enjoybikes

When putting on a chain, which is a better way to go...

To have it a bit long so the chain gets slack in the higher gears while on the little ring, or...

To have it a link shorter and have it pull really tight on the low gears while on the big ring?

The difference in one link seems to make me have to choose one or the other. I would appreciate a couple of angles on this from you mechanics out there. Thanks.

jgedwa

Good question. I am curious to hear what others have to say.

I vote for a tad long, for two reasons:

-if too short is really too short, then you really are putting a lot of stress on the derailleur
-with less chain tension, the shifting is a bit lighter. Less force required at the lever, and sometimes smoother shifts.

jim

oldbobcat

The service manager of the shop where I work and I have a polite disagreement about chain length. He's from a MTB background, where chain slap can be a problem, so he's a tight chain guy. He makes a straight line through the rear derailleur in the big-big combination and then adds a pair of links. Being an old road rider, I've never had a problem with chain slap, but I do occasionally cross-chain (big-big) and I don't like too much friction. I put it in the small-small combination and set the chain just long enough to avoid hitting itself as it passes through rear derailleur. I feel that as long as there's enough tension and wrap around the cassette cogs to prevent the chain from slipping over the tops, it's working fine.

Incidentally, we're usually only a link pair off in our preferred sizing. Also, there are some stock MTB gearing setups that make big-big and small-small impossible. The range on the rear cassette is just to large.

DARKSCOPE001

follow mfg rules for the chain. for sram its biggest chainring to biggest cog (bypassing the derailure) then take this and add 2 links. that is your proper chain length. i think for shimano its 1 link. but either way i think you will be fine by going biggest chainring to biggest cog and adding 2 links. thats what i do. And if you are getting chain slap on your rig then simply go to your lbs and ask for a piece of old bar tape (my lbs saves these) wrap it around your chainstay and secure with a few wraps of electrical tape. cheap easy and effective.

HOPE THIS HELPS
Sean Scott

Retro Grouch 

Too short, if you ever accidentally shift into the big/big, can cause a TON of damage in the blink of an eye. If you have to make a choice, I vote for too long. Even better, get a derailleur that has enough slack take up to handle your gear combination.

DARKSCOPE001

when in the world would you cross chain like that? I have never heard of such harsh crosschaining but then again i don't usually do 53x23 gearing that often. its kind of an illogical gear. besides i think that the chain would pull off into another gear from all the crosschaining before it would snap into that gearing combo. also i doubt that my mech will even allow me to trim the front that far over so the entire time there would be this awful grinding of metal on metal. in my eyes you would never use that gearing combo. with the manufacture of the chain. on all sram chains its going to tell you big ring to big cog (bypassing rear mech) this length + 2 links. this has always worked for me and always will.

kayakdiver

+1

DaveSSS 

With a typical road bike, there is ONE length that will produce the maximum wrap capacity and work with any road cassette that the manufacturer offers. You get that by setting the length in the little ring and smallest cog, to the maximum length that keeps the chain from hanging loose or rubbing on the upper chain guide tab. If you remove 1 inch, it reduces the wrap capacity by 4T.

The big/big plus 1 inch method will suggest the same length, but only if the cassette has the largest possible cog size.

As an example, if you set the length as described, a Shimano short cage RD would work with any cassette from an 11-21 to a 12-27. There would never be a need to change the chain length as the result of a cassette change.

Campy does offer a 13-29 cassette, that should use a medium cage RD, with more wrap capacity. In this case, the chain length is still set in the same manner, but the RD will then have the range to cover any cassette from an 11-21 to 13-29.