Seat post keeps slipping
I've got an 05 Trance, and my seatpost keeps slipping. I know the size is right (30.9), but it keeps slipping. I've tried a QR and a regular collar, but no luck.
It is wreaking havoc with my racing, because I have to constantly adjust the saddle on the fly. I know it is slipping because I can feel more in my quads, and when I take the measurements of the seat post ride, they are different.
I've got a set back Thompson Elite. This also happened with a RaceFace Deus post as well.
Any help I can get would be great!
Wierd. One of the nice things about a Thomson is the knurling which means less clamping force is required to keep it in place. I adjust my post height while riding with one hand and it never moves, even with the stock Giant QR. What sort of grease are you using?
Excluding any equipment/component problems (which you should be able to spot quite easily), it definitely sounds to me that the clamp is not tight enough.
I don't think rigid posts are meant to be adjusted on the fly ... so if you can easily adjust it you are either a magician (Merlin himself if no QR clamp), or not doing a very efficient job and leaving it prone to slippage.
If using a QR you should be able to feel decent resistance when closing it with your hand ... not enough to leave a mark, mind you, but definitely some pressure to it. With a basic clamp it is more difficult to tell, but don't worry too much, aluminum posts can withstand quite a bit of clamping force.
I find lubricating the QR pivot can give more clamping force with less effort.
Plus, try wiping any grease from the seatpost and inside the tube where it clamps.