Tandem Cycling - chains

OK.. a nice easy one: chain recommendations. I was going to order three DuraAce 9sp chains to change out the drivetrain on my CoMo. They shift well and are durable. Have had OK luck with Sram. Nashbar has timing chains on sale for $8 but they're 8sp chains. Does that matter on the timing side? I have Mega Exo cranks/rings/ 9sp Ultegra.... fire away.

You can put anything on the timing side... 8sp, 9sp it doesn't matter.

thanks. no correlation betwen teh width of the chainring and the required chain?

OK.. a nice easy one: chain recommendations. I was going to order three DuraAce 9sp chains to change out the drivetrain on my CoMo. They shift well and are durable. Have had OK luck with Sram. Nashbar has timing chains on sale for $8 but they're 8sp chains. Does that matter on the timing side? I have Mega Exo cranks/rings/ 9sp Ultegra.... fire away.

The only point I would make is that in the case of a chain breakage, and you have different chains on the timing and rear, then you will have to be carrying spare links for both types of Chains. If you fit the same chain on both, then only one spare set of links to carry. Saves the problem of Identifying which link to use in the pouring rain and torchlight.

I currently have 8 speed chain on the timing and a 9 speed on the rear, but as I am up for new Timing rings shortly I will be changing to 9 speed on both. Saying that- an 8 speed chain is stronger, but I have yet to break a Timing chain. Rear chains are another matter though.

Addition to posting-- Chain rings can come in 8 or 9 speed width. A 9 speed chain will run on the thicker 8 speed chainrings, but one point is that the thickness of chainring will add to the life of that chainring. That is all subject to the quality of the ring in the first place, so buy wisely and go for the quality you can afford.

thanks. no correlation betwen teh width of the chainring and the required chain?

Others will know loads more than I do, but I had the impression that, in practice, you can typically use a 9-speed chain on chainrings that were made with 7-, 8-, or 9-speed drivetrains in mind?

I think that many modern replacement chainrings don't specify width, and I've used them fine with 9-speed chains. Also, my bike was originally 3x7, and I'm currently running one of the original Shimano chainrings with a 9-speed chain, and it's fine.

Or...?

-Greg

After breaking a timing chain on a borrowed tandem, we replaced it with SRAM single-speed chain, figuring that would be tougher and keep the owner peddling longer than the original. Worked fine.

Seems sensible, keeping timing and drive chains compatible. But what about 10sp chains? Are they compatible with 9sp Shimano?

But what about 10sp chains? Are they compatible with 9sp Shimano?

You would need to measure the width of your particular chainring teeth and compare it to the interior width of the 10 speed chain you're interested in using to see how much margin there is. There's a certain degree of varability in 9 speed chainring width and 10 speed chain width these days, depending on the vintage/make/model of chainrings and the chain maker's specs.

Keep in mind that if the tolerances are really tight the chain will start to grab on the chainrings as the teeth start to mushroom. You could always file off the mushroom "caps" if this started to happen, but it would be something you'd want to pay attention to as it manifests itself as a "grinding" sound coming from the cranks -- similar to the sound that you get when you put a new chain on worn-out timing rings.

Have broken a couple timing (cross-over) chains in our day. Nice thing about breaking that chain, (and not the drivechain) stoker can keep on pedaling if you are not able to fix the broken chain. Yeh, pilot still has to steer! Bummer!!!
Most types of chains work fine on timing rings and last longer than drivechains as they do not go through the 'derailling' process.