Cassette Change, which one!
Discussion
So my 53/39 12-25 is just too high for many of the Avon hills im starting to cover more and more often.
Im on Ultegra 6700, and am looking at a 11-28 or 12-30 but have no idea if my derailleur and/or chain will fit. They are only a few months old so dont fancy new ones either.....
Can anyone guide me? Internet says a mix of 12-30 will be fine, just try not to Xchain and NO, must buy new stuff to fit!
Cheers
Im on Ultegra 6700, and am looking at a 11-28 or 12-30 but have no idea if my derailleur and/or chain will fit. They are only a few months old so dont fancy new ones either.....
Can anyone guide me? Internet says a mix of 12-30 will be fine, just try not to Xchain and NO, must buy new stuff to fit!
Cheers
My bike has Ultegra from 2006 fitted and on the Autumn Epic in 2010, I fitted a homebuilt hybrid cassette with a mountain bike 32 tooth gear as my lowest. I had to pull the gear cable back with some cable ties but didn't need to lengthen the chain. That's on a 54/39 as well. You should be fine with a 28 (I'm using that at the moment - again on a hybrid homebuilt cassette) or possibly even a 30 without having to 'fiddle'.
t Contador manages it at 60kg E38 said:
No one is going to count the size of my largest cog, and a cassette change is much cheaper and more flexible than changing crankset.
You don't need to change the whole chain set just the inner ring, I've got a 39t and 36t that I can swap in and out with no issues using SRAM Force cranks and Ultegra FD. Edited by Matt_N on Friday 19th July 10:11
Too lean to get out the saddle? WTF surely its easier if you are skinnier
I've got 39-25 (lowest) and ride round BAth/Avon are all the time, I love the ratios, but they aren't suited to everyone , plus some of the hills are short but pretty brutal, it does place a lot of emphasis on your legs over your lungs. A 39-28 would get me up anything though, a 39-25 is fine 99% of the time I can see why people would want to change.
If you want an easier cassette, take what you have to a decent LBS and ask for options and prices thats what I do
I've got 39-25 (lowest) and ride round BAth/Avon are all the time, I love the ratios, but they aren't suited to everyone , plus some of the hills are short but pretty brutal, it does place a lot of emphasis on your legs over your lungs. A 39-28 would get me up anything though, a 39-25 is fine 99% of the time I can see why people would want to change.
If you want an easier cassette, take what you have to a decent LBS and ask for options and prices thats what I do
Unfortunately it's not as simple as a maximum size cog at the rear - it's the difference that matters.
It appears that your rear dérailleur has a 33 tooth capacity - this means that the difference between the biggest and smallest combinations must be 33 or less. Your chain-rings are using up 14 of that 33, leaving a maximum difference of 19 at the rear.
An 11-28 cassette has a difference of 17, so should work just fine. An 11-32 has a difference of 21, so (in theory) won't work but a 13-32 (if it exists) has a difference of 19 so would. Does that make sense?
Personally, I'd go for the 12-30. It should work just fine (18 tooth difference), you don't need the 11t cog outside of racing and it will give you a good bail-out gear if you need it. You can always swap your 12-15 back in at a later date if you want.
It appears that your rear dérailleur has a 33 tooth capacity - this means that the difference between the biggest and smallest combinations must be 33 or less. Your chain-rings are using up 14 of that 33, leaving a maximum difference of 19 at the rear.
An 11-28 cassette has a difference of 17, so should work just fine. An 11-32 has a difference of 21, so (in theory) won't work but a 13-32 (if it exists) has a difference of 19 so would. Does that make sense?
Personally, I'd go for the 12-30. It should work just fine (18 tooth difference), you don't need the 11t cog outside of racing and it will give you a good bail-out gear if you need it. You can always swap your 12-15 back in at a later date if you want.
Two factors play, tooth difference, and the absolute limit on the size (diameter) of cog the RD can take.
You can reduce the effective 'tooth difference' by not being inept / 100% cross chained. The quoted figures protect shimano against the inept, thus are conservative. However, I'm not sure if your RD will take a 30t cog. If it will, go for it.
You'll probably need to wind on some 'B' screw to get it to clear, if it's still a bit tight you can put the B screw in backwards for a little more tension.
You won't be able to put a 34t inner ring on the existing crankset - shimano road stuff is a 110mm BCD for rings <39, and 130mm for anything >=39. Besides a 59/34 combo would shift like cr*p and probably drop the chain.
Frankly I'm becoming convinced that compact is the way to go, despite having run 'standard' rings for a while. I may be able to push 39/25 up the hills, but I'm climbing them faster now I've put the old compact back in, despite being a lot less fit due to injury time. Sitting and spinning / maintaining 85-90RPM works far better for me than doing the contador dance. Different strokes for different folks I guess.
You can reduce the effective 'tooth difference' by not being inept / 100% cross chained. The quoted figures protect shimano against the inept, thus are conservative. However, I'm not sure if your RD will take a 30t cog. If it will, go for it.
You'll probably need to wind on some 'B' screw to get it to clear, if it's still a bit tight you can put the B screw in backwards for a little more tension.
You won't be able to put a 34t inner ring on the existing crankset - shimano road stuff is a 110mm BCD for rings <39, and 130mm for anything >=39. Besides a 59/34 combo would shift like cr*p and probably drop the chain.
Frankly I'm becoming convinced that compact is the way to go, despite having run 'standard' rings for a while. I may be able to push 39/25 up the hills, but I'm climbing them faster now I've put the old compact back in, despite being a lot less fit due to injury time. Sitting and spinning / maintaining 85-90RPM works far better for me than doing the contador dance. Different strokes for different folks I guess.
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