shimano 11-28 chain sizing

Ask for advice or share your fettling tips
bus_ter
Posts: 264
Joined: Thu Jan 05, 2012 19:38 pm

shimano 11-28 chain sizing

Postby bus_ter » Thu Feb 13, 2014 23:20 pm

In the shimano tech docs they outline a different method for measuring a chain on an 11-28 cassette on a SS RD compared to all other combinations. They suggest the chain around both big rings and add 2 links. Does anyone know why this combination is different? And also what do Shimano mean by 2 links. Is it one outer with an inner. Or is it two sets, I.e outer-inner-outer-inner ?

Semantik
Posts: 319
Joined: Sun Feb 24, 2013 09:49 am

Re: shimano 11-28 chain sizing

Postby Semantik » Thu Feb 13, 2014 23:55 pm

They are probably recommending the chain should be fractionally longer as the short cage rear mech is approaching the limits of its design on a 28 tooth sprocket. Add 2 links means 1 x inner+ 1 x outer link.

arlowood
Posts: 1890
Joined: Fri Jul 02, 2010 18:26 pm

Re: shimano 11-28 chain sizing

Postby arlowood » Fri Feb 14, 2014 09:17 am

Just use this to calculate the ideal chain length. Have used it numerous times and it works on cassettes up to 30 tooth with compact 50 chainring.

http://www.epicidiot.com/sports/chain_l ... ulator.htm


BTW I would interpret Shimano's 2 link as 1 outer plus 1 inner link

keef66
Posts: 8739
Joined: Tue Apr 29, 2008 09:46 am

Re: shimano 11-28 chain sizing

Postby keef66 » Fri Feb 14, 2014 09:52 am

It is accepted in chain terminology that one link comprises one inner and one outer link, so two of each would be what Shimano are recommending.

I often use that same method when fitting a new chain. Big ring, largest sprocket, not through the rear mech, then add 2 links. Easy to do cos there's no tension in the chain. Just remember to thread the chain through the rear mech once you've cut it

User avatar
Me-109
Posts: 1045
Joined: Wed Jul 25, 2007 15:39 pm

Re: shimano 11-28 chain sizing

Postby Me-109 » Fri Feb 14, 2014 10:10 am

Although if you buy a Shimano chain it has, for example, 116 links. That's 116 individual links, not 116 pairs., so I would read the instructions as just adding one pair (one inner plus one outer link).

For me, both methods ended up with the chain the same length on an 11-28.

bus_ter
Posts: 264
Joined: Thu Jan 05, 2012 19:38 pm

Re: shimano 11-28 chain sizing

Postby bus_ter » Fri Feb 14, 2014 18:30 pm

BUGGER BUGGER and BUGGER..

Fitted my new 11-28 cassette and resized the chain *EXACTLY* by shimanos instructions. Checked and double checked. It's too short! In the big ring at the front it won't change into the big at the back. If I give the RD pulley a little push forward it will change up but you can feel it's pulled to the limits and you can feel resistance when you turn the crank by hand. One more link would probably have been perfect...

It's not the end of the world. I'll just avoid using that gear combination (which you shouldn't use anyway). Probably buy another chain in a month or so when the weather improves and size it one link longer. Little pissed that Shimanos instructions didn't work for me (unless I did something silly wrong)

User avatar
davidof
Posts: 1030
Joined: Wed Jun 29, 2005 09:26 am
Contact:

Re: shimano 11-28 chain sizing

Postby davidof » Mon Feb 17, 2014 20:42 pm


keef66
Posts: 8739
Joined: Tue Apr 29, 2008 09:46 am

Re: shimano 11-28 chain sizing

Postby keef66 » Tue Feb 18, 2014 13:20 pm

So did you add two links or two half links as others were suggesting?


Return to “Workshop”

Who is online

Users browsing this forum: Semantik and 3 guests