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'19 Stumpjumper Evo Downcountry Project

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'19 Stumpjumper Evo Downcountry Project

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flag johnsonjack1993
O+ FL
Posted: Mar 12, 2024 at 9:48 Quote
Hey all,

Just thought I'd share a project I've been working on. I have a 2019 Stumpjumper Evo Comp alloy 29" S2 that was recently retired to the trainer as I picked up a '23 Evo for my trail/enduro bike.

My 2019 Evo was setup for some enduro racing and the bike park. I have a cascade LT link and 210x55 MRP hazzard shock on it, bumping the travel up to 160mm according to Cascade Components. I also had a 170mm suntour durolux up front. I had a blast riding this bike but was interested in the new evo for the adjustability, mullet option and in frame storage.

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Anyways, with my old evo collecting dust I decided to switch things up. I'm turning my Evo into the ST version for pedaling around flow and xc trails. I bought the ST link from performance online, and a Cane creek DB inline 190x45. Since its hard to find a ST shock (190x42.5) used.
I believe this will have the bike sitting at 130mm rear travel. A little more travel than the normal ST stumpjumper. Its the same link and stroke size as the Stumpjumper ST Downieville edition. So I decided to make my bike an Alloy Evo version of the downieville edition.

https://www.specialized.com/us/en/stumpjumper-st-ltd-downieville-carbon-29/p/173584?color=271542-173584
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Next, I bought a used Cane Creek Helm off pinkbike. And I ordered some travel reduction clips so I could play around with the fork travel. The standard stumpy ST runs a 130mm fork and the Downieville edition runs a 140mm fork, so I'll be experimenting with those options.

To make the bike less heavy, I put on some specialized traverse carbon bars, and an old set of raceface next sl carbon (170mm) cranks. Mine had a broken crank arm, but I found a used crank arm on ebay and replaced it with that. They are different colors but I dont mind. I have a 42.5mm one up stem and keeping my heavy I9 backcountry wheels on it for now. The one up dropper post and code brakes are staying for now, but might get some lighter G2 brakes or throw on some XT's that I have laying around to save a little weight.

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As for geometry, the bike was already low and after lowering the fork will be even lower with a 330.0mm bb height. So I may be looking for some shorter cranks (155-160mm?) in the future.
The HTA will be 64.2* and STA 76.7* after the fork and shock modification. In the High setting.
I'm also considering adding a 9point8 bravo slackr IS angle adjusting headset to steepen up the HTA and raise the BB up.

https://9point8.ca/collections/slack-r-is-kits/products/bravo-slack-r-kit?variant=41077869084823

evo st downieville

Let me know what you think! Will it be excessive for a short travel bike? Probably. Too low to even pedal? Maybe. I think it will be a fun bike!
More pics and updates to come once my fork arrives.
flag johnsonjack1993
O+ FL
Posted: Mar 14, 2024 at 22:06 Quote
So I finally finished completing the bike build this evening. And taking a little test ride around the neighborhood, everythings working great.

After getting the right shock bushings, I bolted up the cane creek db inline along with the cascade link and ST link. It was a tight fit, but I like the way the adjustment knobs and lockout lever are easily accessible from the open side of the asymmetrical frame. The flip chip is in the high setting.

I then lowered the cane creek helm fork down to 140mm with some travel adjust clips on the air shaft.

After that I assembled the rest of the bike. I put some new specialized tires on my i9 backcountry wheels, butcher in the front and eliminator in the rear. Both are the medium trail casing. I took my xt 4piston brakes off my other bike and installed those along with the shimano rotors, 203 front and 180 rear.

For the drivetrain, I used an old Gx eagle drivetrain that is very well used, but shifts pretty well. The raceface next sl cranks with mismatched crank arms were used along with a 34t chainring and some fresh crank boots as I'm sure I will be striking them. I put a mrp 1x chainguide on, I didnt want a bashguard to make anything lower than it already is. And these older stumpjumper models only have the front 2 (of the 3) iscg05 mounts, which is strange but works for this project.

For the cockpit, I stuck with the 42mm one up stem. I switched the bars to some oneup 35mm rise alloy bars. The specialized carbon bars I had on there before didnt play well with the oneup stem as they kept slipping in the oneup stem (which is a common issue with certain bars paired with that stem). I also installed a oneup edc lite tool in the steerer tube. Some lock on deity grips were added to finish off the cockpit.

