SF Cyclotouring

Ride reports and other ramblings from a San Francisco cyclist.

4/01/2009

Another Bike I've Always Wanted...



When I worked in a shop during the summer of 1993, a Proflex rep once visited us and had this bike with him. He let each of us take it for a quick test-spin, and I remember really liking the ride. Sure, this was "primitive" suspension technology, offering barely 2 inches of travel at each end, but it was one of the first (and still only!) full-sus rigs I've ever pedaled. I remember that there was very little pedal bob or brake dive -- overall the bike felt really solid, and I wanted very much to ride it on some nice single-track.

Ever since, I've had a soft spot for this bike.

Proflex developed one of the earlier full-suspension MTB designs, and -- unlike most other brands who seemed to try something new each and every year -- kept the same basic design and simply refined it year after year. I think this basic frame still is one of the longest-running designs, in production for something like 5-6 years (that's a guess?) until K2 bought up Proflex early this decade.

You can sometimes find these bikes used for quite good prices, but unfortunately the yellow MCU elastomers have all either hardened or turned to mush, and working replacements are extremely hard to find. A few years after the bike pictured was produced, Proflex moved away from MCU springs (which I still think are a great, lightweight, no-maintenance design!) to steel coil springs with hydraulic oil dampers. They offered retrofit shock kits for the forks and rear swing-arms for the earlier MCU bikes.

When I tried to build my own full-sus frame a few years later, I modeled the rear swing-arm after the Proflex design, even building the MCU shock unit using Proflex spare parts which were available back then. It worked, kinda, but the rear swing-arm wasn't cross-braced well enough, so it bent sideways at the first strong pedal-stroke. Project scrapped, lesson learned!

I still want one of those old Proflex bikes, though!

7 Comments:

Blogger Yokota Fritz said...

I guess that lateral stiffness is a real bugger on homegrown suspension frames. But wow -- I'm impressed you fabricated something like that.

3:41 PM  
Blogger Jim G said...

Well, the only thing linking the chainstays on my DIY frame was the original chainstay bridge, which just wasn't up to the task. Also, since the frame I started out with had under-the-chainstays rear-brake mounting (it was a ~1987 Schwinn High Sierra frame), there wasn't much room to add reinforcement, although I did think about it for quite awhile.

4:23 PM  
OpenID bikelovejones said...

Seriously? I see one to three of these every year come though one or more of the used bikes shops here in Portland. NO one wants them. Start checking out the backstocks at Recyclery and Community Cycling Center here in PDX and maybe you'll get lucky...

5:32 PM  
Blogger Jim G said...

Beth, yeah I know. I wanted one back in the day, and if time/money were endless I'd want one now. As I mentioned, the problem with those frames is that the MCUs turn to mush, and sourcing replacements is just too difficult/impossible to make it a practical/realistic project. That, and I really have no use for a full-sus rig at this point! ;)

5:01 PM  
Anonymous Anonymous said...

I rode one back around 97 or so in Indiana on our 2 mile single track loop. It was a bit heavy but very smooth and fast. Handled pretty tight through the trees and rocks without any vagueness. It was a shop floor bike. Potis.

6:42 PM  
Blogger Jim G said...

Example: http://sfbay.craigslist.org/sby/bik/1108448536.html

"Excellent condition" -- yeah, except the MCUs are SHOT!!

8:22 PM  
Anonymous Anonymous said...

Hello. You should come check out the proflex riders group. www.idriders.com/proflex

Also, replacement MCUs and springs for proflex products can be found at: http://www.rapiddescentscotland.co.uk

1:33 AM  

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