Mis-matching tires

[Optimaldave]

While it's not uncommon, the idea of mismatching tires being a problem (on a motorcycle) is far from universal. I've run mismatched tires before and there was nothing remotely weird about the bike's handling related to it. Good grief, some OEM's even cross the line into mixing bias and radial tires (BMW for one).

As is the joy of mechanics there is no such thing as universal, and nothing is a set rule without ways to bend it. We just don't do it as a practice as say running two tires that have a different compound can give you and issue cornering seeing as say you run a Metzler M5 up front and a Pilot Road on the rear. You can bail pretty easily when railing on the bike in turns as coming up to the turn you have good grip with the front tire but when transitioning to the rear tire coming onto the throttle it could let go being a harder compound tire that is not able to cope with the current load being applied against it max coefficiant of friction.

Is the average rider going to notice, probably not, but we make it policy to not do anything to the bikes that could compromise safety should someone run the bike to full potential.

and yeah, I know of things like the Michelin Anakee that is a bias front and radial rear but this is again catering to the enduro market when wheel skip or wobble is somewhat of expected due to loose suspension and knobby tires for off-road. Just like how someone driving with 6"lift and huge mudders would expect some drift cornering at highway speeds.

Also one thing I have learned working on European bikes is that they are always an exception. I have gotten to used to peoples confused looks when I tell them why that horrible noise or vibration is the bike operating as designed...

So I am not saying it can't be done, and along with exhaust and oil type every shop policy and rule is based on someones personal opinion or experiance. So I do encourage people to think about the idea, apply the logic, and come up with your own conclusion. But others input gives you something to bounce off of, and maybe a point you didn't think of.

Cheers
Dave

 

[farmer]

i've been running 3 BFG A/Ts and 1 Firestone A/T for months now and no problems, firestone mounted on the passenger back corner

 

[85_Ranger4x4]

PA has some of the strictest vehicle inspection laws in the nation and having the same tires front and rear has never been a requirement. You don't know WTF you're talking about.

In his defense I think he took it as having tires mix and matched on the same axle. I can see where it would be bad to getting on the brakes hard and hit a slick spot with one MT and one AT, you are going to start spinning to the side of the AT.

I used to tractor pull with a bald tire and a good tire on the back (2wd), it became pretty obvious about a third of the way down the track that in order to go straight I was riding the bald tires brake.

 

[Optimaldave]

In his defense I think he took it as having tires mix and matched on the same axle. I can see where it would be bad to getting on the brakes hard and hit a slick spot with one MT and one AT, you are going to start spinning to the side of the AT.

I used to tractor pull with a bald tire and a good tire on the back (2wd), it became pretty obvious about a third of the way down the track that in order to go straight I was riding the bald tires brake.

Yeah, I could certainly see mixing two types on the rear going very bad as if you plant the brakes and one tire lets go the other is going to as well meaing your ass end is now in front of you

 

[straycat]

PA has some of the strictest vehicle inspection laws in the nation and having the same tires front and rear has never been a requirement. You don't know WTF you're talking about.

I used to live in Lancaster near the Susquehanna River and I know way more then most people will ever know, Bro. Running mix matched tire treads could very easy be a huge safety hazard especially to an inexperienced driver as we should well know.

 

[straycat]

Ok guys, before this starts as a flame war, lets discuss everyones opinion as an opinion which will change from case to case.

I belive it is correct that it would not make a huge difference front to rear treads on a truck as the odds of both tires on the axle doing something weird at the same time are slim to the truck would tend to auto correct itself.

I do know however that we will not install different brands or types of tires on the street motorbikes in our shop as two kinds of tires can handle very differently, and if you lose a wheel on a bike you are sliding on the ground before the end of your four letter word...
It is different for enduro bikes though as we will put a nobby tire on the front with a radial on the rear for people doing on and off road that don't want to blow through a rear tire in 5000KM...
So perhaps it is the same for trucks where in for street vehicles it is not a good idea to mic front and rear, but if you are using it dual purpose you are somewhat of expecting some odd handling anyways as you generally have other mods that affect your steering and suspension in negative ways for street driving...

just my 2 cents coming from the powersport world

Cheers
Dave

Yes, bikes are very different (two wheels for instance). I have rode all kinds of street and dirt bikes all my life. I flat tracked BSA's, Norton's and Triumph's single lung bikes with two different types tread on them at over 100 mph with no brakes!! You had to make with what you had as the expression goes...lol. But they are so different than being in a truck and honking at freeway speeds as we know. I just don't want anybody to get hurt or killed. Every day there are people killed on our roads due to faulty tires or other issues...not to mention so many distractions as well.

 

[JohnnyO]

I used to live in Lancaster near the Susquehanna River and I know way more then most people will ever know, Bro. Running mix matched tire treads could very easy be a huge safety hazard especially to an inexperienced driver as we should well know.

This

And now..most states don't have the state inspections anymore. They would never let somebody get away with that as you know.

Is where take issue. I have never heard of a state inspection requirement in any state that all four tires had to be the same, and PA is one of the toughest states there is on vehicle inspection. I've never heard of a motor vehicle code in any state that requires all four tires to be the same make, type, and size. If I'm wrong, then show me. There have been cars and trucks built over the years that came from the factory with different size tires front and rear. Late-70's Ford F-350 Super Camper Special, 1970 Dodge Challenger T/A and Plymouth 'Cuda AAR, Dodge Vipers, and some late-model Corvettes and Porsches, just to name a few off the top of my head.

