8

Is it possible to shorten or extend a chain only one link as shown in the photo (in red square). Or do I have to shorten at least two links in order for the other end to match?

The reason I'm asking is that with my current setup (front 52/36, rear 32/11) if I remove one link the chain becomes too short to shift to 52 front and 32 rear. If I extend the chain one link and shift to 36 front and 11 rear, the chain rubs on the derailleur.

Shorten Chain

  • I think "link" is usually taken to mean a big one and a small one, so you actually want to remove half a link. Or maybe different people use different terminology. (Or maybe I'm just wrong.) – David Richerby Sep 28 '18 at 12:46
  • You could do it but then you'd have to close the chain with a quick-link making it exactly as long as before! – Carel Sep 28 '18 at 13:00
  • Ok then one link = 2 pieces. – Umut Birey Sep 28 '18 at 13:25
  • Single speed and internal gear hub bikes have long dropout slits for the rear wheel so that you do not need more than a double link precision on the chain length. And chain shift bikes have a deraileur that removes any need for precision on chain length. – cmaster Sep 28 '18 at 17:50
  • @cmaster but if the frame was built for a derailleur and is now being used SS, you may need some adjustment – Chris H Oct 2 '18 at 12:07
3

Simple answer is "yes". And as it was said already, you need a half-link to be able to connect the chain again.

The question is - why do you need it for? There are couple of solutions to handle/overcome this issue if your dropouts don't allow it, such as:

  • you can acquire a complete "half-link" chain (they are popular among BMX riders) and be able to break the chain at any length
  • you can replace the rear cogwheel to the one with one cog more or less (depending on your preferences) to stick to the even number of half-links in your chain
  • if the problem is in your dropouts (road-type not allowing for adjustment) you can experiment with the "road-to-pista" dropouts adapters (I know those exist, I don't know how they perform)

The OP has shared some information why the question was asked in the first place.

If I understand correctly, the current derailleur is Tiagra RD-4700 SS, which according to the specs I've found is short cage model:
Tiagra RD-4700 SS

The OP is asking if switching to Tiagra RD-4700 GS (long cage model, according to what I've found) would be the solution to the problem:
Tiagra RD-4700 GS

I'd say: yes, using a longer cage model would solve the problem definitely since the longer cage allows for a longer chain (serving the largest chainrings and sprockets) and takes up more slack of the chain (serving the smallest chainrings and sprockets).

I don't own the pictures presented in this post, I've taken them from "the internet" and those particular were found on a ctbike.pl webpage, a bicycle parts retailer I'm not affiliated anyhow, just found them using a well-known search engine.

  • because i remove one link chain becomes short that i cannot shift to 52 - 32 combo. I extend the chain one link but than when i go to 36 - 11 chain rubs to derailleur – Umut Birey Oct 5 '18 at 18:57
  • Which derailleur cage are you using right now? From what you're saying it seems you need so called "long cage" derailleur or larger jockey wheels (or at least one of them) to accommodate for the extra chain (in both cases you'd need a slightly longer chain) – Mike Oct 5 '18 at 20:13
  • tiagra rd-4700 ss. do you think it will be ok if I go with the gs? – Umut Birey Oct 5 '18 at 20:14
  • I'd say yes, I've edited my answer to give you some context why. – Mike Oct 5 '18 at 20:33
  • Thanks mate I will test it and let you know if it works – Umut Birey Oct 6 '18 at 7:47
14

For 1/8" chains as used on singlespeed bikes (or with hub gears), half links are reasonably common.

They do exist for 3/32" chains (which are sometimes used without derailleurs) but are much less common as single speed 3/32" chains are. They're not needed if you've got a test derailleur as the derailleur provides much more chain length adjustment. A chain tensioner can do this on a singlespeed.

The main reason for using these appears to be on singlespeed conversions, when they lack the horizontal dropouts of a frame built for single speed.

  • Your link is to a halflink for a 3/32 single speed chain. There are no halflinks for derailer chains. – Nathan Knutson Sep 29 '18 at 2:53
  • @Nathan thanks. I saw the question underneath and misremembered the KMC part number as referring to a multispeed chain. Fixed – Chris H Sep 29 '18 at 6:45
7

Unless using a special half link (as mentioned and linked to by Chris H) to shorten a chain you have to remove the same number of outer and inner plate links. The distance between the joining pins is 0.5 inch so joined chain are always a multiple of whole inches long.

This raises the question of why you want to reduce the chain length by less then one inch. Chain sizing and tensioning for both derailleur equipped and single speed or hub geared bicycles can be accomplished without the need to shorten a chain by 0.5 inch increments.

Update based on new info.This is in agreement with what @Mike said but with specs and numbers.

Derailleur total capacity needed is (52-36)+(32-11) = 37

Tiagra long cage GS derailleur has total capacity of 41. The short cage SS 33. SS model can't take up the slack and is bottoming out the A pivot (what the cage rotates around). Going to a GS model will fix the problem.

0

Conventional wisdom is to avoid the big/big and small/small combinations, because of the extreme chain angles. This might well be outdated given more laterally-flexible modern chains, and I certainly do it all the time. But you don't need to, since you have ratios equal or close to the big/big and small/small combinations on the other ring - 52/36 is (almost exactly) 36/25, and 36/11 is (approx) 52/16. So use those, or close equivalents, if you want the gear ratios offered by the big/big and small/small combinations. Go with the longer chain so you can shift into big/big without anything grinding to a halt.

  • 1
    Yes ideally you should not use big/big and small/small but sometimes you can shift to them accidentally so its a good idea to be able to shift to those gear without problems. – Umut Birey Oct 12 '18 at 7:04

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