setting up a tandem : stoker crankset

[jasong]

I'm looking to put together one of the Tsunami tandem frames Chucks bikes sells.

Are most tandems set up with normal chainrings for the stoker, just
doubled the chainring side of the cranks? So you'd just buy the same
size BB you normally would for a road bike, and 2 chain ring sets? Then
just attach both to the BB (and remove the larger chainring [assuming double chainrings] on the left)?

Was wondering if there were any alignment issues (having that much
crank on the left side, or if the left side of the BB is "ok" with
that) since that's not how they normally work.

Also - the stoker handlebars often seem to just be an inverted stem to the seatpost. It seems like a 1 1/8" stem to a 27.2 seatpost is a close fit, at least with a layer of aluminum can shim.

Thanks, anymore advice appreciated.

 

[gclark8]

Contact Greenspeed, they are experts in this area: http://www.greenspeed.com.au/

 

[Retro Grouch]

You're probably going to want to buy real tandem parts.

A tandem crankset is different. The captains crankset has the chairings on the left side. If you try to just put the crank arms on the other side, the pedal threads will be wrong and your pedals will unscrew. The stoker crankset has a conventional chainring set on the right side and a single chainring on the left so both cranks have to have a chainring spider.

I'd rely on the crankset manufaturer's recommendation regarding bottom bracket spindle length. The front bottom bracket generally has an eccentric to take up slack in the timing chain. The eccentric fits into an oversize bottom bracket shell and is secured to the frame with some variation of a pinch bolt.

Iven if a 1 1/8 stem was the right size, or close to the right size, you'll probably still prefer a real stoker stem because you'll probably want one that's longer than a typicle single bike stem.

 

[geoffs]

I'm looking to put together one of the Tsunami tandem frames Chucks bikes sells.

Are most tandems set up with normal chainrings for the stoker, just
doubled the chainring side of the cranks? So you'd just buy the same
size BB you normally would for a road bike, and 2 chain ring sets? Then
just attach both to the BB (and remove the larger chainring [assuming double chainrings] on the left)?

Was wondering if there were any alignment issues (having that much
crank on the left side, or if the left side of the BB is "ok" with
that) since that's not how they normally work.

Also - the stoker handlebars often seem to just be an inverted stem to the seatpost. It seems like a 1 1/8" stem to a 27.2 seatpost is a close fit, at least with a layer of aluminum can shim.

Thanks, anymore advice appreciated.

For the parts, Tandems East is the place to go

A great info resource is the TandemLink

The main forum for tandems is tandem@hobbes

Cheers

Geoff

Co-Motion Mocha Co-pilot
Santana Sovereign