different campagnolo lock rings?

[redearedslider5]

I have a set of older Eurus wheels I went to use this weekend and found that the lock ring I have doesn't fit. It's the 10 speed freehub shape, same as the one I'm transferring the cassette off of. It looks like the diameter of the threaded portion is slightly smaller than the lock ring. Did they make different size lock rings? I have three and they're all the same diameter and thread pitch.

I also have another wheel with a 9 speed cassette lock ring doesn't want to come off, perhaps there was a subtle difference with the 9 speed lock ring and I accidentally forced a 10 speed one on that wheel?

[tuscanyswe]

Campy had a 26mm lockring at one point. One version of 9speed i think?
They currently use 27mm lockrings and these are by far the more common ones.

[redearedslider5]

did a bit of searching and it sounds like I need a 26mm lock ring rather than the 27mm rings I have. I love this place!

[redearedslider5]

Campy had a 26mm lockring at one point. One version of 9speed i think?
They currently use 27mm lockrings and these are by far the more common ones.

beat me to it!

[oliver1850]

I also have another wheel with a 9 speed cassette lock ring doesn't want to come off, perhaps there was a subtle difference with the 9 speed lock ring and I accidentally forced a 10 speed one on that wheel?

I don't think it would be possible to get the 27 mm lock ring even started on a 26 mm hub. Guessing your LR is just extra tight.

I believe all the 26 mm lock rings (at least for 12-13 small cogs) are labeled "9 speed", but I've seen some 27 mm ones with the same designation. The part numbers to look for are CS-201 (for 12-13 small cogs) and CS-301 (for 11). Add a "T" to those numbers for the titanium lock rings. Pictured ring is a CS-201. Note that some ebay sellers are listing lock rings as 26.8 mm and that those are "27 mm" rings.

2nd pick shows another CS-201 alongside the first. Note the small differences in the labeling, spacing of characters, length of arrow. Guessing they came from different production runs of the same part. The third pic is a 27 mm labeled "9 speed". It looks nearly identical to the 26 mm one on the left in the pic above, short arrow, space between 50 and Nm. It has machine marks on the printed face and appears a bit shinier than the 26 mm ring.