Chain fu: Not for you

Hi Lee,
I have a question about my chain. I’m wondering what the common practice is when you replace a chain? Mine seems a little too slack and jumps off of the front ring. how many if any links should I remove to prevent this from further re-occurences?
Thanks for your help, and I always enjoy all the great info you’ve been throwing out here.

The more you click, the more I can post. Lee Likes Groceries dot com!

From the SRAM X.0 manual.

Hi Matt.

Here are some useful chain facts.

Measuring a new chain

Here’s something SRAM and Shimano agree on. Before you cut a new chain, run it around your big ring and big cog, bypassing the rear derailleur. Add two links. That’s your ideal chain length. If you have rear suspension, measure for the longest length.

Matt, on your bike, the chain should just barely let you shift onto the big ring and big cog. If you have extra links, cut ’em out (If you run Shimano, use the magic pin). But I’ll bet that’s not the problem …

How to manage your chain

Rule 1: Keep it as straight as possible. No crossing from small to small or big to big.

Rule 2: Keep it as tight as possible. When you descend, use the big ring and a middle cog. (Matt)

Rule 3: If you’re really pinning it, you need some sort of chain guide.

When to replace the chain

Twenty-four new links measure exactly 12 inches from pin to pin. When they stretch to 12 1/16 inches, replace your chain. Check this pretty often, or else …

When to replace the chain and cogs

If 12 links measure 12 1/8 inch or longer, you blew it. Your teeth have worn to fit the old chain, and now you have to replace your cassette. Probably the rings too.

Too much power

I seldom wear out chains, because my awesome power just snaps them.

Which prominent racer said this in a video?

“With these flat starts, I go through three chains a night.”

10 replies
  1. Olen says:

    In addition to the chain possibly being worn, I feel I must respond to the commment he made regarding the chain jumping off the front ring. Do not overlook the possibility that the high stop on the front derailleur may need to come in a few turns. While a new chain can help with many transmission related issues, it will never remedy an out-of-adjustment derailleur.
    Also, for those that ride freeride and downhill bikes, you will eventually trash a rear derailleur. When you do, consider changing to a mid-length derailleur, if you run dual or single ring cranks. You will experience less chain movement during rough riding, gain a little more rear ground clearance, and can run tighter chain lengths without affecting the shifting performance.
    Good Luck!

    Foothills Cycling

  2. Ryan says:

    Don’t forget to take your bikes chain growth into consideration if you have a full suspension bike. For example, a long travel single pivot bike will typically need more links than a long travel 4-bar like a Specialized that has no chain growth. If you go too short, you may have a rude awakaning if you take a big hit while in a large cog/ring combo. You can take the spring off your shock, (or let all the air out of an air shock) and cycle the supension fully while in large cog/ring to check if it’s long enough.

  3. leelikesbikes says:

    A Santa Cruz Bullet grows about 30mm. That’s four extra links.

    Two is 25mm, but then you need another pair …

  4. Mike Johnstone says:

    On SRAM X.0 and some older Shimano (sorry I haven’t used Shimano in awhile so don’t know about the newer ones) you can increase the tension on the cage spring. This will make the shifting a bit clunky but will decrease chain slap, and hold the chain in gear better when Downhilling. Be careful not to increase it too much though as the spring will start to bind and stop the cage from moving.

  5. slyfink says:

    also don’t forget that the teeth on the chain ring might be getting worn. This could be causing the chain to be thrown down to a smaller ring. It actually happens quite often. I ride if gritty conditions and have to replace the middle chain ring at least once a season. Also remember that it’s a good idea to change your cogset and (most frequently used) chainrings when you change your chain…


  6. Petey says:

    Sly has the problem nailed, chainring is dead.
    Remember the Onza S.S. chain rings. These would last for more than one season of SF Bay Area riding when I could chew through the teeth on the aluminium jobbers in about two months.

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