tjwarren

I recently purchased a Nashbar 7-speed cassette. It has an extra piece that I'm not sure about. In addition to the 6-cog cassette, the small cog, and the lock ring, there is also a very thin ring of metal with inside notches that match the freehub notches.

It's too thin to be a spacer -- it's only about as thick as a piece of paper, maybe two pieces of paper. What is this? Where should it go? Between the cassette and the small cog? Between the small cog and the lockring? Nowhere at all?

laura*

I don't know if this helps or not:

Shimano "Centerlock" style disc brakes mount using essentially a cassette lockring. The lockrings that came with my brake rotors have a thin piece of metal against the locking surface. When assembled, they went: hub, brake rotor spider, thin metal, lockring.

Perhaps your Nashbar cassette does the same thing. In other words: freehub body, 6-cog cassette, small cog, thin metal ring, lockring.

HillRider

The thin ring goes between the first and second (smallest and next to smallest) cogs. It is used to compensate for manufacturing tolerances and some cassettes come with it and some don't.

Try installing the cassette with it in place and see if the shifting is good across all 7 cogs.

tjwarren

Hmm, differing opinions.

I chatted with Nashbar live support, they say it's a spacer and that it should go on to the freehub body first (spacer | cassette | small cog | lock ring).

I'm still not convinced it's a spacer. It's just way too thin.


I took some pictures. The first one shows the ring and how it's notched on it's inside. The second one shows how thin it is. I don't have calipers, but against a ruler I'd say it's about a half millimeter thick.

HillRider

10-speed Simano cassettes installed on 8/9/10-speed Shimano freehub bodies require a 1 mm thick spacer behind the largest cog. Perhaps that is what the Nashbar guy was describing.

7-speed cassettes don't require it on a 7-speed freehub body and need a 4.5 mm spacer if used on an 8/9/10-speed body.

laura*

OK, that's still much thicker than what came with my brake rotors (about the thickness of a pie pan). So never mind my reply.

Could your ring be the spacer that allows the smallest cog to clear the heads of the rivets joining the 6 cog cluster?

DaJMasta

But this is a freewheel


I would install it where they say to. If then you're having troubles shifting in and out of your top gear, move it to between the cassette and smallest cog. If you're having troubles with the lockring loosening itself, perhaps then it could go on the outside between the smallest cog and the lockring.


And I know that doesn't help much, but with such a small change it may not be a problem wherever you put it.

tjwarren

DaJMasta: what's a freewheel? Mine? I'm talking about a freehub cassette.

laura: it's possible that it's meant to help with the rivets. I'll check it out.


Since nobody's really sure where I'm supposed to put this thing: is there any chance I could damage some part of the cassette by putting it in the wrong place?

HillRider

If you are referring to the OP, it's a cassette, not a freewheel, he's describing. He wrote; " I recently purchased a Nashbar 7-speed cassette..."

I've seen that little toothed thin washer/spacer included with some Shimano cassettes and laura may have it correct that it lets the first position cog clear the stack bolts.