I recently swapped/ get new cassettes for my wheels and noticed that the cogs seem to wobble a bit now when I look down at the cassette from above while at speed. I checked and they all seem to be tightly on the hub and am worried that this will cause the cassette and chain to wear quickly. Is there something else I should be doing when installing a new cassette or is this normal?

I've found the same thing on my Shimano cassette. When I asked the guys at my LBS, they said that it was normal. The wear on my cassette and chain seems to be fine. Hope that helps.

I had trouble with a wobbly cassette and a loose rear wheel, but I just tightened everything and it all went away. I just tightened up the cassette and the wobble went away.

Do you have a freehub? If so ... that wobble may well cost you some $$$.

Same thing happened on my SRAM cassette, it was busted.

The cassette on my road bike wiggled like a belly dancer whenever the wheel was coasting. The LBS diagnosed the cause as a bent freehub body. They said it was ok to ride, but they're replacing it under warranty. A good LBS is a treasure.

Not good on a number of levels. Remove the wheel and and cassette, inspect and reassemble.
Good Luck.

You may need a spacer behind the cassette if the wobble is because the cassette is loose. It depends on your freehub and cassette.

Az

My bet is you don't have the right spacer. 10 speed cassette on a 9 speed hub needs a spacer ring (IIRC it's 1 mm). Also some Mavic hubs need a spacer.

It's not normal for your cassettes to wobble, and it will over time eat into the splines on the free hub body.

[Edit AZ you're faster.]

Hmm, interesting b/c these are all cassette replacements and I just reused the spacers that I had on there before. I even kept the same type of manufacturers on there that I had on previously.

IMO it's normal. Every cassette I've owned has wobbled to some degree.

Never had a wobbly cassette. I'd check into that. The spacer theory sounds the best from my point of view. Otherwise, yeah, check the freehub .

Freehubs, I've discovered, only last about 25,000 kms ... I've been through 2 in the 4 and a bit years I've owned my bicycle. Somehow I would have thought they'd be more durable than that, but I guess not.

Anyway the real tell-tale sign that it's the freehub is the wobbly cassette combined with a rather annoying, rythmic, but not very loud, "clunk" that has you wondering, "What is that noise?" and checking to see if your taillight has somehow slipped and is nicking a spoke.