Pulling Forum - Footprint

Print Page | Close Window

Footprint

Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Pulling Forum
Forum Description: Forum dedicated to Tractor and Garden Pulling
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=120855
Printed Date: 21 Feb 2025 at 9:40am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Footprint

Posted By: Charlie175
Subject: Footprint
Date Posted: 24 Mar 2016 at 9:27am

OK, some places limit tire footprint (Say 170 sq inches)

A 13.6x38 is 168 sq in while a 14.9x28 is 170 sq in.

Seemly equal but why does the 38 seem to pull better?

-------------
Charlie

'48 B, '51 CA, '56 WD45 '61 D17, '63 D12, '65 D10 , '68 One-Ninety XTD

Replies:

Posted By: bradley6874
Date Posted: 24 Mar 2016 at 11:58am

Charlie the way I see it the shorter tire digs deeper so your climing of of a wide deep whole instad of a long narrow shallow whole with less taper.

-------------
You can wash the dirt off the body but you can’t wash the farmer out of the heart and soul

Posted By: allispuller
Date Posted: 24 Mar 2016 at 12:23pm

Ground speed plays a big role in that with the same gear ratio a 13.6x38 will speed the tractor up so there for you are getting the bars to the ground faster

Posted By: patrickmull
Date Posted: 24 Mar 2016 at 2:00pm

ground speed is most of it I can pull farther in the 4000 open than I can in the 4000 4 mph

Posted By: cwhit
Date Posted: 24 Mar 2016 at 5:30pm

I don't remember the footprint # but when we used 16.9-28s we could pull in the 5500lbs class and spin out. When we put on the 15.5 38s, it would kill it.

Posted By: DrAllis
Date Posted: 24 Mar 2016 at 8:56pm

16.9 x 28 tire has a 175 sq inch footprint and a 56 inch diameter. 15.5 x 38 tire is 180 sq inches and 61 inches in diameter. If you were traveling 3.5 MPH with the 28 inch tires, the same gear selection would have you traveling at 3.8 MPH with 38 inch rubber.