No problem anytime let me know how you make out. Start with small adjustments first. Also go with standard rr hub like flattop1 said it will stiffen the axle and you don't want that on ashpaltThanks for the feedback. I will try air pressure first. We race tonight so i will post my findings tomorrow. What about a wide RR hub?
Interesting thought on the stiffener and would something pretty easy to test back to back and measure results.I've always found that stiffening the axle helped prevent the hopping and helps unload the LR.
For syrup we even ran a stiffener from the RR bearing out to the hub.
Maybe I'm thinking of this hopping problem differently than others.
More left side percentage first and foremost. More psi split.
Depending on when the hop starts, would tell me what direction to go on air. More psi will build tire temps quicker. Less will delay it.
How much psi increase are you currently seeing (cold to hot)?
A properly cut tire to flatten the contact patch and stiffer shoulder will help as well.
Some internal prep to help control the heat can help tremendously, but it won't make up for an ill set-up chassis.
Thanks and God bless,
Carlson Racing Engines
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On soft axles, sliding the hub out increases the axle flex and resultant "hop." Think about it as a leverage point from the bearing to the hub. This is a reason we use 4" offset wheels instead of 5" right sides, or centered up wheels (like the pavement guys would.) Oval karts run the right rear all the way in against the frame. Part of the reason for this is to eliminate axle flex, or at least limit it's effect. Our Vector DO chassis actually has the motor rails swapped so that the engine sits outside of the main frame rail and you can move the RR in further with likely the narrowest rear tracking of any kart in the industry. In reality, (with the exception of grass tracks or ice racing) we never needed the right rear in that far, but instead ran it further out on the axle. This the cause the right rear to bite up hard (acceptable for big HP or even very low HP) but was not fast when you needed a more balanced car on a track that has much bite at all.Interesting thought on the stiffener and would something pretty easy to test back to back and measure results.
I agree with more left and starting air pressures lower, especially if the hop comes in mid race when the tire temps increase and PSI builds.
The other thing that would be worth a try is sliding your RR hub out in 1/4" increments and see if that helps with the hop.