benripley
Posted: Jul 5, 2016 at 5:42 Quote
jimbob007 wrote:
Thanks for the reply Ben.

So, a zero rise stem and flatter bar has helped you? Thats cool.
I was worried that fitting the same to mine would improve the climbing, but make the likelyhood of going OTB
on descents worse!

Maybe an even shorter stem would help to move my weight back a bit more.... I don't know.

I can't fit a slack-set to this bike because it has a fully integrated headset, so there are no 'cups' to play around with, which is a bit of a blow.

My busted thumb is still busted and will take a few more weeks to heal before I can ride anyway.
I am missing a good chunk of the summer which is gutting.

I will take a look at bars and stems.

Cheers,
Jim

No problem Jim. Yes the shorter, lower stem and lower, wider bar do help me. My main issue was the front washing out ie not enough weight on the front wheel, rather than going OTB. But I have always felt the head angle was a bit steep, which, coupled with the slightly spindly Revelation fork made things a bit nervous.

Update on my bike... I swapped the Maxxis HR2 tyres I was running for WTB Vigilante 2.3 front and Trail Boss 2.25 rear. This has had the effect of slackening the head angle a touch, as the Vigilante is massive. The Trail Boss is narrower but about the same height as the HR2s. The Vigilante is much taller than the Trail Boss and the Maxxis HR2.

On fork thoughts and head angle: I just called Spesh UK and asked about a longer fork as the manual says 150mm only as I mentioned. They told me +/- 10mm travel is ok. I mentioned whether I would need to remove the headest spacer to compensate for the extra 10mm on the fork but they recommended to keep it. That means I can lengthen the fork by 10mm (with a Pike or Lyrik so getting something stiffer) which, especially with the monster truck Vigilante up front, slacken the head angle by about a degree, possibly a bit more.... And the bigger fork can then go on to my 'dream' build next...

I reckon an angleset would work without the 10mm headset spacer. But you'd have to have a 160mm minimum fork to even keep the same geo as a 150mm fork with the 10mm spacer, and even then depending on how it sagged there's a risk of it getting steeper. So to use an angleset would probably need a 170mm fork and removing the spacer I think. Possibly..Confused . Now there's a thought!

Good luck with the recovery and get well soon.

Ben
flag jimbob007
Posted: Jul 10, 2016 at 7:49 Quote
Hi Ben.
Thanks for the update.
You can't fit an angle set to this bike because it has an integrated headset, so there are no headset cups to mess around with.
I emailed Works Components to check this, and they replied really quickly to tell me that.
I have fitted a wider flat bar, and a 35mm zero rise stem.
These have helped the handling and feel of the front end, and helped the front end feel more planted on climbs with less wandering and wheelie-ing.
But even with the new bars and stem I still feel like I am too much over the top of the front hub when it comes to descending. I still feel like I am going to go OTB any second.
So ultimately I will sell this or trade it in for something else soon.
Thanks for the help in any case.
Cheers, Jim
flag MSVF
Posted: Aug 15, 2016 at 13:39 Quote
Hi Guys,

Since you have the same bike I ask directly in this thread:

Have you ever measured the fork travel of your SJ 660b 2015? Because according to my measurements, my pike has 160mm, not 150mm. And my steering angle is 67, not 68, which would makes if I really have a longer fork installed. And yes this spacer under the steering tube is still installed.

Best
flag Dickiescbb
Posted: Nov 3, 2016 at 13:54 Quote
The exact reason i sold this frame and build up a Chromag stylus instead happy times. And i agree the headangle on this bike is f*cking retarded. Dont get me wrong i love specialized my DH bike is from them and its the best thing i have ever ridden but with the stumpjumper they just slapped something together to accommodate the 650b wheel size. The 2016 model looks alot better
flag Dickiescbb
Posted: Nov 4, 2016 at 9:54 Quote
MSVF wrote:
Hi Guys,

Since you have the same bike I ask directly in this thread:

Have you ever measured the fork travel of your SJ 660b 2015? Because according to my measurements, my pike has 160mm, not 150mm. And my steering angle is 67, not 68, which would makes if I really have a longer fork installed. And yes this spacer under the steering tube is still installed.

Best

The stumpjumper headangle is 68 not 67 and with the 160mm for u wont change a thing since u dont change the axle to crown. its a f*cked up bike sorry to say, the geo is off and the BB is crazy low so yeah its money wasted..... and i can know
flag zentrik
O+
Posted: May 25, 2017 at 19:57 Quote
That's my bike and I love it. Never been OTB and I hit pretty big stuff including good size drops. I don't find it to be the messed up geo that everyone says it is. I'm 5-10 and 165#. I ride a large frame and it's set pretty plush. Maybe i'm just not going fast enough to go over. The bottom bracket height is an issue but once you learn to ratchet the pedal properly you'll know where your feet should be to deal with babyheads in the trail. I'd rather have a low bottom bracket on a bike with this much travel than not. Oh yeah, Canfield pedals help even if it just gives another 1/4" clearance, Haha
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