For my own learning, I’m curious if my theory makes sense. He is measuring camber without any load, and it looks like there might be an electric motor controller in one of the pictures. If he has added a bunch of weight (himself, batteries, and electrical) to an antique kart, could the actual camber be much, much higher than what the sniper is showing? High enough that it could explain the difference between the observed wear and the measured camber?
This is an issue for me due my size and the fact that the front porch I run hangs my feet that much further forward past the front axles. I actually start with half to one full degree of positive camber on the stand and end up with negative camber when I am in the kart on the ground. That last time l started with negative or no camber on the stand, it was obvious that it bowed negative on the ground as the outside shoulders of the front tires were still glossy from the mold and the insides had that tell-tailed ridge of rubber build up.
My first try at analyzing tires. Compkart LO206 at a HRKC event Langley Speedway. Low 80’s, running at 110% of the fastest kart, 20 laps of racing, 403 lbs on the scale, started off with 12psi. All the high energy turns are to the right. See pictures above.
Those tires look good, especially for that many laps. Are you running the standard Freeline wheel? If trying to cure a hop I would try a shorter rear hub and also remove the lock collars. If you have issues with hubs sliding in then I like to use the aluminum spacers that go on the inside of the hub.
Thanks I will remove the collars. I am already running spacers so I guess they are redundant. I need the longer hubs to get some track width, my axle was cut when I bought the kart.
Do you think they might look good because I have been running too high pressures?
Assuming you’re running the standard Freeline DF wheel, you could change to an AMV 3F or OTK MXC, both of which have notably less backspacing, and should allow you to run a shorter hub while achieving the same rear width.
Regarding tire pressure, tough to tell. The larger feathering on the inside of the rears COULD indicate slightly high tire pressure, but you’ll have to determine on your own based on pressure rise and stop watch.
Thanks that is helpful, I think I need to go lower. I am running the standard wheels, but for $300 I think I would rather buy a full length axle than spring for another set of wheels that have different spacing.
On the MG Reds on the parking lot asphalt that my home circuit has, apparently going lower than the MG recommended 15.9psi hot is the ticket, I will try lower pressures and see where that gets me.
The hop seems to be there no matter what I change on the rear track, it only get a tiny bit better. My next steps are to get some caster pills that will allow me to take some more caster out and try the wider track width once I get a new axle.
I should have also mentioned that either of the two alternative wheels mentioned will provide notably different handling characteristics from the Freeline DF. The DF is a very high-grip wheel, and can sometimes induce a hop on its own. Going to the 3F or MXC can help with this, especially in higher grip scenarios.
Personally, I would not worry about keeping all of your wheels the same backspacing. Though it’s a common variance across different wheels, it’s an easy measurement to account for, and chassis performance should take priority.
I see, yes the asphalt is very high grip and abrasive. I am at 1360mm now, and getting close to the end of the axle. I might have 30m more which would get me to just about the max legal width.
I would agree with Evan. You have all the components of needed a “free-er” wheel. Low hp, high weight, high grip, high temp. It will help with the hop for sure.
+/- 3psi if I recall correctly, so that’s a large window. I am reluctant to say 15.9psi is recommended, rather it is just in the middle of the recommended range.
Took this picture on the way to the dumpster. This is the front left on a mostly right-turn track (GoPro/Trackhouse). The rears also had similar diagonal lines, but they looked more superficial than this one by far. The track was cold and slick this morning (high 30s overnight), so I think I was around 18psi hot. Tires are getting some age on them, but shouldn’t be falling apart like this just yet (MG Red)
