Not that it's of any consolation or help to those of you running belts, I had a revealation over the weekend with regard to at least some of the timing chains that come on Co-Motion's tandems.... They're 8 speed!
We were out riding with friends on Sat & Sun and during Sunday's ride a new Periscope triplet blew a link off the rear-most timing chain. I figure no big deal, as I always carry at least one 9 speed master link in our seat pack.
So, I go to put the link on and it's not wide enough by about .25mm! Moveover, since the Periscope is a 10 speed and running a Shimano chain on the drive-side there's no way to cannibalize that chain for parts.
I forced the 9 speed master link onto the chain by rolling the chain back onto the timing rings such that chain tension pulled the master link into the closed position so they could finish the ride but wow, what an unwelcomed surprise that was.
I've since re-stocked my seat pack with 8, 9 and 10 speed masterlinks and also threw in three three-link 8, 9 and 10 speed chain segments so I'll be better prepared in the future. I really miss the old days when you could use a chain breaker to fix chains out on the road before Shimano introduced it's one-time use rivet pins and when you could be pretty sure that the drive side and timing chains were at least the same width, e.g., all 8 speed or all 9 speed. It was also nice when a master link and a craft-quality or imported beer cost about the same as it made for an easy pay-back; I'm gonna have to raise my road-side service parts fee to a Margarita going forward.