shimano rear mech question

[e-rider]

Hi,

Will a 10 speed Shimano 105 road rear mech (long cage) work on an 8 speed mountain bike set-up?

cheers

 

[Steve Austin]

yes. but you might want to be careful cross gearing. it might not like the larger sprockets sizes ie 32/34 so you might have trouble with chain length, and the mech looking uncomfortable in the larger gears

 

[PpPete]

Sheldon suggests a road mech will handle up to 30T, but not 32T.

I've not tried 32, but my Ultegra rear mech seems to cope just fine with my 12-30 custom cassette that I assembled from sprockets out of a 11-32 and 11-34, even though the shifting ramps are all out of alignment.