I will chime in here with my impression of running MXC and MXJ rims on a shifter, we run 80 shifter on evinco blue tires out here and one time one of my MXC rims had a manufacturing defect and i was in a hurry so i threw an MXJ on one side and MXC on the other and OMG I almost hit the wall first time hit the front brakes as one tire had so much more grip than the other. Since then having played with them they feel dramatically different to me. I previously never played with rims and did not understand how much they change the kart. To me, and others have validated this, on an OTK chassis, the MXC rim feels āsofterā and has noticeably more side bite at the apex, it feels like the tire digs in a bit harder right at mid corner, and I feel like the MXC rims seem to manage tire temps a small bit better at the very last laps of a race when the temps are higher. The MXJ rims feel totally different and it feels like the rim is āharderā so less dig/bite at the apex but they feel so much smoother coming off the corner and to me it feels like i have greater resolution into what the back tire is doing from apex to exit and can get on the gas a hair faster sometimes, feels like more spring back in the rear especially on exit. Our tracks are quite slippery and bumpy and sometimes little dusty so I find myself almost always racing on the MXCs as we put a good amount of heat into the tires with these little shifters but Iām going to experiment with rims more next year and would not be surprised if I find myself on the MXJ more.
You guys want a mind f**k on the whole OTK wheel discussionā¦
Did anyone notice that this weekend at Orlando that RPG ran MXJās on at least their front running X30 kartsā¦and Norberg walked away from the field on this setup and Jones had enough tire under him to make a last lap pass for P2?
Hot weekend
Soft compound tires
High HP class
Extremely long final
None of that makes any sense for running the MXJās yet they did it with success.
Good callout! I noticed that too.
If I recall correctly, wasnāt it a bit wet earlier in the weekend? Maybe the track greened-out and they were accounting for it taking more time to rubber back in.
But yeah, super interesting.
I donāt know the surface well at Orlando, but on some really worn, old, pavement, where the binder has been scrubbed away and the aggregate is more porous, you can struggle to get the tire to work properly.
Norway was always like that before the repave. That track felt green no matter how many karts and how much rubber got laid down, because the surface was so old. I think what happens is you actually are physically reducing the contact patch because the surface isnāt as smooth and leveled at the microscopic level, so it always feels a bit like youāre skating around on top of the track.
Total speculation though. Also Norberg had a bent steering shaft, and heās an outlier because he has run a million laps at Orlando, so he probably couldāve won with only 3 wheels on the kart.
Jones is a better indicator and he certainly was impressive given his lack of seat time lately.
Orlando gets notoriously greasy during hot/sunny conditions. I know some drivers were searching for grip, so perhaps the need for grip outweighed the need to manage tire temps.
Yeah thatās what I was going to say, every year it seems like the big talk from all the top drivers is how much Orlando changes and gets greasy over the big weekends. Still interesting though, weird to see a top team running mxjs outside of rain/Vegas parking lots.