Why does no manufacturer offer to mix tire types?

[4570Man]

I know that it’s not as simple as slapping on whatever you feel like, but getting the ratios right couldn’t be that hard. R1 front tires are really narrow, leave bad ruts, don’t carry the loader as well, the front causes most of the turf damage, and don’t wear very good. There’s a lot of people that don’t like R4s. It seems like R4s on the front and R1 radials on the back would be the best of both worlds, but just my opinion.

 

[dragoneggs]

but it will look funny and wrong :laughing:

 

[oosik]

Interesting thought - especially in a situation such as I have here. I have nothing sharp(thorns, chopped stobs etc) to puncture tires. People who visit me would not recognize this mixed tire situation as being unusual - even if you left the tread imprint on their backside.

The only down side - I do need R1's up front for summer mud and winter snow and ice. R4's don't pull so real well.

However - I have thought of the advantages of radials all the way around. What holds me back - cost of compatible rims and the extra cost of radial tires.

Trouble is - there is no such critter as one that's best for all conditions.

 

[Monster5601]

Could mixing tire types on 4 wheel drive tractors have something to do with tire circumferences?

 

[rScotty]

I know that it’s not as simple as slapping on whatever you feel like, but getting the ratios right couldn’t be that hard. R1 front tires are really narrow, leave bad ruts, don’t carry the loader as well, the front causes most of the turf damage, and don’t wear very good. There’s a lot of people that don’t like R4s. It seems like R4s on the front and R1 radials on the back would be the best of both worlds, but just my opinion.

I imagine you can use whatever combo you want just as long as you keep the circumference ratio between the front and rear tires the same as it came with.
Which is to say you should stay with a front to rear tire circumference ratio that matches the front to rear internal gear ratio of the 4wd transmission. Getting the ratios right isn't all that hard; it just takes looking through the tire tech specs and matching the "Rolling Circumference" of the original tires/wheel combo. Sometimes that requires buying a different wheel or rim or both. I've done it on a couple of tractors so far.

As for R4s and traction, those industrial tires have really good traction as long as they are on a heavy machine. That's what they were designed for.
You see R4s on all construction machines so R4s do work well on machines that weigh 4 or 5 tons & up.

On a lightweight CUT, the main advantages to R4s seem to be more roll-over stability, puncture resistance, wear better, and being more turf friendly than R1 Ag tires. Industrial R4 tires don't have particularly good traction on light weight tractors. Maybe twice as good as R3 turf tread, but that's not saying much.

Frankly I never mind when my tractors lose traction. It's just another way of protecting the gear train. I just lighten the load and continue.
rScotty

 

[chim]

I've been researching / agonizing over tires recently. I'd like to give turfs a try, and the tractor now has R4's. To do that, I need new rims. The price is around $1,500 for new rims and tires. Some money could be recouped by selling the rims and decent rears. The existing rear tires have lots of tread and the fronts are showing pretty much wear.

One thing I've been thinking about was to just change the fronts from R4 to turf. The R4's have always done a good job. I have noticed that brand new (front) R4's can tend to mark grass when making sharper turns. There's a lot of info about rolling diameter of tires that needs to be considered. Just how much the rolling diameter of the tires has changed with the wear they now have isn't something I know.

I have found turfs that are very close to the R4 rolling diameters and have done the calculations comparing them. The one piece of information I haven't found so far is the front-to-rear gear ratio of the tractor to see what the original tire ratio was. From what I've read, the final ratio (gear plus tire) should be within a couple percent with the fronts slightly pulling.

Without exactly matching the rolling diameter of the original tires, it's virtually impossible to get the ratio to what it should be. For example, if the factory tires were already at the one end of the size parameter, a minimal amount of difference of rolling diameter in one direction might be too much. While a slight difference in the other may even be a tad better than when it left the factory.

 

[Zebrafive]

chim, you are correct; front tires should lead or pull 1% to 5% more than the rears. I would want closer to the 1%, for less constant slip of the front tires.

6000 series JD tractors have multiple rear axle ratios and front axle ratios, plus 10 or more ratios for the transmission drive to the front axle, since there are a wide range of tire choices available from the factory. Such as utility versions with 30" rear tires, AG versions with 38" rears, special high crop with 42 or 48"? . Owners manuals for the 6X10 series even have formulas for calculating which transmission gear pair you needed if you wanted to change tire combinations.

 

[jeff9366]

R4s on the front and R1 radials on the back would be the best of both worlds.

Why not tractor radial tires front and rear?

More expensive initially but fuel savings and prolonged tread longevity for years compensate for some/most/all of the initial cost.

 

[4570Man]

Why not tractor radial tires front and rear?

More expensive initially but fuel savings and prolonged tire longevity for years.

I mentioned the reasons I prefer R4s on the front in the first post.

 

[jeff9366]

I read your opening post with care. I read ALL of YOUR posts with care.

Seems to me front tractor radial tires have all the positive attributes of R4 tires, with less ground compaction, better traction due to larger tire patch, softer suspension due to lower inflation pressures, better fuel economy and less tread wear, especially on the highway.

Factory R4 tires are almost universally six ply on new tractors. I do not know how six ply R4 relates to radials for puncture resistance. In my case, as I maintain a community burn pit that is heavily used, I must consider burn/melt resistance of the front tires. The burn pit and pit lip are hot more than cold.

(I considered optional Kubota radials when I ordered my L3560 in late 2012. However, dealer had no experience with radials mixing with an active burn pit, so I went with "safe" six ply R4 tires.)

Messick's claims in several videos and occasional contributions here that 90% of their new compact tractors are sold with R4 tires in Pennsylvania. My local Kubota dealer in Chiefland, Florida sells about the same ratio of R4s. With our soft, fast draining soil Turf tires are rare.

Why not tractor radial tires front and rear?