You've only been riding off road five min James. Hold up. Try working on you technique for a while rather than throwing money at the problem.
If you do go down the seat post route straight away choose wisely some have more slop than others. A friend of mine has one but I can't remediable which one unfortunately, although I know he got it from rose.de. His has a small amount of slop but all the others he tried had too much, i.e. and inch or so and the saddle nose.
You've only been riding off road five min James. Hold up. Try working on you technique for a while rather than throwing money at the problem.
If you do go down the seat post route straight away choose wisely some have more slop than others. A friend of mine has one but I can't remediable which one unfortunately, although I know he got it from rose.de. His has a small amount of slop but all the others he tried had too much, i.e. and inch or so and the saddle nose.