The stock OTK seat position is 5mm below the frame for someone my height. That’s with the stock OTK seat that comes with the kart.
In general, when swapping to a Tillett is it recommended to stay at the stock height?
I’ve been told it’s common to raise the Tillett up to parallel with the bottom of the frame.
VG stiffness in this case.
We mount almost all Tillett seats flush with the bottom rails unless the driver is over 5’10” probably.
If your track is smooth as marble and you never put a wheel off, then I’m sure you can get away with mounting it 5mm below. However I typically go pretty much flush with the rails to keep from blasting the bottom out of an expensive seat. I also despise fitting seats so outside of the expense I just don’t want to do it twice.
Hmmm… i’m right at 6’0 about 170lbs, so I may experiment with it some.
You will find a tick or two below frame rails will make a difference on weight transfer when you are 6’+. Another way to help is to tilt the seat back a bit. I have the front even with the frame rails and the rear flat a tick below (2-3mm). I find this helps get my CG down a little without dragging the seat bottom around the track. Of course track surface will have an effect. Super bumpy or being prone to dropping a wheel will shorten the seat life.
I had to play with seat position a lot in my otk with tillet seat and ended up just a tick above the frame rails but had to have the seat a bit further forward than otk specs to get it to work right. Evinco blue tires fairly low grip track in a 80cc shifter kart.
Tillett also sells a more reclined seat (e.g. T9.5) but at 5’11" I didn’t prefer it. I also install flush.