Pulling Forum - WC Speeds

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WC Speeds

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=68867
Printed Date: 23 Nov 2024 at 4:02pm
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Topic: WC Speeds

Posted By: Gary(MO)
Subject: WC Speeds
Date Posted: 17 Apr 2013 at 4:19pm

Dose anyone know what the speed difference would be on a WC 1st gear if I went from 13.6/28 to 13.6/36 tires? 1850 rpm,s. Thanks Gary

Replies:

Posted By: wi50
Date Posted: 17 Apr 2013 at 4:55pm

I don't know off the top of my head, but I posted the gear ratios a while back if you search, "allis gear ratios" here or on YTmag you'd find them.

Then if you have the rolling radius of your tires you could figure out the difference.

Just say that 1st gear is for example 64 to 1 meaning that 64 turns of the crankshaft is equill to 1 turn of the wheels. If the rolling radius of the tire is 24" then the circumfrance is 151 inches, at 1850 RPM the tire is turning 28.9 RPM.

28.9rpm X 151 circumfrence =4364 inches per minute or 363.6 feet per minute

363.6 fpm X 60 = 21819.5 feet per hour or 4.13 MPH

Find the rolling radius of the tires in question and then a guy can figure it out from there. I just don't rember the WC gear ratios without looking them up again.

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"see what happens when you have no practical experience doing something...... you end up playing with calculators and looking stupid on the internet"

Posted By: DrAllis
Date Posted: 17 Apr 2013 at 6:15pm

My charts say 2.5 MPH @1300 RPM with 13.6 x 28 rear tires. My math says 3.1 MPH @1300 RPM with 13.6 x 36 rear tires. More math says 4.4 MPH @ 1850 RPM. Now, pulleeze remember, that there is a difference in tire brands and wear on the tire lugs when it comes to total diameter, which will affect MPH. Also, if you are running on a sled that has a speed limit horn, you are under the horns control and what you think you're running doesn't mean squat.