ORBO Sum of 50

Robertk · Thursday at 8:23 AM

Really looking forward to this build off! The name of my build is 'Sum of 50'. Essentially, I will be using a 1959 Schwinn 24" cantilever frame as the basis. The 'Sum of 50' comes from planning to build this project using a 26" wheel up front and a 24" wheel in the back - 26 + 24 = 50 hence 'Sum of 50'. :wink1:

Using a smaller wheel in the back and a larger one upfront harkens back to the classic dirt bike design. Additionally, Raleigh offered The Edge, Ibis offered the Mountain Trials, and Cannondale offered the SM500 26X24 - all with a smaller wheel in the back designed to increase traction.
Hopefully, I'll be able to use some sort of drum brakes front and back along with multiple speeds.

Robertk · Thursday at 8:29 AM

Here we go….

Pondo · Thursday at 9:10 AM

Cool frame! I like the Sum of 50 moniker. I called my version a 46er a few years ago, but I like this better. :cool2:

Bike from the Dead · Thursday at 10:00 AM

Great name for your Schwinn! Looking forward to seeing it all come together.

Robertk · 2025-01-03T07:37:13-0600

So some decisions have been made on parts and overall approach. First up wheels and hubs. Decided on a polished Sun Rhyno Lite wheel set, so a 24" and 26" are on the way. Brakes will be Sturmey Archer X-rd and X-fd. Since I'm going to use a 5-speed cassette and not a single speed free wheel. The rear dropouts will require cold setting. Enter my ultra high tech frame spreader! :21: