Recommend a QR Seatpost Clamp?

Escher303

The QR seatpost clamp on my GF's Rockrider is very hard to do up tight enough to stop the seatpost slipping. I want to get her a decent one but not end up with one just as bad.

Can anyone recommend a brand and model please?

coulddobetter

Hope

Giraffoto

On-one "Simple" clamp. Cheap too!

Chunkers1980

Or just apply a smear of grease to the cam if it is open.

Escher303

Thanks all, Will try some grease,or else I think the On-One is the Right-One