Tires??

[A Ricci]

I find one subject that there are many views and opinions on is tires?

What are some of the problems you guys have experienced over the years either with your own tires and/or have heard about?

examples:
Traction
Tire inflation
sizing
weight sifting and over loading
design

[Dave James]

Bigest problem we had was the shop's insistance on pluging the high speed radials when we would pick up a nail,, and or not replacing tires when needed, because "there's still good tread on'em":mad:

[Guantes]

Traction/Inflation
Pressure is a major factor. Small amounts of pressure change can make a big difference. When we were drag racing, the difference b/t 4 and 6lbs in the slicks was significant.
Construction and materials make a difference. For instance IIRC Michelins with the steel belt would usually hold a little longer (side load) than Pirellis which had glass belt, but the Michelins would let go more suddenly than the Perillis.

Sizing
An easy way to make small changes to the final dirve ratio.
Causes problems with 4wd if one tire circumfernce is off by much.

Weight Shifting and Over Loading
Under inflation with a heavy load will cause heat/pressure buildup eventually causing a blowout.

Design
Multi-use designs perform multiple tasks fair, but no one task as good as a tire designed specifically for it.

[T.O.]

I find one subject that there are many views and opinions on is tires?

What are some of the problems you guys have experienced over the years either with your own tires and/or have heard about?

examples:
Traction
Tire inflation
sizing
weight sifting and over loading
design

Anthony, I've been told to over inflate my tires 10 to 15 lbs over the manufacturers (tire) recommended limit. I was told this will help to increase life span of the tire. Makes sence to me. But then again some people say to not do this. What do you think? I put a little extra air in anyways (maybe 10 lbs over) because I like a stiffer ride, but then again I'm not trying to read the WSJ in the back seat. For the most part I've always kept a little extra air in the tires and luckily never been bitched at by the principle. I drive through a lot of Canyons, the car handles a lot better with more air in the tires. Currently, I'm going w/ about 45psi. When it starts to warm up out here in Cali, I'll probably let some out. That is, when winter is over.. we've been having a harsh winter out here in So Cal... Ha ha, just teasing you East Coasters.
T.O

[Guantes]

TO,
Got news for you the east coast is not the only place that gets winter.
Try N Idaho 50 mi S of Canada.
Regards,
Gloves

[JMusic]

Air preasure needs to be to manufacture specs for proper wear. Now when we raced super late models we varied preasure to help stagger. We also used nitrogen to decrease expantion when the tires warmed up but were off track here. Pardon the pun. Two biggest concerns I have is sidewall strentgh and does it match suspension plus I would rather give up some dry road traction for a better rain tire. I rather have a car loose when dry. Loose and wet is not a good combination.
Jim

[A Ricci]

Anthony, I've been told to over inflate my tires 10 to 15 lbs over the manufacturers (tire) recommended limit. I was told this will help to increase life span of the tire. Makes sence to me. But then again some people say to not do this. What do you think? I put a little extra air in anyways (maybe 10 lbs over) because I like a stiffer ride, but then again I'm not trying to read the WSJ in the back seat. For the most part I've always kept a little extra air in the tires and luckily never been bitched at by the principle. I drive through a lot of Canyons, the car handles a lot better with more air in the tires. Currently, I'm going w/ about 45psi. When it starts to warm up out here in Cali, I'll probably let some out. That is, when winter is over.. we've been having a harsh winter out here in So Cal... Ha ha, just teasing you East Coasters.
T.O

Are you talking Car or Tire manufacturers?? I would assume car since you said your running at 45 PSI??

[Brownie]

I have always run my tires at the highest recommended [ 32 ], or a few over.

I'd rather over-inflate than under-inflate normally. Does that sound right Anthony?

[RAM]

I had a couple Exploders, Veh mfg tire pressure allways seemd to soft so I ran them over inflated, allways got very good tire life (60,000 plus mi). After the last Exploder the roll over issue and tire crap hit the fan at Ford. Looks like over inflation was a good idea in that case.

Also I ride Harleys, Inflating them to HD specs, Especially the rear, seems to causes them to wear real fast down the center.

Big motor bikes are hard on the rears, not just from getting on the throttle but also from down shifting to slow down. Combine all this with a soft/under inflated tire that gets hotter from the extra flexing and the rubber softens from the heat and wears out faster.

I allways get about 30% better rear tire life when running them about 6-8 lbs over inflated on the rear.

I can still run the bike in the mountains banging it from floorboard to floorboard in the turns without hurting the traction if only 8 lbs overinflated.

Motorcycle tires will still wear out in the middle first just at a slower rate.

The only place I have seen them wear out on the side tread first is at the CHP academy, in training those guys hardly ever ride the bike in a straight line. :D

[T.O.]

TO,
Got news for you the east coast is not the only place that gets winter.
Try N Idaho 50 mi S of Canada.
Regards,
Gloves


I take my hat off to you. Thats some serious weather. I have some friends in Coeur d'Alene. Sounds like your even further North.

[A Ricci]

TO and Brownie

I agree with you both saying to over inflate. Like Gauntes says "Weight Shifting and Over Loading -- Under inflation with a heavy load will cause heat/pressure buildup eventually causing a blowout."

There are several factors first we need to consider. What vehicle we are driving and what terrain we are moving through. For instance crossing the desert on some what of a hard packed terrain. Most would think to under inflate the tires for more traction however, under extreme heat and long distance an under inflated tire will heat up. We trained several units that had been back from Iraq and waiting for their next deployment. They were amazed when we spoke about inflating tires to the tires manuf. specified max. They all started to look at each other and one guy finally said we spent a **** load of time replacing blowouts. We need to get the pressure up.

On the streets for you corporate drivers my rule is the max that it says ON THE SIDE OFF THE TIRE is the min. I run.

T.O. when you said 10 to 15 over -- that may be true for the car manuf. limits but not the tire. The best rule is stick to the tire manuf. limits. The number that it says on the side of the tire. Some will disagree and I understand why. However I am speaking from a PERFORMANCE STANDPOINT only. The more inflation a tire has (up to its max.) the more vertical load it will be able to hold back. When we think of weight shift on a car whether Longitudinal force or Lateral force, weight always goes through the suspension into the tires. It is this force that the tires need to hold back. The lower the inflation the more roll a tire will have. A tire that rolls under will eventually reach the rim. Once the rim digs into the pavement the car can vault or flip over. A properly inflated tire is designed to slide across a level surface not roll.


To touch on RAM statement about street bikes. Motorcycle tires are designed to run a bit lower inflation. They actually have three traction patches. The two sides and the middle. When a MC tire is a little softer it will allow the side traction patches to spread out and grip better. This is mostly for race bikes, and works real good on the track. I tend to put a little more air in my tires for the road but I never run my bike tires hard or near the limit. In a 44 PSI tire I usually run arouind 34-36 for the street and 28-32 for the track. On a cruiser or Harley bike I would run them even harder due to the extra weight and construction of the tire, an long distances covered. A hard tire will wear much better but will actually provide a bit less traction. Unlike a car were an under inflated tire will roll under on turns and a straight away the centers will elevate causing the tire to wear on the outer edges. This is mainly due to the fact that a bike tire is not flat from side wall to sidewall but curved.


If you like to read and want to increase you riding skills to best book by far right now is "Total Control", by Lee Parks. It will be the best 25.00 you spend on your bike. I promise... The techniques work for all bikes from gold wings to sport tourers and race bikes.

[Guantes]

AR,

Didn't some of the radial tire mfgs advise against overinflation at one time? I believe it was due to the stiffness of the belt and flex of the sidewalls. Inflation at their rec pressures allowed the sidewall to roll a little and keep the footprint on the road, whereas with over inflation the whole tire would roll lifting the belt and footprint somewhat.

[RAM]

To touch on RAM statement about street bikes. Motorcycle tires are designed to run a bit lower inflation. They actually have three traction patches. The two sides and the middle. When a MC tire is a little softer it will allow the side traction patches to spread out and grip better. This is mostly for race bikes, and works real good on the track. I tend to put a little more air in my tires for the road but I never run my bike tires hard or near the limit. In a 44 PSI tire I usually run arouind 34-36 for the street and 28-32 for the track. On a cruiser or Harley bike I would run them even harder due to the extra weight and construction of the tire, an long distances covered. A hard tire will wear much better but will actually provide a bit less traction. Unlike a car were an under inflated tire will roll under on turns and a straight away the centers will elevate causing the tire to wear on the outer edges. This is mainly due to the fact that a bike tire is not flat from side wall to sidewall but curved.


If you like to read and want to increase you riding skills to best book by far right now is "Total Control", by Lee Parks. It will be the best 25.00 you spend on your bike. I promise... The techniques work for all bikes from gold wings to sport tourers and race bikes.

