I’ll be honest, your best option is probably to buy new elastomers from this guy. His elastomers will make your Proflex fully functional again. Proflex was bought out by K2 some time ago, and official replacement parts, if you can find some, are probably hardening or rotting themselves, so it’s best to go through an outside source like Rapid Descent or similar to get the newest product possible since elastomer’s shelf life is only about 4-5 years tops. edit: Rapid Descent no longer sells these, try here instead. Also David E has another great Elastomer fix, which I wrote up here. Anyways, I’m trying to illustrate how to at least get one of these bikes back on the road and functional until your new elastomers come in. I pulled my Proflex 656 out of the garage one summer night in 2004 and rode it around the block, to find that something was wrong. My elastomers (shock absorber/springs) had turned to the consistency of cheesecake and had been squished out of their usual location. This wouldn’t be an issue if it didn’t cause the bike to sit unusually low, and the piston in the rear didn’t push through to block the tire tread. So the bike has been in storage now, unusable, for five years and finally last week someone at a bike shop reccomended something to me I’d never thought of before. – using old bike intertubes wrapped around the piston to emulate the elastomer.
Here’s a brief photo essay of what I did, and shockingly enough, it works rather well. I’ve only put about 5 miles on the design, but I don’t see any immediate failure points. Travel distance is only about 1/2″, and can be adjusted an extra 1/4″ by removing one of the zip ties.
Your elastomer may look something like this. At 80 degrees this stuff is like play-doh, but at 70 it’s more the consistency of gouda cheese. I’ve heard stories that this stuff can harden, but I find that a little hard to believe.
You can cut it out with a butter knife. It really does look like cheese! My cats kept trying to eat it while I was working.
First start by taking some old inner tubes and cutting the valve stem out.
Next up, match the innertube to the piston and start wrapping. What seems tedious at first actually goes by very quickly, since the tubing is thicker than you realize. Make sure the tubing lays flat so the final product won’t shift under your weight. You’ll probably need 8-10 wraps for the rear end, and if you have a Girvin Vector 2 front shock like me, 6 or 7 wraps for the front.Note that the innertube isn’t wide enough to fit the entire gap. If you pop wheelies or do anything extreme the piston is going to slide a little bit but there isn’t any issue unless you’re doing advanced technical trails.
Secure the innertube with zip ties, one on each end at minimum, and for additional stiffness or durability, add one or more zip ties in the middle.
Final product, rear (I realized I had a flash function on my camera phone)
Final product, front:
The final product doesn’t give you much travel, perhaps half an inch, but if you’ve picked up one of these bikes 2nd or 3rd hand only to find that regular spring shocks don’t work well on this bike, this will at least get you out on the road, and provide a little bit of travel. This is a Proflex 656 and to the best of my knowledge the only 656 I’ve ever seen with a Vector 1 front shock. I think this is a 95 or 96 model that was the store demo on sale at the time (in 97 perhaps?) for $680. While pricey by today’s standards Proflex, bikes are great bikes. This bike has been in the Cascade Mountains, the Olympics, Moab Utah, and numerous places in Texas and has never let me down (except the elastomer of course). If you ever come across one on craigslist give it a try, you might be suprised.