2019 Stumpjumper Evo

PB Forum :: Specialized
2019 Stumpjumper Evo
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flag Brasher
Posted: Jan 2, 2020 at 23:53 Quote
R-M-R wrote:
Brasher wrote:
It’s 9.5% in high and 9.7% in low.

What's the source for these numbers?

https://www.pinkbike.com/news/behind-the-numbers-specialized-stumpjumper-evo-29-suspension-analysis.html
flag R-M-R
Posted: Jan 3, 2020 at 0:41 Quote
Brasher wrote:
R-M-R wrote:
Brasher wrote:
It’s 9.5% in high and 9.7% in low.

What's the source for these numbers?

https://www.pinkbike.com/news/behind-the-numbers-specialized-stumpjumper-evo-29-suspension-analysis.html

Ah, I see. I trust my numbers more. Dan does the same thing I do - and what every suspension engineer does when modeling our competitors' products: we find good photos or tech drawings of frames and click on the points in Linkage. Pretty straightforward.

I go farther than most:

• I usually do about two to five iterations for each bike, using different photos, if I don't fully trust a photo.
• I try to compensate for photo distortion by triangulating the central plane of the bike.

I've calibrated my methods: if I were to use just one good photo, as most people do, the error is maybe 5% - 15% for a Horst link bike and vastly more with a twin-short-link bike, especially a dw*link. With a few iterations and careful calibration, the magnitude of my error is cut by about 75%.

To cite numbers to two significant figures using these methods is pretentious nonsense. Even the actual bike, built from the actual CAD files, may not be accurate to two significant figures due to manufacturing tolerances on the frame and components!
flag Benduro83
O+
Posted: Jan 3, 2020 at 4:53 Quote
moity wrote:
How's everyone liking the stock Fox Rhythm? Gotta say I'm not really a fan, feels over damped and gives a choppy ride.

Considering swapping out for Lyrik...

Felt terrible in stock form with 3 tokens in my opinion. Took them out and cleaned all the excessive gunk from the negative air spring and now I like it. Seems plusher off the top with no tokens and about 10psi higher than recommended. About 15% sag.
No complaints on performance since mods.

A lyrik is definitely better though
flag jaydawg69
Posted: Jan 3, 2020 at 8:06 Quote
Brasher wrote:
It’s 9.5% in high and 9.7% in low.

I love these bikes to bits but the rear suspension platform is sub par to the rest of its geometry and purpose.

http://linkagedesign.blogspot.com/2019/09/s-stumpjumper-evo-29.html

LR from 3.0 to 2.65 would yield 11.7% (if my maths are correct)
flag R-M-R
Posted: Jan 3, 2020 at 8:18 Quote
jaydawg69 wrote:
Brasher wrote:
It’s 9.5% in high and 9.7% in low.

I love these bikes to bits but the rear suspension platform is sub par to the rest of its geometry and purpose.

http://linkagedesign.blogspot.com/2019/09/s-stumpjumper-evo-29.html

LR from 3.0 to 2.65 would yield 11.7% (if my maths are correct)

If we scrutinize Antonio's chart, it's closer to 2.98 to 2.66, resulting in 12% - which is, again, just Antonio's model, created by clicking points on a photo. My number is slightly different, but we're all in the same range.

You could download the free version of the software and generate your own number in under five minutes. You could go a step further by taking about an hour to do a few iterations and some triangulation, as I've done. It's not terribly difficult.

The two main observations:

1. The Stumpjumper Evo 29 has a mildly progressive motion ratio curve.
2. Don't be overly trusting of numbers on the internet or of "experts" whose work can be replicated in a few minutes!
flag moity
Posted: Jan 3, 2020 at 10:10 Quote
Benduro83 wrote:
moity wrote:
How's everyone liking the stock Fox Rhythm? Gotta say I'm not really a fan, feels over damped and gives a choppy ride.

Considering swapping out for Lyrik...

