I don't own one and need to know how many inches or whatever it takes up (without extra recline, of course that's a partial option as well).
TIA!

 

sorry, no easy answer...different for every helmet, head, butt and seat...if you are a big guy you will want a lower seat to clear...if you are talking stock seats it depends on your size, neck, head and the helmet...better borrow a friends helmet and test fit...

 

Well I'm saying if you don't move the seat or anything, how many inches or cm does it add. I know all helmets are different (I hear GForce sits lower on the head), but I'm asking for someone to give a reasonable guess is all (or go look at a helmet you have a give a more precise number if at all possible).
I'm just looking for a number for the EXTRA space the helmet takes, not an overall number which of course is dependent on height and so forth.

 

Well, I can put it to you this way...I am 6'5" tall and I fit with the seat all the way back and all the way down and I sit up straight.

 

Try this test. Sit where you are comfortable and see if your fist fits between your head and the roof (with knuckles on your head). If that fits, no problem. I've never seen anyone in a 997 that has had an issue and I know some tall guys...