Bicycle Mechanics - 7-speed shifter, 8-speed cassette

Hello,

I have a pair of new, old-stock Shimano above-the-bar 7-speed shifters that I just love. Will the shifters, when set to "friction only" mode, work with an 8-speed Shimano cassette? I know they won't work in SIS mode, but SIS never really worked right anyway.

Thanks!

Dustin

yep they should work fine as friction shifters

Yes, they will work just fine. In fact, they'll work about 95% of the time setup in Index Mode. I'll write up a more full explaination of that when I get home shortly...

... if I don't... PM me... I can get scatter brained at night. :)

Friction mode is the way to go.

the spacing between the sprockets of a 7 and 8 speed cassette system is the same, so you can use the 7 speed shifter, but you'll (of course) only be able to use 7 of the gears in index mode.

- Joel

Ok, here's what I've got going right now on my Gazelle: 8sp rear Shimano Cassette w/ 7sp Shimano 600 shifters, running indexed. I'll get a perodic rough or ghost shift, but most of the time as long as I keep the system trimmed well it works good:

Start with the gear in the Big Ring, Little cog in back. Take up the slack in the cable till the derailleur starts moving inward. Since the 7sp & 8sp spacing is very close if not the same, all the way up to the second to top cog you should be able to dial in smooth shifts. Now for the top gear, after the last index, you should have more 'friction' range that you can use to shift the cassette into that top cog. The important thing here is to make sure that the derailleur limit screws are set properly to make sure you can't over shift into the spokes! :eek:

In the end, with a little playing with it, you can get a 7sp indexed + 8 up to the cable stop.

Not the perfect solution, but as close as you can get without a perfect match in my experience.

Ok, here's what I've got going right now on my Gazelle: 8sp rear Shimano Cassette w/ 7sp Shimano 600 shifters, running indexed. I'll get a perodic rough or ghost shift, but most of the time as long as I keep the system trimmed well it works good:

Start with the gear in the Big Ring, Little cog in back. Take up the slack in the cable till the derailleur starts moving inward. Since the 7sp & 8sp spacing is very close if not the same, all the way up to the second to top cog you should be able to dial in smooth shifts. Now for the top gear, after the last index, you should have more 'friction' range that you can use to shift the cassette into that top cog. The important thing here is to make sure that the derailleur limit screws are set properly to make sure you can't over shift into the spokes! :eek:

In the end, with a little playing with it, you can get a 7sp indexed + 8 up to the cable stop.

Not the perfect solution, but as close as you can get without a perfect match in my experience.


I did the same thing on a Raeigh Technium that had six speed Accushift shifters and I put a wheel with a seven speed Shimano cassette. It shifted as crisply as the Ultegra rear on my Trek. Just push past the index for the next to the largest cog and it would go into the large cog perfectly. The uppshifts to 12 were crisp and smooth. Should work exactly the same on the seven / eight combo. Pretty sure the cog spacing is close enough.