Saturday, September 25, 2010

Bob Jackson tandem

Completed, if not finished, this morning.

I have had the frame for about 20 years, but have not ridden it since the mid '90s.
Earlier this year I had some good rides with Gayle on Worrall's tandem, so I decided to build this one up with modern components so that we can shift gears while climbing or sprinting out of the saddle

Fortunately, when I was younger and stupider I had respaced the dropouts back so that a modern rear wheel would fit.
The drivetrain is a Campagnolo/Shimano/SRAM hybrid, with Campagnolo Chorus 10 speed Ergopower and rear derailler and a Shimano Ultregra hub with SRAM PG970 12-26 cassette.
A J-Tek Shiftmate corrects the cable pull of the 10 speed Campag shifter for the 9 speed cassette.
Cranks are Suntour Superbe Pro, rethreaded by Bruno at Cycle Express, on Campagnolo Veloce 111mm bottom brackets.

Chainrings are 52/38, which should give us a low enough bottom gear, but might leave us a bit short at the top end.

Because of the curved seattube, the front derailler needs to be positioned a couple of centimeters further back, hopefully easy to achieve by making an aluminium packer to go between the mounting bracket and the derailler.

The brakes are self-energising cantilevers. Front is Scott SE, rear is Suntour XC Pro.

All the Bob Jackson tandem photos

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