Clare - are smaller car tires easier to balance than SUV tires?
formatting link
A neighbor was in need of tires who knew that I had bought a few extra for her long ago where they've been sitting outside in the rain & mud for months waiting for her to need them.
formatting link
She finally wore through the belts and had to stop over for an "emergency" tire change, which I did for her, but she was in a rush so we did it in about 20 minutes from start to finish.
I had to do it so fast that I didn't see the yellow dot until I looked at this picture, where I mounted the red dot to the valve stem instead of the yellow dot as you had recommended for when there are no match mounting marks.
I did statically balance and she reported no vibration whatsoever. I didn't spend a lot of time cleaning up things so I'm surprised there's no imbalance given how quickly I did the job for her.
Just wondering if you've found that these tiny 14-inch tires are a piece of cake compared to the normal truck SUV tires (like the Optimo's that I'm used to) both in terms of mounting and balancing?
Yes and no. The smaller tire has less total mass so a small amount of weight has more effect than it would on a bigger tire - but it is not as far from the center (shorter moment arm) so it has less effect.
GOOD tires of any size are easier to ballance than crappy tires. Ealy Hankooks were a real pain to ballance. Apparentlythey have gotten better.
Thanks Clare as I never mounted and balanced a tire so fast on purpose, not even taking time to clean the wheel or even remove the old weights until AFTER I put it on the static balance stand.
These tires are Lexani LXTR 203 model tires, of size P185/65R14 with load range 86 and speed range H (traction A, temperature A, and treadwear 500), where I don't know WHAT specific thing makes these so easy to balance, but they're so easy that something is very different.
I was surprised that I skipped a bunch of steps, and yet, the wheel _still_ didn't cause any perceptible vibration, according to the driver, even as it's a front wheel drive vehicle with the tire being the driver side front tire.
I had told the owner to take it to Costco for the $5 wheel balancing, but that wasn't even necessary, even as I skipped a bunch of balancing steps.
The old tires on her car were model "Grand Prix" of size P185/65R14 load range 86 and speed of T (traction A, temperature B, and treadwear 500) which seem to be wearing on both edges, where here are the front two tires of this FWD vehicle with the tires set up in the appropriate position.
formatting link
I had previously replaced her passenger front tire due to this gouge
formatting link
Where the driver front tire wore into the steel belts which jutted out
formatting link
She needed to be somewhere so I was in such a rush, that I didn't even _see_ the yellow (weight) dot when I mounted the valve stem to the red (uniformity) dot:
formatting link
Where I only noticed the yellow dot when I looked at this picture!
formatting link
Back to how easy it was to statically balance these tires, not only did this tiny car have the only four-lug wheel I've ever worked on, but popping the first bead of this tiny 14-inch P185 tire was so simple that it took only a couple of pumps and about triple that to break the second bead.
Removing the third bead and fourth bead was, likewise, surprisingly simple. Popping on the fifth bead was almost entirely done by hand, it was that easy, where only the sixth bead took any effort whatsoever that required a force that any teenager could exert.
With two wheel weights already on the rim, and by match mounting the red dot (I didn't even _see_ that yellow dot until I looked at the picture afterward), the balance was spot on in the middle of the bubble level.
So I didn't even remove the _old_ wheel weights, which I normally would have done as part of the wheel prep after breaking the bead and removing the old tire. I didn't even replace the valve stem, as I recently used up the four valve stems I had bought after speaking to you about getting the bolt-in kind so I didn't have any available.
The tires have been waiting for her outside in the mud and rain, so I simply bounced and blew out the leaves and crud where I would have cleaned the tires more had I more time, where I might have noticed that yellow dot which was slightly worn away from being outside all winter.
Funny you mention the Hankook's where I just snapped this for you!
formatting link
Those are Hancook Optimo H724 model tires of size P225/75R15, with the load range of 102 and speed range of S (traction A, temperature B, and treadwear
500), which were MUCH HARDER to mount and dismount and harder to balance too, it seems.
I'm planning on mounting and balancing them this weekend on an SUV which keeps wearing out the front tires which I have to get alignment tools to check the camber mostly since they're wearing on the outside edge.
