How much longer does my chain need to be?
#1
Senior Member
Thread Starter
How much longer does my chain need to be?
Changing from 12-27 cassette to 12-30 and Dura-Ace RD circa 2008 to Ultegra long cage 2018. How much longer does my chain need to be?
#2
Senior Member
It needs to be the correct length. It's not worth trying to figure out how many links that is, it's just easier to put a chain on and size it correctly. Don't overthink simple tasks.
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#3
Really Old Senior Member
How much too long is your current chain?
https://sram.zendesk.com/hc/en-us/ar...g-a-new-chain-
https://sram.zendesk.com/hc/en-us/ar...g-a-new-chain-
#4
Senior Member
If your small/small combo stays the same, and the length was correct to begin with, the usual method will only tell you that you have the longest chain possible. If that length doesn't work on your big/big combo you are SOL. I went from a 13/26 to a 13/29 just this past week and didn't change the length as the small/small measurement was already correct based on maximum wrap. It happened that it still worked.
#5
Senior Member
Which version of Ultegra rear derailleur? The Ultegra 11 speed rear derailleurs will not work with 2008 10 speed shifters
#6
Senior Member
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Bikes: 1986 Cannondale SR400 (Flat bar commuter), 1988 Cannondale Criterium XTR, 1992 Serotta T-Max, 1995 Trek 970
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If your small/small combo stays the same, and the length was correct to begin with, the usual method will only tell you that you have the longest chain possible. If that length doesn't work on your big/big combo you are SOL. I went from a 13/26 to a 13/29 just this past week and didn't change the length as the small/small measurement was already correct based on maximum wrap. It happened that it still worked.
Since it is a new cassette, the chain should be replaced. Just add a couple of links and see how it works. Chances are the old length might work.
Once on the bike you can see the derailleur swing with a shorter chain, by folding it.
John
#7
Senior Member
Anyway it all worked out and I'm happy with my new chainring/cassette combo and chain. It is all very quiet. I need to find a hill steep enough to try the 34/29 combo where I'm not just spinning furiously. Maybe I'll retry Haleakala someday, and also get out west again.
#8
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If you try Haleakala, make sure the brakes are good... lol!
I’d want discs.
John
I’d want discs.
John
#9
Senior Member
I think I had a 34-27 as the lowest gear going up, and I'd had a cold all week. Training for a ride like that is difficult when you live in flat Brooklyn. No amount of riding here will prepare you for the nonstop climbing that Haleakala is. I'd go to the hills in Northern NJ/Rockland County but they don't compare. Here's a thread from immediately after I did it:
All the reasons and excuses I didn't make it up the volcano
Last edited by zacster; 09-22-20 at 08:23 AM.
#10
Senior Member
To tell the truth, I didn't think the small/small measurement made much sense either, but I have Campy. It is part of the secret Campy initiation ceremony.
Anyway it all worked out and I'm happy with my new chainring/cassette combo and chain. It is all very quiet. I need to find a hill steep enough to try the 34/29 combo where I'm not just spinning furiously. Maybe I'll retry Haleakala someday, and also get out west again.
Anyway it all worked out and I'm happy with my new chainring/cassette combo and chain. It is all very quiet. I need to find a hill steep enough to try the 34/29 combo where I'm not just spinning furiously. Maybe I'll retry Haleakala someday, and also get out west again.
#11
Senior Member
If your drivetrain is within the spec (total capacity AND large cog) using small/small gets you the longest (safest) chain w/o having slack in small/small. If you swap wheels and/or cassettes out for different types of rides this definitely comes in handy. If you don it guarantees the smoothest possible running drivetrain when you go big/big.
#12
Senior Member
Thread Starter
Update: So the Ultegra 11-speed chain with 116 links and quick link connector was the perfect length out of the box. I had temporarily lengthened my old chain for the new cassette to get a couple of short rides in while waiting to receive the new chain. This allowed me to match lengths. Assuming 12-30t cassette, 53-39 rings and a long cage RD are a popular combination, makes sense that chain length would be right out of the box. First experience with direct link connector and after some frustration, a trip to local bike shop was very helpful for getting it to snap in place. Thanks Roswell Bikes.
#13
Senior Member
Thread Starter
So the next upgrade will be 11 speed shifters.
#14
Senior Member
Technically there is no such thing as an 11 spd 'long' cage road derailleur. There are short (ss) and medium (gs).
#15
Senior Member
If there is one area that Shimano has over Campy it is in long cage derailleurs since their MTB components all fit into that category. I put an XT 10sp Dynasys rear derailleur on my commuter bike and I have an 11-34 cassette and triple up front and it shifts every bit as well as my Chorus and with a light touch too all the way up and down. It makes its way into their road groups.