This was a fun 'special needs' build.
The customer has COPD so he needs to take a battery powered breather along.
He picked out the Sun EZ3 USX HD 21-speed trike and had me 'make it go' with a generous budget.
http://www.utahtrikes.com/PROD-11617617.html
I put a SickBikeParts.com 48V...