Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Longer or shorter chain?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Longer or shorter chain?

Old 04-28-10, 04:29 PM
  #1  
Senior Member
Thread Starter
 
Chalupa102's Avatar
 
Join Date: Jan 2010
Location: Monson, MA
Posts: 485

Bikes: Catrike Trail Recumbent trike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Longer or shorter chain?

I just recently changed out my rear cassette and want to do everything the right way. I am wondering if i would need a longer or shorter chain? I went from an 7 speed 14-28 cassette to an 7 speed 13-34 cassette. I would guess a longer chain, but could be wrong. I have some new noises with the new cassette when i switch to the lowest gear while climbing hills. Also, i'm usually in the lower gears and never go any higher than the 17 ring on the cassette.
Chalupa102 is offline  
Old 04-28-10, 04:43 PM
  #2  
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,239

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1102 Post(s)
Liked 560 Times in 447 Posts
A search would bring up numerous request about chain length. The answers are always the same. You can wrap the chain around the big ring and largest cog, bypassing the RD. Bring the ends to together and add 1-inch (two links) if the ends that come together can be joined (inner plates and outer plates). If the plates that come together are the same, add 3 links. That is the shortest chain length that will wrap the big/big combo.

The other method is the little/little method, that insures the maximum chain length and wrap capacity. This method routes the chain the through the RD. The length should be the longest that does not allow the chain to hang loose or rub on the RD cage due to a lack of tension.

The problem you may encounter is a lack of wrap capacity and clearance between that 34T cog and the upper jockey pulley on the RD. You can't just just change cassettes like that without knowing the RD's wrap capacity and largest cog capacity.
DaveSSS is offline  
Old 04-28-10, 05:10 PM
  #3  
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Posts: 2,407

Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
To expand on DaveSSS' reply...

First off, it's generally best practice to replace the chain each time you replace the cassette. Otherwise, the old chain will prematurely wear the new cassette.

Secondly, if the chain was previously sized using the "shortest chain method," then you run the risk of having to short of a chain if you try to shift into the bib/big combo. Generally, you shouldn't be in the largest one or few cogs while in the large chainring, but it's still good to be able to do it in case you shift there accidentally (like forgetting you're in the large chainring).

Thirdly, your cassette and chainring choice may be exceeding the rear derailleur's chain wrap capactity, which is primarily dictated by the rear derailleur's cage length. The longer the cage (greater the capacity), the wider difference in large and small chainring sizes and largest and smallest cog sizes the RD can handle. Basically, the derailleur wants to be able to handle the two extreme combos (large/largest and small/smallest).

If the RD lacks sufficient capacity, then one of two things will occur: 1) if the chain is long enough for large/largest, then the RD won't be able to take up the slack created in small/smallest and the RD will fold into itself and no longer provide tension on the chain or 2) if the chain is short enough for small/smallest while providing tension, then it will be too short for large/largest, which could lead to something breaking if you ever shifted there.

Generally, the best way to deal with this (short of getting a RD that has greater capacity) is to set up the chain as short as possible and just don't use the small/smallest combos. RDs designed for triple (as opposed to double) cranksets have greater capacity.

Fourthly, the new RD may not have a large enough max cog capacity. Max cog capacity is determined by the design of the upper parallelogram of the RD. RDs with larger max cog capacities naturally sit further down away from the cassette. RDs designed for mountain (vs. road) bikes generally have a greater max cog capacity (32/34T vs 27/28T).

You may just need to screw in the B-tension screw on the RD to move the RD further down from the cassette and make room for the 34T.

