8 Speed Shifters With 7 Speed Cassette?

[Markone]

I'm thinking of running a 7 speed uniglide cassette with 8 speed RX100 shifters.

Will this combo index ok?I'm assuming the rear mech travel stop will not allow the shifter to click to its final position,therefore operating as a 7 speed shifter?

 

[CBguy]

I use indexed Shimano Ultegra 8 speed bar end shifters and Shimano 8 speed brifters each with Uniglide 7 speed freewheels. Work perfect. I have no experience with shifters you mention but I would assume would work fine.

 

[Markone]

Thanks,good to know!

 

[Markone]

By the way,which rear mechs' are you using may I ask.

 

[CBguy]

I apologize I was mistaken and do not have 7 speed Uniglide freewheels with shifters I describe above.

Rather the shifters I described above are used in conjunction with a 7 speed 11-34T Shimano Megarange freewheel with Hyperglide cogs in case of Shimano 8 speed brifters (RD is lower end Tiagra GS) and 7 speed 13-32T IRD freewheel in case of Shimano Ultegra 8 speed bar end shifters (RD is 1990 m735 Deore XT).

I have a 6 speed (13-30T) Uniglide freewheel on another bike that I have only used with Suntour Barcon friction shifters and Campagnolo Nuovo Record RD.

I do have another 6 speed (13-28T) Uniglide freewheel used with 6 speed Shimano indexed downtube shifters on a late 80's Peugot. Works well. I don't have bike available to check and so cannot comment on RD. It is Shimano.

Sorry to mislead as I cannot answer your question from my own experience, at least re 7 speed Uniglide rear cassette (or freewheel) and 8 speed indexing shifters. However I see no reason it shouldn't work with scenario you describe and a Shimano RD from indexing era other than perhaps DuraAce. From what I understand 7 and 8 speed cassettes have identical spacing.

Doug

 

[Markone]

Thanks Doug and no problem,of course I'm sure the setup will work just fine.

Mark.

 

[hamster]

7 speed pitch is 5.0mm for everyone.

8 speed Campag is also 5.0, but Shimano is 4.8mm.

Usually you can get 8 speed shifting to work OK with a 7 speed cassette, but is usually better to set it up on the middle of the cassette not using the top gears. The jockey float in the mech takes up the errors.
But it will be more tetchy and susceptible to dirty cables.

 

[Markone]

7 speed pitch is 5.0mm for everyone.

8 speed Campag is also 5.0, but Shimano is 4.8mm.

Usually you can get 8 speed shifting to work OK with a 7 speed cassette, but is usually better to set it up on the middle of the cassette not using the top gears. The jockey float in the mech takes up the errors.
But it will be more tetchy and susceptible to dirty cables.

Thanks hamster,maybe I'll just run it as full 8 speed then.