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 Enduro Sport, Hase Kettweisel Tandem, Merin Bear Valley beater bike
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.