I was wondering if that meant that there would be different tires needed for different types of karts. It seems like normally you get to pick only one brand of tire. I guess what you are saying is that they will make the insides different within same brand depending upon engine
Ohhh right, i understand now.
I think its a good idea to give a rundown of how the CIK homologate tires and what it actually means within the context of karting, it may give some cool insight for newcomers and oldtimers alike
Much like the homologation of chassis and engines, tires go through a dedicated protocol that needs to be followed to ensure the respect of both chemical, mechanical and performance related parameters. Within the realm of international CIK karting, only homologated products are accepted for international events (Including FIA Karting events, of course)
As such, and as per the regulations, manufacturers are free to homologate the following types of tires:
- 1 âPrimeâ compound tire (what is considered to be the soft compound, usually used by seniors and KZ, for instance, the new SM2 by MG, the Vega XM4âŚ)
- 1 âOptionâ compound tire (what is considered to be the hard compound, ussualy used by Juniors, for instance the new SH2 by MG, the Vega XH4âŚ)
- 1 âMiniâ compound tire (for mini karts)
- 2 âwet weatherâ compound of tires (one for adults, and one for minis)
What is important to note, above the required mechanical stress tests that the compound has to pass, which are done in a lab in Italy, is for the necessity of a 2% delta lap time between a Prime and an Option of the same brand to exist (ergo, the SM2 must be 2% a lap quicker than the SH2)
Until the last gen (prior to 2024), homologation tests were carried out behind closed doors on the Sarno circuit, in Italy, with the help of multiple chassis manufacturers and their factory teams, over the course of two days. The ultimate performance of all tires going through the homologation process was tested, along with their longevity. All tests were carried out on KZ karts, for the adults, and on mini karts for the minis.
For this new homologation period, we have transitioned to homologation procedures that take place on a proprietary tire test test bench, which subject the tire to multiple duty cycle to quantify its wearlife in clinical conditions and, more importantly, in a repeatable manner.
Eliminating outside, external variables and replacing them with a scientific method allows us to randomly check any homologated tire found on the market at any point during the homologation period, and make sure it corresponds to the values that were outputted during the official homologation test, on the test bench. This well help us assure that tires do not evolve during their homologation period, which is clearly unwished. If you want to read more, check out Art 31.8 of the Homol. Regs:
CIK-FIA Homologated tires are developed to answer to the requirements seen at international level, which is why they are always developed with 2 stroke racing in mind. It does not mean you cannot use a CIK-FIA homologated Option tire for 206 Racing, but it more often than not will have too much grip for the speed of the kart. Nevertheless, manufacturers make many more tires outside of the CIK-FIA range, such as the Vega SL4 (the Reds), which are harder, non homologated and offer less grip to be much more suited for 4 cycle racing .
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Very insightful, thank you for educating us 
Very thorough information thank you. It is worth noting that not all tires designed for low horsepower have less grip than for example the MG homologated tires. The Vega red VAHâs we have in the US (Vega red but different from the SL4s) have significantly more grip (especially in the sidewall flex) than the MG Red and possibly the MG yellow. Really depends on the series though, some run softer than 2 stroke tires and some run tires meant for rental karts 
Interesting info, thanks for correcting me. I defaulted to âLower hp = harder tire requiredâ, purely from a mechanical perspective. Iâm sadly not familiar with non-homologated tires outside of Europe, and i know there are a lot of them around the worldâŚ
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The 206 is CKNA should ABSOLUTELY NOT be on that Vega Red tire. Way too much grip for that low horsepower class. Just sticks the kart to the track and bogs the motor down.
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The Vegas are a million times nicer to drive than the MG Orange imo.
The old MG Red was my favorite, a good balance of not too much or too little grip. Havenât tried the new one yet though. The Vegas are too soft in the sidewall in my opinion but the racing is still good and it has some advantages (cleaner starts, defending without killing lap time etc.)
Letâs go back to running Dunlop gumballs and make tire management a thing again. Even the old spec MG Yellows would be good. Those felt way softer than todayâs Yellows.
206 is over-tired on anything softer than an MG Red.
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I had the same takeaway. Softer sidewall seems evident from this data.
I heard fairly recently that the reason why tires from the 90âs (and maybe early 2000âs) are so much grippier isnât because some now-outlawed forms of rubber/chemicals which were banned, but because in more recent times homologation required a higher level of wear resistance in order to pass. I didnât really know what to think of this. After reading the document that @Simone_Perego uploaded above, I see that the latter is true:
Additionally, the tyre Manufacturer must establish a self-certification
stating that its tyre can cover 150 (Prime) or 250 (Option) km under
all circumstances; the CIK-FIA reserves the possibility of carrying out
controls.The CIK-FIA may verify, by means of a test bench or track tests
(according to the âTesting method for tyre classification by wear
lifeâ), the correlation of the self-certification submitted by the
Manufacturer at the time of homologation with the denomination of
the compound indicated on the Homologation Form.
In order to do this, the Inspector will take and seal six tyres for each
model during the homologation inspection, and have them
transported by the Manufacturer at the designated time and place
described in the âTesting method for tyre classification by wear lifeâ.âŚThe objective is to check the tyre type registered by the Manufacturer
at the time of homologation, by means of bench tests:
For the Prime specification, 180 laps (corresponding to 150 km on
test track) and for the Option/Mini specification, 300 laps
(corresponding to 250 km).The CIK-FIA will ask the recognised laboratory to carry out the
prescribed tests below in order to establish a Prime/Option/Mini test
to verify the wear life.
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When I read this I wonder are we seeing new tires because of this testing change or is it just a coincidence?
âNew tiresâ as in new model of tires or different constructions?
If itâs new models, it is because the old homologation expired on the 31st of December 2023. As such, all older models are now de-facto âillegalâ for events that mandate the utilization of currently homologated material (it would be like a chassis homologation expiring, and not being valid anymore). In the US, as there is no national sanctioning body active which aligns with FIA regulations, all private seriesâ promoters defaulted to the new homologation tiresâ based on the fact that the tire manufacturers themselves do not produce the old homologation anymore.
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Great information and truly shines some light on the current changes. I think the trend is very positive from what Iâve seen so far. Time will tell.
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Is anyone aware of these tires making it to a kart shop yet, or are they still focused on provisioning the series running them at this stage? Are these tires indeed marked âSH2â on sidewall?
They are definitely clearly marked on the sidewall with SH2 (saw plenty of pictures of them from Florida). I have not seen any in person or at kart shops yet, but I havenât looked either. Comet said they expected to have them by the end of January (woah, thats today).
Apparently Kartsport NA has some which wouldnât surprise me
Kartsport website says:
*** SH2 online preorders not available to ship until mid February. Stock only available for SKUSA Winter Series pickup at Homestead, FL. ***
Ah my bad then, Mid Feb isnt too bad tbf
Considering that Trackhouse (next door to KartSport NA) has their first round mid February, it sounds terrible. They havenât announced which tire will be ran, but I am guessing there will be a mad-dash on the SH2s
Yeah thatâs true. I didnât realize they had a race that early but I wouldnât be suprised if it turns out to be a mess all over the country.