Tractor Pulling Madness

Ah... the other question... tire ballast.

There's advantages and disadvantages to ballasting techniques.  When doing tractor-pulling, you'll see that most guys don't run substantial amounts of liquid ballast, and there's several reasons why.  Here's a short list of the advantages and disadvantages, and that'll sum up why they employ ballast the way they do:

Liquid ballast advantages:
Cost
Mass (it can get heavy fast)
Position:  tire fluid CAN present the lowest center-of-gravity of any ballast technique... but only if the tire is partially filled.  The maximum CG of a ballasted tire will NEVER be higher than the center of the wheel, as such, a half-filled tire will lower the tractor's composite CG.
Inertia- the tire can spin without the fluid 'following along', so the wheel can start or stop motion and not cause an appreciable strain on the drivetrain.
Load:  Tire fluid is in the tires, so it's not carried on the chassis, not loading bearings or axle housings.

Disadvantages:
Position: your ballast is ALWAYS centered on the centerline of the axle.  If you need more weight FORWARD of the axle, tire ballast will NOT help.
Predictability:  Adding or removing 34lbs of tire ballast to suit a competition scale is not fun... you'll be standing out there, helping the tire pee into a graduated cylinder, and weighing buckets of fluid to sort it out.  Really fun trying to get two ballasted tires to weigh the same amount.
Track adaptability:  Tire changes suck... and carrying several sets of tires to accomodate a varying track makes your trailer really heavy, really fast.
Tire flexibility: Gases are compressible, liquids are not.  When you use a tire filled with air, the amount of deflection the tire will produce under a given force, is a function of the initial pressure (sitting on a jackstand) to the final pressure (sitting on the ground).  Since air compresses, the tire deflects fine, and pressure inside the tire will rise just a smidgen.  If you replace HALF that air with fluid, you're effectively removing half the compressible volume, so the pressure CHANGE between jackstand and ground DOUBLES.  Now remove all but just a tiny bit of air, replace it with fluid... the pressure change will be dramatically higher.  This is why, when driving a tractor with fully-filled tires... the ride is rough... no compliance to the earth.

Iron/steel/lead weights:
Advantages:
Predictability: a 68.3lb iron weight, will generally always be 68.3lbs, unless you drop and chip a chunk out... and paint is a pretty good indicator of damage.  Nice thing, is that a 68.3lb iron weight can easily be measured out on your wife's digital electronic bathroom scale, and while the scale may NOT be perfect, it'll be a whole lot closer than say... a 3-gallon bucket of liquid, where part of it spilled on the ground... and of course, you won't be stealing your wife's bathroom scale to weigh buckets at the track...
Placeability:  You can put it behind the wheels, under the wheels, in front of the wheels, above the wheels... alongside the clutch, out on a bracket up front, all on the left side... wherever you want, in segments you want.  {important note here- if you use iron wheel weights, it will increase the polar moment of inertia of the drive wheels, which can be dangerous in competitions where high wheel speed is allowed... a wheel that breaks loose, and has a high polar moment, will want to continue to spin, and roll through all sorts of stuff before stopping).
Iron weights, especially easily removable ones, can be moved from tractor to tractor, so that if you have two machines, and pull in five classes, you can do it all with just one set of weights- by moving weights from tractor to tractor.  Start with the tractor extra-light (aluminum wheels, etc) in the smallest, and add weights as you move up in classes.

Disadvantages:
Cost to obtain.  Yeah, they're pricey compared to liquid, but then again, you won't spill too much iron on the ground, and not be able to FIND it...
Cost to use:  Iron weights and old men aren't a great combination.  When using iron weights, one either needs to have a good medical card, or bring along a pair of high-school linemen as a pit crew, and they eat lots of expensive pizza.
Cost of gloves and shoes:  When having iron weights lying around in the shop, they frequently tip over onto your fingers and toes.  Best to budget for thick gloves, band-aids, and steel-toe'd boots.  Did I mention a good medical card?


Edited by DaveKamp - 31 Oct 2011 at 9:55am

Good stuff Mr Dave Kamp.

Hi Ken!  I will add a couple pictures from pulling with worn Goodyear 13.6 to like new Firestones at 7 to 8 lbs PSI. I like my newer Stones that was on the rims that you now have.  DeWayne

boone county?

YES to Boone County!!!!!

Not that hard to figure out JW. There are sometimes two separate Q&As going on the same time. I only have 2 gallons of green stuff in the 13-6s on my work tractor. I don't even think it gets slushy. If it did, whats the hurt? It has been in there for a long long time. The pullers stay inside and it seldom gets anywhere below freezing in the barn if I remember to close the doors. They got just plain water in them. Plain water weighs like 8.3 lbs to the gallon.

I can see now that I need a pulling crew to help me do all the checking of this and that carefully before the track maintainer covers up all the evidence.

Hi Ken! I do not have any ballast in the tires. The tires are 4 ply. The 7 to 8 lbs of tire pressure gives me the flat bottom track when I am done pulling.  My Drawbar is the standard snap-coupler with the twisted clevis as hig as it will go. I had the weight bracket fabricated to hold 2 sets of engine sideweights or hang suitcase weights on. I have 2 sets of rear wheel weights along with front wheel weights. I had another weight bar fabricated to mount on the front cultivator bracket. The lightest class we pull in is 3600lbs which is the class with the goodyear tires. The 2nd photo is from this year with the Stones tires and 4000 LB class. Hope that I have answered all open questions. DeWayne

That's about it for this year JW.

well ken.....i got me another 45-diesel today...pick it up when we go deer hunting at the farms...

dave...thx for the glycol/water ratio.very close to what i had figured out...thx again

Paying for the Sled and Scales?  I hope this answers the question.

  It is paid for and has been for years.  The East Texas Antique Tractor and Engine Association Owns it. It was built and maintained by association members. Club Members, as a team, volunteer their labor to operate and maintain the equipment. Pull back tractors are usually donated by local dealers. A few Sponsors buy advertizing displayed on the sled and on banners at events.

Our Club Members bring our Sled to the State Fair of Lousiana at Shreveport and area EDGETA pullers from 4 states put on a Friday and Saturday Antique Tractor Pulling Contest & Show at the Fair. When we are not pullin we are workin so the others can pull. We are in our tenth year now of putting on this show. The Fair in return provides a space for a track and makes a sizeable financial contribution to the clubs general fund for our efforts. The Fair  provides the awards for the 1st, 2nd, and 3rd place winners in each class.  The sled was built by the membership and maintained by the membership . Funding for Updates and general maintainance of the Sled, Scale and related items is paid for out of the clubs general fund.

The club also puts on a local 2 day show and pull at the Rusk County Ag Center in the spring. The public is charged Admission to the show. Exhibitors and pullers get in free by showing their current EDGETA Membership / insurance  card. At this event again it works like this. When your not pullin and there is work to do or a job needs doing you volunteer.

 

    We find no need to charge a actual per hook fee nor do any of the other regional clubs maintaining a sled and scales and putting on a show. The regional Clubs are all Branch Member Clubs  of EDGETA and pull under EDGETA Antique Tractor Pull Rules.

So how fast can you spin a ballasted tire? I see some hot farm tractors with incredible wheel speed.