MOPED ARMY

I’m running the 16 inch k55, on my magnum and they are very sticky once they get hot. I’m also running like 12 psi in the front and 22 in the rear. On my other racer a couple years ago I was on a pair of 2.5 mc11 and people were talking shit until I was putting down better lap times with a stock full rigid puch than 70cc Peugeot’s. That year I also brought a Sebring with a 3 year old set of sava slicks and yeah I couldn’t get enough heat in the tire in the warm up lap and had to take it easy for the first few laps. Alex got his nice and toasty flopping around on the warm up lap, but I’m just not gonna do that. I’ll probably end up putting k56 on that Sebring if I bring it back to the track and shelf those slicks. They’re pretty old at this point.

IMHO: Run the BT39SS if you can afford to. they are about the same size as 2.75 - i wouldn't be scared off by the min rec rim width. We run the 2.5" x 18" on MB5s and they are skinny by fantastic even in the wet. They have done very well on the CVMP track on French bikes (as have the Sava slicks).

cheap enough straight from japan. https://japan.webike.net/products/1688200.html

the next step toward slicks on moped sized rims is going to be the 90/580 Battlax v02 https://japan.webike.net/products/21721792.html

they are significantly wider - but moto3 spec slicks. you will most likely want appropriate rims to ensure the correct contact patch size and location to get the most out of them.

with the right rims you can run the dunlop KR189 rains. bikes aren't heavy or fast enough to shred them in the dry, and offer crazy grip.

Good tires will flush out weaknesses in your frame and suspension as you corner more aggressively.

tracks like CVMP won't push that limit as much because of the lower speeds.

SO, I think you would be fine continuing your program with heidenaus - i think they are more substantial than gp-1's which have a wimpy sidewall.

but if you got the BT39's you would not be disappointed and I think it would be a good low risk, high confidence investment.

Everyone racing 17" minis uses GP125/Moto 3 slicks. bridgestone, Dunlop, sava/mitas and PMT all make a set. the fronts are generally 90/80-R17 the rears are generally 115/75-R17. You should use tire warmers unless its a pretty hot day, but they aren't absolutely essential. people jam them on 1.4" rims all the time. The profile isn't optimal but it's fine. You could also just lace up the correct 1.6" excel

were I you, I'd be designing my frame around running 12's and using the Sava mc36 120 width or the PMT slicks. the 12's are well known for being the best for kart tracks. It's pretty noticeable how much quicker you can throw the bike around and the width and profile makes it feel impossible to low side.

https://www.73motoparts.com/product-page/honda-crf150r-rb-mag-wheels-set (edited)

fyi i was today years old when i was informed heidnau had race compound offerings of a lot of moped sized shit. i know treats lists the k56 as a racing tire, but the k56R is the non DOT version RSW compound

https://www.moto-amore.com/shop/k56r-heidenau-racing-tires/