For more on choosing the correct rear dérailleur, see post# 114: https://www.bikeforums.net/showthread...=1#post5968998
JiveTurkey is offline  
Old 04-28-10, 08:19 PM
  #4  
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Posts: 1,606

Bikes: Indy Fab steel deluxe, Aventon cordoba, S-works stumpy fsr, Masi vincere, Dahon mu uno, Outcast 29 commuter

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 100 Post(s)
Liked 84 Times in 53 Posts
I would advise against the small/small method. My boss always insisted on using this method, claiming that he just never crosses over big/big. The first time he let someone else get on his bike, guess what happened. Can be an expensive lesson if you are using an X.0 short cage RD.
frankenmike is offline  
Old 04-29-10, 07:54 AM
  #5  
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,239

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1102 Post(s)
Liked 560 Times in 447 Posts
The little/little method always works, unless you've got the oddball situation where the RD has insufficient wrap capacity. I always use a RD with enough wrap capacity. With road bikes, that allows any road-specific cassette to be used and never have to change the chain length. This works with Campy, Shimano or SRAM road drivetrains.
DaveSSS is offline  
Old 04-29-10, 07:53 PM
  #6  
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Posts: 1,606

Bikes: Indy Fab steel deluxe, Aventon cordoba, S-works stumpy fsr, Masi vincere, Dahon mu uno, Outcast 29 commuter

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 100 Post(s)
Liked 84 Times in 53 Posts
Originally Posted by DaveSSS
The little/little method always works, unless you've got the oddball situation where the RD has insufficient wrap capacity. I always use a RD with enough wrap capacity. With road bikes, that allows any road-specific cassette to be used and never have to change the chain length. This works with Campy, Shimano or SRAM road drivetrains.
While I agree that the way you describe this method will work, the only way to guarantee optimum length is with the big/big method. Why would someone want anything but the optimum length? Is it really worth it to not have to size a chain if you switch components? Perhaps so...
frankenmike is offline  
Old 04-29-10, 09:51 PM
  #7  
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Posts: 2,407

Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
Originally Posted by frankenmike
While I agree that the way you describe this method will work, the only way to guarantee optimum length is with the big/big method. Why would someone want anything but the optimum length? Is it really worth it to not have to size a chain if you switch components? Perhaps so...
I use the big/big method.

However, your use of "optimum" is an opinion.

My understanding of the advantage to the little/little method is that it is supposed to actually create a longer chain, ensuring greater wrapping around the cog. A problem occurs though if the wrap capacity of the RD is exceeded.

For folks that like the little/little approach, it seems like the best thing is to size it using little/little, but ensure it is at least as long as big/big would produce. If little/little produces a shorter chain, then the advantage of greater chain wrap isn't actually achieved.
JiveTurkey is offline  
Old 04-30-10, 06:44 AM
  #8  
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,239

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1102 Post(s)
Liked 560 Times in 447 Posts
The little/little method always suggests the longest possible chain (that will never hang loose) and maximum wrap capacity from your RD. At least for road bikes, it's the most sensible length. I've read many posts from people who are bummed that they need a longer chain when they switch from an 11-23 to a 12-27 for a hilly event. If they had made the chain 1-inch longer, that would not be necessary, since modern most road RDs can handle a compact with any road-specific cassette that is sold by the drivetrain manufacturer. Campy still sells a medium cage RD, just to handle a 13-29 cassette, but the new 11 speed uses one RD for all setups, including a 12-29. There is nothing "optimum" about a 1 inch shorter chain.

The MTB setup with a RD the deliberately has insufficient wrap capacity is an odd-ball. That situation requires a chain length set with the big/big. It would be rare for a road bike to be setup to have the chain hang loose in the smallest 3-4 cogs, just to have one larger cog.
DaveSSS is offline  
Old 04-30-10, 07:05 AM
  #9  
Senior Member
 
well biked's Avatar
 
Join Date: Jul 2005
Posts: 7,491
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 143 Post(s)
Liked 163 Times in 89 Posts
The problem I have with advising people on the internet to use the small/small method is that in doing so it's being assumed that the rear derailleur is properly matched with the rest of the drivetrain in regard to chain wrap capacity. Half the time people don't even know what that means. I think better advice is to have them use the "big/big plus one inch" method along with the explanation that this gives the shortest chain possible with their particular drivetrain and if the largest cog or chainring gets switched out for something larger they'll likely need a longer chain.

The bottom line is that, by far, the most important thing is having a chain that is long enough to safely cover the big/big combination, because a chain that's too short for big/big can (and probably will at some point) cause catastrophic damage.

