Mojo D5 struggle with side bite. run seat higher?

Hello guys,

Previously i have suffered from my kart jerking in corners, i swapped to a stiffer seat and the problem seem to be much better and my lap times have started coming back down again. I was doing some competitive lap times on my used Maxxis orange tires, until i swapped to new set of Mojo D5’s (what we are running for the next race) and i started struggling to find grip and have more hand movements. It felt like the sidewall isn’t digging into the corner and my inside rear wheel lift is inconsistent. after the session i pit in to take my tire temps and my outside corners were quite cold, and the center part were not as hot as it should be, using mostly the inside tires. Unlike Maxxis i was getting highest tire temps in the center part, and it felt great, i could really lean on the kart and it bites into the pavement.

This is with used Maxxis Orange

This is with brand new Mojo D5’s

What tire temps should i be looking? i am running around 0.9 bar hot. i also saw a youtuber mention they run their seats a little higher with Mojos since they couldn’t get enough side bite, seem to be the case with me too (im running lowest position at the moment).

Currently debating on testing a few things:

  1. Run a bit more postive camber for better front outer edge tire temp (for better bite?)
  2. Narrow the rear track width 5mm
  3. Move the ballast on the seat upwards
  4. Increase rear ride height for better rear binding (but would that change rake and make it slide more?)

Also, i am still suffering a little from kart jerking (its not my hands aren’t strong enough and couldn’t hold it), specifically on mid speed left hand corner exits. i am currently only running one seat strut on the non-engine side (DD2 is left side), debating if i should run more.

Would love to hear your thoughts! thanks for the love guys!

What frame are you using? If it’s not a T Kart I’d try a stiffer axle. T karts react differently :joy:

Also, CRG factory engineer dude once told me never ever run only 1 or uneven seat struts. Always the same each side.

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Tire pressure sounds insanely high for a D5. I’ve run those as low as 6.5 pounds cold in the right conditions.

Struts and harder axle if that doesn’t fix it but you are on top of the track and not letting the tire roll over on the sidewall at all.

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Could this theory hold water:

Too-high pressure would cause the middle of the tire to heat up more than the edges but it could also cool off faster on the way to the pits because it is in more contact with the 32C road than the outer edges of the tire. Therefore, the measured temps look like how they do with the middle being cooler.

Tire pressure too high as Dan said. Get those tire pressures down and allow the tire sidewall to flex so it can dig into the track and not skate around on top of the track.

Start around 0.55 bar on the rear tire that will get the most action (mostly left turns set the right rear the lowest). 0.58 bar on the other rear. 0.62 bar on front tire that sees the most action (right front from the example). Finally 0.65 bar on the other front tire.

You want to come in hot around 0.78 to 0.85 bar. If they come in high after a session bleed them down to your target pressure and record the cold pressure once they have sat there and fully cooled off.

Also want to add those hot temps seem very low. Could be how/when you took temps. You want them up around 80-95C for them to be in the optimal temp window.

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