Penny tech: servicing your Scotts damper

[malcolmzilla]

Stealing the topic theme from Axel99, my Scott's damper had underperformed as of late. Or at least I choose to blame it for my rhubarb excursions.

Tools required:

fork oil
solvent
15mm socket or box end
very small metric allen key set
scotts arm puller (optional)
6 pack (optional but highly recommended)

Issue #1 Oil quality and level.

The damper oil, in 4+ years I never serviced it. Literature all read that it had to be sent out to Scott's for a specialized service (thus it never went out ).
Well, these things, while beautifully designed and intricately machined, are NOT space shuttles.

Step 1: have a beer, tell yourself "nothing to lose by trying", remove damper
Step 2: clean damper of mud crud blood and other residues, back off hi speed dial (full open)
Step 3: remove top cover make sure allen keys fully insert that bolts are not plugged with residue from Step 2, easy to strip small hex hardware
Step 4: carefully remove cover, shouldn't require any prying implements
Step 5: drain and clean damper and cover, inspect cover o ring and shaft seal, note chunky black residue coming out, they say not to use brake clean... so they say... flush with fresh fork oil after should prevent seal damage from said unrecommended brake clean... hi and lo speed circuits were left alone

Step 6: overfill with fresh fork oil, replace cover with seals, lightly set all bolts in a criss cross pattern - excess oil will drain as you tighten cover down, hose down and wipe off damper
Step 7: test damper arm resistance working it a few times to purge circuits, replace on bike, for me set about 10 clicks from full open on hi speed, beer reload admire your handiwork
Step 8: test resistance on bike twist bars on stand - OPTIONAL for ongoing extra credit: notice a ton of play off center WTF think you messed damper up

Step 9: remove damper again, beer 3
Step 10: inspect arm, notice shaft roll pin very loose
Step 11: root thru house for 45 minutes to find Scotts damper arm puller tool you bought 4 years ago used once
Step 12: root around garage for 15mm socket, cant find it, just about to use 5/8" socket then relent and use 15mm box end wrench to remove shaft arm retaining bolt NOTE Machined shoulder orientation
Step 13: use puller tool to remove arm guess its worth the $40 now
Step 14: shaft pin falls out in 3 pieces, only find 2 pieces for picture,WELL THERE'S YOUR PROBLEM ISSUE #2 identified (maybe stop wadding it up Malcolm, prolly not a feasible solution tho)

Step 15: Beer 4, no replacement pin onhand
Step 16: notice bucket of old drill bits on workbench, root thru find one that fits shaft hole (left of pic) PERFECT cut it grind it to fit wallowed out arm from broken pin finish beer 5
Step 17: replace pin in shaft, tap arm back on, bit of blue loctite and tighten shaft bolt in correct orientation
Step 18: reinstall on bike, test, WORKS EFFIN AWESOME
Step 19: crack beer 6 and go watch PVR supercross
Step 20: blast a real ugly kicker the next day and save it while your buddy with no damper piles it on same one

Caution: dunno if this procedure is applicable to GPR or Fastway

[malcolmzilla]

Edit: some youtubing reveals

https://www.youtube.com/watch?v=0YcVUf7hAnc

I might pop it off the bike yet set upside down, and top up.

I noticed the lower fill passages with the top open, but was reasonably sure I had the reservoir full, but this method would certainly help prime the circuits machined into the cover.

I might not get the grime and residue out tho, depending on your service conditions and intervals. Mine was filthy - worse than 60 hour forks!

[axel99]

Penny tech was actually cedric's term, it's ok though cause I steal all his good ideas. I think he may have caught on cause he doesn't share as much

[Brass]

By any chance did you measure the diameter of the shear pin?

[malcolmzilla]

~4.45mm or 11/64"

[malcolmzilla]

Did the upside down youtuber thing a couple times. Noticeably firmer off center.

So, pop the cover to clean out and do majority of fill, upside down work the damper a bit to prime curcuits, then top up upside down via the fill plugs.

[dirtyboy]

Nice work. You will need replacement seals for the shaft in the future. They are very cheap but hard to get (from USA). Or maybe you will find a square ring that fits perfect from Home Depot.

I wonder if that shear pin is meant to break so other parts don't? Might be another part to pick up? I also think the pin needs replacement around the 5+ year mark.

My Scotts damper is now a teenager and with yearly oil changes and seal replacements it is still perfect, except for the scratches.

[malcolmzilla]

Thanks Dave, yeah I was looking at those, not a regular o-ring.
And the pin, no doubt its meant to shear under duress.
Where do you mail order from?

[dirtyboy]

Scotts Performance or BRP. I like their stabilizer oil too.

[bikingagain]

X2 for Scotts Online. They sent me a couple shear pins and just threw them in an envelope to save on postage. I might have one around if you need one soon. Great write up