When I mount those thick-sided Hancooks, on steel wheels, I will mount by the _yellow_ (minimum weight) dot for the first time, instead of by the red (maximum runout) dot, as I recall you recommended for when there's no match mounting mark on the rims.
Thanks for being helpful where you're just about the only guy on this newsgroup who knows anything about this subject matter, which I greatly appreciate your advice, and where I try to remember it all over the years, where I'm starting to lose count of how many tires I've done in the past five years with the crappy Harbor Freight tools (they work, but they suck).
You can check the camber all you like but the answer is more likely in the SAI angles and you will be able to do SFA about that. Quiz the owner about type of use instead. If it is all city and suburban driving, tyre wear on the outside of the tread can be considered 100% normal. Turn the wheels to a high level of lock and the obvious will confront you. The type of feathering will tell you what the actual cause is.
Hi Xeno, I typed up a super detailed response, after viewing every second of those three videos, where the first and last seem to have the same graphics, and the middle (whiteboard) one was a bit different - and where that wheelcam shot of the tire literally bending away from the rim - and the temperature methods of determining footprint on hard cornering were illuminating.
I hate losing data, but I lost it when the PC rebooted, so suffice to say I appreciate the videos, from which I learned good stuff, particularly about that "scrub radius".
I didn't find a lot on the net about "camber scrub", and those videos didn't cover specific tire wear on the slow speed (less than 40mph) constantly lock-to-lock turns we perform on the mountain, where the goal is how to modify the set up for the vehicle in a compromise to minimize that 'camber scrub' on FWD and RWD vehicles without adversely affecting straight-line handling.
Everyone says you need a perfectly flat garage floor, which, as far as I know, mine is pretty flat based on putting a level on it - but I don't really know how flat is flat enough.
Given that a millimeter or two of height adjustment in any one corner might be necessary for most garages, I guess your suggestion above adds two nice-to-have tools to the home DIY alignment check mix... o Steering wheel centering lock o Some kind of way to put the 4 wheels on a wormscrew-adjusted plate
Googling found the first, but the second was in the thousand dollar range.
Are there good redneck solutions for leveling the four tires?
That is only true for ONE risk - the risk of the rear tires breaking away on a corner due to hydroplaning or poor traction.
In his case if he always put the best tires on the rear he would continually be putting half worn tires on the axle that is eating tires and requires the most traction (the downhill steering wheels and the uphill "scrambling" wheels.
The best tyres to the rear is for handling, keep the oversteer under control. In that case, we're referring to the best *type* of tyre. Radial versus crossply or steel belted radial versus textile radial. Most run steel radials now so the basic premise is academic but the basic rule is the best handling tyre when mixing tyre types. When it comes to tread depth, yes, you are dealing then with the risk of aquaplaning. More weight on the front means better water removal even on lower tread depths. At the rear, on a FWD, there may be very minimal mass on the rear tyres so pushing through water may be more difficult. In summary, the best place for the newest tyres on a FWD is the rear.
You NEVER mix types from axle to axle - for MANY reasons - one of which is legal.
For cornering in wet weather or loose surfaces, yes. For powering through corners or straight-line accelleration on clean dry pavement? Mabee not.
Anywhere understeer is a possible problem , more than oversteer, you want the best rubber on the front. On a FWD vehicle it is quite difficult to induce oversteer to combat understeer - and FWD vehicles tend towards understeer where you do NOT want bald front tires - - - . On SEVERE trailing throttle you don't want bald tires on the rear either.
Personally, I virtually ALWAYS replace tires in sets of 4 - and WELL before the thread is gone !!! I don't put miles on fast enough any more to wear good tires out before they "time out"
Yes, I learnt a couple of points from those videos too so it seems you can teach old dogs new tricks. I have found, in order to gain a better appreciation of steering geometry and suspension systems, one needs to look at those places that are extreme. In this case, it's in motor racing.
You won't. Information on it is scarce since it is an undesired effect. However, if you look at what the wheel is doing vis a vis camber during high angle (note - not high speed) cornering, then you can visualise the issue. Note too that tread blocks have a limited degree of flexibility and, as such, are likely to exceed that during high angle cornering resulting in tread scrubbing.
