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Today I've finally ordered some new wheels for my car. I ended up with Technomagnesio's Indianapolis/ sport. Size 7j 17"
Here's a little picture of them.
 

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Nice looking wheels - how much do they weigh? One thing I've never understood, though - why such an asymmetrical design? How can all the angles between the spokes be exactly equal when 360/7 yields a repeating decimal that never ends? Perhaps one or more of the angles differ? Does this make balancing in the axial direction any easier? Anyway, I still think they look nice
 

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Great choice, Injectie! They should look good on your car. Almost look like a seven spoke version of a Hirsch wheel.

Anyways, for robert, I used to have somewhat similar wheels on a US spec Ford Escort GT. There are no balance issues. If you look at the wheel and imagine cutting it in half from the middle of one spoke, through the center cap and down through the middle of an opening, you'll see that there will be three and a half spokes on each side.
 

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Also Robert, the amount of error caused by the repeating decimal would be so small that the manufacturing processes which make the wheel could not account for it anyway. If designing wheels and tires were THAT precice we wouldn't need weights to ballance them.


Cheers,
Dubbya
 

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Mind you thats the important thing. Trying to visualise wheels on the car. Not always easy and I would hate to buy and then find they don't suit the car. pretty safe with these though, would look on most cars.
 

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Does anyone know what they weigh, though? They're nice looking wheels, but there are two things that give me concern. Maybe in the UK it's different, but here in Massachusetts the roads are in a horrible state. Hard to figure because one of the most expensive engineering projects in the world has been taking place in Boston, but the roads, in general, are probably some of the worst in the nation. I'm digressing, but the point is a 17" wheel with low profile tire may look nice, but it's only a matter of time before it gets bent on a deep pot-hole. Also, there's the matter of weight, the tire with low-profile may be a bit lighter, but the 17" wheel is probably heavier than a comparable 16". There's a company in California called Panasport that makes a 16" x 7" wheel for the 9000 that designed/copied after the Minilite, and it is lighter than the 16" Aero or SuperAero. If anyone is interested in viewing, I included the URL. minilite clone
 

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My friend and I use the racing version on his racecar. You can kinda see them in the picture here. They are very light, but not terribly strong in racing form. I would imagine the street version is stronger.

Aso for bending wheels, California has the most roadways of any state, and does not have the highest highway budget. Our roads are also terrible. I have so far bent 4 17" wheels without running low tire pressure (always at 44 psi or so). It only bothers me at 35-40 mph, otherwise you can't feel it, but I may need to get either 16" wheels, or forged wheels sometime in the future as it's costing $100 per wheel to get fixed every time one bends. If you live in a place with bad roads I'd reccomend staying away from 17" wheels. I'd say the panasports are a good route. The only trouble with 16" will be that it will eventually restrict brake size. But hopefully that won't be a problem. Good luck!

Cheers,
Dubbya
 

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Thanks, can you quantify exactly the restraint? What's the largest size caliper/rotor arrangement I can use with 16" x 7" wheels on my Aero? Not that I'm in the market, because my present arrangement is more than sufficient for road use: I've got stock ATE's, braided lines, Ferrodo 2500 pads and a set of Firestone SZ-50's - unless I'm doing Pikes Peak , downhill, or track, the brakes are more than sufficient for road use. I really think the lighter wheel will give me the most bang for the buck, at this point.
 

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Originally posted by robert lavergne:
[qb]Nice looking wheels - how much do they weigh?  One thing I've never understood, though - why such an asymmetrical design?  How can all the angles between the spokes be exactly equal when 360/7 yields a repeating decimal that never ends?  Perhaps one or more of the angles differ?  Does this make balancing in the axial direction any easier?         Anyway, I still think they look nice       [/qb][/b]
This isn't an issue at all. Do you think that if a wheel is a three spokes then the angles between them are EXACTLY 120°? I don't think so. The differences in the shapes of the spokes outweight any diiference in orientation.

Unlimited decimal numbers exist, and we have to live with them. Even the 3.14 doesn't end, so it would be impossible to know how much road we've done just counting the revs of the wheels, as we do, but we do. It all depends on the precision you want. And be sure that a 3 spokes wheel isn't more dimensionally precise than a 7 spokes one.

Anyway, spokes are in odd number more often than not in wheels. This is to reduce tensioning and stresses while the casting is cooling down.

Balancing isn't an issue too. Just think at the valve, or to the unavoidable errors in the drilling pattern of the wheels. Or the fact that the tyre is partly rubber, and you can't be so precise with rubber. They are much larger problems than a misaligned spoke.
 

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> How can all the angles between the spokes be exactly equal when 360/7 yields a repeating decimal that never ends?

It doesnt matter whether 360/7 is a repeating decimal or not.

The spacing between spokes can just be 360/7 degrees, and that is an exact description of the angle, no need to represent it in a decimal form.

Effectivly 360 degrees in a circle is a legacy (when we should all be using radians). There might just as well be 280 degrees in a circle in which a factor of seven fits.

The wheels look nice
 

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Anyway, spokes are in odd number more often than not in wheels. This is to reduce tensioning and stresses while the casting is cooling down.

Ok guys, your point has been made - it's not important, relative to machining or balancing as to the number of spokes. However, you'll have to admit that 7 is an unusual number to divide 360 by. 5 and 3 are odd numbers, but when they divide 360 the result is an integer. In fact, of all the first ten integers, 7 is the only one which wont give an integer result. I wasn't trying to make aesthetic judgement, just a curiousity about why 7 was considered by the designer - it's the nerdy, Fermatish-side of me that ponders such questions - sorry
 
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