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MK3 Raven Twin chain tensioning

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martinf:

--- Quote from: Pavel on August 19, 2020, 03:28:23 pm ---Is there a chainglider product that would fit onto a Tandem?

--- End quote ---

Almost certainly not on the (front) timing chain. It might be possible on the (rear) drive chain if:

- the timing chain is on the left side (crossover drive).
- the tandem uses a Rohloff hub.
- the chainring and sprocket sizes are one of the limited combinations that work with a Rohloff-specific Chainglider.

martinf:
If it is compatible with the crankset, sprocket and required gear range constraints, it might be worth trying this KMC wide chainring/chain/sprocket system:

https://www.kmcchain.eu/10000km

Though I doubt if they would guarantee 10,000 kms on a tandem.

Danneaux:

--- Quote ---If it is compatible with the crankset, sprocket and required gear range constraints, it might be worth trying this KMC wide chainring/chain/sprocket system...
--- End quote ---
As a data point, I am running a 1/8in chain, sprocket, and chainring on my Fixie and found the wider bearing surface has so far reduced chain "stretch" (lengthening due to wear) and the gear teeth are lasting longer as well. Unlike my Nomad's Rohloff sprocket, the Fixie's is heat-treated steel rather than stainless.

A fixed-gear bike (mine, anyway) tends to load the chain not only under drive but also during backpedaling/braking and I didn't find the 3/32in setup to last so long over time despite the straight chainline. It seems Japan's Keirin racers agree; bikes for this high-stakes form of parimutuel betting are setup for high strength and maximum reliability and though light, the bikes are built for stout as muscular riders really hammer away in the closing sprint of each heat. See:
https://en.wikipedia.org/wiki/Keirin
https://www.youtube.com/watch?v=pVK0iwScTvs

My own tandem used 3/32in chainrings and an older 6-sp SunTour indexed freewheel. It gets good service life from the derailleur components as well as the timing chain. The timing chain of course lasts longer because it is a straight run, the same as you would find with an IGH. I set my timing chain up initially for 12.5mm/or a half-inch of slack in the lower run. It has worked well for me after centralizing the two timing chainrings to make sure they were turning as round as could be. My tandem doesn't flex enough to make the chain too tight under high pedaling loads, but this can occasionally be a problem for a strong team on a cheap or lightweight tandem, especially in hilly country.

Best,

Dan.

Pavel:
Is it a better idea. to buy a 1/8th" chain for a tandem versus a 3/32", for longevity purposes?  What about the 1/6 gram weight penalty, I wonder, if going ultra light, versus ultra smart?

Aleman:

--- Quote from: Pavel on August 20, 2020, 12:37:28 am ---Is it a better idea. to buy a 1/8th" chain for a tandem versus a 3/32", for longevity purposes?  What about the 1/6 gram weight penalty, I wonder, if going ultra light, versus ultra smart?

--- End quote ---
My Mk 2 was supplied with KMC-e 1/2 inch by 3/32 chain. I'm going to stick with that, and see what sort of wear rates I'm getting, before worrying too much about it ... As I said, I may also by a couple more lengths of it to try and minimise wear anyway.

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