There is an option of upgrading the shock of a current-gen Stumpjumper Evo to a Super Deluxe Ultimate. The issue is that the shock on offer is intended for the MY19 Stumpjumper 650b - it comes in a 210x52,5 mm length and is an L/L tune supposedly.
The stroke is not an issue (the graphics will be wrong, but 55 mm can be had from the shock by removing the plastic spacer inside, it's a half an hour job at most), my question is if the tune is somewhat correct for the newer model? Does anyone have any info regarding this issue?
I'm guessing it's not a major problem as a listing for a MY23 shock for the current EVO lists it as LC compression, progressive rebound and light Check tune. Specialized of course only markets it as 'Rx Tune' which is... SO helpful.
the Rx tune is basically soft compression so LL is similar, I believe most prefer m/m though
Well the L/L tune shock is a Stumpjumper 'specific' shock, but for the MY19 variant, not the MY2x that this bike is. The L/L designation is just in the listing.
FYI the Fox Speshy RX tune for current Stumpy is light comp and firm rebound.
Are you planning to cut the spacer off without taking the shock apart? Pretty easy to change the tune and rebuild those at home. I assume you mean "regressive" rebound for the current RX tune, as in preloaded. So the rebound on the shock you want to use will be quite a bit softer (faster).
If it were me I'd pull the old shock apart and put a firmer rebound tune in it. The new bike has a higher leverage and you will be running higher pressures than a '19.
It says progressive:
https://r2-bike.com/ROCKSHOX-Rear-Shock-Super-Deluxe-Ultimate-RC2T-Debo…
I thought about cutting the spacer, but as there's another metal shim in there besides the plastic spacer, cutting that cleanly might be a bit more cumbersome than the plastic one. So I'll likely open up the damper, it's going to take less than an hour...
Rebuilding the tune isn't much of a problem if you have the shims at hand, which I don't. We'll try it out as is and go from there.
Oh, the new one. That thing is a whole different ball game, not very tuning friendly and pretty sure all rebound tunes are regressive due to the dished piston. You are way better off with the older version IMO.
The older SD shims are a very common ID and should be easy to find. You would only need 2-3 to stiffen up the rebound tune.
If there are any 0.15mm thick shims on the comp side, you could swap them to rebound to help some. What do you weigh?
Can't answer the weight question, this whole shenaningans is not for me
Primoz, why don't you just buy the 210x55 Super Deluxe RC2T instead of messing around with cutting the spacer our of the 52.5 version? I run the stock RC2T tune on the EVO.
you can run 55 or 57mm stroke on those bikes no problem, refer my Avi to the left. I killed 6 shocks on that bike.
Great bike let down with one of the worst kinematics in recent MTB history, cascade link and or EXT Storia is the only solution.
Primoz is talking about the current gen Stumpy EVO.
a) the MY23 one (or the correct one in general) is not in stock.
b) the more important reason, I ordered the previous gen Super Deluxe (for the MY19 Stumpy) for 260 €. I'd call that a daylight robbery.
Come on man.
New SDLX has flat pistons (Comp, Rebound and Rebound Check)- it actually uses the the same main and check piston as old SDLX.
Also the progressive rebound tune makes a progressive curve, linear tune makes a linear curve (line) and digressive makes a digressive curve. All easy to measure and see when you have the correct tools to do so. I'm not going to say it.
Dave, thanks for chiming in here!
Question, can you please elaborate on the real-world difference between a progressive rebound tune and linear? The EVO is spec'd with a progressive, but SDLX shocks available in the US are linear. Which is what I'm running now.
I've done a lot of Googling and have also looked through Rockshox manuals/info but have found no good explanation of 'curves' or use-cases for the rebound tunes. I have also asked some 'suspension people' but have been given conflicting answers. I totally understand progressive vs. linear springs, but not the rebound side of the equation. I think the confusion comes from not knowing what start and end point is used for determining the 'progression'. Is a progressive rebound heavier damping deep in the stroke, or at the top of the stroke? What characteristics would one get from running a progressive rebound tune vs. linear?
Thank you!
Sorry to thread hijack @Primoz but I know you love it...
Progressive generates more force on big hits and remains open/fluttery feeling on small bump. I like that tune on all bikes so far. Linear is a close 2nd- hard to tell which tune you have (linear vs progressive) unless you do back-to-back testing on the same trail/same day/same bike/same shocks...
Digressive is basically the opposite of progressive and Linear splits the 2 tunes.
It's only fitting that the topic of the head forum offtopicer get offtopiceed by someone else.
