Tires turf tires and gear ratios...

blangham10 · Oct 19, 2014

I'm looking into converting to turfs or R4s on my YM 2820D. I've tried Hoye and they can't get them. Once I understand how to do the math I can start my search for the rims and tires. Any help on how to size them without wrecking the transmission would be greatly appreciated.:thumbsup:

Baby Grand · Oct 19, 2014

Measure the diameter of the front & rear R4 tires presently on the machine.
Divide the rear diameter by the front diameter - this is the ratio you will need to match with the front & rear turfs.

winston1 · Oct 19, 2014

The parts manual for my 2002d gives gear tooth numbers for the gears in the drop box. Simple math will give you the ratio if your manual has that information. You can then go to the forumula for calculating for correct tires.

I am supposing your 2820 has 12.4-26 on the back and 7-16 on the front. BKT tires gives RC as 3557mm (87.283") and 2217mm (87.283"). That equates to a 1.6044 ratio. Not all tire manufacture's maintain the same specs so don't take that as the for sure application.

Don't know if any of that will help or not.

blangham10 · Oct 19, 2014

Baby Grand--I currently have R1 ags and am wanting to change to either R4s or turfs. Thanks for the tip though!! Thats the kinda ciphering I can handle.

blangham10 · Oct 19, 2014

winston1-- You're correct on the rear tires but the fronts are 8-16. I'm confused by the conversion from mm-inches though. ["BKT tires gives RC as 3557mm (87.283") and 2217mm (87.283")"] The inch nums are the same?

winston1 · Oct 20, 2014

blangham10 said:
winston1-- You're correct on the rear tires but the fronts are 8-16. I'm confused by the conversion from mm-inches though. ["BKT tires gives RC as 3557mm (87.283") and 2217mm (87.283")"] The inch nums are the same?

Sorry about that, 3557mm (140.0394").

Do you have a parts manual and do you think the 8-16 is the correct tire for your tractor? Hoye shows 7-16 for your tractor?? Yanmar Tractor Tire Sizes

blangham10 · Oct 20, 2014

winston1 said:
Sorry about that, 3557mm (140.0394").

Do you have a parts manual and do you think the 8-16 is the correct tire for your tractor? Hoye shows 7-16 for your tractor?? Yanmar Tractor Tire Sizes

No problem... I'm not sure that the ones on my tractor are the right size tire. At this point, it wouldn't surprise me. I've been working on the cooling system and realized after removing the thermostat housing, it had no thermostat in it from the time I bought it 8yrs ago! I'm kinda scared to go in much deeper of what else could be missing!
Thanks for the link to hoyes tire page.