Fronts in, backs out?

Michael Polizzi · Joined: 18 Jul 2001 Posts: 1565

Is there a preferance on moving the front tires in verses moving the back tires out? I realize the european karts usually have hubs that seat on the end of the axle but couldn't you put in a round 40mm spacer? My tony extreme is well within the rear wheel width spec. Or should all the rear adjustments allways be made with the different rear hubs and axles.

Thanks in advance
Michael Polizzi 69n
Full Bore Karting

John Valerio · Joined: 24 Jul 2001 Posts: 650

quote:
Originally posted by Michael Polizzi:
Is there a preferance on moving the front tires in verses moving the back tires out? I realize the european karts usually have hubs that seat on the end of the axle but couldn't you put in a round 40mm spacer? My tony extreme is well within the rear wheel width spec. Or should all the rear adjustments allways be made with the different rear hubs and axles.

Micheal,
we run an energy chassis with the same stop on the hub. We had it machined off to allow the rear to narrow up more then if the hub had the stop. We make most of our chages to the front end first. its less time consuming and as long as you have your rear width where it works best you can for the most part dial in the chassis by adjusting the front end. Just my 2 cents

John Valerio

Thanks in advance
Michael Polizzi 69n
Full Bore Karting

Oscar Aguilera · Joined: 18 Jul 2001 Posts: 1614

The trick is you are looking to optimize your tires. The further out you go the lower the air pressure you can run. The closer in you go the higher air pressure is required. If you run at say 52 inches in the rear and 15-18 pounds you may notice a small narrow wear patch in the middle of the rear tire. If you just lower the pressure it to use the whole tire it may roll the tire. If you widen it you can lower the pressure and lower increase the use of the full tire patch.

Tune your kart front or back to get the most out of your tires with ample grip. Each tire compound and manuf. has a recommended tire pressure range.

Rodney Ebersole · Posted: Wed Jul 25, 2001 5:07 am Post subject: Fronts in, backs out?

I would think that adjusting the front end will change caster imput. wider front = more weight transfer. narrower front= less weight transfer. So changing the front end should make for a bigger effect than the same change in the rear. Thanks Oscar for making me understand the relationship of air pressure to width changes. I hadn't thought of it that way.

Keith Archambeau · Posted: Wed Jul 25, 2001 8:51 am Post subject: Fronts in, backs out?

Michael, Our experience has been the following.
1) Rear at maximum, adjust traction with, hubs, axel hardness, frame height, wheels(aluminum, spun or cast, mags)or bars, rear bumber.
2) adjust front for best turn in, exit ect.
Hope this helps, Keith

Ed Weathers · Joined: 19 Jul 2001 Posts: 36 Location: Hood River, Oregon

Don't claim to know a whole lot about tuning a chassis but I am learning everyday. My experience is that front end adjustment's effect the kart far more than the rear ever does. I almost always run the rear full width and adjust with hubs or axle stiffness. The caster/camber combinations have made my kart go. I ran without pills last year and no matter where I put the seat or widths the kart was a pig. I believe that the front of the kart is where the majority of the focus belongs.

John Valerio · Joined: 24 Jul 2001 Posts: 650

quote:
Originally posted by Ed Weathers:
Don't claim to know a whole lot about tuning a chassis but I am learning everyday. My experience is that front end adjustment's effect the kart far more than the rear ever does. I almost always run the rear full width and adjust with hubs or axle stiffness. The caster/camber combinations have made my kart go. I ran without pills last year and no matter where I put the seat or widths the kart was a pig. I believe that the front of the kart is where the majority of the focus belongs.

thanks Ed well said!!!!!!!

Michael Polizzi · Joined: 18 Jul 2001 Posts: 1565

Thanks

I moved the backs out from 53" to 54.75" moved the fronts out two spacers. Tony 'N' axle, long hubs, Mag wheels, YGC's Front tires at 14.5 Backs at 14. Bar under seat set soft, rear bumper tight. I am 5' 10' 200lbs. The chassis is a '99 tony extreme 125. The kart seems allot less bound up through the turns. the tire wear looks allot better.

Hard to tell about lap times as our track ran a different configuration this week. fastest laps on 10-13 out of 20.

Still getting a slight hopping in a few corners. Am I to high on tire pressure ?

Thanks again
Michael polizzi 69n
Full Bore Karting