I'm going to say nothing that's "cost effective" like a just change tires and go type of "cost effective". I have a CRF110 for my son, the problem is the front....it's a 14inch wheel....don't know anyone that makes a front for that. And the rear wheel is pinched on the stock rim. I got my son a set of wheels from K&J Racing Solutions in LewZeeeeeAnnna. Wasn't all that cheap, wasn't horrible for the set of wheels with Mitas tires on them, either. Then, the rear wheel is too wide for the "direct swap" with the stock chain. It rubs the swingarm IF you can get it on, and the chain will be as tight as a guitar string. Luckily, 420 chains are pretty cheap. That was my experience.
I didn't see the 140...and was thinking of the KLX110 in my original response. Sorry to the OP....MY mistake.
It’s an L. I should be clearer, this has (I believe) the 19” front 16” rear and I was curious what street type tire people might use for kart track just for fun/practice. I know ZERO about the little bikes. I thought I’d read that people use BT45s for this type of use before they drop $1000 Or more on a set of SUMO wheels. Neighbor is cleaning out his stable and giving me a screaming deal on low hour 140 (like new).
Hey Mark, The BT45V are the easy way to go, 100/90-19 for the front and 110/90-16 for the rear (these are both front tires).
ok - best source for the BT45s cheap? (Cheaper?) Looks Bike Bandit is about $240 shipped for the pair.
try rockymountainATV. https://www.rockymountainatvmc.com/...-battlax-bt45-v-rated-front-motorcycle-tire-p
I don't think you're going to find them for too much less than $230-240/ set. https://www.ebay.com/itm/110-90-16-...251512&hash=item56db39a108:g:WDcAAOSwTx1etHyv
Yes, unless you do a tubeless conversion where the spoke nipples are sealed up with sealer and sealing tape.