Author Topic: Racing wheels (rims)  (Read 11448 times)

0 Members and 1 Guest are viewing this topic.

Offline TomC

  • Turf Warrior
  • **
  • Posts: 122
  • Karma: 0
    • View Profile
Racing wheels (rims)
« on: November 05, 2005, 09:35:19 am »
*Racing wheels (rims)*
Post by Tom on Aug 23, 2005, 10:41am


Doc here at ARC has been working on a racing lawnmower and he used
split rim halfs for the front wheels.

These split rims used to be very popular with karters as they allow
you to mix and match rim-half widths to come up with different total
wheel widths and offsets. This is done to stand up or strecth out the
tire sidewalls to adjust both spring rate to produce more or less
rebound and tire circumference to produce more or less stagger. It is
also done to get the wheel to clear the spindle arm on the front end
when you want to have your hub a set distance on its axle away from
the kingpin barrel of the spindle to obtain the scrub radius intended
for a given spindle.

A rubber seal is used between the two rim halves as they are bolted
together to from both sides of the tire. It is quick and easy, and
the wheels Doc put together about a month ago still have full air
pressure.

We carry both the 1 piece wheels and the split rims, but I often think
that the handling adjustment potential of the split rim is underrated.
In karting, the racers have all but forgotten how to tune with wheel
widths in favor of the use of chemicals that make the tire more
pliable and soft.

Tom
------------------------------------------------------------------------
*Re: Racing wheels (rims)*
Post by Squidd on Aug 24, 2005, 6:36pm


Thanks Tom for the insight...

I've been debating between one piece rims with hubs/bearings built in
and "seperate hub/wheel combos for next years ride...

Now I have to decide if I want one or two piece rims and then what width
for each half as well!!!
------------------------------------------------------------------------
*Re: Racing wheels (rims)*
Post by George Herrin on Aug 25, 2005, 7:09am


keep in mind that US rules call for same size tires and wheels per axle.
Would not want you dq'd. Fx can run stagger but cannot run offset. It is
measured from center of frame to outside tire wall.
George
------------------------------------------------------------------------
*Re: Racing wheels (rims)*
Post by Tom on Aug 25, 2005, 8:45am


Thanks for that clarification George, I was totally ignorant of that!
Everyone needs to understand that my knowledge comes from karting and
may not make a clean jump to lawnmower racing. But I learn different
ways of doing things in karting from you guys every day, and I hope to
reciprocate somewhat.
If anyone is interested, I made an Excel spreadsheet that calculates the
correct stagger necessary based on rear trac-width, the radius of the
turn, and the banking of the track.
I have also found that the tire prep Hotlap II can be a great aid in
shrinking or growing a tire's circumference depending on application method.
------------------------------------------------------------------------
*Re: Racing wheels (rims)*
Post by crafty on Aug 25, 2005, 4:02pm


Afternoon all. Ok, so the measurement is from center of frame to outside
tire wall. So does that mean that if you built your steering beam short
to the left or right side, either one, you can make up the difference
with rim width and still be legal? And, what if any difference would
that make to the handle of the machine? Would you be able to load more
weight to one side or the other by doing so? Not that I would try it,
but I had to ask.
------------------------------------------------------------------------
*Re: Racing wheels (rims)*
Post by George Herrin on Aug 28, 2005, 10:40pm


Nope that would be offsetting the chassis and that would be illegal.
George
------------------------------------------------------------------------

Offline George Herrin

  • aka SUPERMAN
  • Superman
  • Highly Mowtivated
  • *
  • Posts: 17732
  • Karma: 102
  • Gender: Male
  • I am going to Race Every Race like its my last one
    • View Profile
    • BTMRA Home/Forum An Independant Club.
Racing wheels (rims)
« Reply #1 on: November 13, 2005, 06:55:59 pm »
I race a 1997 MTD chassis and my engine model number is tvt-691
George
George Herrin #6
Indian Power.. You gotta Go big to beat em or Go HOME
8 time ARMA National Champion
4 time USLMRA National Champion
Retired from BP
www.herrinmowersports.yolasite.com
www.allamericanmowerchampionships.yolasite.com
My other racer is a 1/5th scale Dirt Late Model!!!!

Offline Red Horse Racing

  • Turf Warrior
  • **
  • Posts: 135
  • Karma: 0
    • View Profile
Split vs One piece /\ 4on4 vs 1.75x2.5
« Reply #2 on: December 29, 2005, 08:19:58 pm »
Today the discussion was types of wheels, and types of hubs.

First, the wheels.   The split rims look a good idea as stretching those little tires over the 5" and 6" rims isn't the easiest, and when working with aluminum I can see some bent lips in my brutish hands.

