microSHIFT M21 Rear Derailleur - 6,7 Speed, Super Short Cage, Black

I purchased an old Tern Link seven speed folding bike that was a complete wreck. Among other issues the Shimano Tourney derailleur was a blob of rust. After I wasted money derusting it purchasing a new pivot bolt and shims for the pivot bolt etc. I noticed that there was a lot of friction when trying to pedal. Turns out the derailleur had been bent in an accident and was at an angle to the rear wheel inducing drag.

The bike has only a singe chainring on the crank and the rear is 14-28T (28 minus 14 is only 14 tooth chain wrap capacity) so a short cage for quick shifts is ideal. Also since the wheels on the bike are only 20" in diameter it is desirable to have a short cage for as much road clearance as possible. It was a bit difficult finding a short cage derailleur at a decent price but this one is great. It seems like by the time the Revoshift hits a new number it has already shifted into that gear.

I have many bikes and the Link is the one I want to use when I travel as it folds cost the least and looks like a beater so hopefully will be less prone to theft. But now it is the most responsive bike I have. It's really nice not having to wait for it to shift while negotiating traffic like with long cage derailleurs.

The deraileur took around ten minutes to install. The cable feed is towards the bottom rear so it needs more cable sleeve than the Tourney (where the feed was at the top rear). Fortunately I had left a few extra inches of cable sleeve on the bike. Interestingly around six inches of the the cable itself needed to be clipped off upon installation. There is very little naked cable after the sleeve enters the housing. So if you find the cable sleeve to be too short you probably will only need a new sleeve but not a new cable.

All in all I was very happily surprised by the quality of this derailleur and the improvement it made on my bike.;

Good for 7 speed. It is quiet and easy to tune.

Good for 7 speed. It is quiet and easy to tune.;

The derailleur body and internals are made primarily of steel including where the set screws are used to set top-bottom range. This made the setup easy and gives a sense of durability. At this price point everything on a Shimano derailleur is plastic. This Microshift setup shifts fast and smooth and I like the compact short cage design. Initial rides have been really enjoyable. Nice replacement for lower end Shimano derailleur.

The derailleur body and internals are made primarily of steel including where the set screws are used to set top-bottom range. This made the setup easy and gives a sense of durability. At this price point everything on a Shimano derailleur is plastic. This Microshift setup shifts fast and smooth and I like the compact short cage design. Initial rides have been really enjoyable. Nice replacement for lower end Shimano derailleur.;