Finally, its finished off with a oneup 180mm dropper post and an old specialized phenom (i think?) saddle.
And the dyedbro suzuki DR650 stye frame protector was a must when I saw it online, so that added some color to this raw frame.

Better detailed pics coming soon.

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flag johnsonjack1993
O+ FL
Posted: Mar 19, 2024 at 16:30 Quote
I took the stumpjumper evo project over to the 18 Road trails in Fruita Colorado over the weekend for its first ride. These trails are very flowy and pretty easy going, aside the endless braking bumps, so I decided it would be a great place to test and get a baseline. The bike handled great, however I need to tune the rear shock a bit more. Will probably be adding some volume spacers and slowing down the rebound a bit.

The old clapped out sram drivetrain didnt work great either, so I'll be getting a fresh shifter and derailleur to fix that problem. And the 4 piston XT brakes did great, as expected. And are a lot lighter than the Code R's I had on originally.

Its definitely too low, even with the 170mm cranks. I plan to get some of the sr suntour 142mm cranks (theyre cheap like $74 with BB) and add a boost chainring. I think this will solve my pedal strike issues. More updates to come once I get some shorter cranks on there.

The bike currently weighs just a little under 32lbs with pedals and no tire inserts. It feels light compared to my 36lb 2023 stumpjumper evo. And the low weight and low center of gravity makes for a pretty fun ride.

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flag theukrainian1
O+ FL
Posted: Mar 21, 2024 at 8:01 Quote
142 Cranks might be way too short. I have a 2019 SJ Evo with stock suspension and 160mm cranks seem to work well as long as I'm mindful. Amazon will have the hollow 160 mm or 150mm crankset, and you can use SRAM chainrings with it unlike the SR Suntour ones.
https://www.amazon.com/dp/B0CBX25WCC?th=1&psc=1

Only issue with those is that they may have bad threads on the non drive side, use a tap or just carefully thread new pedal in.
flag johnsonjack1993
O+ FL
Posted: Mar 21, 2024 at 8:45 Quote
Theukranian wrote:
142 Cranks might be way too short. I have a 2019 SJ Evo with stock suspension and 160mm cranks seem to work well as long as I'm mindful. Amazon will have the hollow 160 mm or 150mm crankset, and you can use SRAM chainrings with it unlike the SR Suntour ones.
https://www.amazon.com/dp/B0CBX25WCC?th=1&psc=1

Only issue with those is that they may have bad threads on the non drive side, use a tap or just carefully thread new pedal in.

Hey thanks for the link. I'm a little hesitant to buy amazon cranks. I have had good luck with Suntour stuff, I think its highly underrated and competitively priced.

Whoops, I meant 152mm. https://www.srsuntour.us/products/zeron-1-x?variant=45338041742
Compared to canfield cranks (150 or 155) that go for $375 these seem like a great option to try shorter cranks.

Suntour cranks are $80 with BB and $17 for a boost offset chainring. The only problem is that you need their lockring tool that is out of stock online (Part# CET002). I'm going to experiment with some other lockring tools that look compatible, like the Park Tool LRT-3 that was used for old specialized, fsa and cannondale cranks. They are both 8 notches but I dont know if the suntour lockring is close to 47-48mm. Will post with updates if that ends up working.
flag johnsonjack1993
O+ FL
Posted: Mar 26, 2024 at 11:48 Quote
Yesterday I got and installed the new Sr Suntour zeron cranks 152mm.
The cranks with BB were $80 and the boost chainring was $17. You need to order the boost chainring because on the smaller cranks they have a chainring with a 50mm chainline and the boost chainring is slightly offset to a 53mm chainline.
They came with a 30t ring installed and the boost ring I got is a 32t.
I also emailed suntour and asked them about the tool. They responded quickly and said that they did have them in stock and then updated their website. The tool was $17. $114 total, which is a great way to try out shorter cranks on a budget. Without having to buy canfield, 5dev or other shorter crank options.

Removing the original ring was very difficult. Using a vice and a torch to heat it up, I eventually got it off. After that, installing the BB with correct spacers for the 73mm BB was easy. On the cranks non-drive side they have a wave washer and two other small spacers that need to be added to the axle before installing the crank.

Overall, I'm very happy with how it turned out. I gained 18mm of crank clearance (0.71"). Unfortunately there are no crank boot options that I am aware of but I don't really care as they were so cheap compared to all the other options out there.

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