frontend /spindle

flattop1

flattop1

Dawg 89
Thinking about scrub radius.
Frontend design has evolved to better utilize tire patch
My coyote chassis has the king pin completely outside the wheel . Them being a sprint kart mfg seems normal . Pill adjustment. the chassis is an lto design though. This chassis always seemed to push.
The phenom has a large king pin that always seemed to rub the wheel when going all out on adjustment. With hiem adjustment.
Icon came out with short spindle, fixed that problem.
now the triton has a bigger king pin angle to better load the tire.
I am wondering now if I were to cut off the coyote spindles and install a modern type with a better scrub radius , would this cure the push issue? Maybe, who knows, Its outdated anyway being 1 1/8th I might put that on my ta do list.
 
No I have not . This is a virgin Thrasher, I believe before the oval rocket.
I could, how would you suggest the angles?
My assumption would be to tip them in.
 
Is the caster adjustable? Any idea how much spindle angle build?

If the RF spindle has a low angle build (low kpi setup) under 10*, you have to run lower caster or it'll push. I had a RF spindle with only about 6*, the kart finally turned on a dime when I dropped the caster to 7*. Just something to check and try before going through with your modifications...
 
I have had good luck putting a 12 degree spindle on the RF of my Assassin (Came after oval rocket and Thrasher). It kept more contact patch on the track. I know a lot of sprint guys will probably have them sitting around cheap. I actually just sold all of ours, otherwise I would offer to send you one.

I would suggest talking to Jim at the shop and see what he recommends. Dialing out caster (as suggested earlier) is a good idea as well, anything you can do to keep the RR tire from loading hard and being so dominant will help.
 
flattop1 said:
No I have not . This is a virgin Thrasher, I believe before the oval rocket.
I could, how would you suggest the angles?
My assumption would be to tip them in.
Click to expand...

Without reading on further I don't think your seeing it as needed.

Your first thoughts I read were about how the king pin was point differently, left and right, at the surface of the RF tire. Now in what I quoted it appears your thinking angling the whole RF spindle area via heating and bending top to the left will change how the kingpin projects. ... it won't. ... I think? ... :)
 
I agree you should try dropping caster at the RF before you get into bending stuff. I also think trying a different spindle first before bending stuff would be a way to go too.

My reading of what's being suggested is all about getting less camber gain and being able to lay more of the RF tires surface on the track. Just bending the spindle down a little though it would not change camber gain, would also get you more RF tire surface on the track in both turns and on the straights.

I also just saw your in Iowa and I'm not sure solutions for the track your racing on would be the same as for a big high speed dirtfault track some may be thinking about when offering suggestions. But I don't know what others are relating to except how they fixed a push and that's what your interested in. Thinking back when we fixed a push it was also with more over all RF tire presentation.


... oooops forgot to ask. What is the on track problem you have? You only told us push, but there's push trying to start the turn, push going in, push in the middle of the turn, an exit push and just push all the way around the turn. Sorry to push that question on you. ... :)
 
I believe they are. 10 degree, I have a 12.
Paul pushing for answers is the only way to get them.
Push was always corner exit, exaggerated by a driver that drives in hard and fast.
Caster is adjustable.
What really. Brought this up was scrub radius.
I know this chassis as well as one of the bullers we had were
Similar in the king pin was outside the tire.
No real on track problem to fix as it's never been assembled, sold the other one.
Food for thought though.
 
The adjustable spindles while nice can get you into trouble just by constantly turning the screw.
Had a buller LTO that had the knob on the right front found it hard to leave along.
 
I was just thinking about the plates and l block/ spindles system. By the ad for his chassis, lots of available kpi choices.
I too had a Buller with adjuster. Same problem as you. Lol.
 
https://4cycle.com/karting/threads/frontend-spindle.81989/

Great old thread you brought back in another post.
I posted this instead of hyjacking the coyote assin thread.

I read thru it and saw no real answers but it brought in good thought process to look at the operation, presentation and use of the RF tire.

The king pin location in or out towards the hub is about leveraging or how long a lever you use to apply weight to the RF tire.
John Learmonth in Australia was instrumental in presenting thought and change to how sprint karts leveraged their front tires.
The main difference I see between sprint chassis needing and being able to use additional leverage up front and LTO's is pretty much the difference between a sit up sprint chassis seat and a sort of lay down LTO chassis.
With a sprint chassis it also brings in your need to unload the inside rear tire and with a LTO it brings in your need to control maintaining of weight on the LR tire.

How you point the king pin then becomes where you aim weight you leverage at the RF tire.
The LF then becomes because LTO's turn left how you leverage weight dragging the LF tire as apposed to pushing on or at the RF tire.
Beyond that which is the application of weight it becomes how you want or need to use the RF tire and when weight goes to and from it(the magical timing talked about).

edit: I ain't never sure about anything especially what I just wrote and it's all just IMHO and ain't necessairly right anyway. ... :)

edit again: corrections of dumb stuff written especially when parts are specifically point out, appreciated very much
 
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