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For those who mount their own tires ... important!

Instead of attacking his spelling and/or grammar, why don't you question the validity of the argument. If you have nothing else, then don't post. Nitpicking spelling only tells me that you have no counter arguments. PVD, I agree with Omegajeff. If you could run some numbers with a greater offset or wheel spin to see if there is material differences.
 
Hmmm....the model is a little oversimplified. You're assuming that a perfect static balance also equates to a perfect dynamic balance, which is not the case. You're fogetting that the wheel is turning, and this introduces higher order harmonics. This is where the method espoused by Alan and ElSkipador is going to come in its own, since the cross adjusted weights will better deal with the vibration. That's the key, of course...the balancing is actually done to reduce vibration, and is not the actual point itself.
 
"Higher order harmonics"? Explain? Do you mean that as the wheel spins faster, parts of the wheel/tire resonate at different but combinative frequencies? Hrrm...

It would seem that if you took all the heavy spots of the tire and the wheel and aligned them all on the same side in superposition of each other (thereby making the wheel the MOST unbalanced that would be possible) and then stuck the maximum amount of weight on the opposite side to counterbalance, you've created more of a problem than you need to.

The tire deforms as it's spun and the tire's heavy spot moves outward from the axle, right? So wouldn't that increase the moment of inertia of the tire in that spot and create (some) instability?

Would putting the wheel's heavy spot, the tire's heavy spot, and the counterweight into an equilateral triangle configuration be an improvement?
 
once the tire is mounted you dont know where heavy spot of tire is,that is heavy spot of whole wheel with tire.
if tire is not seated on rim perfectly same all around you have high spot,or what they call tire out of round.it is actualy common.in this case heavy spot is not where tire itself is heaviest but where tire is furthest away from center of rim.you can put weight oposite of spot but you still have wheel that is out of round.
90% of time I mount my tires myself and never pay attention to dots or anything,I just mount tire on,balance where it asks for with whatever weight it needs.sometime it takes less weight,sometime more,who cares.
 
I've experimented with my balanced wheels and put them through their paces on my lift. I wound my racebike up to an indicated 175mph on the swingarm stand to see just how much shake or lack thereof there was. It didn't shake or vibrate at all. The actual height of the center tread grew approximately 5mm at this speed.
 
ALANRIDER7 said:
I've experimented with my balanced wheels and put them through their paces on my lift. I wound my racebike up to an indicated 175mph on the swingarm stand to see just how much shake or lack thereof there was. It didn't shake or vibrate at all. The actual height of the center tread grew approximately 5mm at this speed.
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how in gods name did you measure the diameter or circumference delta at 175 mph??? :confused
 
I watched the gap between the swingarm and the tire. The GSXR750 has a pretty beefy front brace that runs close to the tire tread. It was an educated guess.
 
pvd is the fastest man with an integer on BARF.

I used to redesign electrical jobs that were carefully and expensively designed by electrical engineers. So they would work.

No insult to engineers intended, real world practice is often very different from text book analysis.

PS: Peter, calling skippy names is so incredibly fucking childish and immature that it just completely takes away from anything you have to say. I had some interest in your argument, but none after your name calling rant.

Your pedantic and hostile intellectual pretensions are kinda funny for about five minutes, then they are just puerile. Grow a pair and grow up. Your education is not a free pass for you to make disparaging comments about your betters. Name calling is THE lowest form of social intercourse that occurs on BARF, unless it is in jest. Yours is not jest.
 
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afm199 said:
No insult to engineers intended, real world practice is often very different from text book analysis.
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i would be the first to agree with that myself! the problem that working things out on paper tends to be that the sheer quantity of variables is infinte. this example is about as basic as you get and lends itself very well to my static example. as a freind of mine says almost every time we talk, "It won't tell you what will work, but it will tell you what won't!"

1. i am currently in boston, away from my home computer. later in the week i will post a very nicely worked out example of this on my site. the math that i posted earlier is crude and full of typo's and some translational issues regarding TANGENTS and EXCEL. those have been worked out and the resultant postition angle of the weight is now correct, but not posted. the mass of the weight, however, is correct in the example.

2. this is a static example. the dunlop tent and i both balance tires statically. dynamics would be nice to work out, but i have lots of other things to do other than punking skippy. and alan has even stated that in his test the wheel was solid up to 175mph.

3. nobody has even mentioned the lateral position of the weights! in a true balance, the wheel must be balanced laterally as well as radially. this would mostly come into play in dynamic situations. but again, the tire master made no mention of this critical peice of information. why? dude, they don't even know how to radially balance, forget lateral.

4. regarding units. if you could not tell that i was dealing with grams, millimeters, and degrees, then you must be one hell of an engineer. the moment would be in g*mm. i have already corrected it offline. sheeezh.

5. the degree of tire spin, no matter how much, results in the same amount of missbalance in each case. so 10 degrees shows that same equality as 180.

6. no word from skippy. i guess all of his engineer bro's at dunlop won't return his calls. and, after hanging out for two days at AFM with the rest of the dunlop crew, he has still not been able to figure out why the lightest point on the tire should be mounted over the valve or why a balancing technique that adds more weight to the wheel than necessary is good for top racers.
 
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In case you missed this

afm199 said:


PS: Peter, calling skippy names is so incredibly fucking childish and immature that it just completely takes away from anything you have to say. I had some interest in your argument, but none after your name calling rant.

Your pedantic and hostile intellectual pretensions are kinda funny for about five minutes, then they are just puerile. Grow a pair and grow up. Your education is not a free pass for you to make disparaging comments about your betters. Name calling is THE lowest form of social intercourse that occurs on BARF, unless it is in jest. Yours is not jest.
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afm199-

i agree with you. i am sorry. i rarely cut this deep, as you know. i am just really, really, really angry with him for attacking me the way he did starting on the 3rd post in this thread and being wrong on every count. we have been through this before, but this time i'm actually pissed.

outside of this thread, i will return to my ordinary asshole self. i will play nice (or at least as nice as i usually do).

i do applolgize for the mood that i am continuing to set.
 
"A man's got to know his limitations."

Dirty Harry, Magnum Force.

2476426-dirtyharrysm.jpg
 
ALANRIDER7 said:
I wound my racebike up to an indicated 175mph on the swingarm stand to see ...
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dude!!! you have more faith in your rearstand that i'll ever have!!

if that puppy comes loose at that speed, you'll have a hole in your garage wall, the living room and maybe the neighbors fence!

i'd have to explain that to the police...

... i'd just claim a small airplane just struck the neighborhood....

:twofinger
 
Spin that bad boy up Alan!
Nice thread BTW, other than the name calling I found the science and the real world science to be very interesting.
 
afm199 said:
Name calling is THE lowest form of social intercourse that occurs on BARF
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I think its the second lowest.

The lowest is pointing out bad spelling. :twofinger

(thats all I have to say, I'm a noob who's never gotten new tires)
 
I don't know shit about nothin' but I do know that everybody has an asshole.

and Alan, Sonny and Shawn oh and Billswim too all have a lot of experience....Not sure about you PVD :confused what's your background? Shed some light on the situation... It might help me understand why you are so adamant about your side of the story.

P.S. my father was an English teacher. Spelling is not a sign of intelligence...but reading skillz and speech are so that makes me a BAGAgOOGGGA GENIUS.


:laughing
 
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