Difference between a 7 speed chain and a 10 speed chain I have already upgraded to a 10 speed casette from a 7 speed freewheel. I was wondering if a 10 speed chain is narrower than a 7 speed?
Yes, while the internal width is the same, the external width of 10 speed chains is narrower.   Refer https://www.parktool.com/blog/repair-help/chain-compatibility