Is it better to have all four tires the same? Sure. But having different tires front and rear, in size or tread pattern or both, isn't the horror leading to certain carnage on the highway that you make it out to be.

 

[kimcrwbr1]

Full time 4X4 keep all the same and rotate front to rear regular. Otherwise front to rear dont matter as far as size but side to side you want the same size and type for handleing and wear on the differentials. If your running 4X4 on the street with different size front to rear it will damage the drive train and wear the rubber down faster from the stresses.

 

[Optimaldave]

Full time 4X4 keep all the same and rotate front to rear regular. Otherwise front to rear dont matter as far as size but side to side you want the same size and type for handleing and wear on the differentials. If your running 4X4 on the street with different size front to rear it will damage the drive train and wear the rubber down faster from the stresses.

Yeah, talking to an auto tech friend of mine he pointed out that the biggest problem with doing what I want to do is making sure to calculate the difference in stock true size against the tread depth to make sure that all four tires are worn the same amount. Otherwise in 4x4 I would screw up the driveline...

Cheers
Dave

 

[Optimaldave]

You had to make with what you had as the expression goes...lol.

Yeah, such is unfortunately my situation as my current tires are not going to serve me well through the winter, but I cannot afford a full set of tires this time of year seeing as I will be laid off for winter soon...

Running two different sets is my thought because I do have 2 Firestone Destination A/T's in the shed from my other ranger, and could afford a used set of two tires, but am having issues finding matching ones....

So it is somewhat of a toss up between running crappy tires, mis-matched tires, or no truck... thus my reasoning for wanting to know if I can do this without worrying about breaking the truck or having a major issue...

Cheers
Dave

 

[bobbywalter]

meh.....


too much bullshit in this thread.

dont mix bias and radials..pretty much the only thing to say.

...if your in a bad situation where you have to temporarily mix bias and radial...and it happens, you will definitely drive accordingly, it will suck. but you will get where you need to go driving accordingly.


my tires end up mixed and matched at times. blow out three tires on the freeway and your fawked...you take what you can get.

depending on 4x4 system, tolerance will vary. 50 50 split needs tires close to keep bind down.



anybody that owns boggers that has driven wet roads can tell you to drive accordingly...you will figure it out or you will wreck your shit.

i usually run swamps front and bogger rear....sometimes at triple digit speeds for periods of time on the road....though i dont like to drive them on the road.

having a 33 at in front and cooper at in front with a firestone atx/remington mud brute on the back will affect my handling potentially...it sure did....but i drove home through a shitty wet blizzard from cynthiana to detroit just fine. out side of being fuggin pissed my tires got slashed at the hotel.

 

[Optimaldave]

meh.....


too much bullshit in this thread.

dont mix bias and radials..pretty much the only thing to say.

...if your in a bad situation where you have to temporarily mix bias and radial...and it happens, you will definitely drive accordingly, it will suck. but you will get where you need to go driving accordingly.


my tires end up mixed and matched at times. blow out three tires on the freeway and your fawked...you take what you can get.

depending on 4x4 system, tolerance will vary. 50 50 split needs tires close to keep bind down.



anybody that owns boggers that has driven wet roads can tell you to drive accordingly...you will figure it out or you will wreck your shit.

i usually run swamps front and bogger rear....sometimes at triple digit speeds for periods of time on the road....though i dont like to drive them on the road.

having a 33 at in front and cooper at in front with a firestone atx/remington mud brute on the back will affect my handling potentially...it sure did....but i drove home through a shitty wet blizzard from cynthiana to detroit just fine. out side of being fuggin pissed my tires got slashed at the hotel.

Ok, I have gotten what I need from this thread so before any flame war continues I dunno if you mods want to lock this thread or what have you...

I think I am going to not worry too much about it, I have a spare set of 4 rims so I will mount the Firestones on 2, and find an equililent set in size and tread and mount them on the other two. I will then leave that full set in the shed mounted and balanced and leave them until the day that snow hits.(assuming it ever does snow here )

This will mean that the only time I would be running them is when the ground has give to it (so I don't need to be too concerned with driveline binding) and I would be driving incredibly carefully and conservatvely anyways (so would already be expectiong a lack of traction and odd handling)

Cheers all for your inputs
Dave

 

[bobbywalter]

theres no reason to lock it.


theres no reason to worry about mismatched radial tires either.

its not ideal, but will suffice till you can afford to get some matched rubber.


if you end up with mis match tread, take some time and test the limits is the worst to worry

 

[Optimaldave]

theres no reason to lock it.


theres no reason to worry about mismatched radial tires either.

its not ideal, but will suffice till you can afford to get some matched rubber.


if you end up with mis match tread, take some time and test the limits is the worst to worry

How precise do you think I should be when pairing the front and rear tire sizes to deal with 4x4 while on road? I have a 90 so to my knowledge the 4x4 is very picky as it has no slip in the diffs...

Cheers
Dave

 

[bobbywalter]

How precise do you think I should be when pairing the front and rear tire sizes to deal with 4x4 while on road? I have a 90 so to my knowledge the 4x4 is very picky as it has no slip in the diffs...

Cheers
Dave

under 35 inch....within a 1/2 inch over 35 within an inch



4x4 system is the real factor...if you have a spool or locker it will list or jerk noticeably outside of that from side to side if say you have an undersize spare on... front to rear you will notice bind in 4x4 on dryish pavement. with open diffs and awd you wont notice much.