A,

Well said.

When I said I over inflate I did mean over the MC Mfg. suggested PSI.
That is still within the Max inflation rating for the tire, your discription is much more elloquent than mine but it looks like were on the same page.

[A Ricci]

A,

Well said.

When I said I over inflate I did mean over the MC Mfg. suggested PSI.
That is still within the Max inflation rating for the tire, your discription is much more elloquent than mine but it looks like were on the same page.


Sorry Ram I was a bit confusing on my last post. I tried to answer several posts in one message.

With the Manf. vs. tire man. question that was in reference to T.O.'s post. About inflating his tires 10 -15 over. 10 -15 over the the tire manf. would be crazy. Now 10% over the tire manf. could work depending on the situation but not 10-15psi. over that would be crazy.

But on the motorcycle part of the conversation I was just elaborating on your thoughts. You post makes sense to me too.

[A Ricci]

AR,

Didn't some of the radial tire mfgs advise against overinflation at one time? I believe it was due to the stiffness of the belt and flex of the sidewalls. Inflation at their rec pressures allowed the sidewall to roll a little and keep the footprint on the road, whereas with over inflation the whole tire would roll lifting the belt and footprint somewhat.


Sorry Gauntes - I knew I missed a post.

I am going to get long winded here cause you ask great questions. Hopefully by answering this I hit on some of the questions asked by others as well. Sorry for rambling and answering you a bit indirectly.


It would depend on what we are calling over inflation? For years we over inflated our training tires due to the large amount of stress and number of laps the cars are doing. We also wanted a driver who got out of control to slide and not roll, so it was a safety issue too.

Now over inflation is NO MORE THAN 10% (thats % notPSI) OVER the tire manufactures recommended limit. Thats it. So if your tire takes 44 psi we would TRAIN at about 48 -49 PSI. So in theory for PERFORMANCE REASONS ONLY I agree with slight overinflating. For regular street use I personally always run the Max. tire mauf. specs. Whatever it says on the side of the tire is what I put in my truck or car. So we like to says Max. is Min. The Max on the side of the tire is the Min. you should put in.

So what are the Neg. to the above theory??
Well the car will ride real hard and you will feel the bumps. You will get used to it... The problems come in to play for corporate Sec. Drivers. Their bosses want to use the computer, read the paper, etc. They want a smooth ride no bumps. So we recommend slowly inflating your tires 2 PSI per week untill the boss notices then let a pound or two out. It is a happy medium between performance and comfort. For a passenger car that takes a 44 PSI tire anywhere between 38-44 would be fine for everyday use. I would not recommend anything lower than 4 - 5 PSI lower that the tire manf. limits.

The reason I say this is do to the vertical load acting on the tire. Each tire has a vertical load capacityor limitation. That number usually can be found on the side of the tire where it says P225/60R16 98H the 98 is a reference number that is found on a load index. It refers to the amount of weight that this particular tire can hold back which for this tire would be very close to 1653. This Max. Load can also be found on the side wall where it says something like Max. Load 1653 LBS. @ 44 PSI. So this tire will hold back 1653 LBS. of vertical load at 44 PSI. You have four tires and as weight shifts the majority of weight goes down through these four tires. Depending on how and what you do and with the brake, gas and steering wheel will decipher how much weight is tranfered to one of these tires at any moment in time. If the weight/load you transfer is greater than the max. Load on the tire this tire will begin to exceed it's capibility and slide in the direction that the car happens to be going.

So if you lower you pressure would your tires be able to hold back more or less vertical load?

We used to play with the thick headed guys in the class who wouldn't listen. We would take 4 -5 PSI out of the back drivers side tire when the students where doing the slalom. If the drivers and cars were almost equal. The car with more PSI could hold back more force which meant it could carry more speed throught the slalom. The nit-wit who busted our balls all through class about tire pressure would spin out about 2 -3 miles an hour slower than the other driver. We would laugh and get him real mad and than say ok switch cars. Suddenly he could go faster then we asked the class to tell us why? You get the rest of the story...

For performance reasons I like properly inflated tires but slightly overinflated will not cause a radial to lift they are designed to contour to the pavement or stay flat to the suface as the car shifts. Extreme over inflation will cause the tire to become round and wear the middle out first. This means you have less rubber on the road.

A Bias ply tire will lift with the car because the side walls are very stiff.