SHIMANO Nexus 16 tooth cog, black

This is the smallest (fastest) cog for the Alfine/Nexus hubs. 16T is 13% faster than the 18T that came on my 2011 Dahon Cadenza XL which uses a 32T chainring. This is the difference between keeping up with traffic and getting passed by angry drivers. Take it to a shop where the mechanic knows about hub gears. This will REQUIRE tensioning your chain after installation. I will buy another one when it wears out. Then another one after that. The price is right. My mech wanted "a beer's worth" to install it. I gave him $15 but I could have easily given him $5 and made him happy. Takes 5 minutes to install the cog, but the chain tensioning on my bike is very complicated and that's what you'll end up spending the labor on.

Works great with a 42T Alfine crankset. I originally had a 20T cog and this gearing was too low for me. I wanted the direct drive gear to be something I actually used. This cog did the trick. I think this cog is the smallest you can fit on a nexus / Alfine without rubbing.

Bought this for my Shimano Alfine 8 hub because I wanted to go up in gear ratio but didn't have much space on my frame for a bigger chain ring. This fit with just the right amount of clearance for the chain and the shifting mechanism. Though the cir-clip was a bastard to get off and on, otherwise it was a simple operation to install. Took out a couple of links from my chain and it was good to go. Now I'm keeping up with traffic and slamming it down hill's.

Good cog. Doesn't fit very snug. Feels cheap. The metal is a lot darker than it is in the picture.

It's a bit tricky to install--check YouTube for instructions. Anytime someone says circlip, you're probably going to be a bit frustrated. It works though and a perfect fit.