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Old 05-12-20 | 04:05 PM
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Prowler
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Joined: Nov 2013
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From: Near Pottstown, PA: 30 miles NW of Philadelphia

Bikes: 2 Trek Mtn, Cannondale R600 road, 6 vintage road bikes

Suntour Alpha 2000 RD - for posterity

I've had good experience with Suntour transmissions so keep my eyes open for RDs, FDs, FWs and shifters. Recently I noticed a Suntour Alpha 2000 (accushift) RD in the scrap pile at the LBS. It was 'binned' as the jockey wheels were frozen from decades of crud, no service and dried lube. Not worth the expense to overhaul so it was replaced. I brought it home. As was said in Alice's Restaurant - if you know someone in a similar situation or if YOU are in a similar situation - I'll post what I've learned. 15 years from now someone will find it and benefit.

Accushift was developed in the "autumn of their lives". There was an Alpha series of RDs and the 2000 was the lowest price unit. It has steel front and back plates on the parallelogram, alloy rear knuckle and a plastic front knuckle/torsion spring housing. The cage plates are steel too so its a heavy RD. What was most disappointing was that it is mostly unservicable. The tension wheel will come out, the guide wheel will not. In the second photo the green arrow points to the inside end of the shaft that captures the torsion spring, the outer cage plate and the guide wheel and enters the inner cage plate. There it is peened over, no threaded shaft or nut. I had to grind off the end to disassemble. Destructive approach. The blue arrow in the second photo shows the results of grinding the peened shaft end, plate is ground too to get it free.

If you want to get to that torsion spring and shaft you pry the plastic cap off the housing. Very tight fit - it should slide out to the side. I did not know and popped it out the top, damaging the cap a bit. It would go back in but might then fall out again. See the red arrow in the first photo.

Also in the second photo the purple arrow shows the pin that holds the torsion spring housing in the wound up position. Again, peened in place, cannot be removed without grinding and destroying. Cheap and functional but no service allowed.







BTW, in several minutes of searching I found no parts diagrams (no surprise) and no articles on overhaul. I may be the first (an influencer, eh? Yeah!). The second photo shows the salvage level. Parts common to other Suntour RDs are saved. Ex: I've found that the adjusting screws on Suntour RDs are not the same size and thread as Shimano so its handy to have spares. Always nice to have spare Suntour jockey wheels, especially practically new ones. The rest goes to the recycler to be made into paving and golf clubs. At least some of it may have a second life.
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