This is my BOBike. I have a detatchable rear shelf that locks on and can carry my 65 lbs. BOB (yes I know that is a heavy BOB). I have riden 20 mile with it and my BOB in 90 minutes. That is a little longer then it takes me to ride that far without the BOB - but lets face it - it was heavy. BUT I covered 20 miles in 90 minutes. I doubt all but a few could walk or even run that distance with our without a BOB but not likely in that time frame. I have the DW's bike set up the same way but she was not carrying nearly as much as I was (50 lbs).

Just my 2 cents