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Clare - are smaller car tires easier to balance than SUV tires?
On Wed, 12 Jun 2019 21:37:49 -0400, Clare Snyder wrote:
> 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. 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. <https://i.postimg.cc/JzvTyjKg/mount18.jpg> I had previously replaced her passenger front tire due to this gouge <https://i.postimg.cc/4dTBPZDQ/mount19.jpg> Where the driver front tire wore into the steel belts which jutted out <https://i.postimg.cc/85Bwn9DQ/mount20.jpg> 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: <https://i.postimg.cc/7L8HPbtb/mount16.jpg> Where I only noticed the yellow dot when I looked at this picture! <https://i.postimg.cc/kG1M7cLd/mount15.jpg> 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. > GOOD tires of any size are easier to ballance than crappy tires. Ealy > Hankooks were a real pain to ballance. Apparentlythey have gotten > better. Funny you mention the Hankook's where I just snapped this for you! <https://i.postimg.cc/zGVtXxwK/mount17.jpg> 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). |
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Clare - are smaller car tires easier to balance than SUV tires?
On 13/6/19 2:32 pm, Arlen G. Holder wrote:
> On Wed, 12 Jun 2019 21:37:49 -0400, Clare Snyder wrote: > >> 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. > > 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. > <https://i.postimg.cc/JzvTyjKg/mount18.jpg> > > I had previously replaced her passenger front tire due to this gouge > <https://i.postimg.cc/4dTBPZDQ/mount19.jpg> > > Where the driver front tire wore into the steel belts which jutted out > <https://i.postimg.cc/85Bwn9DQ/mount20.jpg> > > 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: > <https://i.postimg.cc/7L8HPbtb/mount16.jpg> > > Where I only noticed the yellow dot when I looked at this picture! > <https://i.postimg.cc/kG1M7cLd/mount15.jpg> > > 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. > >> GOOD tires of any size are easier to ballance than crappy tires. Ealy >> Hankooks were a real pain to ballance. Apparentlythey have gotten >> better. > > Funny you mention the Hankook's where I just snapped this for you! > <https://i.postimg.cc/zGVtXxwK/mount17.jpg> > > 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. 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. > > 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). > -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
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Clare - are smaller car tires easier to balance than SUV tires?
On Thu, 13 Jun 2019 17:11:14 +1000, Xeno wrote:
> 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. Hi Xeno, Thanks for your purposefully helpful advice on kingpin inclination angle (aka steering axis inclination), and perhaps included angle, neither of which have I delved into yet (as I'm starting with camber, which is the basis for caster calculations, and where toe is relatively simple). <http://www.valleyofhastings.com/WheelAlignment2.pdf> Other than Clare, you and maybe one or two other folks here are knowledgeable in the important details of home alignment checks & adjustments, where I don't usually disagree with anything you guys say, as you know more than I do. We have to remember a home DIY alignment check & adjust is sort of like doing a DIY tuneup versus a complete engine overhaul o A DIY caster/camber/toe check/adjust is to a professional alignment o as a DIY tuneup is to a professional engine blueprinting overhaul The fact is that the SIA is a "non adujstable" angle: <https://www.freeasestudyguides.com/included-angle.html> The fact it's not adjustable means it is in a different category than o caster o camber o toe While SIA is not normally adjustable, looking this up anyway for more insight, it seems SIA checks generally simply need yet _another_ magnetic bubble gauge, much like the camber gauge apparently, but offset by 90 degrees, according to this cite: o Checking the Steering Axis Inclination Angle <http://route66hotrodhigh.com/Inclination.html> Which says: "To measure steering axis inclination, the method is identical to caster measurement except that you use the steering axis inclination guage [sic] which is at a 90 deg angle to the caster gauge. The wheel is turned 20 deg inward. The steering axis inclination gauge is centered for 0 deg caster. There is an adjustment screw on the back of the gauge that allows you to set it for 0 deg. The wheel is then turned to 20 deg outward for a total movement of 40 degrees. The steering axis inclination angle is read off the gauge." The key question is where to get that SIA gauge, which, apparently, can be replaced with a normal magnetic caster gauge according to this patent: o Device & method for measuring SAI on a steerable wheel (#4,546,548) <http://www.freepatentsonline.com/4546548.pdf> In short, if we're aligning a vehicle that we own and drive often, then we don't