I'm getting an electric assist motor for my sport utility cruzbike and
the company (ecospeed.com of Portland, Oregon) needs to know the outer
diameter of the front "downtube" on my V1. Freerider (the tube that
runs from the crank/bottom bracket to the actual front wheel downtube,
and that has the adjustment on the rider's side of the handlebar
post). I don't have any calipers handy and it occurred to me that
this should be a stock answer.

So, if you know the answer -- the outer diameter of that tube on the
crank side of the handlebar post, please advise. The company says I
need it accurate to a millimeter.

Thanks!
John Gear