I am looking for replacement front tires for my RT and wonder what size of front tire can I put on it without changing the handling?
If you swap out the Kendas & put just about
anything else in the way of an a/mkt quality tire on it,
I'm sorry, but you WILL change the ride & handling for the better!! 
pps:
Anything from a 155/65R15 thru to a 175/60R15 will fit; go much larger & you'll find it difficult to squeeze it in under the OE fenders without
some modification; much smaller & it won't corner too well at all! (& Yes, I know that for a fact! :sour: I did the testing on someone else's dime, so can't say much more, but at least I didn't hafta
pay for those 155/50's!!

)
Apart from that, there are literally
HUNDREDS of tire threads on the Forum discussing at length things like brands, sizes, pressures, what fits, what doesn't, balancing, not balancing, using balance beads or discs, and a heap more besides -
it's WELL worth doing a bit of searching (top right corner - enter tires & tick 'Search Titles Only'
) and a fair whack of reading.... or you could just go out & buy whatever good quality tire the tire place of your choice will fit on the 15"
'J' type CAR rim that's up front on the Spyders

hyea: I reckon whatever they fit, it's
STILL gonna be better than the OE Spec Kendas in all respects! But if they suit your needs..... that's all most Dealers will fit! :gaah:
Enjoy! :thumbup: