Archive

Archive for November, 2010

Idle Hands

November 29th, 2010 Comments off

The plans require two idlers to route the tight side of the chain through an elongated ‘Z’ (over the chainstay and under the seat) on its way to the chainrings. Since I don’t have any chainstays I intend to keep a cleaner line and just use one of these mighty sprockets. It was initially too wide to fit my multispeed chain but was easy to modify. A couple of further adaptations are plausible, namely:

  • making a keeper from an old front derailleur
  • allowing the sprocket to float laterally on its shaft so it can slide as the chain shifts gears

but I don’t think either will be critical. Although the chain will run on the underside of the sprocket it should be pulled tight enough by the chainrings to maintain contact. The distance from the idler to the rear cluster will likely be more than the span on a regular bike, and there should be enough flex in the chain to allow smooth shifting at that distance. We’ll see.

Deconstruction #2

November 19th, 2010 Comments off

A moderate amount of cutting and grinding later, and here are some parts for reuse:

Clockwise from left:

  1. front forks with head tube
  2. rear suspension arm
  3. bottom bracket with derailleur mount tube
  4. head and steerer tube for under seat steering.

The suspension arm includes the pivot tube surgically extracted from the old frame, and that head tube will be cut down significantly as the USS doesn’t need the heft.

I’ll also reuse most of the components from the donor bike, including the brakes, cranks, derailleurs, levers and shifters. They are all serviceable though not high-end. Once I have a working bike it’ll be trivial to upgrade them if I’m so inclined.

Deconstruction #1

November 8th, 2010 Comments off

The donor bike broke down into its constituent parts quite easily. Everything seems to be in reasonable shape, just in need of cleaning up and a good greasing.

The parts I’ll be using are:

  • rear wheel, suspension arm and brake
  • entire drivetrain (I’ll have to cut the bottom bracket from the frame)
  • shifters and brake levers (unless I find better ones)
  • head and steerer tube (for my under-seat steering)

The LongShot front wheel and fork will come from another scrap bike.

Seat Construction #2

November 6th, 2010 1 comment

The seat is now full of holes, sanded and ready to prime and paint:

Then I’ll stick some suitable foam to the face and it’ll be done. The oval slot at the top is a handle for wheeling the bike along as using the handlebars won’t be very practical.