The reality is that you are faced with a *compromise* and there are many such in steering and suspension geometry. Any gain in the tyre wear scenario will negatively affect high speed. If you happen to see a Porsche Cayenne in a parking lot with its wheels turned at a high angle, the camber angle displayed will amaze you. I know it amazed me. Of course, when you realise that vehicle's suspension is *optimised* for high speed and high power operation in a very narrow band either side of straight ahead, it all makes sense.
A level will only give you a localised point. You need something that can verify any point in the garage floor against a common datum point. These can be used for that purpose and aren't expensive;
formatting link
you could hire one for a day just to verify your garage floor. A professional one of these should have been used when the floor was poured and leveled anyway.
Most wheel aligners that I have used come with ramps that have the added benefit of raising the vehicle a couple of feet off the floor. Ramps, even without the aligner heads, provide a relatively easy means of leveling the required work area. They don't even need to be raised more than an inch or two. If the floor area is really out of whack, two or four ramps made of wood of varying thicknesses might suffice. You can even check the level easily these days with laser levels as I mentioned above. My brother has one of the professional units since he is a concreter but cheaper DIY versions, like the one in the link, should suffice for this purpose.
Yes, I am well aware of that but it used to be legal, within limits, and some unknowing individuals still do it.
I am not referring to *bald* tyres. I don't even let my tyres get to the wear indicators as a rule. I like wet weather handling to be as optimal as possible.
You do not want *bald* tyres anywhere on a vehicle. I am not referring to bald tyres, just relative tread depth.
As I said before, ditto for me. I do clock up the mileage however. I am
25-30% above average mileage now in my 3 year old car.
Did I not say that it isn't just for *aquaplaning*? The idea is to reduce slip angles at the rear to control oversteer tendencies. This is all the time, not just when aquaplaning. All cars are designed with inbuilt understeer - even rear wheel drive cars. If you want to argue the toss, then take it up with the tyre manufacturers. After all, it's their recommendation for their own product so I feel safe in assuming they would have a better idea than Joe Blow off the street.
It wasn't illegal in this country back in 1969. There were specific limits to what you could do but the only legal requirement, as I recall, was the tyres had to be the same on the same *axle*.
I found, even though you could in that era have different tread patterns front to rear, you needed to ensure the best *handling* tyre was at the rear. This was not always easy to determine as I found out when I couldn't buy tyres to match the tread pattern on a car I owned and bought two tyres which looked very similar tread wise to the existing pair. Both types were textile radials and I fitted the new ones to the front. The rear tyre tread depth was very close to that of the new front tyres. What I found however was that the new tyres were way too precise with very low slip angles. When in even moderate cornering situations, the front would spear into a corner with minimal understeer characteristics whilst the rear displayed tail happy behaviour. The car felt *pigeon toed* as if the front wheels had extreme toe in settings. I couldn't leave it like that because my wife was the primary driver of that car so I reversed the set and it made the car stable once more. Not long afterwards I bought another 2 tyres and matched the existing new ones to give much more balanced handling and used the originals on a trailer. Whilst it appeared only to be a tread pattern difference, it soon became obvious that handling characteristics were vastly different between the two types and probably involved much more than the tread pattern alone. It wasn't possible to deduce this from merely looking at the tyres, it required a run on the road to discern the characteristics.
When I first entered the automotive industry, crossply tyres were king and radials were just entering general use. It was the recommendation at that time, if mixing types, to place crossplies at the front, the radials at the rear. As steel belted radials entered the scene, it was recommended that, if mixing the two radial types, that the steel belted radials were fitted to the rear and textile radials to the front. The reasoning back then was simple - cross ply tyres had the greatest slip angle characteristics, textile radials had lower slip angle characteristics and steel belted radials had the lowest slip angle characteristics of all. It was always mandatory to have tyres matched on the same axle according to roadworthy laws but the front to rear placement was Ok if you followed the above guidelines. As I found however, it wasn't always that simple and there were situations which were a case of try it and see. Since that time I have always bought tyres as a set of four at a minimum, fitted them all at the same time and followed tyre rotation procedures.
As for the legality of different tyres front to rear, some new vehicles would fall afoul of that since they have a larger rim size at the rear, usually in width but occasionally in diameter. Some small vans have a larger diameter wheel at the front, a smaller on at the rear for a flatter cargo space but, in these cases, the rear are *duals*.
