I recently bought a spare wheelset for my cyclocross bike that I intend to use on the road. The bike currently has a SRAM 1x setup with 11-36 gearing. I would love to use a cassette with a 10-tooth ring on the spare wheelset to account for the higher speeds on the road as opposed to cross.
My question is: if I choose different gearing for the spare wheelset, would I need to adjust the derailleur each time I swap wheels? Both cassettes would be 11 speed, just different gearing. Are there any other issues I may run into, such as chain length?
I wouldnât think you need to adjust the derailleur, at least I donât when changing wheels, though they have the same type of cassettes.
Chain length - sram recommend setting this by the largest sprocket (assuming you donât change chainrings). You should be ok keeping it the same (after all, your current chain works fine on the smaller sprockets right now) though check that there is still tension on the chain when its on the 10t sprocket
I have a 10-42 cassette on my wheels, but an 11-42 on the trainer as Wahoo didnât have the XD driver for the trainer when I got it. No issues swapping between, donât have to adjust the derailleur when swapping.
I keep the same chain swapping between 42 and 46 tooth chain rings and it works fine as well (not recommended but it works).
IME the derailers (and chain length) are set using the largest portion of the cassette.
I run Eagle gear on my MTB and thereâs no issue changing between the NX 11 tooth version vs the 10 tooth XD spindle cassettes. A little different to your setup but the fundamentals should be the same.
The âroadâ cassette will probably have a smaller low gear as well, which would in theoary dictate a shorter chain - but apart from the one-tooth high gear difference, you"ll be working in the same range as with your current cassette. It is possible that you will need to adjust your rear derailleur when switching wheels, as derailleur setting is a function of cassette alignment vs wheel axle face. As long as the distance from the axle face to the first gear is equal, youâll be fine. If not, you may have to give the barrel adjuster a touch.
Based on responses here, it sounds like youâre ok if you have the same biggest gear in each cassette? What if youâre doing some kind of N=1 gravel/road bike setup with, say, a 11-28 for the road wheelset and a 11-40 for the gravel wheelset? Would that require swapping chains and adjusting the B screw on the derailleur every time you swap wheels?
The chain is long enough to go over the biggest sprocket
There isnât more slack in the chain than the derailleur can take up (when on the smallest sprocket)
In each extreme case, you want the derailleur to allow for some extra movement of the chain for shifting and âchainslapâ
In the example above, if you size your chain to accomondate the 11-40, it will also accomondate the smaller range of 11-28. Essentially you are only using a part of the range of the 11-40 cassette. If you were only running a 11-28, you could likely shorten the chain a bit, but it should work even with a longer chain (youâll just make the derailleur work more to keep the tension).
Assuming the bike is set for the gravel wheelset, not really. Thereâs a 28T cog somewhere in that 11-40, and those two 11T cogs are the same, so the âroadâ cassette is within the operating range of the gravel one. Now if you went and set chain length based on 28T largest cog and tried to swap in a 40-11, that would be another story.