Cycling UK Forum

Is there a way anyone knows of, to fit a 7 speed cassette to an 8 speed spline with the spacer by the lock ring?
Thanks folks.

Why would you fit a spacer at the locknut end? A benefit to fitting the spacer at the spoke end is that if you mess up setting the rear mech stops then the chain can overshoot into the space instead of jamming against the spokes. Agreed of course nobody every sets the limit screw wrongly

I have 7 Campag spaced sprockets on a Shimano 8 spline as described above.

The 11 tooth cog draws the chain too close to the frame ( ok it’s a recumbent) with the 8 speed cassette.
I’d like to occupy that area with a spacer and still have an 11 tooth cog. Just on a 7 speed cassette

jimbaab wrote: ↑14 Jun 2022, 4:05pm The 11 tooth cog draws the chain too close to the frame ( ok it’s a recumbent) with the 8 speed cassette.
I’d like to occupy that area with a spacer and still have an 11 tooth cog. Just on a 7 speed cassette

respace the axle?

You will need an 11t sprocket that can slide in along the freehub body splines for your idea to work, standard sprockets can't do this due to the overhang bit.
I have never seen or heard of one. If one existed, would there be enough metal between the teeth to hold itself together? You might try grinding the overhanging part of an 11t sprocket so you can slide it along the splines, and see what is/would be left. Suggest you try a used sprocket first. If grinding, excess heat might affect the hardness of the teeth.

How much is the clash between the chain and the dropout? You could respace the hub to move it over and use the 8s cassette as normal (but making any wheel dish a bit worse). Spacing out could vary from adding a thin washer on the RH end of the axle, to adding a thicker spacer between the RH cone and lock nut, and reducing the LHS spacing the same amount. If the frame is a bit wider than the lock nuts and or you can spring the frame (only a little bit, excessive not recommended), you might get away with not having to reduce the LHS spacers.

Shimano Capreo cassettes have 10 and 11t 2nd from top sprockets with a smaller sprocket to the right of that, so you could use one and just fit but not use the top sprocket. Downside is you need a Capreo cassette hub (different fitting for the smaller sprockets), and it is in 9 speed: -
https://www.sheldonbrown.com/capreo.html
Capreo stuff is designed for small wheel folders and the like, hence the smaller sprockets to still get a reasonable top gear.

If you want to go none standard these days, it usually takes some effort as everything is designed to be use as designed!

Capreo hubs and the matching 9 speed cassettes getting super rare these days... been a couple of years since Shimano withdrew them. As I know to my cost.

jimbaab wrote: ↑14 Jun 2022, 4:05pm The 11 tooth cog draws the chain too close to the frame ( ok it’s a recumbent) with the 8 speed cassette.
I’d like to occupy that area with a spacer and still have an 11 tooth cog. Just on a 7 speed cassette

If its a 135mm oln wheel could you get 130mm oln wheel and put a 2.5mm spacer on both sides to give the chain more room on the 11t?