Cassette sizing
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Cassette sizing
I currently have an 11-28 cassette on a compact Shimano r7000 105 (50-34). I'm wanting to move to a cassette with a larger rear cog. What can I upsize to without requiring a new chain?
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You need the rear derailleur with the medium cage to handle a 32 or 34-tooth cassette, fyi. Shimano claims that it maxes out at 34t.
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Yeah, assuming that the chain was properly sized in the first place, you not going to be able to go bigger without a new chain. There is a chance that it wasn't properly sized, though; shift to your big/big and look at your RD - it should be stretched forward with some, but not a lot, of bend at the elbow. If there's a lot of bend, you might have a couple extra chain links to play with.
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How old is your current chain? Unless it is almost new it is never a good idea to install a new cassette without changing the chain as well
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Yeah, assuming that the chain was properly sized in the first place, you not going to be able to go bigger without a new chain. There is a chance that it wasn't properly sized, though; shift to your big/big and look at your RD - it should be stretched forward with some, but not a lot, of bend at the elbow. If there's a lot of bend, you might have a couple extra chain links to play with.
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This is also true.
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He said that assuming it is properly sized, that you wouldn't be able to go larger without a new chain, with an r7000 SS that has a capacity for a 11-30, a chain sized using small+small would work for anything from an 11-25 to an 11-30 without needing the length to be changed. Since the OP is using an 11-28, if the chain was sized using this method then they could go to 11-30 without changing their chain
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The drivetrain is all fairly new. It has ~1500 miles on it. It's all the factory stuff that came on my 2018 Specialized Allez Sprint.
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
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The drivetrain is all fairly new. It has ~1500 miles on it. It's all the factory stuff that came on my 2018 Specialized Allez Sprint.
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
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The drivetrain is all fairly new. It has ~1500 miles on it. It's all the factory stuff that came on my 2018 Specialized Allez Sprint.
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
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Most likely yes on the new chain, not necessarily on the new RD - I haven't tried it, but many people seem to get on just fine when exceeding Shimano's largest cog spec by two teeth (check to see what the official spec is). Alternatively, you might be able to use something like a Wolftooth Road Link as long as the RD can handle the wrap.
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Regarding chain length sometimes you get lucky. I wanted a more robust spare wheelset and run easier gearing on my Dura-Ace Di2 Roubaix and was able to handle an 11-32 cassette without changing the chain even though the bike was supplied with 11-30. I found this online tool helps with approximating chain length.
Javascript Bicycle Chain Length Calculator
Javascript Bicycle Chain Length Calculator
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It cost me $400 to upgrade from a short cage 11-28 drivetrain to an Ultegra 8000 long cage RD, 11-34 cassette and chain installed by my LBS.
IMHO, worth the extra $ to have a finely tuned drivetrain.
IMHO, worth the extra $ to have a finely tuned drivetrain.
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Thanks for all the help, guys. My next question: is it even worth it to try such an incremental change, or should try a 32 or 34 first? I feel like I'm exerting too much energy powering up any grade >6%. I see guys on 34-36 having an easier time at it. I want to change my cassette not because I want to keep up with the Jones', but because my legs feel exhausted by the time I plateau.
Last edited by Princess_Allez; 08-19-19 at 12:27 PM.
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You answered your own question.
I have been able to complete several long ascent bucket list rides because of the 11-34 cassette offering 27, 30 and 34 cogs with my 34 chain ring. Sometimes you need the climbing cogs to 'rest' the legs. I was really fatigued always grinding in the 25, 28 cogs.
I have been able to complete several long ascent bucket list rides because of the 11-34 cassette offering 27, 30 and 34 cogs with my 34 chain ring. Sometimes you need the climbing cogs to 'rest' the legs. I was really fatigued always grinding in the 25, 28 cogs.
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You answered your own question.
I have been able to complete several long ascent bucket list rides because of the 11-34 cassette offering 27, 30 and 34 cogs with my 34 chain ring. Sometimes you need the climbing cogs to 'rest' the legs. I was really fatigued always grinding in the 25, 28 cogs.
I have been able to complete several long ascent bucket list rides because of the 11-34 cassette offering 27, 30 and 34 cogs with my 34 chain ring. Sometimes you need the climbing cogs to 'rest' the legs. I was really fatigued always grinding in the 25, 28 cogs.
It's called a "long cage" mech, right?
Last edited by Princess_Allez; 08-19-19 at 01:47 PM.
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The drivetrain is all fairly new. It has ~1500 miles on it. It's all the factory stuff that came on my 2018 Specialized Allez Sprint.
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
So the takeaway here is that I can go 11-30 without changing chain or rear mech, but if I want to go 32 or 34, then it would require a new chain and mech?
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He said that assuming it is properly sized, that you wouldn't be able to go larger without a new chain, with an r7000 SS that has a capacity for a 11-30, a chain sized using small+small would work for anything from an 11-25 to an 11-30 without needing the length to be changed. Since the OP is using an 11-28, if the chain was sized using this method then they could go to 11-30 without changing their chain
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Maybe, but not likely. The most common sizing method for road, and what Shimano recommends, is big/big + 2; this would leave your chain too short for the additional teeth.
Most likely yes on the new chain, not necessarily on the new RD - I haven't tried it, but many people seem to get on just fine when exceeding Shimano's largest cog spec by two teeth (check to see what the official spec is). Alternatively, you might be able to use something like a Wolftooth Road Link as long as the RD can handle the wrap.
Most likely yes on the new chain, not necessarily on the new RD - I haven't tried it, but many people seem to get on just fine when exceeding Shimano's largest cog spec by two teeth (check to see what the official spec is). Alternatively, you might be able to use something like a Wolftooth Road Link as long as the RD can handle the wrap.
#24
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I ride a 2018 Trek Domane AL3. It came with a 11-28 rear cassette, with Shimano Sora 9 speed group set. I installed a 11-32, 9 speed cassette on the rear, and have been riding for a year now without a new chain. Seems to work fine for me. And I do occasionally go big/big. Never had an issue.
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I ride a 2018 Trek Domane AL3. It came with a 11-28 rear cassette, with Shimano Sora 9 speed group set. I installed a 11-32, 9 speed cassette on the rear, and have been riding for a year now without a new chain. Seems to work fine for me. And I do occasionally go big/big. Never had an issue.