Originally Posted by
Timmi
Chains from 7spd and 8 speed are the same. same spacing, same cogs. the rear cluster is just wider, and the wheel not as good structurally as a result. 8speed is popular out of china no-name factories and is junk that should be avoided.
This structural weakness goes for all the 8, 9, 10 and even more so for 11 speed.
However, using a MTB (wider) 135 mm wide hub with an 8-9-10 speed system provides very good structural strength. 7 speed is better though.
What 6 and 7 speed systems lack is the bearing strength, at least the freewheel ones. 8 speed is easily found in cassette/freehub combination (hard to find as a freehub), while 7 speed is hard to source as a cassette.
