Join Date: Nov 2009
Location: Lander, Wyoming
The OEM front inner tube seems to be of medium thickness rubber, good quality.
I will suggest that light or medium duty tubes with a coat of talcum powder on the tube and in the tire will run cooler and chaff less than thicker tubes. Easier to carry spares.
If the nail / thorn / rock or stick is long enough & sharp enough to go thru the cording of the tire, it doesn't much matter what inner tube is inside that tire.
Modify at "YOUR OWN RISK"!
Still riding my 1987 KL650-A1. 85,000+ miles & counting