have any reason to suspect SIA changes (which will only occur with bent or worn parts), and hence, they aren't part of what typically changes (which is caster, camber, and toe). <https://www.motor.com/magazinepdfs/062002_05.pdf> > 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. On this mountain, everyone wears tires sooner than people who drive in flatland do, where there is just "something" horrific about five miles of steep driving, Most seem to wear on the outside edge, which I still haven't figured out exactly why. The road is about 5 miles at about a 9 percent angle with very many 180 degree and even 270 degree switchbacks, but the speeds are rather slow, where the road is too narrow to even have panted centerlines and where the nominal speed limit for such roads is 25mph. Given nobody drives 25 mph anywhere, we can figure it's something like 30 mph to 40 mph top speed but there's a lot of braking in between. Me? I just put the tranny in neutral and roll down the entire five miles by giving up potential energy, where I only brake when I must and I take the turns very wide (as most people do) which helps maintain speed. Somehow, _that_ process (which most people do, I think, but in gear most likely), wears tires out like you can't believe, where tires get half the stated mileage, as far as I can tell by aggregate conversations. > 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. I do admit that I can't 'read' a tire very well. I've tried, but rotations screw up the readings, and certainly there can be multiple causes. The type of feathering I mostly see is the kind you can feel after only about 1000 miles on the outside edge, for about 3 inches of tread, where there is a sharp lip that is feathered into that outside tread that you can only feel moving your hand clockwise over the front tire tread on the outside 3 inches. I need to learn more, but I think that's "normal" since it happens even after I get a professional alignment. I'm due for one soon for a couple of cars, which is why, instead of paying the $150 per vehicle, which for the 3 cars I want to do first, will be almost five hundred bucks, I'd rather buy the tools to do it myself for that same five hundred bucks. o Caster gauge (to measure caster & calculate camber) o Caster jig (to lock onto the wheel for the caster gauge to be accurate) o Wheel plates (to move the wheels for adjustment under suspension loading) o Toe plates (to enable single-person linear measurement to centerline) After having discussed this with Clare in the past, I know we can redneck some of that, but overall, those four items seem to be the key items needed for a home DIY check/change of caster, camber, & toe, do you agree? |
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Clare - are smaller car tires easier to balance than SUV tires?
On 14/6/19 6:28 am, Arlen G. Holder wrote:
> On Thu, 13 Jun 2019 17:11:14 +1000, Xeno wrote: > >> 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. > > Hi Xeno, > > Thanks for your purposefully helpful advice on kingpin inclination angle > (aka steering axis inclination), and perhaps included angle, neither of > which have I delved into yet (as I'm starting with camber, which is the > basis for caster calculations, and where toe is relatively simple). > <http://www.valleyofhastings.com/WheelAlignment2.pdf> Use the term Steering Axis Inclination (SAI) as your vehicle likely does not have kingpins. They are only found on trucks these days. I am of the old school so I still use KPI but I found, when teaching apprentices, the term is meaningless to them because most have never seen kingpins much less worked on a vehicle so equipped. > > Other than Clare, you and maybe one or two other folks here are > knowledgeable in the important details of home alignment checks & > adjustments, where I don't usually disagree with anything you guys say, as > you know more than I do. > > We have to remember a home DIY alignment check & adjust is sort of like > doing a DIY tuneup versus a complete engine overhaul > o A DIY caster/camber/toe check/adjust is to a professional alignment > o as a DIY tuneup is to a professional engine blueprinting overhaul > > The fact is that the SIA is a "non adujstable" angle: > <https://www.freeasestudyguides.com/included-angle.html> > > The fact it's not adjustable means it is in a different category than > o caster > o camber > o toe SAI, to the serviceman, is a *diagnosis angle* in much the same way as *toe out on turns* (TOOT) is a diagnosis angle. If your toe is correct but TOOT is incorrect, you can be assured that you have something that is *bent*, usually a steering arm. Note, you cannot *adjust* TOOT in cars as it is *designed in* as part of the Ackermann Angle. > > While SIA is not normally adjustable, looking this up anyway for more > insight, it seems SIA checks generally simply need yet _another_ magnetic > bubble gauge, much like the camber gauge apparently, but offset by 90 > degrees, according to this cite: > o Checking the Steering Axis Inclination Angle > <http://route66hotrodhigh.com/Inclination.html> > Which says: > "To measure steering axis inclination, the method is identical to caster > measurement except that you use the steering axis inclination guage [sic] > which is at a 90 deg angle to the caster gauge. The wheel is turned 20 deg > inward. The steering axis inclination gauge is centered for 0 deg caster. > There is an adjustment screw on the back of the gauge that allows you to > set it for 0 deg. The wheel is then turned to 20 deg outward for a total > movement of 40 degrees. The steering axis inclination angle is read off the > gauge." > > The key question is where to get that SIA gauge, which, apparently, can be > replaced with a normal magnetic caster gauge according to this patent: > o Device & method for measuring SAI on a steerable wheel (#4,546,548) > <http://www.freepatentsonline.com/4546548.pdf> > > In short, if we're aligning a vehicle that we own and drive often, then we > don't have any reason to suspect SIA changes (which will only occur with > bent or worn parts), and hence, they aren't part of what typically changes > (which is caster, camber, and toe). > <https://www.motor.com/magazinepdfs/062002_05.pdf> > >> 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. > > On this mountain, everyone wears tires sooner than people who drive in > flatland do, where there is just "something" horrific about five miles of > steep driving, Steep driving, urban driving, same thing really. You are at a greater lock more often, even at slow speed, than when you are out on the highways and freeways. > > Most seem to wear on the outside edge, which I still haven't figured out > exactly why. The term is Camber Scrub, and it caused a particular type of feathered wear (for and aft feather IIRC) on the outside of the tyre, but it isn't caused by the *camber angle* per se. It is caused by what SAI does to the camber angles in a turn. Here is a video clip describing *one* of the reasons for SAI. https://www.youtube.com/watch?v=IZLiP_37Oso The narrator focuses on the need to reduce unwanted feedback through the steering. No mention is made of the other major reasons for SAI and that is steering self centering and torque steer reduction. There are a number of factors involved in steering stability and self centering including; SAI, Caster, Camber, mechanical trail and tyre trail. In this video clip he mentions the self centering effect at the end. He states that turning the steering forces the axle (and wheel) down and, in effect, lifts the front of the car. That provides the self centering effect as the weight of the car will tend to return the steering to its central or straight ahead position. That downward force also creates a change in the *camber angle*. https://www.youtube.com/watch?v=IUcZ63unEyU But it is the camber angle the wheel adopts when at the turn position, caused by SAI, that causes *camber scrub*. This clip https://www.youtube.com/watch?v=VbReLNi2JP4 provides a very good description of the steering functions. Skip to 13:50 for a graphical display of the camber angle change when turning. > The road is about 5 miles at about a 9 percent angle with very > many 180 degree and even 270 degree switchbacks, but the speeds are rather > slow, where the road is too narrow to even have panted centerlines and > where the nominal speed limit for such roads is 25mph. Definitely camber scrub territory. > > Given nobody drives 25 mph anywhere, we can figure it's something like 30 > mph to 40 mph top speed but there's a lot of braking in between. Me? I just > put the tranny in neutral and roll down the entire five miles by giving up > potential energy, where I only brake when I must and I take the turns very > wide (as most people do) which helps maintain speed. > > Somehow, _that_ process (which most people do, I think, but in gear most > likely), wears tires out like you can't believe, where tires get half the > stated mileage, as far as I can tell by aggregate conversations. Do the same distance on straight roads and you will have fairly even tyre wear. > >> 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. > > I do admit that I can't 'read' a tire very well. I've tried, but rotations > screw up the readings, and certainly there can be multiple causes. It takes practice and, since I haven't operated a wheel aligner for a very long time, I am *out of practice* but I've had the priciples hammered into me over the decades ably assisted by having taught the principles for some 20 years. > > The type of feathering I mostly see is the kind you can feel after only > about 1000 miles on the outside edge, for about 3 inches of tread, where > there is a sharp lip that is feathered into that outside tread that you can > only feel moving your hand clockwise over the front tire tread on the > outside 3 inches. That sounds like camber scrub feathering - if I'm reading your description correctly. > > I need to learn more, but I think that's "normal" since it happens