Cast vs. spun wheels

Kathy Barton2 · Joined: 17 Oct 2001 Posts: 35

I wonder if anyone would be willing to offer their experiences with handling characteristics of cast vs. spun wheels.

After running all of 2001 with cast rear wheels (to address excessive grip at the rear of the kart), we were faced yesterday with a huge oversteer that we never completely solved. We had the stiffer axle, long hubs, axle tuners and psi changes -- all these changes helped, but only to a modest extent. Would a more flexible wheel have helped?

For reference, we were running brand new Bridgestone YHCs (rather than our familiar MG Yellows) and track temperature was in the 60s during qualifying and heat races.

Thanks in advance for any observations.

Kathy

Patrick Hubbell · Posted: Sun Jan 06, 2002 8:27 am Post subject: Cast vs. spun wheels

quote:
Originally posted by Kathy Barton:
I wonder if anyone would be willing to offer their experiences with handling characteristics of cast vs. spun wheels.

After running all of 2001 with cast rear wheels (to address excessive grip at the rear of the kart), we were faced yesterday with a huge oversteer that we never completely solved. We had the stiffer axle, long hubs, axle tuners and psi changes -- all these changes helped, but only to a modest extent. Would a more flexible wheel have helped?

For reference, we were running brand new Bridgestone YHCs (rather than our familiar MG Yellows) and track temperature was in the 60s during qualifying and heat races.

Thanks in advance for any observations.

Kathy

Kathy,

generaly a cast wheel will provide more grip than a spun wheel as would a stiffer axle,longer hubs etc.

You could have tried a cast wheel in the front and a spun wheel in the rear.

This is how I ran my Invader in 98'. I used a Burris cast wheel in the rear and Invader spun wheels in the front. Worked very well as I won 7 out of 8 club races for the championship plus 2 more wins at another track for 9 consecutive.

Gary Lawson · Joined: 21 Aug 2001 Posts: 547

Do you run seat struts that connect to the bearing hanger? What is your castor at, how wide are you front and rear, air pressure,seat height, front weight %?

Gary Lawson

Kathy Barton2 · Joined: 17 Oct 2001 Posts: 35

Dear Patrick and Gary --

My first few sessions with the chassis about a year ago were with the stock spun front and rear wheels. I had way too much grip. When I switch to cast Burris wheels for the rear, that calmed things right down.

I currently run pair of seat struts attached at the bearing hangers. Perhaps a second pair would have helped increase grip to the rear wheels. My rear track was 54 inches, 43-1/4 inches in the front, measured to the outsides of the tires. I reduced rear psi and dialed some caster OUT of the kart and it improved grip modestly. My current weight is 57-58 percent rear.

I still have the spun wheels sitting on the shelf and I think I will just try them in anticipation of a cool track again this weekend.

Many thanks for your observations.

Charlie Tackett · Posted: Tue Jan 08, 2002 5:03 am Post subject: Cast vs. spun wheels

If you went from MG yellows to teh new "C"s, depending on whose data you want to believe, you went to a tire between 5-10points harder on a durometer adn with very different sidewall characteristics. Seeing you are in Calif., have you run YBNs before?

SOften the 'chassis' itself up as much as you can take out any rear torsion bar, loosen any pinch bolts etc. If you have added weight on the kart, raise it or pivot your seat back forward 1/4-1/2in to raise the CG some. Need to get more weight transfer into the outside rear to get it to bite. Even though your softening teh chassis, stay with a med to stiff axle set-up.

DUh...suppose I'd better not answer wihtout sticking to the topic of the thread

!
Go with the Cast at least in the rear, as mentioned, their stiffer. Keep or ad seat struts, too.

[ January 08, 2002: Message edited by: Charlie Tackett ]

David Mayhew · Joined: 31 Jul 2001 Posts: 209

If you can't get the proper setup with all the changes you said you made then you need to start over and move the seat. Move it up to get more grip and then go back to your original or what would be your nuetral setup. The seat has to be close first, then small changes to the kart should get you close to your "perfect" setup. There are also many ways to adjust the kart with your driving style to make the kart work better. Just some thoughts.

Gary Lawson · Joined: 21 Aug 2001 Posts: 547

With the air pressure you go up on air to get more bite, uless you were overheating the tires with too much. The extra seat struts will not do much more than just one but you can do it anyway. Narrow up the rear if you can and keep the chassis as stiff as possible it will give you more grip. Have you had the kart on the scales? If the front is planted real well just move some weight to the back and get it to close to 40% front weight. If it wants to push then put a little castor back in.

Gary Lawson

Kathy Barton2 · Joined: 17 Oct 2001 Posts: 35

Thanks to all. I will be trying these ideas tomorrow.

Kathy

Prowrench22 · Joined: 09 Dec 2001 Posts: 8

Kathy do you have a picture of you and your kart together ? I collect pictures of women in racing for my daughter. If you do mail it to RicXman@aol.com. Thanks