Cassette question

[2LeftCleats]

I was replacing my Ultegra 10 sp. 12-25 cassette with an Ultegra 11-23 that I hadn't previously used on that hub. Using the same spacer on both. With the lock ring in place, there's no play with the 12-25. There's enough wiggle with the 11-23 that it rattles and shifting isn't precise. The smallest 3 cogs on the 11-23 and the smallest 2 on the 12-25 are the thicker type. The smallest cogs on both are designed to sit on the end of the freehub, so it can only be tightened to a certain limit. There's maybe a millimeter of play. I could possibly add a second spacer, but not sure there's enough room to fit that and still tighten the lockring. But I'm thinking I shouldn't have to add anything as I would expect these to be exactly interchangeable. Don't recall a previous problem with this cassette on a different hub. Any thoughts?

Thanks.

[skijoring]

What type of hub? Some are designed for a 12 tooth final cog.

[Ralph]

I was replacing my Ultegra 10 sp. 12-25 cassette with an Ultegra 11-23 that I hadn't previously used on that hub. Using the same spacer on both. With the lock ring in place, there's no play with the 12-25. There's enough wiggle with the 11-23 that it rattles and shifting isn't precise. The smallest 3 cogs on the 11-23 and the smallest 2 on the 12-25 are the thicker type. The smallest cogs on both are designed to sit on the end of the freehub, so it can only be tightened to a certain limit. There's maybe a millimeter of play. I could possibly add a second spacer, but not sure there's enough room to fit that and still tighten the lockring. But I'm thinking I shouldn't have to add anything as I would expect these to be exactly interchangeable. Don't recall a previous problem with this cassette on a different hub. Any thoughts?

Thanks.

Are you sure the final small cog is seated properly? I'm a Campy rider, but fixed this same problem on a friends Shimano bike by redoing his cassette. When he put on the lock nut, he allowed the final cog to slip out of place. So when he tightened down the lock nut, the cogs had play in them.

[Black Dog]

I know that campy has different lock rings for 11 vs 12/13 tooth cogs. Does shimano? If so then thus could be part of the issue.

[Ti Designs]

10-speed is slightly narrower than 9-speed, so there's a small steel spacer that came with the cassette - that needs to be in there before the first set of cogs goes on.

[2LeftCleats]

As noted, same spacer on both.
Alchemy hub.
The 11 tooth cog seems to be well-seated.

[pinkshogun]

shimano uses a smaller lockring for their 11t first cog. the bigger lockring will rub on the chain in the first position

[oldpotatoe]

As noted, same spacer on both.
Alchemy hub.
The 11 tooth cog seems to be well-seated.

Add a second 1mm spacer...and adjust your rear der.