# Restoring and updating an old '08 Stumpjumper FSR Comp



## DeoreDX (Jul 28, 2007)

I ran across an old 2008 Specialized Stumpjumper FSR Comp being given away for free. The initial visual inspection showed all the pivot and shock hardware to be intact. The frame components were in good shape for a bike of this age with no obvious defects except for some signs of chain suck on the drive side chain stay. The rear shock was blown and the damper had obviously lost all it's oil. Brakes were dragging bad. The F120RL front shock felt tight but held air and was springy. Shifting was for crap and there were signs the drivetrain was worn out. I was initially thinking I could get it running and serviceable for $300-400 with a bunch of elbow grease depending on if I could find parts to service the Fox Triad shock or if I had to buy a new one.

1st day home:









I found parts to service the air piston but I couldn't find parts to service the blown damper and I couldn't charge the nitrogen charge anways. $155 was the quote from Fox to rebuild the shock. 184x44 was an odd size but there was some other options out there. I saw some brand new Rockshox Monarch RLs for $220ish. I ended up the new RL for 230 shipped. $25 for some new fork seals, $20 for some suspension fluid, and $10 for some brake fluid. $30 for some new brake pads. Lots of elbow grease cleaning the brake pistons 100 times to get them moving (sort of) smoothly again. Took some old Kona WahWah pedals I had laying around and threw those on. $305 later I had a rideable bike.










Shifting still sucked. I couldn't get the rear dialed in right. There was a lot of slop in the derailler cage. I really liked how the bike performed and I was still under my initial $400 budget so I decided to address the drivetrain next. I was just going to replace the cassette and rear derailleur and chainrings then realized for a few bucks more I could convert it to a 1x. Since Deore groupset supply was non-existant I decided to give Microshift a try. Advent X shifter, clutched derailler and 11-48 cassette $164. Amazon Chinesim chainring with chainring bolts $18. New SRAM 1051 chain $25. Some cable and housing $5. This was the era of trail bikes with 640mm handlebars so those had to go. Had a cheap chinesium 720mm handlebar laying around the garage and threw those on. I picked up a new derailleur hanger just in case ($15) and aligned the existing one for smooth shifting. Another $237 later and I now have a wide range 1x10 converted full suspension bike. This was as far as I had originally planned on taking the bike. I got everything working as it should and I now had a fully functional and restored bike.

Total: $534










The new drivetrain is great. But I started warming up to the bike so I decided it fit it and personalize it a bit more for me. Bikes rides great except the front fork is very progressive. I have to run very low pressure to get the fork to feel like it's working and even than I never come close to bottoming the fork out. I pull the air shaft out and chop about 20mm off the top to enlarge the air chamber. The 175mm cranks are also longer than I normally run. Since I've come this far I decided to invest in some 165mm cranks so I can pedal the bike without knee pain. $75 for some cranks and $2 for a pillow pack of shock oil later and I now have the bike running great it fits me will and both front and rear suspensions are working great. I fitted a specialized side release cage ($25) but the shock hit the cage when the shock was compressed. So $20 for a wolftooth cage mount thingy later I now have a bottle cage. $30 for my favorite Chromag grips. $10 for a new Bike mojo that my son picked out for me while we were biking in Chattanooga while visiting my parents. I put about 200 miles on it so far and it's been a great bike. I've explored new trails and found some new lines on old trails. It has been a really rub project bike.

Total Budget $686


























I was originally going to pass the bike on to recoup my expenses and look for a new project bike but after I fixed up it but I've grown attached to it and decided to keep it. At sub 27lbs it's a fun nimble little bike that works well on most of the local single track. I never budgeted new tired in the original budget as good 26" rubber is pricey nowadays. Since I decided to keep it for a while I decided I need new rubber to replace the old aging hardened rubber X-kings. $104 for a set of Ardents front and rear. Just wrapped the hoops in the new rubber. I have officially declared the Stumpjumper project finished.

Total project cost: $790


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## Mudguard (Apr 14, 2009)

I always liked that shape Stumpy, reminds me of the Enduro killer Pitch they made for awhile before it turned into a hardtail.


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## Monty219 (Oct 26, 2020)

Nicely done. I love old bike revivals.