Just exactly how do these work?   On the two piece wheels of a dolly or something, they bolt together with one set of bolts, then attach over an axle.  On looking at the pictures of the split rims for karts, it would appear the only holes there are for mounting the wheels.
Okay, it just occured to me, is it you have use the lightweight hubs?  Bolt the wheels together with 3 holes, using the other 3 to mount?  Or do these beasts have to be put together on the hub?  Will the full circle hubs work?  Or just the lightweight ones I previously mentioned?

On a similiar note.  Tubeless has never been kind to me, and I'm figuring on running tubes.  Do these work okay with the split rims?  How many of you use tubes and how many go tubeless?

The second topic is the hubs themselves.  I see many people using the 4on4 layout with a few of the American 1.75"x2.5" layout.  My guess is the 4on4 is stronger, but the American layout seems to be much more available.   Will the American 1.75" register x 2.5" bolt circle stand up to the abuse of the rough lawnmower tracks?   I like the idea of lightweight aluminum, but not if they won't last.

Thanks for all your opinions,  the order for these things will be going out soon, and we can't afford to change our minds midseason.  Or even at seasons end!  LOL  One shot deal.

Dale, in Michigan
Wheel Horse of Course!!

Offline George Herrin

  • aka SUPERMAN
  • Superman
  • Highly Mowtivated
  • *
  • Posts: 17732
  • Karma: 102
  • Gender: Male
  • I am going to Race Every Race like its my last one
    • View Profile
    • BTMRA Home/Forum An Independant Club.
Racing wheels (rims)
« Reply #3 on: December 29, 2005, 10:25:55 pm »
Quote
Okay, it just occured to me, is it you have use the lightweight hubs? Bolt the wheels together with 3 holes, using the other 3 to mount? Or do these beasts have to be put together on the hub? Will the full circle hubs work? Or just the lightweight ones I previously mentioned?


Yes they bolt together with 3 and then the other three are used to bolt to hub. Any hub (kart hub) will work with the split wheels.

Secondly, tubes is the only way to go if you don't want to be black flagged for a flat. TIP, put some baby powder in the tire before you put the tube in this will keep it frm pinching the tube if running very low pressures.

Thirdly, 4 0n 4 is the way to go as far AS RACING ALUMINUM WHEELS. They are readily available in  billet aluminum in 1 1/4 and 1 inch sizes. Wheels are readily available check out http://www.apskarting.com could say about the the us pattern you speask of never seen them of used them.
George Herrin #6
Indian Power.. You gotta Go big to beat em or Go HOME
8 time ARMA National Champion
4 time USLMRA National Champion
Retired from BP
www.herrinmowersports.yolasite.com
www.allamericanmowerchampionships.yolasite.com
My other racer is a 1/5th scale Dirt Late Model!!!!

Offline Red Horse Racing

  • Turf Warrior
  • **
  • Posts: 135
  • Karma: 0
    • View Profile
Racing wheels (rims)
« Reply #4 on: December 30, 2005, 10:44:34 am »
Great!  

Only now I really am confused.

After cruising the APS catalog, then the website, I see the 4on4" hubs with 4 bolts on a 4" circle, but the wheels all have 6 holes with no description of mounting type.  

There are also plenty of hubs listed as either American Standard, or International, as are all the one piece wheels.  This where I orginally found these mounting types.

I can't believe the split rims will fit just anything when the hole spacings are so different.  Can they?  Line up with a 4" circle with 4 bolts AND at the same time a 2 1/2" circle with 3 bolts?

Yeesh, building racers.....  LOL

Dale
Wheel Horse of Course!!

Offline George Herrin

  • aka SUPERMAN
  • Superman
  • Highly Mowtivated
  • *
  • Posts: 17732
  • Karma: 102
  • Gender: Male
  • I am going to Race Every Race like its my last one
    • View Profile
    • BTMRA Home/Forum An Independant Club.
Racing wheels (rims)
« Reply #5 on: December 30, 2005, 12:16:54 pm »
The 4 on 4 hubs is for 8 inch rear rims. Look in the catalog under lawnmowers and Jr. Dragster. The American bolt pattern you reffering to are the 3 hole for the 5 and 6 inch wheels for the front
George Herrin #6
Indian Power.. You gotta Go big to beat em or Go HOME
8 time ARMA National Champion
4 time USLMRA National Champion
Retired from BP
www.herrinmowersports.yolasite.com
www.allamericanmowerchampionships.yolasite.com
My other racer is a 1/5th scale Dirt Late Model!!!!

Offline Red Horse Racing

  • Turf Warrior
  • **
  • Posts: 135
  • Karma: 0
    • View Profile
Racing wheels (rims)
« Reply #6 on: December 30, 2005, 01:40:16 pm »
Okay then!  Sometimes I feel like an idiot, the rest of the time I am.

