Champ right rear

[12jr champ]

Just curious why tight to frame on rr...to prevent axle flex? Hopping? What would be the max out on rr... thanks

 

[racing promotor]

Moving it out has more effect on just loosening the rear of the kart VS flex, 1/2" is not tight to the frame.

 

[CarlsonMotorsports]

It'll help some on hopping, but going from 1/2" to 1/8" isn't going to fix that issue alone. Axle stiffness, RR hub length, RR bearing inner race direction, left side percentage, vertical CoG, tire pressures and split, all will have a greater impact on "hop" than moving that tire in 3/8."


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Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com

 

[Andy Collier Racing]

Brian, Can you explain the inner race direction and the effects?
Thanks,
Andy Collier

 

[CarlsonMotorsports]

Andy, Just that the longer side of the inner race with the set screws extends further on the axle, so if you put that side toward the right rear, it limits the amount of axle flex to that point of the bearing.
On chassis with the 3 bolt hangers where you can bolt the cassette to either side of the hanger, we would bolt the cassette on the outside of the hanger to get the bearing that much closer to the RR hub. (Particularly on high grip tracks where we were experiencing increased axle flex and/or hop.) Syrup racing is a good application for this as well.
Think of it as widening the frame stance at the rear.

 

[Andy Collier Racing]

Andy, Just that the longer side of the inner race with the set screws extends further on the axle, so if you put that side toward the right rear, it limits the amount of axle flex to that point of the bearing.
On chassis with the 3 bolt hangers where you can bolt the cassette to either side of the hanger, we would bolt the cassette on the outside of the hanger to get the bearing that much closer to the RR hub. (Particularly on high grip tracks where we were experiencing increased axle flex and/or hop.) Syrup racing is a good application for this as well.
Think of it as widening the frame stance at the rear.

Thanks for the answer Brian

 

[CarlsonMotorsports]

Thanks for the answer Brian

I appreciate your appreciation.
That's something not often shown on here, but more often understood.
There's a lot of great guys on here that are very knowledgeable in their areas of expertise.
I try to cover the areas that I keep on top of, and leave the other areas alone -- ie, you will rarely see me answering questions in the Predator/clone sections. I did learn a few things about chassis, tires, clutches, and Briggs engines though after all these years.

 

[alvin l nunley]

I appreciate your appreciation.
That's something not often shown on here, but more often understood.

I think, just as important, maybe you remember all the solutions you found to cure your mistakes. I know that's true for me.