Almost started off on a 'rant' about "doesn't the digressive tune give more support and thus more pop on small bumps", but that would be the case for a digressive compression tune (more support) and a progressive tune will give more pop as it will literally make the bike pop more by the shock 'bucking' some more through less damping. On that note, are compression tunes digressive/linear/progressive too? Or is the approach to tuning different there?
you can have digressive/linear/progressive compression tunes but basically anything other than VERY digressive will feel insanely harsh as the range of velocity on compression is so much wider. Especially on a fork- damping forces are tiny and velocity is very very fast.
Specialized has a helpful lil chart on the stumpy shock tune here:
http://s7d5.scene7.com/is/content/Specialized/Specialized%20Website/Pag…
Wow @Dave_Camp thanks so much for sharing that graphic. Makes total sense now. That should be something that isn't that hard to find or research for laypeople, but it is! It looks like now I need to find someone to change my shim stack to progressive
I’d like to point out that just because a bump is small doesn’t mean shock speed will necessarily be small. If you’re riding fast, shock speed might have to be quite high for the wheel to track the ground over chatter. I have personally found progressive tunes initiate very nicely, but when too extreme can cause the bike to essentially be unable to respond to anything high frequency. On the flip side I’ve had issues with more digressive tunes where it always feels too firm except for when I really need it and then it feels too soft. Riding style and terrain is so specific that I don’t think there is a one size fits all here.
when talking about rebound- shock velocity tracks with bump size most of the time.
Agree compression speeds vary with shape of the bump and bike speed etc.
Bump size in general, but in actuality with the stroke caused by the bump (thus preloading the spring more and putting more energy into the system). Nitpicking, you could say more compression dampening would dissipate more energy and cause less stroke on the shock (though giving a harsher ride) and thus decrease shock speeds somewhat.
But this is the same situation as when you have to close off rebound damping when increasing air pressure (or using a stiffer spring), so we're back to square one - rebound tuning is dominated mostly by the spring characteristic (thus leverage ratio, curve and rider weight or bike-end-loading), while compression damping is affected by the spring characteristic, type of terrain, speed of riding, etc. So there are a lot more factors involved.
(the dampening is there as a gift for Charlie
)
Yeah was talking about compression specifically. I've found I'm not too picky about rebound as long as it's on the faster side. Until you're hitting things large enough that you really need a moment to regain composure after an impact I think fast rebound is easy to deal with at any point in travel and has substantial benefits when hauling. How large of a an impact it would take to hit that threshold would vary depending on what people are used to I suppose. For one person it might be rampage and for another it might be Aline.
My two cents on the shock from the point of view of a 150ish lb rider... L/L tune works fine for me on this bike. I end up running compression about mid-range and rebound more towards the open end of things. So pretty decent usable range for adjustments. Doesn't work great for one of my coworkers who's substantially heavier though.
Sorry, must have been thinking of the Charger 3 or something else. I know there's a dished piston somewhere in your new stuff!
Thanks for the insight, I appreciate it.
Cool, thanks for the info, weight wise the L/L tune looks like it will be spot on then (similar weight).
Devil is in the details on suspension.
I have a 2022 Stumpy EVO and messed around with the Fox Float X with and without cascade link, could never get it to feel right.
I put on the 2021 model Super Deluxe air with medium/medium tune with a MegNeg and the cascade link and it feels AMAZING, did some bracketing on a couple rides and changed some things and this is what I've settled on. Got rid of the very chattery overwhelmed feeling I was getting and still getting tons of support deep in the stroke.
180lbs/6'2"
Megneg with 2 bands
1 volume token
have to check PSI after I've changed it a bit but I'm currently right at 30% sag.
rebound and compression are somewhat open, if I was lighter id probably prefer the L/L tune.
This shock was originally a 52.5 stroke as well and I just cut out the plastic spacer, the metal washer is a non issue, the spacer measured exactly 2.5mm.
I'd be interested to hear what you're running for shock pressure.
22MY stumpy evo, after a full year of the float x + CC link I've made the jump to the 2023 Rockshox SDU. Still waiting for the spring thaw, as well as the high volume air can and HBO to arrive before I install it.
good to know about the bands and volume spacers you're using
Ill put a shock pump on it when I get the chance, my shock is the older model though not the new ones I wanted to try the new one but couldn't find any stock at the time and $600 vs a slightly used one for $200 was a big factor also.
I don't know why but I just couldnt get on with the Float X on this bike. It was fine for most trail riding but higher speed stuff that was chattery and really anything in the bike park it was not ideal tried different volume spacers as well.
@Tanner_Carl How did you manage to find a HBO Super Deluxe in the US? As far as I know, no distributors had them. Well, at least as of a month ago. It's optional on the new Super Deluxe, so make sure you got one with HBO on it, if you want that feature.
I had to buy the HBO and the HV air can separate, sounds like the HBO is out until late May...
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