Just realized my Park Tool CT-5 chain tool was binding up because I picked the wrong pin size

I had a Shimano 12-speed chain to break yesterday, and the choice was between using the 5.5mm pin hole or the 6mm one on the tool. I went with the 5.5mm because it looked closer, but it started to stick halfway through pushing the pin. I backed it out, switched to the 6mm hole, and it went smooth as butter. Has anyone else run into this with newer 12-speed stuff? I'm wondering if the pin diameters are shifting a bit.

3 comments

3 Comments

beth_reed22d ago

Honestly, is that even a real problem? Sounds like you just picked the wrong hole and fixed it. Took what, an extra thirty seconds? My old chain tool only has one size and I've made it work on everything from 9 to 11 speed. People get too hung up on having the exact perfect tool for every single new standard.

the_emery22d ago

Read a bike mechanic's blog that said the wrong pin size can actually weaken the link over time.

kaih3622d ago

What gets me is the tool makers not updating their guides fast enough. My CT-5's little chart still lists 12-speed as 5.5mm. So you follow the tool's own instructions and it binds up. That's a design problem, not a user error. They should at least put a sticker over the old chart or something. Makes you double-check everything, even the manufacturer's info.