Recreational & Family - Trail-a-bike spins seat normal?

Hi,
I just received a Instep Pathfinder from a neighbor and tested it out yesterday -- attaching it to my MTB. It attaches to the seat post with 4 bolt clamp. It then has a coupler and quick release.

Anyway, I had problems with it causing my seatpost/seat. Basically, when I take turns, the trail-a-bike weight (with my son on it) causes my seat to slowly go out of alignment. It's not really dangerous b/c I notice it before it gets really bad. But I want to know if this is normal or not.

Is it just a matter of tightening the seatpost collar more? I though I had clamped pretty tight. Or, is this just normal for trail-a-bikes?

Thanks in advance.

Not normal.

Clamp is too tight, and possibly the wrong shim is being used. Also, a little grease inside the hitch point, on the seat post, wouldn't hurt.

From what I see, the Pathfinder is properly attached to the seatpost.

It could be that the seatpost clamp is not tight enough.

Definately not normal!

Thanks for replies.
I guess I should have asked is this a "common" problem? -- I realize it's not normal and should not happen. If it's a common problem, I guess I can live with adjusting my seat every 15 mins. or so.

DieselDan: If anything, I think the problem is the seatpost clamp is not tight enough b/c the whole seatpost is being turned (slightly) out of alignment after about 15 mins. of riding.


I'm not using any shims as the Pathfinder clamps tight enough onto the seatpost.