The split rims, which by the way I only see in 5" and 6" sizes, are the 3 bolt pattern, and only the three bolt pattern.  That makes sense, but I kept reading where "such and such" fit "all" hubs.  Well they don't!  LOL

We were figuring on 6" rims for the rear, and either 5" or 6" front.  The reason for the 6" rear is to get the frame down to 4 1/2" (I'm allowing for "slop" and still pass tech for SP) either the fenders have to be moved significantly, (which may or may not pass depending on "discreet") or run a shorter tire.  Even the 13x6.50-6's will keep me from attaining a true lowest minimum frame height.  Given the relationship between frame and fender on the stock tractor, lowering the frame to 4" lowers the fender to 11 1/2".  To get an 8" wheel in there with a 16" tall tire means changing the frame/fender relationship by 5".  That simply does not sound discreet to me, it would show up big time!!!  Not to mention raising the seat and driver up by 5".  LOW center of gravity is a good thing, and this would not be conducive to that end.

Right now I'm thinking..................... 13x6.50-6 on the rear and 11x4-5 or 13x5.00-6 on the front.  Comments on those tire sizes?  Gotta start somewhere.

Sorry for all the long posts and questions, but I'd rather appear dumb, than order a couple hundred dollars of parts and prove it.

Dale
Wheel Horse of Course!!

Offline Smokingunz351

  • Newbie
  • *
  • Posts: 77
  • Karma: 0
  • Gender: Male
    • View Profile
Racing wheels (rims)
« Reply #7 on: December 30, 2005, 02:35:33 pm »
i run a 13-6.50-6 tire on the back of my wheel horse and it sits at 4.5 inches from the ground and its a little close to the fender but ive never had it rub so its all good. i know with running these shorter tires the mower gets up like theres no tomarrow and still has a good topend. i run  13-5-6 tires on the front and have had good results with them. there not to big to where they rub but there just big enough to give me a decend contact patch. now u said something about running SP with the 13-6.50-6 back tires. i think the smallest rim aloud in SP has to be at least 8 inches in diameter. guys correct me if im wrong but im pretty sure thats wat is in the rule book. but other than that that tire setup has worked for me quite well. hope this helps

Bill
Custom doesn't come in a box! It comes one saw blade at a time"

Offline Red Horse Racing

  • Turf Warrior
  • **
  • Posts: 135
  • Karma: 0
    • View Profile
OOPS!
« Reply #8 on: December 30, 2005, 03:49:02 pm »
Read those rules a hundred times, but you're right.   8" rear minimum.

It might be a simple way to list rules like they do, but with general requirements in one place, prepared in another, and yet a third for a specific class, it makes it REAL easy to overlook something.

Dang, now how am I going to get sucker down?  Time to read the Michigan rules, and the local rules, for these are all different as well.   The odds of running at a USLMRA event are small, but it would be nice to be legal at one.

Oh well!!!!!!!!!!!!!!!!!!

Dale
Wheel Horse of Course!!

Offline Smokingunz351

  • Newbie
  • *
  • Posts: 77
  • Karma: 0
  • Gender: Male
    • View Profile
Racing wheels (rims)
« Reply #9 on: December 30, 2005, 09:29:11 pm »
thats a tough one, with the lowering part. i know the fenders on these wheelhorses sit low on the frame and make it hard to tuck a large tire and still have a low ride height. honestly if i were you id build it the way you think you should build it and race it in any class it would fit in. thats what i did with mine and so far theres not much out here in the OHV class that comes close. now me only wieghing 120 pounds and the mower only weighing 250 pounds maybe why, kind of a power to wieght thing there. anyways just do what you think u should do and when it comes time to race with the USLMRA run it in the class u fall in. Hope this helps

Bill
Custom doesn't come in a box! It comes one saw blade at a time"

Offline Red Horse Racing

  • Turf Warrior
  • **
  • Posts: 135
  • Karma: 0
    • View Profile
My Plan
« Reply #10 on: December 31, 2005, 09:21:27 am »
Well, here's my plan.

The Michigan rules basically follow the USLMRA's rules on fenders and tires.  The local group, not affiliated to anyone, just a good ole bunch, will pretty much let me do anything.  2005 rules at least.  Don't you love the build in winter and hope you fit the rules the following summer?  LOL

The fenders overlap and bolt to the footboards.  I'm going to raise the fenders until they are a butt joint fit, with a plate behind them bolting things together through the original holes.  This will give me some, but not all of the difference, and hope it's enough to be stable.  At least as much as these beasts can be.  It'll pass local and if it doesn't pass anywhere else, well, it'll pass into something!  LOL

I had other ideas, but, uh, I don't think they'd be allowed.  LOL   At least this one stands a chance.  I hope.

I went ahead and ordered an axle, mounting hardware and hubs, once I get those I can figure the offset required in the rims and will get those.   Soon as George and company goes back to work, (Hey, I got a long holiday break, he can too!) I'll order the transmission mounting plate for the transmission which is on backorder!

In the meantime, there is plenty else to do. Like get the old engine off.  It has an electric clutch well rusted to crankshaft and it won't fit through the hole in the frame.    My trick of drilling the pulley and using a puller won't work this time........................

Dale
Wheel Horse of Course!!

 

anything