New tandem owner and a question
 

howdy!

i usually post in classic & vintage. i'm new to tandems, and just picked up a 2003 bike friday tandem to start tandem riding with my 6-year old daughter. so far i love it and am very happy with the design and construction. i just gave it a tune-up, replaced all the cables and did some drivetrain upgrades (from low-end SRAM to middle-end shimano deore). i am amazed at how light, fast and agile this is... even when ridden without a stoker! i've never ridden a small-wheeled bike before, and it's an interesting and pleasant experience.

my question pertains to the timing chain and crank synchronization: how are the cranks supposed to be synchronized? in phase? 90 degrees out of phase? 180 degrees? or other?

thanks in advance!

Usually bikes are delivered in phase. However, there are those who prefer different degrees of out of phase.

I'd say 90% of bikes run in phase. Some people get crazy if they are even a link out. Those that want to be OOP are equally certain that it works better for them. There are lots of threads here if you want to investigate further. As far as a Bike Friday versus other tandems goes, there's no difference in how you would want to set the phase. Personally I like IP.

We had a Bike Friday Tandem Traveler XL. Great bike to ride with a child stoker, and not a bad bike for two adults, particularly travelling.

As already mentioned, In phase,or out of phase is a personal preference thing.

Although I'd argue that having a child stoker, there is one more reason to prefer in phase. You just won't be getting much power from the back, so the smoothing benefits from OOP become less significant.

And in phase you always know where the stokers feet are when you're cornering, without needing to think about it.

But never 180 degrees out of phase. The three common versions are in phase; 5-10 degrees out of phase, captain leading; and 90 degrees out of phase. 180 degrees makes cornering an issue, since there is no good place to put the pedals.

thanks, everyone! i'll start be keeping them IP... then maybe experiment later on down the road.

I actually have mine with a 38t front ring and 48t rear ring so I can spin faster than my wife. She's not used to the roadracer cadence and I'd go bats if I had to mash gears at 70-80 rpms.

So how many strokes before you are in phase for that split second?

I think it's something like 4 strokes for 3 of hers. Only concern I have is flying around corners. We just have to make sure neither of our inside pedals are down.

38/48=0.79. therefore the stoker is pedaling at almost 80% of the rate as the captain. so for every 5 crank revolutions for the captain, the stoker makes 4 (3.96, actually, but let's call it 4!).