Can radial tires be mixex with bias

[ernemats]

Can I put regular tires on the front of my tractor when I have radials on the rear ? It is four wheel drive and I don't want to damage the transmission or gear cases. Thanks

 

[Texasmark]

Opinionated reply: For a given tire size, being air pressure dependent, especially at lower air pressures, your main concern would be "rolling circumference". Since you said "I put", past tense, you already mixed them. I'd get on soft ground in 4wd and make some zippers. Tweak your radial air pressure (should be the most sensitive to this trial) until you don't see any squirming on either set of tire marks. That would be what I would do.

Fronts are auxillary power so main drive needs to be rears. Any differences should favor rears with no sliding marks. Course in turns you want the fronts pulling you around the turn rather than the rears pushing straight ahead and forcing the fronts to slide/being pushed through the turn.....analogous to a front wheel drive sedan pulling you through a turn vs a rear wheel drive pushing the fronts for an example.

I noticed European farming Utube videos where large 4wd, radial equipped, farm tractors pump up the tires for road use and once on the field deflate the tires. I would assume 2wd is used on the road and it's obvious 4wd was the necessity in the field. So pumping them up for road use may have been to reduce sidewall flexing for longer tire life, not an attempt to maintain the proper drive ratio between fronts and rears.

I have mixed the two on drive and driven vehicles on the road and with 4 ply type tires, the radials will squirm while the bias won't and makes for a funny feel, not unsafe, just different. I would prefer bias on the fronts with a FEL if mixing, unless the fronts are near the diameter of the rears, like older Fords, JD, and IH machines I have seen.

 

[PILOON]

On a tractor I'd not be overly concerned as long as sizes are OK.
BUT
Once they did that on a company car I once drove and that darn car squirmed all over the place.
I had to take serious measures to force them to change them out to a correct matching set as that car was looking for an accident.
That was back when folks only installed snows on rear driven wheels and kept all seasons up front.
Dang car would jump and leap whenever I changed lanes and dangerous at higher speeds.

 

[RNeumann]

No issue on a tractor......unless you are doing 40+ mph for hundreds of miles at a time.

 

[ernemats]

Have not done it yet just thinking about it. Rears are 16.9 x 30 fronts 11.2 x 24. I do very little road running and not over 15 mph if I do and if so no more than1/4 mile at a time.

 

[ernemats]

Talked to a tractor tire dealer yesterday and they do not recommend doing it as the radials have a tendency to squat where as bias do not do it as much and therefore changes the rolling circumfrence a little.

 

[PILOON]

Talked to a tractor tire dealer yesterday and they do not recommend doing it as the radials have a tendency to squat where as bias do not do it as much and therefore changes the rolling circumfrence a little.

Heck, why not simply use higher PSI then.
The whole idea is that the smaller fronts will wear faster than the rears so there will almost never be a real match hence they usually suggest a 5% oversize to start.
On 'non hard' surfaces slippage compensates anyway.

 

[kthompson]

Have you talked with a dealer? Radials do squat so to speak but it is rather common with tractor tires to bump up the pressure for side loads or for front end loader as has been pointed out. Just wondering, any chance the circumference of radials might be same as bias belt with same air pressure.

 

[AWSubie]

The reason why bias and radial tires should not be mixed applies to the difference in spring rates between the two types of tire construction. On a vehicle that is road driven at higher speeds, the handling of the vehicle is negatively effected when one tire reacts differently than another. For a tractor operating at slow speed, you don’t need to be concerned about mixing tires.

 

[Bird]

Once they did that on a company car I once drove and that darn car squirmed all over the place.
I had to take serious measures to force them to change them out to a correct matching set as that car was looking for an accident.
That was back when folks only installed snows on rear driven wheels and kept all seasons up front.
Dang car would jump and leap whenever I changed lanes and dangerous at higher speeds.

I had the same thing happen years ago. It was a city car that had been driven by someone else and I couldn't believe anyone could have driven it and not get that "fixed". It even had a radial on one front wheel and bias ply on the other front wheel.