Last edited by well biked; 04-30-10 at 10:12 AM.
well biked is offline  
Old 04-30-10, 08:06 AM
  #10  
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Posts: 1,606

Bikes: Indy Fab steel deluxe, Aventon cordoba, S-works stumpy fsr, Masi vincere, Dahon mu uno, Outcast 29 commuter

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 100 Post(s)
Liked 84 Times in 53 Posts
Originally Posted by JiveTurkey
I use the big/big method.

However, your use of "optimum" is an opinion.

My understanding of the advantage to the little/little method is that it is supposed to actually create a longer chain, ensuring greater wrapping around the cog. A problem occurs though if the wrap capacity of the RD is exceeded.

For folks that like the little/little approach, it seems like the best thing is to size it using little/little, but ensure it is at least as long as big/big would produce. If little/little produces a shorter chain, then the advantage of greater chain wrap isn't actually achieved.
As well as the opinion of : The Sheldon, and every chain manufacturer that supplies instructions with their chains.
frankenmike is offline  
Old 04-30-10, 08:47 AM
  #11  
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,239

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1102 Post(s)
Liked 560 Times in 447 Posts
Originally Posted by frankenmike
As well as the opinion of : The Sheldon, and every chain manufacturer that supplies instructions with their chains.
Not Campy. Their instructions suggest the little/little method. As I noted, with road bikes it is the most sensible way, assuming that you are smart enough to select a RD with the proper wrap capacity.

https://www.campagnolo.com/repository...s_UK-03-09.pdf

Chain sellers want to sell more chains and if they can get you to need two lengths when only one will do, why not?
DaveSSS is offline  
Old 04-30-10, 02:40 PM
  #12  
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Posts: 1,606

Bikes: Indy Fab steel deluxe, Aventon cordoba, S-works stumpy fsr, Masi vincere, Dahon mu uno, Outcast 29 commuter

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 100 Post(s)
Liked 84 Times in 53 Posts
Originally Posted by DaveSSS
Not Campy. Their instructions suggest the little/little method. As I noted, with road bikes it is the most sensible way, assuming that you are smart enough to select a RD with the proper wrap capacity.

https://www.campagnolo.com/repository...s_UK-03-09.pdf

Chain sellers want to sell more chains and if they can get you to need two lengths when only one will do, why not?
Good point Dave- I must admit I've never used a Campy chain. I've also never replaced a cassette without also replacing the chain-regardless of length discrepancies- but I can understand why someone might like the option.
frankenmike is offline  
Old 05-01-10, 03:01 PM
  #13  
Senior Member
Thread Starter
 
Chalupa102's Avatar
 
Join Date: Jan 2010
Location: Monson, MA
Posts: 485

Bikes: Catrike Trail Recumbent trike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Well, i took all of your advice and got a Shimano rear derailleur and a brand new chain from the LBS. I just spent the last few hours changing them out. The one noob question that i have: the new chain came with a "missing link" and the size of the chain is actually a perfect fit. Is this "missing link" just used for fitting or is it a permanent thing used for the chain?
Chalupa102 is offline  
Old 05-01-10, 03:11 PM
  #14  
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Posts: 2,407

Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
The pins of newer chains are not meant to be removed and re-installed as the removal and installation of the peened pin by a chain tool damages the hole of the outer link, making a weak spot. You're supposed to discard that outer link and use the missing link instead. Did you already install the pin? I hope not, as I'm unsure how you'll find that one.
JiveTurkey is offline  
Old 05-01-10, 03:20 PM
  #15  
Senior Member
Thread Starter
 
Chalupa102's Avatar
 
Join Date: Jan 2010
Location: Monson, MA
Posts: 485

Bikes: Catrike Trail Recumbent trike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by JiveTurkey
The pins of newer chains are not meant to be removed and re-installed as the removal and installation of the peened pin by a chain tool damages the hole of the outer link, making a weak spot. You're supposed to discard that outer link and use the missing link instead. Did you already install the pin? I hope not, as I'm unsure how you'll find that one.
Awesome, thanks for the reply. Nope, i just used the missing link as directed by the paperwork that came with it. The chain was perfect size, so i didn't modify it or take out any links.
Chalupa102 is offline  
Old 05-01-10, 03:21 PM
  #16  
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Posts: 2,407

Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 4 Times in 4 Posts
Originally Posted by Chalupa102
Awesome, thanks for the reply. Nope, i just used the missing link as directed by the paperwork that came with it. The chain was perfect size, so i didn't modify it or take out any links.
Sounds like you did it right.
JiveTurkey is offline  
Old 05-01-10, 07:30 PM
  #17  
Senior Member
Thread Starter
 
Chalupa102's Avatar
 
Join Date: Jan 2010
Location: Monson, MA
Posts: 485

Bikes: Catrike Trail Recumbent trike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks a lot for all the info and help guys. Did a test ride after i finished everything up. It was the most quiet ride i've ever had as far as pedaling goes (chain, RD, etc). I also felt a bit more efficient.
Chalupa102 is offline  
Old 06-06-10, 11:33 AM
  #18  
Senior Member
 
AndyK's Avatar
 
Join Date: Jul 2005
Location: Northern N.J.
Posts: 2,022

Bikes: '11 TIME NXR Instinct, '03 De Rosa Planet '79 Paris Sport (Moulton)

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked 15 Times in 11 Posts
Interesting thread since I am debating which method to use to install my new Campy 11 chain. Campy says use small-small, measuring 8 divided by 15mm??? What do they mean by that?
__________________
'11 Time NXR Instinct / '79 Paris Sport by Moulton


AndyK is offline  
Old 06-06-10, 01:07 PM
  #19  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by DaveSSS
Not Campy. Their instructions suggest the little/little method. ...
[strike]Shimano does too. Or more properly, they do in some of their instructions (others use big/big).

There seems to be a missing step in the descriptions of the method posted above, though. Route small/small and through the RD. The size is proper when the RD cage is perpendicular to the ground.[/strike]
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers

Last edited by DMF; 06-07-10 at 02:06 PM. Reason: Brain fart.
DMF is offline  
Old 06-06-10, 06:05 PM
  #20  
Senior Member
 
AndyK's Avatar
 
Join Date: Jul 2005
Location: Northern N.J.
Posts: 2,022

Bikes: '11 TIME NXR Instinct, '03 De Rosa Planet '79 Paris Sport (Moulton)

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Liked 15 Times in 11 Posts
Originally Posted by DMF
Shimano does too. Or more properly, they do in some of their instructions (others use big/big).

There seems to be a missing step in the descriptions of the method posted above, though. Route small/small and through the RD. The size is proper when the RD cage is perpendicular to the ground.
I believe that would only be achieved in Big-small.
__________________
'11 Time NXR Instinct / '79 Paris Sport by Moulton


AndyK is offline  
Old 06-07-10, 02:05 PM
  #21  
Elitist Troglodyte
 
DMF's Avatar
 
Join Date: Jun 2006
Location: Dallas
Posts: 6,925

Bikes: 03 Raleigh Professional (steel)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Ooops! You're right. Big ring, small sprocket.



"My mind is going, Dave. I can feel it."
--- HAL9000
__________________
Stupidity got us into this mess - why can't it get us out?

- Will Rogers
DMF is offline  
Old 06-07-10, 03:29 PM
  #22  
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,239

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1102 Post(s)
Liked 560 Times in 447 Posts
Originally Posted by AndyK
Interesting thread since I am debating which method to use to install my new Campy 11 chain. Campy says use small-small, measuring 8 divided by 15mm??? What do they mean by that?
The instructions mean to have a gap of 8-15mm between the upper and lower sections of chain. In practice, use the length that is as long as possible, but it must cause the lower pulley to swing down (creating some tension) and the chain should never rub on the upper chain guide tab.
DaveSSS is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TrojanHorse
Bicycle Mechanics
11
11-06-18 09:09 PM
fthomas
Fifty Plus (50+)
32
04-16-16 09:28 PM
Brewsmith
Bicycle Mechanics
3
09-10-15 04:02 PM
Mark9
Bicycle Mechanics
18
10-16-14 06:15 PM
sknhgy
Bicycle Mechanics
1
04-19-13 08:24 AM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.