Hi, everybody! I'm a longtime mechanical tinkerer with cars and anything that ticks, I'm working on converting an early 60's Columbia tandem to a longtail cargo bike to use on Cape Cod rail trails to the beach. I'm sure its been done, anybody have examples of theirs? I'm starting with moving the rear crankset to the front and leaving the rear crank empty, any issues with one really long chain? I assume I'll need to replace the tensioner and keep it good and tight. Any tips or lessons learned would be appreciated.
Old tinkerer new bike project
- Thread starter JimmyK
- Start date
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Welcome aboard.
One thought would be to run a chainring at that second BB equal (or larger) to your front ring to act as a "ghost gear" and keep tension. At least then you'll have everything in line and you don't have to mess with any mechanical tensioner. It'll increase your drag though. If you're worried that much about it. Plenty of loooooooong chain runs around this place
Or do like this guy
One thought would be to run a chainring at that second BB equal (or larger) to your front ring to act as a "ghost gear" and keep tension. At least then you'll have everything in line and you don't have to mess with any mechanical tensioner. It'll increase your drag though. If you're worried that much about it. Plenty of loooooooong chain runs around this place
Or do like this guy
I like the look of Cap's post with the rear crank acting as a jack shaft. That's cool. And genius.
Welcome to RRB!
Cool project
! @GuitarlCarl has experience with custom tandems and various stretch bikes...maybe he'll add some ideas.
Cool project
! @GuitarlCarl has experience with custom tandems and various stretch bikes...maybe he'll add some ideas.
Long chains work fine. This bike ( Harlequin T ) did run no tensioner for a while but does better with one. I used a heavy plastic roller with a brass bushing pressed into it that fit a long U-bolt. The U-bolt went around the tube and clamped tight. Then I cut one sides extra threads off to make room for the roller on the other one, effectively a "J-bolt". Savvy? I've also used a skateboard wheel that I center beveled with a hand grinder. It works well on DoorK/Nodor and lights up when it spins. Really the idlers help route the long chain thru the stays very well, where before they rubbed at times.
GC.
I was out in the garage today and snapped a couple pics of Nodor's drivetrain with the skateboard wheel.
GC.
GC.
