Trailer on a Motobecane roadbike
 

I'm getting a trailer to haul groceries about 25 miles. Its going to be a lot of weight, and volume, so space and strength are a major issue weight not so much. Should I use a single wheel or a dual wheel? also, http://www.babygiftusa.com/instep-12-qe125.html is a $75 trailer, I don't mind paying more, but I don't want to if that one will work fine. any other hints from people that have tried this before? BTW I posted this in touring instead of commuting because I think you guys would have the most experience with this stuff. Also, I like to go fast, recklessly so, and I think I have the power to do so pulling a 100 lbs. too, any pointers on when not to go fast?