I have a 7 speed bicycle (7 speed shimano shifter). I changed my hubs to Alivio FC-M495. Rear derailleur is an Acera RD-M340 and the Crankset is a FC-TX71.
In order to make this combination work, the mechanic that installed the hub put a 7 speed cassette (cs-hg30-7i) with an additional -supplementary- ring (replacing the 8th sprocket).
Since I am experiencing some problems when the chain is on the 3rd sprocket (it makes a bad noise as if the chain were not fitting on the sprocket correctly), I am planning to change the cassette to an 8 speed one so I wont need to use the additional ring.
What would happen if I use an eight speed cassette such as Alivio CS-HG50? I guess the only problem would be I wont be able to reach the biggest sprocket. Is that ok? Is the space among sprockets the same for a 7 and an eight speed cassette?
I hope I was clear enough :-)
Thanks in advance,
Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Hase Kettweisel Tandem (redundent recumbent), Merin Bear Valley (The gopher).
The space between cogs is very close, but not exactly the same for 7-speed and 8-speed cassettes. Many mechanics report they mix and match shifters with 7 or 8-speed cassettes with good results. However I've personally never been able to make such mixed combinations work to my satisfaction.