I have a ford 1715. A little while back I changed the rear tires from a 13.6x16 to a 12.4x16 to get a r-4 tread pattern. The fronts are 25x8.50-14. To achieve the correct drive ratio for the 4x4 would the 25x8.50-14 be ok when I change to the r-4 patten for the fronts or do I need to go to a different size? Any help would be appreciated.
Tire size
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LD1
Epic Contributor
Have no idea. What are the tires that were on it? turfs or R1's?
Look up the specs of the tires. Either rolling radius or circumference. Just make sure the front and rear ratio is the same or close.
Say...take the rolling raduis of the old front tire and divide it by the rear tires rolling radius. F/R
Then do the same with the R4's. Sould be nearly the same number for correct ratio
Look up the specs of the tires. Either rolling radius or circumference. Just make sure the front and rear ratio is the same or close.
Say...take the rolling raduis of the old front tire and divide it by the rear tires rolling radius. F/R
Then do the same with the R4's. Sould be nearly the same number for correct ratio
LD1
Epic Contributor
Well, I am not having any luck. You may wish to call a ford dealer ad ask what size R4's were original.
Cause here is what I got...
Your old turfs:
The 13.6-16 mounted diameter was 38"
The 25x8.5-14 mounted was 25"
25/38 = .658
The new 12.4-16 r4 mounted diameter is 37.2"
37.2x.658= 24.48. So you need a front tire with a mounted diameter of 24.5" or so.
Looking around, I am only seeing 23x8.5x14 coming it at 23". And the 25x8.5-14 you mentioned show a 25.8" mounted diameter.
So what you need is right in the middle. So i would question weather the 12.4-16 is what ford used for the R4 choice. Cause there dont seem to be a good match for the front. I am betting original was 15-19.5 R4's for the rear, as those match out perfect with the 25x8.5-14 and is the combination that several other MFG's and tractors use.
Cause here is what I got...
Your old turfs:
The 13.6-16 mounted diameter was 38"
The 25x8.5-14 mounted was 25"
25/38 = .658
The new 12.4-16 r4 mounted diameter is 37.2"
37.2x.658= 24.48. So you need a front tire with a mounted diameter of 24.5" or so.
Looking around, I am only seeing 23x8.5x14 coming it at 23". And the 25x8.5-14 you mentioned show a 25.8" mounted diameter.
So what you need is right in the middle. So i would question weather the 12.4-16 is what ford used for the R4 choice. Cause there dont seem to be a good match for the front. I am betting original was 15-19.5 R4's for the rear, as those match out perfect with the 25x8.5-14 and is the combination that several other MFG's and tractors use.
Soundguy
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here's the link from NH parts for the rim and tire sizes for that machine.
I see 3 fronts available from a traction and non traction ag, and a flotation tire.
rears also have ag/turf option etc..
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
I see 3 fronts available from a traction and non traction ag, and a flotation tire.
rears also have ag/turf option etc..
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
millertire
Advertiser
The 12.4-16 will work, you are allowed a 5% variance with 4WD tires. 38" - 5% = 36.1". 12.4-16 is 37.2"
Ed Miller
m. e. MILLER tire
Ed Miller
m. e. MILLER tire
LD1
Epic Contributor
Not saying you are wrong, but I would want more to go on than that. General rule is you want the fronts running faster than the rears. By 1-6ish% faster. IF he is already on the upper end of % lead, then going to a smaller rear (while being within 5%) And a larger rear (still being within 5%) he could end up with quite a bit mroe than 6% lead. And wear out front tires quicker.
Thanks for the info guys. What I have gathered from this is that I really need to find something that is a 24 x .......... Since that size doesn't really exist, either the 25x8.5 or the 23x8.5 should work. I don't put a lot of hours on the machine yearly, I just need some new shoes for the front before winter. Between the two sizes, what would you run.