Hi all. A friend has a Spesh Dolce road bike with a triple and an 8 speed cassette (all unnamed shimano). She would like easier gearing, can I fit the shimano HG51 8 speed mtb 11-30 cassette or is it likely to be too big a stretch for her rear derailleur? (it must have reasonable range to work with a triple already I would have thought?). I assume the freehub will be the same?

Cheers!

you haven’t told us what the rear derailleur is.

most road derailleurs work up to 28T (stated) depending a bit on the design and the frame (hanger geometry) you may well get a couple more teeth on there.

If i were you i’d probably have a crack and at the derailleur 😉

Range is not the issue…a road mech can have a long cage and be good for 45T range.

What counts is the max sprocket it will work with, and this is probably rated as 28 or 30.

New SRAM road will do 32T.

Old Shimano road often did 30T easily, so I would try any (7-10sp) cassette with a 32T and see if it is OK (indexing across the whole cassette is not important to check this out). If so, buy a **-32 8-speed and ride.

PaulD

I’ll have to have a closer look, it just says shimano on it so below Sora in the pecking order…..I guess as 8 speed is relatively obsolete they just make them as OEM for Spesh to get their bikes under a certain budget.

Paul- good idea, I’ll stick a 9 speed -32 cassette from the spares bin on and see if it works, then order up something. Cheers

Update, went and had a gander at the mech, it’s a RD-2300 which a quick google tells me has a max cog size of 26T. Does that mean there’s no way it’ll take higher? (30?)

Cheers

It should be OK with a 28 and I would try the 32T cassette to see if it will track the 28 and 32.

Remember the B-screw will need to be fully screwed-in on the derailleur to give you max clearance of the guide pulley.

PaulD