So a friend of mine who rides CX gave me a 1/8" chain, it was free so i couldnt say no, he told me that I might not be able to use a chain tool on it becuase of the "Mushroomed" pins that prevent the chain from stretching, its a BMX race chain, so my question....Is my friend right and ill just be wasting my time be trying to take a few links out of it with a tool tomorrow, or is he talking crap?

Once you punch it out, it's done - if it's mushroomed. Unless you like chain failure. Rejoin with a quicklink. You may be able to get away with it on some SS/Fixed specific chains but on derailleur chains = disaster waiting to happen.

You can use your chain tool to break the chain, but I would not try to just push a used pin back in the rejoin it. Such chains usually use a quick link system. I am sure you can get a spare at your LBS.

EDIT: operator beat me to it, but he is right

Dude, it's totally worth the $10-15 dollars spent on the new chain of your choice to have the peace of mind of knowing what you have, the condition it's in, and its fitments.

Remember, the chain is your transmission AND brakes of this vehicle.



You can always say "no." A chain that isn't right for your bike will just make work for you.

i agree with what has been said so far.

https://www.parktool.com/repair/readhowto.asp?id=25
go down to the part where it talks about shimano chains, it has good information and pictures about mushroomed pins.