I refuse to be outsmarted by an inanimate object, in this case my Alta SM. the tires I installed (see above pictures) suck in the dirt, the 19 and 21 inch wheels won't clear the front brake caliper, so now I'm going to order real knobbies but can't find a wide enough front knobby. is there any reason I shouldn't run a rear tire on the front wheel? I'm not going to street ride that way, I have the extra sm wheels with sport bike tires and same sprocket and discs so it's a quick switch. I'm leaning towards a Kenda k670 120/90/17 front and the same rear except 130/90/17 any reason why not or does anyone know if I can go wider either front or rear? my ONLY other choices are irc ve35/ve33 and those are only available in 100/100/17...110/100/17...460/100/17 0r 510/100/17 the kendas are dot approved and the irc's are not. all are rear tires!