PB,
No, I would say the opposite; the sled feels very stable on it. Sure, you can move it some what side to side while it's elevated because of all the weight lifted up on it but it stills feels sturdy. The only thing that would be nice is if the wheels locked in place so it wouldn't move on you while your working on the sled. I just finished removing my carbs tonight and I have to say of all the years I do this during the pre-season prep & cleaning, this was the first time my back is not sore from bending over to work on the sled. 8)