nope dont get kenda, their knobs fall off hell easy (soft compund) and are not good for diff kinds of riding, eg, rocky, dirt, cement etc.
get a hold of Race Wear and they now have Shinko's in 12" which are the most aggressive & long lasting tyre on the market.
their web site doesnt show the 12"s (bottom of page) but they emailed me last week saying they are in http://www.racewear.com.au/product/subcategory.cgi?sc=32
I got my kenda from my thumpstar dealer but not goin to get kenda unless i really have to. im doin a buy from the USA shortly and going to get the 'extreme' tyre widest & most aggressive tyre on the market. http://www.xtrememotorco.com/accessories/Default.aspx
5th product from bottom of page.
WHEEL/TIRE-3.50 x 12 XTREME KNOBBY
3.50 x 12 Xtreme Knobbies are agressive in tread and price.This tire is made exclusively for XTREME. Wide body and agressive tread along with a tall profile give 12 inchers an advantage on rutted or soft tracks.
80 x 100 is either 80mm wide x 100 high or viceversa, 3.00 is 3 inches wide. if the new tyre is 100mm wide you will have 4 inches or if its 80mm you will have a 3 inch wide tyre.