[Jared Russell]

You really ought to have more chain wrap on that gearbox sprocket. Either use idlers or two separate chains to go to the middle and rear wheels. You will also probably want another point of support for the CIMple boxes - currently, they are just attached by that single flange, and will want to toe downwards due to chain tension.

What are you using for axles? (Is it a shoulder bolt?)

Looks like a great start!