Looking for recommendations on tire make and size based upon other’s experience. I’d rather not have to test the combinations and permutations… Here is the scenario:
Running a club LO206 Sr. class at 325 pounds.
Club rules allow multiple tire options: MG Red, Vega Red, and Bridgestone “C”. 6.00 and 7.10 sizes are allowed.
Track is GVKC in Avon, NY. Very old school design - narrow with tight turns. Always green as no big events are held and motorcycles also use the track. Mixture of old and newer pavement, the surface is not overly abrasive.
Races are classic 3 heat format, with heats of 8-12 laps. Typical lap time depending upon track configuration is 37-40 seconds for the class.
That’s a tough one… low HP low weight class? I’d run 6’s vs 7.10’s. just my opinion.
Have you checked times of the other drivers and tire combo’s? What does the common tire seem to be?
I’d also use aluminum rims and not magnesium. Try to get as much heat in the tires as you can.
That’s what I’d think. Higher HP and heavier class yes, I’d go the 7.1’s. Thing is the LO206 at 325#, and a tire in that kinda harder compound leans me toward using a 6" in the rears.
But, I have no idea of the track and just how much grip is there.
In comparison, I run a modified Kohler 360# class. We are about 14hp, but we need to run YDS’s on a low grip track (Road America Kart Club). We run 6’s, and the World Formulas 370# also ran 6". This year the Word Formula class has switched to YLC’s at the same 370#, I’ll bet most of them are going to run 7.1’s.
Yes, The class is “Sealed Animal Light” , which is basically a LO206 without the ignition limit. the local kart shop seals the heads. Easier to describe it as a LO206 class.
The previous rules listed the tires as “open”. They have since defined the eligible tires.
I’ve checked it out a bit last year - more are on the BS C, some on the MG Red. No one on the Vega…But when I ask, no one has experimented.
Same with a mix of rims. Most chassis are 2 stroke converted for the class and are still running the original rims meant for 7.10. I’ve seen 6.00 stretched onto the 212mm rims.
Chassis is CRG FS4, I have both 180 and 212 mag rims. OEM size is 212. Have run the BS C only, but have tried both 6.00 and 7.10. As a 2-stroke guy the 7.10 feels great,the chassis unloads the IR nicely, but may provide too much grip for the low power. The 6.00 doesn’t provide the same level of IR lift and it isn’t as consistent but aren’t significantly faster or slower.
If you have a good local supplier for MG’s, go that route. Plus the BS YLC’s are being phased out if I’m not mistaken.
Again, I don’t know your track.
Given your first question, and what would I do if I was showing up to race there? I’d run 6" rears and try the aluminum rims first only because I have both alum and mag.
I remember back in Yamaha Can, the 6.00 rears were faster than the 7.10s since the can engine was lower hp, so it was getting bogged down more from the extra grip on 7.10s. I would imagine the same applies for 206 as well.
The same applies for tire compounds to some extent as well I would assume. I know CKNA uses Vega Reds for their classes. I remember looking up the durometer readings for each tire, and the Vega Reds were significantly harder than the MG Red and Bridgestone YLC’s, but they were supposedly faster on a 206. My guess was that they didn’t bind up the kart as much brand new, since the Vega Reds slowed down as soon as they were put on, but the YLC’s actually got faster the more sessions you put on them.
Personally, I’d start with whatever you’re familiar with, or if there’s another series that runs a certain tire, go with that one. Asking around at your club might help too.
HI Aaron, Thanks for the thoughts. I was equating grip with speed - the more grip, the faster in the corners, the better the lap time. I assumed that if you could get the IR to unload the chassis won’t bind and you can manage the higher grip. Evidently this may not be the case as all three harder compounds may provide more than enough grip relative to the power available from the LO206. So it’s really a matter of finding the right level of grip in the setup to optimize corner speed vs. bogging down the motor with excess grip…
No problem, it’s a very common mistake to make especially with karting. Understanding that there can be such a thing as too much grip in a kart is really important to being able to tune a kart well.
One other thing to point out that you had mentioned is that when tuning a kart, you’re not really adding or removing grip from the chassis but adjusting how well the IR lifts through a corner. @tjkoyen explains it pretty well, however changing tire compounds is the one thing that actually does literally add grip to a kart.
Theoretically, if you have a kart that is able to unload the rear tire completely through the entire corner, from the turn in until you finish cornering, you could put the stickiest tire you could find and not bind up from too much grip. However, in reality that is not going to happen, so you have to find the balance between cornering speed from the tire but not binding up the kart on exit.
Also, when I say “back in Yamaha Can” that was only like 2 years ago. I am still very new to karting, and there are many people here that have been here longer and with more experience than I have. Don’t just take what I have to say as absolute truth, I’m sure I’ve gotten something wrong in explaining the tire compound stuff with you
