[AdamITR]

Posted in Clydesdale Forum also, may fit here better.

Hey all, been riding Hardtails most of my life, and just purchased a lightly used 2019 Stumpjumper. Size XL, fitment is great, although may need to make small cockpit adjustments.

Hoping someone can lead me in the right direction with Suspension upgrades though:

First, 74 inches, 255 geared (camelback, multi-tool(s)) using clip Shimano X3's. (Trying out flats next week). I don't do a ton of jumping, but the terrain that I ride in Upstate NY has quite the downhills, technical climbs, and flats with large shale, cave-type rocks, etc. Of course roots, and more roots.

I have had the bike on 2 good rides, although still feel 100% more confident on my Hardtail if I am being honest.

So, here are the questions:

The front fork is a 150mm RockShox Pike RC, the rear a RockShox Deluxe RT3.

At my current weight, the front fork is a non issue, works as it should, might add a spacer to run a bit lower air pressure. However, when compared to my Marzocchi Bomber Z2, I actually prefer it to the Pike, but again, not too many rides on the Pike. I do have the kit to convert the Z2 to 150mm, so something to ponder.

The MAIN issue is the rear shock, at full air pressure (300psi), and going through all the correct setup directions, and even having a buddy who I trust explicitly, I am bottoming it out, and there is no way I can get near the 20-30% sag. We were taking about the possibility of going with a coil-based rear shock. I have no idea where to begin looking, or what even fits, or how to measure. Hoping someone can give me some help. Also, zero spacers installed, would that make help or just mask the problem. Cascade Compontent rear link is on the bike also.

Thanks for hearing me out!

 

[Kiwibaconator]

That Cascade link is not helping at your weight. The stock rocker has a lower leverage ratio through the entire shock stroke.

 

[OldMike]

As noted removing the Cascade link should help, but adding spacers/tokens will also aid in ramping up the compression near full travel.

 

[Cary]

The issue you are running into is that bike runs a high leverage ratio, which requires higher pressures for a shock to support the same weight as a lower leverage ratio. Stock the leverage ratio is 2.9 to 2.6 which is relatively linear (but still a bit on the high side), with the Cascade link, they are bumping that up to 3.4-2.6, and at sag from about 2.8 stock to 3.0, approximately a 10% change (i.e. you would need 10% more pressure to get the same sag).

This is also being compounded by the shock, the Rockshox Deluxe shocks are known to want to hit a certain sag and not want to change regardless of pressure changes (has to do with their equalization design), combined with your weight putting you at the edge of the where the shock would be to begin with on a normal leverage rate bike, much less with the link.

My suggestions are:

1) Try the stock link if you have it. It should improve things. See if you can get proper sag, then add volume spacers as needed to control the bottoming. You will still have an issue that you may not be able to get good rebound (the high speed rebound will be insufficient) as you are outside the normal tuning range.
2) Try a Manitou Mara Pro- The Mara Pro uses a much larger air volume and hence lower pressures (as opposed to having to set the PSI to higher than your body weight, generally about 20-25% below your body weight). The Mara has a max pressure of 250psi, but given its design, I would expect you to need about 200 psi to get sag where you need it. It will match well with the Cascade link, is highly adjustable and easily retuned if needed.

 

[socalrider77]

I’ve run into this same problem before, 250lbs on a high leverage bike and an air shock with a huge negative chamber air shock, had to run it at max psi which put me around 40% sag. Not the answer, but I ended up on a new bike and made sure the leverage ratio was within a usable range for my weight.

I don’t think a coil shock would help you with bottom outs, unless you put a progressive spring on it, but that’s a whole different conversation.

Another option would be to move to a fox dpx2 shock that has a max pressure of 350psi so you can shove more air in it to get correct sag. The dpx2 + stock link, or manitou Mara pro as mentioned are probably your best options.


Sent from my iPhone using Tapatalk

 

[AdamITR]

Great information, cannot thank you guys enough. Thinking about the next step …. I did reach out to Lost Co. and they reiterated in an email what Cary said. I don’t have the original specialized link, but I know that can be purchased.

 

[AdamITR]

Manitou Mara Pro on the way, will test, report back, thanks again all

 

[Moosedriver]

I see that you’re going with a Mara Pro, that’s what I have on my 2019 SJ and it works like a dream. I’m around 170, so I can’t offer a pressure for your weight, but I’m right around 20% lower than my body weight, so Cary’s recommendation works well.

I will also copy my post from your other thread as an FYI:
Don’t get a coil shock for a 2019 SJ... lots of people report shafts snapping and causing damage to the frame. Something about the flex Specialized designed into the frame causes too much side load for coil shocks with smaller shafts. If you can find a coil shock with a larger shaft, it will most likely work, but since it’s not common for shock manufacturers to post shaft size, it may be frustrating trying to figure out.

 

[Moosedriver]

Also, AMain Cycling (amaincycling.com) usually has Specialized parts in stock, sometimes they’re out of stock on parts but re-stock relatively quickly.