The Forestry Forum

General Forestry => Forestry and Logging => Topic started by: rick f on June 16, 2011, 01:34:30 PM

Title: skidder tire size?
Post by: rick f on June 16, 2011, 01:34:30 PM
Guys, my old clark has 16.9 x 30 tires now. My buddy found a pair of 18.4 x 30 skidder tires. How much diffrence is there in the rolling circumfrence of these sizes? Would it be a no-no to have diffrent sizes on the bak then the front?

Thank you
Title: Re: skidder tire size?
Post by: tyb525 on June 16, 2011, 06:42:52 PM
I'm not sure how the 4x4 works on skidders, but on most vehicles with 4x4 the front and rear rolling circumference should be the same.

As long as they're all the same size, they should work.
Title: Re: skidder tire size?
Post by: overtime on June 16, 2011, 06:49:13 PM
Don't miss match sizes
Title: Re: skidder tire size?
Post by: ga jones on June 16, 2011, 07:45:48 PM
8 inches taller aint gona work.............
Title: Re: skidder tire size?
Post by: tyb525 on June 16, 2011, 10:40:17 PM
It will if there arent fenders in the way
Title: Re: skidder tire size?
Post by: WH_Conley on June 16, 2011, 11:17:53 PM
Profile of the tire will make a lot of difference. The main thing is circumference, if that is the same they will work. It has to be exact.
Title: Re: skidder tire size?
Post by: acco1840 on June 17, 2011, 04:41:22 AM
My old 1977 cat 518 runs 18.4 x 34 as standard. I ran 2 16.9 x 34's on the back and had no problem.
Title: Re: skidder tire size?
Post by: rick f on June 17, 2011, 07:03:25 AM
Thanks guys good advice as always
Title: Re: skidder tire size?
Post by: oldseabee on June 17, 2011, 10:05:48 PM
The Clark has no spins in both axles and no seperation  of the front and rear drivelines.  Odd  sizes will give you driveline wrap up and you will either be pushing two tires or dragging two tires, extra load on the machine and doesn't help tire wear either. Keep the sizes equal front to rear.
Title: Re: skidder tire size?
Post by: thumper on June 21, 2011, 11:04:46 PM
i think the width of the tires is the only diff. the height is close  with those two sizes..??
Title: Re: skidder tire size?
Post by: chevytaHOE5674 on June 22, 2011, 08:14:44 AM
Quote from: thumper on June 21, 2011, 11:04:46 PM
i think the width of the tires is the only diff. the height is close  with those two sizes..??

A firestone 16.9-30 is 59.2" tall with a rolling circumference of 178"
An offbrand 18.4-30 is 60.9" tall with a rolling circumference of 196.5"

So one of the tires is going to have to travel/slip almost 20" more for every revolution. That is quite a bit.
Title: Re: skidder tire size?
Post by: tyb525 on June 22, 2011, 03:33:31 PM
only thing I can think of would be to lower the air pressure in the taller tires, essentially reducing the rolling circumference. I'm not sure that would be a good idea, though.
Title: Re: skidder tire size?
Post by: lumberjack48 on June 22, 2011, 04:00:01 PM
Do not run different size tires or you will be paying dearly in days to come.
Title: Re: skidder tire size?
Post by: rick f on June 22, 2011, 08:30:33 PM
A firestone 16.9-30 is 59.2" tall with a rolling circumference of 178"
An offbrand 18.4-30 is 60.9" tall with a rolling circumference of 196.5"

Can you tell me were this info was found? I tried to find it and could not.

Thanks for all the replys.

I'll be putting on the 16.9 x 30. So they all will match.
Title: Re: skidder tire size?
Post by: chevytaHOE5674 on June 22, 2011, 08:46:01 PM
I got it from the firestone ag website, and some other website that listed a 18.4-30 tire.
Title: Re: skidder tire size?
Post by: saltydog on June 23, 2011, 12:55:01 PM
there both 30 s i would run them. no different than having well worn rears and putting on new fronts. who can afford all new tires nowadays? mine are over 2000.00 each. ill be runnin used tires the rest of my life.
Title: Re: skidder tire size?
Post by: thumper on June 23, 2011, 06:49:18 PM
Quote from: saltydog on June 23, 2011, 12:55:01 PM
there both 30 s i would run them. no different than having well worn rears and putting on new fronts. who can afford all new tires nowadays? mine are over 2000.00 each. ill be runnin used tires the rest of my life.
exactly.. i looked at mine today, worn rears newer fronts. big diff in height.. id run them and make some money.  its not like we run skidders on hot top roads..
Title: Re: skidder tire size?
Post by: rick f on June 23, 2011, 06:54:54 PM
Thumper you have mail
Title: Re: skidder tire size?
Post by: thumper on June 23, 2011, 10:02:09 PM
rick i tried to reply to your email but it wouldnt go thru..