Rockshox Quadra 21R -- Removal tips for old brittle elastomer

Question

I am tuning up the mountain bike I purchased in 1994, which has the old yellow Rockshox Quadra 21R front suspension fork.  I have found a nice video on YouTube which shows how to service the suspension, and replace the elastomers, and also found an elastomer replacement kit for the fork at suspensionforkparts.net.

My concern is, when I unscrew the top plastic nut to remove the old elastomers, that I have found the old elastomers to be very brittle, several of them breaking into pieces upon removal, with brittle chunks still stuck within my fork.  I can get the top-most units removed, but I know there is still at least one or two layers of elastomer in the bottom of the fork.

Does anyone have experience removing old brittle pieces of elastomer without damaging the tubes of the fork? My intuition says I should get in there with a long flathead screwdriver and a hammer, but I do not want to damage parts within the bottom of the fork that I cannot see.  I also will need to access the very bottom of the fork with a long hex wrench when the elastomers are removed to fully disassemble and service the the bottom shafts.  So, I am a bit worried that my screwdriver approach will jam the old elastomer pieces in the bottom of the fork, preventing access to the hex screw.

Thank you in advance for any tips you can offer on safely removing the old brittle elastomers.

Emyr · Accepted Answer

I've never dismantled a fork intending to reassemble it, but...

Could you use a J-end spoke or a knitting hook to pull the elastomer rather than pushing it?

You should be able to get plastic knitting hooks so the inner surfaces aren't scratched.

Ryan · Answer

Thank you for your tip, Emyr.

I ended up using my screwdriver and hammer method to work around all of the brittle elastomer sections.  However, at the bottom of the last section of elastomer was a round piece of plastic with a hole in it.  I did just what you suggested to remove it -- I bent the end of an old spoke into a "J" shape, and pulled it out of the fork.

My new elastomers are coming in this weekend, and I look forward to repairing my front suspension. Thank you for the help.

Here's a photo of the old elastomers from the Rockshox Quadra 21R fork, now 20 years old!  They are laid on the table with the botom of the fork toward the top. The small plastic ring you see is what I removed with the "J" shaped spoke.

Ryan · Answer

The replacement elastomers I ordered from suspensionforkparts.net arrived and I replaced them this past weekend. Easy job, and the front suspension works like new!

The Lizard · Answer

So this was helpful to me, but I had to use some different techniques. The elastomers weren't that bad, but the old lubricant was thick and sticky so everything was stuck.
I needed a really long lag bolt, LOTS of WD-40 to dissolve the old oil, and one of those grabby things. The grabby thing does not hold on to stuff very tightly at all, so I'd squirt some WD-40 in there, bang on it with the long bolt, and carefully grab the little plastic nub with the grabby thing and try to work it until it started to come out.
The long bolt of the right size (about twice the diameter of the nubs on the plastic pieces) worked really well to slip into the hole of the rubber elastomers, give it a couple of twists to screw it in tight, and the pull them  out.
I'm posting pics of the tools I used, the elastomers pulled out, and the bike I'm working on.

Rockshox Quadra 21R -- Removal tips for old brittle elastomer

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