Can I use the 10 speed casette that comes with the Zwift Hub?


Sorry, a newbie question. I’m interested in buying a Zwift Hub.

I just want to check if I can use my bike with the 10 speed cassette that comes with the Hub without any issues.

Zwift state that:

“If the T number for your cassette doesn’t align with the T number of the pre-installed cassettes on Zwift Hub, you might want to purchase your cassette separately.”

I got a Shimano hyperglide cs 6600 (Ultegra) cassette on my bike.

number of cogs: 10

the number of teeth on the smallest cog on the cassette: 12

The number of teeth on the largest cog on the cassette: 25

Zwift 10 speed cassette is 11-28T and mine is 12-25T.

Will Zwifts work or will I have to buy an identical cassette that I use already for the Hub?


You should be ok.

The only issue is if your chain has been shortened so much that there’s not enough slack to get into the 28.

Unlikely though. If your chain has been installed by anybody competent then chances are it’s within tolerance.

I’ve alternated between a 25 and 28 without issue. You could easily add a couple of links if required.

I believe the RD-6600 has a max cog size of 27 teeth, which means using a 28 tooth cog is probably OK. The Shimano estimates are conservative and people routinely exceed them. What actually happens depends on the shape of the derailleur hanger on the frame. Your existing chain is likely to be too short, but that’s not guaranteed. I would check carefully that the bike can shift into the large chainring and large cog without completely stretching out the derailleur. You may also need to adjust the B limit screw on the derailleur so that the upper pulley is not too close to the 28 tooth cog.

You can actually get away with a 30 on a short cage 10 speed. It’s very tight but doable.