Started building the Streetfighter around March 2009, and this is where it has got to currently ...

The first set of wheels I have ever laced and trued...

The next thing I made was a sliding seat, I have 4 boys aged 4, 6, 6, & 8, and they all wanted to be able to ride Dad's pedal-cart, which meant making the important things adjustable position, steering linkages, chain length etc.

Here is the seat fully back and the next pic shows the seat fully forward

Then came the fun part of making telescopic steering, and I happened to spot an old scooter that a friend was throwing out, so I grabbed it and hacked it...

This was later refined to a better looking, slim-line model

Finally got the front wheels attached to the chassis, and the boys were so excited being able to sit on their pedal-cart

Then came the really fun bit, sorting out the gearing structure that I wanted, and after much experimentation and hacking various bikes for gears and chainrings I have settled on the following:

The chaindrive is a custom built quadriple chainring

and the rear is using a complex gearing with a multiplier set-up
which is used to drive the final shafts.

The Axle has been made a live axle, ie., all the internal bearings have been removed, the bearing races tightened to just below shearing point, with the lock nuts also tightened to just below shearing point, finished off with a nice weld to make sure that nothing ever moves.
The axle then runs on external bearings, which allows motion to be transmitted to both sides of the chain line. Attached to each side of the live axle is a freewheel hub with a big gear, which is coupled to a very small gear to drive the shafts.

Here it is just a push-cart, the day I got the steering connected