×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Tractor Pulling Tyre Dynamics

Tractor Pulling Tyre Dynamics

Tractor Pulling Tyre Dynamics

(OP)
Please can someone provide formulae that explain the very high drawbar pulls that can be generated by competition Pulling Tractors. I am aware of cut down tread lugs and tyre peripheral speeds of maybe 200 mph. Is it some form of energy transfer from speeding up hunks of clay?

WillTurner

RE: Tractor Pulling Tyre Dynamics


It's the combination of the tire and weight transfer. Even a bald tire can get quite a bit of traction if loaded down enough.

RE: Tractor Pulling Tyre Dynamics

As I understand it, the idea is to get the entire powertrain up to high speed at the short end of the track while the transfer sled pulls relatively easy, thus the cut tread to allow wheel spin, and traed cleaning. As the weight starts to come down onto the hitch at mid-track it increases traction. The momentum of the drivetrain can then be hooked up to the track and that momentum can carry you out the far end. This seems to work pretty well, and gives an impressive show, although I always wondered what would happen if you put some tall lug tires on and pulled in a low gear without the wheel spin. My son pulls a garden tractor with the no-spin, slow speed approach and wins almost every time. Not nearly as impressive as the National Quarter Scale tractors antics though.

RE: Tractor Pulling Tyre Dynamics

(OP)
Thanks for these, guys.
However, my first guesses are that "something" is adding maybe 100% to the drawbar pull obtainable from friction on moist clay..
That is allowing for weight transfer effects and pulling chain angles
Some mathematics would be most welcome...

Willturner

RE: Tractor Pulling Tyre Dynamics

With little tire slip the traction force is limited by the strength of the soil. Standard tractor tires are designed to push loose soil to the side as the tire slips so that the tire can try to grip some stronger soil below. Significant additional thrust is obtained at very high tire slip if a large mass of dirt is thrown back at high velocity. Its know as jet power smile.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources