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Discussion Starter #1 (Edited)
I've been looking at lightweight wheels for motorcycles, and they are sooo expensive! Almost $2000 for a set of wheels!!! :eek: That's 25% the cost of the whole dang complicated bike!!

The online catalogs etc don't describe the weight either, that seems to me equally if not more important than looks.

Anyone know how much stock rims for R6/R1/GSXR600/6R etc weigh?

Thanks for the info!

PS. What are the most common brands of wheel for sportbikes, and why aren't harley/bicycle style spokes used on sportbikes??
 

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I think the high price has to do with all the R&D that has to go into making them round.
 

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badchad said:
....why aren't harley/bicycle style spokes used on sportbikes??
well, for one, that would look retarded. For 2, you can't (with a few minor exceptions) run a tubless tire on spoked rim. Running a tube in a high performance tire wouldn't work. The friction between the tube and the tire would develop too much heat (among other problems).

But, I think the biggest is, that would look really really really really stupid.... Unless your wearing a Huge gold necklace with your name as a pendant, and flashing signs.
 

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Also, have you noticed the materials and processes of aftermarket wheels?

Most aftermarket wheels are made from magnesium, for weight reduction... basically for racing. Magnesium is a "flamable" material, so the process for making them is different than... say stock "casted" wheels.

Some wheels, like OZ wheels are forged. Remember "forging" pennies when you were a kid? Take your hammer and make it about 5,000 times bigger. Then try machining a forged metal after that.

So the cost is in R&D (as mentioned), material, and process.

On the spoked wheels thing... like Kevlar said... it would look REALLY REALLY stupid.
 

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Plus a spoked rim would have massive wind drag. A racing bicycle only goes about 35 mph and they use solid disk wheels for wind resistance. Imagine the drag of all of those spokes chopping through the air at 180mph.
 

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Regardless of the matterial (forged or cast aluminium, carbon fiber, or magnizum) another advantage sportbike wheels have over spoked (also called laced) wheels are that they are more rigid and let the suspension do it's job better as well as being more stable and providing more feedback in turns.

In addition to all of the above mentioned reasons for the prices there is also the fact that it's a small market requiring more of the companies overhead to be put on to each item sold.

Let's just create a hypothetical example. If it takes 10,000 man hours to R&D a wheel at $20 an hour and you only sell 1,000 of them (500 bikes) that's $200 a wheel in R&D. If it's a car wheel the market is much larger and lets say you can sell 100,000. (25,000 cars) That's only $2 per wheel.

Not to mention labor, operating costs, materiels, capital, and make enough profit to be able to make it worth doing again next year instead of working at Kentacohut.
 

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Mostly they cost so much because we'll pay it.

Try getting some used from a racer classified add??

And yes, I will put weight savings over looks when I finally build my keeper. Gonna be MAXED out with Ohlins front/back, cf bodywork, maybe cf wheels cause by the time I do this they'll have those figured out, everything that'll make it faster and handle better.
 

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Another question

As regards to weight, and replacing items with lighter ones- what is better to replace first, unsprung weight (i.e rims)or sprung weight? Besides affecting suspension, reducing weight for more HP, what is the difference between the two in terms of gained benefits?
 

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I had a pair of 3 spoke magnesium Dymags on my track SV. Not that my ability justified the $ but they sure did look good. A few weeks ago I was in Putnam T4, a left, I have no idea 75-80 mph? A front end low side, I separate from the bike cleanly and we’re both sliding, no problem. Then the bike goes onto the grass, catches, and starts violent tumbling. Lots of damage all over the bike, the worst is a big hunk out of the rim of the rear Dymag. When an aluminum wheel reaches it’s limit it tends to bend and is often repairable. Magnesium breaks.

The front end took a hit hard enough to break the steering stop and bend the forks. The front Dymag seems ok, but might have cracks that can only be found by expensive testing.

For now the stock wheels are going back on the bike, this winter I’ll have them powder coated Dymag yellow. ;) If I was sure it’d take 5-10 years of track time to break another Dymag then that’s what I’d get. 1.5 years for an $800 wheel isn’t enough.

And remember this was a lowside in flat area with nothing to hit at a speed a lot of street riders do. S___ happens. If you can’t look at your bike scrapped and say “ok” then you either have too much $ in it or you should have kept the bike in the living room.
 

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With the last in mind.................My opinion is to go with the "forged" OZ WHEELS or the "forged"/"spun" PERFORMANCE MACHINE WHEELS! :drool:

Choices, Choices, Choices ;)


Johnny
Team No Limit Racing &#169 1996-2002
http://www.teamnolimitracing.com
 

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I needs me some hunnet spoke 22's fo my whips! Den ma CBR be blingin'!
 

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Re: Re: Why are wheels so expensive?

Kevlar7R said:

For 2, you can't (with a few minor exceptions) run a tubless tire on spoked rim.
Bicycles have been doing it for years. Roadies have had it for a long time, and MTBers just recently adopted it (although that trend seems to be dying, but mainly due to reasons non-applicable to sportbikes).

I think motocross tires are tubeless as well, and they are all spoked for shock absorbtion.
 

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Discussion Starter #13
Re: spokes?

Kevlar7R said:
well, for one, that would look retarded....

But, I think the biggest is, that would look really really really really stupid.... Unless your wearing a Huge gold necklace with your name as a pendant, and flashing signs.
Subjectively, coming in 2nd looks worse; if the spokes in fact decreased lap times, you'd see every racer riding them. Posers don't care about going fast anyway.

Kevlar7R said:
...you can't (with a few minor exceptions) run a tubless tire on spoked rim.
My mtnbike had tubeless/spoke wheels and they withstood abuse including 6'+ drops with no flats. Never mind those cost $400 each! :rolleyes: There has to be a way on sportbikes, all sportbike wheels do is spin. Probably not worth the trouble for all the reasons mentioned (air resistance, rigidity, etc) plus they'd probably cost more initially plus the maintenance... ugh!




 

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Don't correct me, I know what I'm talking about. You want intelligent advice, then don't try to correct it.

The type of spoked rim I am referring to is the laced type, where the rim is manufactured seperate from the spokes, and then assembled. Its very expensive to make a laced rim run a tubless tire. The nuts where the spokes connect will leak air. I said there are minor exceptions. These exceptions are very expensive. And you have to remember that Sportbikes are designed to handle enormous speeds and stresses. I know most of you don't care because you will never acheive those things (I never cease to wonder why you people have sportbikes at all.) A spoked rim is very flexible, and will not stand up to the kind of cornering stresses exerted by a bike being ridden with any kind of spirit.

The upside of a laced wheel is, its easy to straighten when it gets bent. This may come in handy for bikes that are frequently crashed. No special tools are required (unless the wheel is majorly screwed up), just a wrench.

The pictures you posted are NOT spoked wheels. Those are cast Rims. Get those, they look good.
 

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Discussion Starter #15
Thanks

Kevlar7R said:
Don't correct me, I know what I'm talking about. You want intelligent advice, then don't try to correct it.

The pictures you posted are NOT spoked wheels. Those are cast Rims. Get those, they look good.
Hi,

Thanks for the input. I'm not correcting you, just saying if I can take crazy drops on tubeless mountain bike tires without problems, seems like at least the air containment part of the tubeless/laced spoke equation could be solved pretty easy. Maybe not lighter or cheaper or as strong or as responsive or as pretty, etc, all the things you mentioned, as the photos there, but at least possible. If you say laced spokes don't work at 140mph at a 55 degree angle to the asphalt, I'll just believe it. :D

I know the pics are not the spoked wheels we're talking about... unfortunately these cost $2000 for the set, which is why I started this thread. The price seems illogical - a couple hunks of shaped metal shouldn't cost 40%of all the intricate technology/assembly in a $5000 SV650. Maybe when I find a sponsor, she'll be less pragmatic and just equip them.

Would you be nervous buying lightweight aftermarket rims like these secondhand? I think I'm nervous about it, kinda like I wouldn't want a used helmet... I know a new one is structurally intact.
 

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Re: Another question

FastHawk said:
As regards to weight, and replacing items with lighter ones- what is better to replace first, unsprung weight (i.e rims)or sprung weight? Besides affecting suspension, reducing weight for more HP, what is the difference between the two in terms of gained benefits?
While changes in mass do not (cannot) affect the HP of the engine, reducing the mass allows the bike to accelerate faster. F=MA Force=Mass x Acceleration Same force with a lower mass equals more acceleration.

Unsprung mass is the major part of the deal when it comes to handling. By going with lightweight wheels, rotors, sprocket, hell - even some tires are significantly lighter than others, you are killing two birds with one stone. Lower unsprung, and lower rotating mass. When I put Marvic magnesiums on my Duc, I also added a full compliment of Galfer Wave brake rotors. The total reduction was around 15lbs of rotating, unsprung mass. This is a BIG deal. The difference in "tossability" and handling on the bike is pretty amazing.

Same is true with things like a lightweight flywheel. I went from a 4lb flywheel to an 8oz flywheel. The engine revs up and down instantly, and the net result is a bike that much stronger "feeling" throttle response, even though the horsepower of the machine is exactly the same. Although the power and torque are the same, there is simply less mass on the crank to accelerate.

I'd rank them as follows, in order of importance:

1. - Rotating Unsprung (wheels, brake rotors, tires, sprocket, etc)
2. - Unsprung (swingarm, fork lowers, calipers, fenders)
3. - Rotating Sprung (flywheel, clutch and basket, crank, pistons, etc)
4. - Sprung (tank, bodywork, frame, etc)
 
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