thehammerdog

i have a plan to get new longer rear der. to accomodate my new larger cassett going to 32 teeth from 27.
i plan to use 2 sets of wheels one with 27 & one with 32. one is more gravel tire other cross.
can this idea work/ shift well.
went from a dura ace rear der to new xt coming in mail today 9 speeds.

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JerryZ

With the chain sized to be safe using the 32, you may find while with the 27 the chain going slack if you use the smaller cogs w/small chainring. I'd recommend you just try it and see how it goes.

DaveSSS 

If the RD has the proper wrap capacity, the chain can be just long enough to work with the big/big and 32T sprocket. It would only cause a problem with the 27, if the RD has inadequate wrap capacity. The wrap is the combination of the front chainring difference and the rear sprocket difference.

woodcraft

I do this & it works fine, but shifting big cogs on smaller cassette is not as crisp.

thehammerdog

thanks guys. do u think current chain is too short.
i got caught largest cog and big ring And it locked up..to tight.
i assume new chain is in order.

JerryZ

I would say you do need a bit longer chain; don't wanna mess up your new derail. Prob 2 more links, but you should check it before you break to size.

alcjphil

What you have to look at is not only the largest cog size but also the smallest. If you have, say an 11 32 cassette and a 12 27 cassette on different wheels it is obvious that if your derailleur/chain can work on the smallest cog of the 11 32 it can also work on the smallest cog of the 12 27. The only concerns are the amount of chain wrap the the derailleur can handle and having a chain long enough for the big/big combination for the larger cassette

SethAZ 

I've got a "climbing" cassette with more teeth in the largest couple sprockets, and my normal cruising casette. I just keep an extra chain that's properly sized with the climbing cassette, and a properly sized chain with the cruising cassette. Chains are cheap, and when used with master links are easy to swap out, so why not use a properly sized chain for each of them?

melikebikey35

THIS.

If you were switching between something like a 28 and a 30, then I'd say you'd be fine (assuming the chain was properly sized, to being with). But going from a 27 to a 32 is too big of a jump to work properly.

dsbrantjr

This would be my solution.

woodcraft

I currently have 12/27 on, and can switch wheels to an 11/36 in under a minute. It works properly.

thehammerdog

this sounds like the move. tomorrow i will take on the task.
thanks.