Chain length question swapping wheels with different cassettes

Quick question, getting a second wheelset soonish.

My current beater wheels have an 11-30 and would like to use this for the trainer. I was thinking of getting an 11-34 (assuming the Shimano SS rear can handle it, which by all accounts it can). Would the current chain work for both, or should I size up a new chain for the new cassette and assume it will work fine for the 11-3o ok the occasion I go on the turbo

Easiwst way is to put the chain on your new set up and check that you can go onto both the largest chainring and the largest sprocket at the same time with about 2 links slack. The chain does not need to go through the derailleur when checking this.

Cheers. I was wondering if there was a solution that didn't require breaking my current chain

You can use two quick links to insert the extra links you need for the 11-34T cassette, then remove it to shorten the chain for the 11-30T cassette. Then you'll have the right chain length for each cassette, and it's very easy to change between them.

Didn't think about that. And assume this wouldn't lead to any catastrophic outcomes on the road. Mind you, those links ain't cheap, but cheaper than getting two 11-34 cassettes and a new chain

Make sure you get the reusable ones, and not the one time links.

Can you point me in the right direction. I didn't think there was any difference in them

E.g.:

https://www.bike-components.de/en/KMC/MissingLink-Reusable-Master-Link-p68895/

The 11-speed ones are indeed pricier than I thought.

By the way, you might want to verify if a short/SS cage derailleur will fit an 11-34T cassette, because I don't think it will. By original specification it won't, at least; I think 30T is the max (depending on which series). On top of that, it might not have enough capacity, but I don't know your chainset setup.

Good point. I've seen online that it's worked with the SS cage with B-screw adjustment. I've got a 52/36 chainset. And reason to think it won't work?

I've got a 52/36 chainset. And reason to think it won't work?

Which RD? R7000-SS for example only has a 35T capacity. Meaning with your 52/36 chainset, the biggest cassette this RD cage would be able to handle in terms of chain tensioning is an 11-30T:

(52-36) + (30-11) = 35.

Coupled with the max biggest cog being a 30T, I don't think this will work properly (according to the specs).

Seems like a good place to post my question..

I’ve just picked up my 3rd set of wheels for my bike, a rondo HVRT.

I’ve got a posh set for summer with a 11-28 cassette. But during the winter I’ve been running with an 11-32 on the stock 700c wheels for more chilled rides and to make the Hills more friendly. I’d set this up to run on the same chain length no probs.

However, I’ve now picked up a pair of 650b’s which also fit this bike. I figured I’d might as well get a bigger cassette, so have put on an 11-34. Having x1 chain for these x3 cassette sizes seems a bit of a push.. so I’ve got another chain.

So now I’m wondering do I set up this chain specifically for the 28 that’s only long enough for that (with the other chain set up for the 32 & 34)

Or whether I set up for the 34 only (leaving the current chain working ok for the 28 & 32).

Hope this makes sense..

Or does anyone think I can get away with the x1 chain across the x3 different cassette sizes?

try this: http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html

Thanks @lf

I’d actually found this video pretty handy previously too..

https://youtu.be/Vg2SoOOrpE8

I’m ok with getting right length.. it was more of a question about whether I have one of the chains just set up for the 34 or the 28 only as I can use the other chain to cover x2 cassette sizes still (either 34&32 or 32&28).

If you use the chain length calculator above, it'll show you that you need just one link more for 34t than 28t. So just use one chain, set up for the 34t. It'll be slightly long for the 28t but doubt you will notice it.

(You might theoretically be hitting the max capacity of your rear derailleur to take up the slack (which is the front chainring tooth difference + highest-lowest cassette tooth difference) but unlikely to cause any real problems.

Edit: assuming medium cage Shimano rear derailleur, you should be fine. Front chainring difference is almost always 16t, 34-11 is 23t, total 39t, and that's the stated capacity of e.g. 105 R7000 medium cage. And they tend to allow more than that, I have an 11-36.)