While I don't race, our conditions are "extreme" enough, in that constant incessant repeated nearly full back-to-back wheel locks are causing "something" to scrape away rubber, so this "camber scrub" is intriguing.
I snapped this photo of tires that I mounted about a month ago, which only have about 1000 miles on them, where they clearly show this pattern which "might" be what you've been referring to as "camber scrub".
formatting link
Does _that_ feathering look like what you're referring to as "camber scrub"?
That is also considered *extreme* even though you aren't doing it fast.
It does indeed! Same kind of feathering I'm getting on my Toyota's front tyres - a feathering that you can easily feel in the early stages as you run your hands for and aft along that section of tread area. Now try to imagine what those tread blocks are doing as they roll around in a tight circle with heaps of camber gain. It's not pretty and, worse, there is SFA you can do about it.
BTW, positive caster will accentuate the camber scrub. Caster is generally not a tyre wearing angle. However, the more caster your steering has, the more camber *change* you will get when turning the steering. Positive caster will give you a beneficial gain in terms of handling. You will get more camber gain (more +ve) on the inside wheel but the outside wheel will experience camber *loss* and become more vertical or even negative. Since the more vertical tyre is on the outside, the tread will get more grip with reduced slip angle aided by weight transfer. This is great for cornering at speed. However when travelling at slow speeds, weight transfer is not as significant and the camber angle on the inside wheel, the one at the tightest lock, heads towards positive extremes. It is, in effect, riding heavily on the outer edge of the tread and this is where, and why, the damage is being done. The tread blocks have only so much flex before they are forced to break contact with the road and slide. You've seen the evidence of what that does.
Caster specifications are usually given as a range, say between 1 and 2 degrees with a side to side variation limit. All you can really do to mitigate the effect is to set your caster to the low end of the specified range.
Thanks for that information, where the one correction I need to make is that you can only feel this feathering running your hand "*backward*" (clockwise) over the outside quarter of the tread pattern.
formatting link
If you run your hand toward the front (counterclockwise), you can't feel the feathering because each "lip" is downward.
formatting link
When you run your hand toward the rear of the vehicle, each lip is upward.
formatting link
That's the oddity. The feathering is only one way.
formatting link
It's reproducible for years - so it's always the same. That one-way lip feathering should be diagnostic, should it not?
formatting link
Hmmmmmmmm.... maybe I can consider lessening positive caster a teeny bit?
This is very useful information, as all our lock-to-lock cornering is at
30mph to 40mph ... never faster because I ran a test last week where anything over 40mph is impossible to do even remotely safely, as all the turns are blind turns and the file miles of 9% twisty road can't even be twenty feet wide at the maximum (I should measure it but it's something like that, as it's too narrow for the county to center stripe it legally).
I need to study more - where your conclusion is spot on perfect but where I don't get the individual steps only because I think of alignment as being 'static' so to speak. I know it changes - but my brain doesn't know 'how' it changes under those slow speed lock-to-lock downhill (or uphill) turns.
Yes. That's for sure. The outer tread blocks "feather" such that you can feel it, and barely see it, after about 1000 miles. The only thing I can do, is change the alignment or rotate every 1000 miles (but even rotation won't stop it - it just evens it out with the rears).
That's EXACTLY what I'll do! I have to admit I need to read, and re-read and re-read again what you wrote above, as my brain needs to work in step-by-step fashion.
You didn't skip a step but I don't quite "believe" in my brain all the steps, if you know what I mean. It's not that I don't believe you, but that my brain has to understand EACH step before moving to the next step when it comes to UNDERSTANDING why this happens. (It's kind of like a series of math equations where I need to understand every step.)
On the other hand, once there is a conclusion, I can EXPERIMENT easily, which is how a lot of cars get fixed (by throwing parts at the problems without understanding them). So I will change the caster.
I have an alignment shop which runs a sale for $30 off to drop the $160 price to $130 who lessened my bimmer's rear camber from negative 2 degrees to almost 0 degrees - where if I go to him - I can ask for the least caster in the spec.
Better yet, I need to buy the tools to do that caster change myself - but that's a topic for a different thread since I have to MEASURE it first.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.