Chain Length when changing cassette

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frede
Posts: 6
Joined: Fri Jan 27, 2017 12:46 am

by frede

Hi there,

Running a Dura Ace setup with 52/36T and 11-28T cassette.

I'm looking at the new 11-30T which is compatible with my setup . Wondering if I need to lengthen my chain to support the extra teeth?

Thanks, Fred

by Weenie


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spud
Posts: 1261
Joined: Sat Feb 07, 2009 5:52 am

by spud

unless your current chain/cassette is at the limit, no, you won't need to change the length.

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stockae92
Posts: 295
Joined: Fri Sep 25, 2015 5:13 pm

by stockae92

Would swapping wheels with 28T and 30T (or even 32T) cassette affect the chain length?

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dj97223
Posts: 822
Joined: Sun Nov 06, 2005 7:27 pm

by dj97223

No, the chain will still be the same length. :lol:
“If you save your breath I feel a man like you can manage it. And if you don't manage it, you'll die. Only slowly, very slowly, old friend.”

ooo
Posts: 1590
Joined: Sat May 21, 2016 12:59 pm

by ooo

for chainstay=410,420,430 it's the same recommended chainlength, for chainstay=425 chainstretch=0.14 of link for 30T over 28T - it's ok,
for chainstay=415 chainstretch=0.36 for 30T over 28T chainlength, it will work, but it is better to add extra link (even if you plan to swap 30T/28T)

chainstay length=410mm 52x11-28T chain length unrounded=53.51 recomended=54 links
chainstay length=410mm 52x11-30T chain length unrounded=53.97 recomended=54 links

chainstay length=415mm 52x11-28T chain length unrounded=53.89 recomended=54 links
chainstay length=415mm 52x11-30T chain length unrounded=54.36 recomended=55 links

chainstay length=420mm 52x11-28T chain length unrounded=54.29 recomended=55 links
chainstay length=420mm 52x11-30T chain length unrounded=54.76 recomended=55 links

chainstay length=425mm 52x11-28T chain length unrounded=54.68 recomended=55 links
chainstay length=425mm 52x11-30T chain length unrounded=55.14 recomended=56 links

chainstay length=430mm 52x11-28T chain length unrounded=55.07 recomended=56 links
chainstay length=430mm 52x11-30T chain length unrounded=55.54 recomended=56 links
'

frede
Posts: 6
Joined: Fri Jan 27, 2017 12:46 am

by frede

This is excellent information, thank you everyone..!

Marin
Posts: 4035
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

If the chain is at the limit for 52/28 then shifting 52/30 will rip off your derailleur/hanger/dropout, simple as that.

Unthread the chain from the rear derailleur and put it over the 52 and the 30. If you can do this without tension, you can carefully try it with the derailleur and see how stretched out the arm is.

My bet would be that the chain is long enough, but the price for when it isn't is too high to not check.

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BRM
Posts: 817
Joined: Sun Mar 16, 2014 3:43 pm

by BRM

Yes very simple just to try it.
Also look how old your current chain is maybe better buy a new chain anyway?

kode54
Posts: 3740
Joined: Tue May 23, 2006 9:39 pm

by kode54

also, seems that 11 spd has tighter tolerances according to Park Tools. they are now making a chain check tool that is .5/.75 instead of .75/1.0.

i run mine at 53 links...with the KMC missing link =54 total. that's for a 52/28.
i read somewhere here that someone put a 30 on the short cage and it works fine...just adjust the B limit screw.
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frede
Posts: 6
Joined: Fri Jan 27, 2017 12:46 am

by frede

Just letting you know that I purchased and installed the 11-30T Cassette with my 52/36 chainring combo and it fit and works perfectly. As it's Di2, I updated the config in the Shimano e-Tube software and all is fine even with Synchro Shifting. There was no rear derailleur adjustment necessary.

Thanks for the advice and thoughts.

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wheelsONfire
Posts: 6280
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

Haha, well come again when you mounted a 11-36T (Sram 1170)
Bikes:

Ax Lightness Vial EVO Race (2019.01.03)
Open *UP* (2016.04.14)
Paduano Racing Fidia (kind of shelved)


Ex bike; Vial EVO D, Vial EVO Ultra, Scott Foil, Paduano ti bike.

BikeAnon
Posts: 399
Joined: Sun Mar 02, 2014 6:36 pm
Location: NY USA

by BikeAnon

Here's my sad tale, when I put on a 32.
DIY Carbon fiber repair - seatstay.

I see you have things sorted... I only put this here as a caution to others.

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TonyM
Posts: 3376
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

ooo wrote:for chainstay=410,420,430 it's the same recommended chainlength, for chainstay=425 chainstretch=0.14 of link for 30T over 28T - it's ok,
for chainstay=415 chainstretch=0.36 for 30T over 28T chainlength, it will work, but it is better to add extra link (even if you plan to swap 30T/28T)

chainstay length=410mm 52x11-28T chain length unrounded=53.51 recomended=54 links
chainstay length=410mm 52x11-30T chain length unrounded=53.97 recomended=54 links

chainstay length=415mm 52x11-28T chain length unrounded=53.89 recomended=54 links
chainstay length=415mm 52x11-30T chain length unrounded=54.36 recomended=55 links

chainstay length=420mm 52x11-28T chain length unrounded=54.29 recomended=55 links
chainstay length=420mm 52x11-30T chain length unrounded=54.76 recomended=55 links

chainstay length=425mm 52x11-28T chain length unrounded=54.68 recomended=55 links
chainstay length=425mm 52x11-30T chain length unrounded=55.14 recomended=56 links

chainstay length=430mm 52x11-28T chain length unrounded=55.07 recomended=56 links
chainstay length=430mm 52x11-30T chain length unrounded=55.54 recomended=56 links


How do you calculate this?
Is there any online tool for this?

by Weenie


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