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## robbbery (Jan 12, 2021)

Beautiful job and beautiful bike!


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## Harold (Dec 23, 2003)

did you check the chain length on that thing with the suspension compressed?


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## DeoreDX (Jul 28, 2007)

Harold said:


> did you check the chain length on that thing with the suspension compressed?


Yes. I did +2 links in the big cog with the suspension compressed to max chainsaw length like the microshift instructions say but that left me with zero chain tension in the smallest cog. So I did the old take links out until you get tension in the small cog method. Which was one link shorter than by the directed method.


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## Harold (Dec 23, 2003)

DeoreDX said:


> Yes. I did +2 links in the big cog with the suspension compressed to max chainsaw length like the microshift instructions say but that left me with zero chain tension in the smallest cog. So I did the old take links out until you get tension in the small cog method. Which was one link shorter than by the directed method.


did you realize that you can use the b-screw to get that tension back into the small cog? my shimano 12spd drivetrain worked the same way. I fumbled with the chain length at first, but a little bit of a b-screw adjustment got things dead on. these wide range 1x drivetrains are a lot more sensitive to b-screw adjustment than old drivetrains were.

The way it looks right now, the derailleur cage looks to have very, very little room to move in the big cog. So with a suspension compression, it looks like it'll damage the derailleur.


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## DeoreDX (Jul 28, 2007)

Harold said:


> did you realize that you can use the b-screw to get that tension back into the small cog? my shimano 12spd drivetrain worked the same way. I fumbled with the chain length at first, but a little bit of a b-screw adjustment got things dead on. these wide range 1x drivetrains are a lot more sensitive to b-screw adjustment than old drivetrains were.


I'm no stranger to B-screw adjustments and I could be convinced that adding an extra link is the best thing to do. I added a link and took a couple of comparison pictures so other can see what I saw when I set up the drivetrain.










Setup A setup: 114 links (you can see the extra quick connect I added to add an extra link). Chain overlap at suspension full extension 3.5 links. Overlap at full compression 2.5 links (2 link overlap is the recommendation). B-gap adjustment screwed all the way in and only have 13mm of B-gap short of the recommended 15mm. Rear derailleur has zero preload in smallest cog and chain is loose and sags in smallest cog. With smaller than recommended B-gap it doesn't multi-down shift very smoothly as it feels like the derailleur wants to bind as it tries to climb up the larger cogs. Single shifting works great.

Setup B: 113 links. Overlap at full extension ~2.5 links. Overlap at full compression 1.5 links. B-gap at recommended 15mm. Shifts smoothly in every gear even multi-down shifting. Even tested with the shock detached to make sure it worked properly when fully compressed. But like you said the derailleur looks stretched more than I am used to seeing. This is also my first time setting up a Microshift Advent drivetrain so I don't know what the limits of the derailleur look like. Even Setup A looks more extreme than I'm used too. Abandoned 114 links when I reached the limit of B-Gap adjustment in Setup A and did not have the recommended B gap and had no tension in the smallest cog. Setup A shifted smoother on the stand. Maybe taking into account a bit of chain growth when the suspension sagged at 25% I might find that setup A performs better under power but I only tried them on the stand.


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## Monty219 (Oct 26, 2020)

DeoreDX said:


> I'm no stranger to B-screw adjustments and I could be convinced that adding an extra link is the best thing to do. I added a link and took a couple of comparison pictures so other can see what I saw when I set up the drivetrain.
> 
> View attachment 1916290
> 
> ...


I have been unscientifically (but still carefully) installing drivetrains and cutting chains since 1999, and to my eye either chain length looks long enough but I would trust your own judgement. I tend to look more at what is the maximum chain length I can run and still have tension on the smallest cog given enough b tension but not too much for the shifting between the two largest cogs. Sounds like that's what you did too, plus all of those extra measurements you discussed. Overall I'd venture to say you are on the right track. But I appreciate learning more about the set up details/ intricacies of 1x. And is it just me or is SRAMs system where you need to use a gauge and have a buddy help check it at sag seem a bit much? The accuracy is cool and all but i don't like the sound of a drivetrain that is so finicky to set up.


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