Odd clicking coming from cassette, need advice

[CallumRD1]

I just built up a pair of new wheels and put on a new Ultegra 11-32 cassette that I've had sitting around for about a year. I went out for a ride this morning and found that the cassette clicks once per wheel revolution, but only in the 7th cog (16 teeth). There is a faint ticking when in 6th and 8th gear, but I only heard those on the work stand, not on the road. The clicking in 7th gear is far louder than in 6th or 8th. I verified that the ticking doesn't occur when coasting and occurs exactly once per wheel (or cassette) revolution when the cranks are turning, both in the large and small chainrings. There doesn't need to be much power going through the pedals. As long as the freehub is engaged I'll here the clicking. I switched over to my old wheelset with an 11-28 cassette with ~3000 miles on it and it's as quiet as it has always been.

Does anyone have any ideas about what could be causing this and potential remedies for it?

(My bike is a 2015 Felt F3x with a full Ultegra drivetrain and a GS rear mech)

[2old4this]

Had something similar with a DA cassette. Per the advice I read here, I greased between the cogs and the freehub body and tightedened lockring to the spec. That fixed the issue...

[CallumRD1]

I tried removing, regreasing, and reinstalling the cassette to no avail. It still clicks. I don't have a torque wrench that goes up to 40nm, but I was using an 18" breaker bar attached to my cassette lock ring tool, so I'm pretty sure that I got it tight enough!

[spud]

had a similar issue with an old 10 sp dura ace. Had ticking in the 7th and 8th cogs that wouldn't go away, even with lubing the free hub shell and retightening the lockring. Got so sick of it I just replaced the cassette, problem solved.

[sp3000]

have you checked your hanger alignment? If it's out the indexing might just be off and is pronounced on the new cassette..

[CallumRD1]

It looks fine visually but I don't have a proper tool to check the alignment. The shifting is nice and crisp through the whole range of both cassettes and I'm only getting the ticking in 1 cog, so I'm fairly confident that it isn't the indexing. Additionally, it ticks exactly once per wheel/cassette revolution which isn't consistent with an indexing problem.

[kookie]

Problem with one/more of the "tooth" on the problematic cog? (damaged/mis-aligned)

Since your old wheelset is fine, switch cassettes to rule out the wheels/skewers.

[topflightpro]

I once received a new cassette where one tooth was slightly twisted. It caused a click as the chain wouldn't slide on, rather it would hang a bit then fall on.

[jobvisser]

is your rear derailleur straight ?

[CallumRD1]

It does appear to be straight and well aligned. I'll take the problem cog off tonight and see if one of the teeth is a little bent or something.