Cycling UK Forum

... if you leave off the top sprocket, making it 8 speed. I have 27.5" wheels from a 7-speed Cannondale hybrid and wanted to fit the rear one to my P-38 recumbent which is limited to a 28mm tyre on a 700c rim. I belatedly realised the Cannondate was 7-speed so anticipated problems but thought I'd try it in case some kind of removable spacer had been fitted to the freehub. No spacer there but the 9 spd Tifosi cassette fits well if I leave the top sprocket off. I reused the Cannondale lockring which looks to have a good size flange on it. It tightened nicely without bottoming out.

So I have a converted to 8-spd 13-34 cassette to be operated by a 9 spd shifter.

Extract from Sheldon Brown.
https://www.sheldonbrown.com/k7.html#bodycompat
Any 7-speed Shimano Hyperglide Freehub will actually work with 8 or 9 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 -- or 9 of the sprockets from a 10-speed cassette.
Use the appropriate shifter or down tube friction shifters.

in some cases the 13t sprocket has a recess in it,and the lockring won't tighten the shortened cassette unless a spacer of some kind is used. I have found that you can make a suitable spacer using an old spoke. The trick is to wind the spoke around something about 30mm dia before trimming to the correct length.

I use the Shimano 11-32 9s cassette on a couple of 7-speed hubs with the 11t cog discarded. The 12t cog on those cassettes already has the serrations for the lockring - all you need is a lockring intended for a 12t cog, as the lockring for the 11t cog is too small a diameter to work with the 12t cog.

Here's one of the aforementioned hubs.

you can use the smaller lockring with the spoke spacer.

NickJP wrote: ↑3 Apr 2024, 12:13pm I use the Shimano 11-32 9s cassette on a couple of 7-speed hubs with the 11t cog discarded. The 12t cog on those cassettes already has the serrations for the lockring - all you need is a lockring intended for a 12t cog, as the lockring for the 11t cog is too small a diameter to work with the 12t cog.

Here's one of the aforementioned hubs.
IMG_0109.jpg

The 10s 11-32 cassette is built the same way, it has the 11t and 12t serrated cog.
Now what can you do with a sack of 11t cogs ?

scottg wrote: ↑3 Apr 2024, 7:27pm.....Now what can you do with a sack of 11t cogs ?

give them to MickF

Brucey wrote: ↑3 Apr 2024, 8:47pm

scottg wrote: ↑3 Apr 2024, 7:27pm.....Now what can you do with a sack of 11t cogs ?

give them to MickF

Or me cos that's the one I wear out on my mtb

https://www.ebay.co.uk/itm/255078792375 ... media=COPY

Cowsham wrote: ↑4 Apr 2024, 8:58am

Brucey wrote: ↑3 Apr 2024, 8:47pm

scottg wrote: ↑3 Apr 2024, 7:27pm.....Now what can you do with a sack of 11t cogs ?

give them to MickF

Or me cos that's the one I wear out on my mtb

https://www.ebay.co.uk/itm/255078792375 ... media=COPY

Probably better than sending to Mick F. In a previous post he was railing against 11t sprockets because they wear out so fast (viewtopic.php?p=1793896#p1793896). I see Brucey has an evil sense of humour