Originally Posted by
BigBri
*DANGER* - A seat post mount will transfer the weight of the trailer to the seat post when the brakes are applied. During a turn, that weight transfer will have a tendency to topple the bike since the attachment point is high up and the load is being applied sideways. Trailers mounted at the rear axel or chain stays do not have that problem to the same degree, since the weight transfer is much lower down on the bike. A lower mount limits the amount of leverage given to the sideways pushing force.
This is right. When I was a teenager I got one of these seat post mounted heavy duty steel trailer. I got it for free from the trash and rebuilt it with a wooden box. Similar to that:
Swedish Military Bicycle Trailer - $149.95 :: Colemans Military Surplus LLC - Your one-stop US and European Army/Navy surplus store with products for hunting, camping, emergency preparedness, and survival gear
My parents had a leased a small property outside our town where they grew stuff and which was used for partying. To mow the grass I hauled the lawnmower on this trailer. The trailer itself was way above 50lbs. I guess 60+. With the extra weight of a gasoline lawnmower, gas can and some tools this trailer was pushing really bad. Not just in corners but also on the straight. Plus my bike back then was only a 3 speed with weak brakes. Fortunately there were no hills.
But nowadays I would still be interested in getting a seat post mount trailer for grocery shopping. Something like that:
http://www.amazon.de/Fahrradanh%C3%A...SZ6RVZJWSPRH1W
The reason I like these: You can take them into the grocery store and use them as shopping cart. But I have not seen these type of trailers here in the US. And not for a cheap price.