Old Schwinn Road Bike Chop Chop Build

I thought some of you may be interested in what's going on with my Latest build - I am doing some radical engineering to rig up a swing arm dual suspension bike.

First, I started with a gigantic road bike that was given to me, set up for very tall riders. I chopped the head tube and the seat tube, removing almost 4 inches of tubing.

I'm going to affix a 1/2" axle perpendicular to the seattube with heavy welded steel. The swingarm axle hold a welded double sprocket offset about an inch that will feed the left side 36 tooth sprocket, anchored via clamshell on a 24" wheel. The swingarm width will be 7 inches, with my custom hub being 6 1/2" wide. The hub will ride on a 1/2" axle! It will take something to break that.

I am shooting for a 47" wheelbase.

I did some test fittings on the frame to get an idea of how it would look.

I'll need to dish out some money for sprockets, tube and tire, stepup drillbit (to put 5/8" bushing into swingarm), and two shocks to support the swingarm.

I will be running a 1' piece of heavy Duty unistrut along but slightly below the top tube/ down tube interface. That will hold a spring saddle and grab the top of the shocks.

 

[Timbone]

Update: due to a bent frame on my beloved OCC Chopper Bike, I've stepped up my timeline for finishing the Old School Schwinn Dual Suspension.

This is pretty close to a build from scratch design. Hub is homemade w/ 1/2" axle. Fashioning adapters for brakes front and back. Swingarms and the swingarm axle bracket are my own design. Will require a spring tensioner for the pedal chain. Top of seat will be even with top tube. Finally took the time to weld up some custom chain tugs. So many details..

Just need two sprockets, 2 shock absorbers and at least one disk brake.

Here are pics of a very raw pair of swingarms and my new chain tugs:

 

[FurryOnTheInside]

Whoaa I was not expecting that. Those look very industrial / steam punk!

 

[Timbone]

Whoaa I was not expecting that. Those look very industrial / steam punk!

Looks better in real life.

Here's a rough idea of what I am shooting for:

 

[Frankenstein]

And people look at me weird for cutting just an 18 inch section of my downtube out.

 

[Timbone]

I am going to start with a suspension front fork for a 26" wheel. But I want two 24" wheels. Why? The bike will sit lower, I'll have a bit more trail for a more stable ride, and it will look better.

Here are the rudiments of a front v-brake adapter:

 

[Frankenstein]

Yeah that looks like something one could find in my yard or basement.

 

[Timbone]

I have finished the rough welding of the frame. The support tail piece is on - it will attach to the tops of the shocks that will connect to the swing arms. Like a real motorcycle! I had intended to place the seat on there but I may not have allowed enough room for my pedaling feet. Something will have to change.

Another pic:

 

[Timbone]

Rough fitting of the completed swingarm assembly.

 

[Frankenstein]

Looks good, I wonder what are you going about the chain slack, are you doing a jackshaft type deal and use the pivot as the center of the connecting sprocket?