23

cross chaining

Accepted wisdom is that cross chaining is bad and that we should never do it. However, most of us set up our bikes so that we can run any gear combination. Invariably, I'll occasionally look down and see that I'm running my big chainring against one of the bigger cogs.

Is there any measurement of how much faster equipment will wear out from cross chaining, or energy loss or whatever?

Improve this question
4
  • 11
    It's like crossing the streams in Ghost Busters -- it's will end the universe as we know it, except when it saves the universe. (Don't worry to much about it. The main problem with a big/big or small/small combo is that your derailer may not have the tooth capacity for it, plus you're apt to get more chain noise, and possibly some skipping. Avoid it over the long run, but don't worry about it for a minute or three, if the derailer handles it.)
    – Daniel R Hicks
    Commented May 29, 2012 at 15:19
  • @DanielRHicks I admit I've had an inkling that it's not as bad as some folks let on.
    – Darth Egregious
    Commented May 29, 2012 at 15:45
  • 3
    It used to be worse, before derailers were designed to handle larger tooth ranges, et al. But that's been 20-30 years.
    – Daniel R Hicks
    Commented May 29, 2012 at 16:25
  • 1
    (Though note that if you do it a lot that's a sign that you're not taking the best advantage of your gearing options. Or perhaps your front derailer is simply too "fussy" and you avoid mucking with it, suggesting that you need to get your bike tuned up.)
    – Daniel R Hicks
    Commented May 29, 2012 at 16:28

2 Answers 2

Reset to default
7

The problem with cross-chaining is that you put more stress on the chain which causes wear and tear on cassette teeth, eventually leading to the chain slipping gears.

The chain line is one factor. The chain should ideally run in a plane from the front derailleur teeth back to the rear derailleur. It shouldn't be forced into a line on the teeth, and then angle as soon as it clears the teeth to get to the cassette as happens when cross-chaining because that causes teeth to wear. You're not going to fix the chain line except by making the chain and gear spacing narrower which requires weaker chains at a given price.

The length of the rear derailleur cage determines how much slack it can pick up in the chain. If you size your chain big-to-big, and have a derailleur capable of picking up the slack then shifting into big-big shouldn't do damage. Shimano XT rear derailleurs have a 43 tooth capacity which should cover just about anything, but I had a touring bike with a wide range of gears that exhausted it. I managed to wedge things pretty well when my shifters got pushed into awkward positions on a train and I started riding without checking.

Improve this answer
3
  • I wonder if there's a transmission system that loses the parallelogram deraileur, and instead moves the entire cluster/rear cassette back and forth "under" the chain. So the derailleur turns into a mere chain tensioner, and maintains the perfect straight line. I suspect not.
    – Criggie ♦
    Commented Aug 27, 2015 at 23:59
  • 2
    @Criggie, If the cluster had to move sideways then the rails it ran on would be one more thing that can collect dust and gunk. Internal gear hubs do away with the complicated interface between chain and cluster. See the Rohloff hub for example.
    – Mike Samuel
    Commented Aug 28, 2015 at 4:31
  • I wonder if there are published stats on chain wear. It has always seemed to me that everyone "knows" this because everyone else says it. Without tangible evidence it could just as easily be argued that using the large front ring (crossed or not) puts less tension on the chain and therefor less wear.
    – Philip Couling
    Commented May 29, 2022 at 10:14
12

The only study I know of concluded that cross chaining in relatively modern 9spd gear systems at the angles typical of bicycles had no measurable effect on the efficiency of the gearing system.

Even back in the bad old days of 52/42 with five cogs in the back, I never worried about cross chaining. Use the gears you like and replace the chain when it starts to show wear and your relatively expensive cogsets will last a very long time.

Riding with a worn chain destroys gears, not cross chaining.

Improve this answer
1
  • 2
    Very interesting paper. Two unexpected results: 1. Sprocket size and chain tension have a considerable influence on the efficiency which can vary between 85-98%), with larger rear sprocket and more tension being more efficient. 2. Cross chaining is irrelevant for efficiency.-- That said, if you count maintenance down time against average speed, cross chaining may still be inefficient...
    – Peter - Reinstate Monica
    Commented Nov 3, 2016 at 12:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.