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Shimano 600 Compatibility Question...(3 posts)

Shimano 600 Compatibility Question...jkantor1312
Apr 5, 2003 9:08 PM
If a Shimano 600 wheelset is set up for 7 speed...will an 8 speed cog work?

thanks
jay
you can turn it into an 8spd using some 9spd stuffridingthegyro
Apr 6, 2003 3:27 AM
According to Sheldon Brown:

Any 7-speed Shimano Hyperglide Freehub will actually work with 8 sprockets, without any modification! What you need to do is to use 8 of the sprockets from a 9-speed cassette, with the 9-speed spacers.

To make this work, you'll also need to use a 9-speed chain and shifters. Your old 7-speed derailer should work OK if it isn't too badly worn. The limit stops on the derailer will cause the useless 9th position on the shifters to be locked out, so this will work as a perfectly normal 8-speed rig.
Not as such.Spoke Wrench
Apr 6, 2003 7:07 AM
7-speed and 8-speed cog spacing is almost, but not exactly, the same. Consequently, an 8-speed cassette is one cog too wide to fit onto a 7-speed freehub body. Also, if you mix and match 7 and 8-speed parts, the shift indexing isn't perfect.

8-speed and 9-speed cassettes are the same width. As a result, you can remove one cog from a 9-speed cassette and get it to fit onto a 7-speed freehub body. There are a couple of catches.

First, to get it to index, you have to use a 9-speed shifter. That's a biggie because the shifter is usually the most expensive part.

Second, all of the cogs on a cassette aren't the same. The first position (smallest cog) is different from the others. That means that you either have to remove the largest cog or you'll have a cassette with a goofy progression. On higher end cassettes, the three largest cogs are attached to a carrier so removing the largest would be more of a job than I want to do. Lower end cassettes can be taken apart much more easily.