Felt terrible in stock form with 3 tokens in my opinion. Took them out and cleaned all the excessive gunk from the negative air spring and now I like it. Seems plusher off the top with no tokens and about 10psi higher than recommended. About 15% sag.
No complaints on performance since mods.

A lyrik is definitely better though

I've cleaned up the air spring too, mine was the same, half a kilo of excess grease. I've also removed 2 of the 3 tokens, I'll try removing the last one and give that a go (and up the pressure a little to balance).

I also recently installed SKF low friction wipers, made no discernable difference.
flag R-M-R
Posted: Jan 3, 2020 at 11:19 Quote
moity wrote:
I also recently installed SKF low friction wipers, made no discernable difference.

Everything helps, of course, but wiper friction is a tiny fraction of the total friction when it matters - i.e. when the fork is subject to large bending moments.
flag Benduro83
O+
Posted: Jan 6, 2020 at 18:37 Quote
moity wrote:
Benduro83 wrote:
moity wrote:
How's everyone liking the stock Fox Rhythm? Gotta say I'm not really a fan, feels over damped and gives a choppy ride.

Considering swapping out for Lyrik...

Felt terrible in stock form with 3 tokens in my opinion. Took them out and cleaned all the excessive gunk from the negative air spring and now I like it. Seems plusher off the top with no tokens and about 10psi higher than recommended. About 15% sag.
No complaints on performance since mods.

A lyrik is definitely better though

I've cleaned up the air spring too, mine was the same, half a kilo of excess grease. I've also removed 2 of the 3 tokens, I'll try removing the last one and give that a go (and up the pressure a little to balance).

I also recently installed SKF low friction wipers, made no discernable difference.






Interested to hear what you think of the change. I haven't used the fork with tokens since installing a new air shaft with less grease.
I read on mtbr that 3 purple tokens was supposed to be the sweet spot on this fork but when I tried it previously it felt ever too wallowing with lower 30% pressure and too stiff otherwise.

Might play around with a shockwiz at some stage
flag R-M-R
Posted: Jan 8, 2020 at 19:51 Quote
R-M-R wrote:
Brasher wrote:
R-M-R wrote:


What's the source for these numbers?

https://www.pinkbike.com/news/behind-the-numbers-specialized-stumpjumper-evo-29-suspension-analysis.html

Ah, I see. I trust my numbers more. Dan does the same thing I do - and what every suspension engineer does when modeling our competitors' products: we find good photos or tech drawings of frames and click on the points in Linkage. Pretty straightforward.

Interesting "Behind the Numbers" article today.

If this is how all the bikes in the series have been analyzed, then I take back what I said about the reliability of the numbers in the articles. I still don't fully agree with some of the interpretations, but at least the raw data ought to be top notch.
flag 3gdean
Posted: Jan 9, 2020 at 14:07 Quote
Any one know if its the same mod 52.5 to 55 on the standard stumpy fox performance DPS shock? Looked for a vid/how to for removal,,,is it easy enough to do? (explain like i'm 5 :-)
flag NotNamed
Posted: Jan 17, 2020 at 11:54 Quote
There is a Aluminium spacer on the shaft- so be careful that you dont damage your shock
flag jasonwd
Posted: Jan 18, 2020 at 7:16 Quote
Has anyone made a list of which shocks fit?

I'm looking for an air shock for my Pro and this thread is _looooong_!
flag kwapik
Posted: Jan 18, 2020 at 9:38 Quote
The only shock I hear that has interference issues is the Fox X2 on the alloy frames. It does fit the carbon frame. Other than that - all the big players fit.

What I'm finding works the best for the Evo is what I'm calling "big air". An air shock with a big air can. The X2 works really good too, but again just for cf frames.

I'm told a coil with Cane Creek's progressive Valt coil works really good, but I haven't tried it myself.

If you feel like searching and reading, there is a lot of good information here:

https://forums.mtbr.com/specialized/2019-stumpjumper-evo-thread-1077199.html
flag Arierep
Posted: Jan 18, 2020 at 11:29 Quote
Wasn't there some issue with a Ohlins coil shock in the high setting?

 


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