MrEss

I bought this Cyclone Mk. II short cage rear derailleur from the LBS with a "it's so worn out you couldn't actually use it" discount. The pulleys were completely knackered but everything else loosened up and worked fine after a full teardown, cleaning, and lubrication.

While it was apart, I filed out the worst of the road rash (you can still see how much was beyond my help) and decided to give it a quick polishing. Since I only had 220 grit paper, 00 steel wool, and white compound in the house, those were the steps I used. There's still a ton of the 220 grit scratch marks but I think it looks pretty good anyway -- they blend in with the remaining gouges.

Some blue CNC sealed-bearing pulleys from eBay finished out the overhaul. It was easy to drill out the included spacers to 1/4" so the SunTour pulley bolts could pass through.

So, here's my take on saving one example of the nicest Japanese friction derailleur ever made:

illwafer

i'm glad you got it working again, but your polish job could use a little work. why not go all the way and get it super spiffy? WWDDD?

jimmuller 

I had the "pleasure" recently of replacing the cage spring on a Cyclone Mk2. It wasn't easy but was possible. It did not strike me as an especially good engineering design for longevity. In this case the spring seems to have snapped due to rust. The design seemed a perfect trap for water. But if it works, then great. I'll find out in a few month when I finish a build which will use it.

Nice polishing job.