check this web site out dozer
go to
www.holeshotktm.com
it has a KTM only message board monitored by a KTM dealer(20+years)
the board is an incredible asset to a KTM owner.
along with board you will have all the info u need
i think your mechanic is wrong i have both progressive and straight rate springs for KTM and the way u described them i think WP is right they are progressive springs. i like the straight rate for mx and playing but the progressives are supposed to be more plush but i weigh about the same and i was told heavier riders wont see any advantage to progressive rates (your weight will blow through the soft progressive part of the spring)
thats my 2 cents
check out the holeshot message board
happy landings
Lawndart Dave '98 380M/XC