even > after I get a professional alignment. I'm due for one soon for a couple of A *professional alignment* cannot fix a *symptom* that is considered *normal* for the kind of driving you do. Any changes made to mitigate camber scrub will cause a reduction in handling capability at speed. > cars, which is why, instead of paying the $150 per vehicle, which for the 3 > cars I want to do first, will be almost five hundred bucks, I'd rather buy > the tools to do it myself for that same five hundred bucks. > o Caster gauge (to measure caster & calculate camber) > o Caster jig (to lock onto the wheel for the caster gauge to be accurate) > o Wheel plates (to move the wheels for adjustment under suspension loading) > o Toe plates (to enable single-person linear measurement to centerline) > > After having discussed this with Clare in the past, I know we can redneck > some of that, but overall, those four items seem to be the key items needed > for a home DIY check/change of caster, camber, & toe, do you agree? > Yes, that is basically all the small service station had next door to where I did my apprenticeship. You have missed the primary requisite however - a guaranteed dead flat and level garage floor. Also a lock to lock the steering wheel to the desired centre position; https://i.ebayimg.com/images/g/sJIAA...58p/s-l225.jpg -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
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Clare - are smaller car tires easier to balance than SUV tires?
On Fri, 14 Jun 2019 12:58:31 +1000, Xeno wrote:
> Use the term Steering Axis Inclination (SAI) as your vehicle likely does > not have kingpins. 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. > Yes, that is basically all the small service station had next door to > where I did my apprenticeship. You have missed the primary requisite > however - a guaranteed dead flat and level garage floor. Also a lock to > lock the steering wheel to the desired centre position; > https://i.ebayimg.com/images/g/sJIAA...58p/s-l225.jpg 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? |
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Clare - are smaller car tires easier to balance than SUV tires?
On 15/6/19 2:55 am, Arlen G. Holder wrote:
> On Fri, 14 Jun 2019 12:58:31 +1000, Xeno wrote: > >> Use the term Steering Axis Inclination (SAI) as your vehicle likely does >> not have kingpins. > > 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. 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. > > 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 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. > 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. 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. > >> Yes, that is basically all the small service station had next door to >> where I did my apprenticeship. You have missed the primary requisite >> however - a guaranteed dead flat and level garage floor. Also a lock to >> lock the steering wheel to the desired centre position; >> https://i.ebayimg.com/images/g/sJIAA...58p/s-l225.jpg > > > 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. 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; https://www.bosch-do-it.com/au/en/di...898-199931.jsp Or 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. > > 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? > 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. -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
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Clare - are smaller car tires easier to balance than SUV tires?
Xeno wrote: "number of factors involved in steering stability and self centering
including; SAI, Caster, Camber, mechanical trail and tyre trail. " One question I have never been able to find an answer for: Which, per degree of angle, plays a bigger role in self-centering of the front wheels, and stability: Caster, or SAI? |
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Clare - are smaller car tires easier to balance than SUV tires?
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Clare - are smaller car tires easier to balance than SUV tires?
Xeno:
Thanks for that explanation! Makes a lot of sense. So SAI is more relevant in front-wheel drive, and Caster angle in rear-wheel drive. One thing that sticks out in my mind regarding SAI, is that if it is more than half-degree unequal side-to-side, it tends to cause vehicular pull to one side at LOWER, vs higher speeds, where unequal Caster and Camber angles have the most implications. Interesting! |
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Clare - are smaller car tires easier to balance than SUV tires?
On Sat, 15 Jun 2019 14:14:27 +1000, Xeno wrote:
> 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. Hi Xeno, 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". <https://i.postimg.cc/zvvyL2tq/mount24.jpg> Does _that_ feathering look like what you're referring to as "camber scrub"? |
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