Originally Posted by
carleton
There is something that you guys should know about the seat mast and the collar.
It is not designed to be adjustable. It is designed to sit RIGHT on the seat mast. There will be no up/down fine tuning. You fine tune it with the hack saw.
I've seen people slide the collar up and try to pinch the two bolts to hold it in the new elevated position, just to have it slip down...because it's not designed to float above the top of the seat mast.
The idea is to cut the seat mast at EXACTLY the right height. But, when you get it cut, have the mechanic shave off 5mm, 1cm, and 2cm sections of the leftover part. Use these as shims to go up if needed.
Edit:
It may be designed to float above the seat mast...but it doesn't do so very well and often slips down...even for normal sized riders. It's the odd bump in the road that will do it.
i think you can have it a little above the top of the cut and be okay, i know there's some leeway on road frames with ISMs. the danger of having it too high above the cut comes from damaging the tubing.
maybe throw some carbon anti slip in the clamp-tube interface to prevent slipping.