Well, I've out done myself again......
My old record was 141Kg/310lbs, today I did 153.8Kg/339lbs
Let me tell you, that is a heavy load
I was stopped at one intersection near my house, the road slopes away from the traffic light every so slightly. When I put one foot down with both brakes on, the trailer started to drag me backwards, I had to put both feet down and hold the bike and trailer from going in reverse. The when I went to leave as the light turned green, well, that first 10' or so was hard work!
Otherwise, no problem at all!
Oh yeah, the bike weighs 18.2Kg/40lbs so the total I was moving down the road was 172Kg/379lbs

I don't need much of a hill to get a GOOD workout
