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Discussion Starter · #1 ·
So, I got a set of the PVM 5 spoke "H" style wheels the other day. And I'm curious about what I should look at to make sure the set is fine? I know about general stuff like scrapes, dents and the straightness of the wheel, but what about bearings and things?
 

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If the wheel's straight and bearings are fine I say there isn't much else that can go wrong with a wheel. Only other thing that comes to mind is the cush drive.
 

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I am in a similar situation with a set of 6 spoke magnesium marchesini's and have been doing a lot of research regarding the same question.

You can pay to have Non Destructive Tests performed on them to determine their internal and external structural integrity, but unless you know someone in the in the aerospace field it may cost you more than what you paid for the used wheels. The 2 types of tests that I have learned about for wheels are eddy current testing and x-ray, both costing over $450 min.

As far as everything else, there are motorcycle frame/wheel service shops around the country that can check your wheels for straightness, check & replace bearings and straighten your wheels if need be.

I'll be taking mine to dr. john's frame service in anaheim as soon as I have the $$$ for the all the services Im going to have performed. Dr. John's Motorcycle Frame Straightening
*don't be fooled by his chopperesque website, he is the top wheel guy for most US pro roadracing teams.
 

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Many pro race teams mount up a tire x amount of times on their forged magnesium rims and once they hit the max number of mounts they just throw them away.

I have seen a published spec from one leading brand on expected longevity of the forged mags under race use and failures while rare are not unexpected. Granted street use & track use are two completely different things in 99% of the cases. Even aggressive street riders who think they are riding hard usually aren't even 1/10 as hard on a set of aftermarket wheels as pro racer is during a sanctioned event.


The PVM cast mags seemed to be pretty bullet proof, but there were quite a few failures with the PVM forged mag 5 spoke. It seems the compression-braking of the fat-assed RC51 was putting too much stress on the spokes on deceleration and they would just snap.
 

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I am in a similar situation with a set of 6 spoke magnesium marchesini's and have been doing a lot of research regarding the same question.

You can pay to have Non Destructive Tests performed on them to determine their internal and external structural integrity, but unless you know someone in the in the aerospace field it may cost you more than what you paid for the used wheels. The 2 types of tests that I have learned about for wheels are eddy current testing and x-ray, both costing over $450 min.

As far as everything else, there are motorcycle frame/wheel service shops around the country that can check your wheels for straightness, check & replace bearings and straighten your wheels if need be.

I'll be taking mine to dr. john's frame service in anaheim as soon as I have the $$$ for the all the services Im going to have performed. Dr. John's Motorcycle Frame Straightening
*don't be fooled by his chopperesque website, he is the top wheel guy for most US pro roadracing teams.
Dr John's has fixed my Marchesini wheel before. Definitely a good place to go.
 

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My 2 cents

There are several spray type crack and fracture kits. As for the bearings and stuff if it were me I would just put new stuff in them anyway. Why take a chance??:D HOOVY
 

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Discussion Starter · #7 ·
That doesn't sound too bad. So, the bearings and cush drive are the only other things I need to add to the list. I'm glad there isn't much to do, even though they're just wheels, I wanted to be sure.

LDH, you say that the rear had an issue of snapping, did that only happen on the mags? These that I've got are the forged aluminum, would that make them more prone?
 

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I know of no failures of any brand with the forged aluminum models. It may have happened somewhere, but I am unaware and being in the industry as I am I usually have a pretty good feel for most issues of importance in this sport.

Having said that, when you buy forged aluminum wheels instead of the much lighter forged magnesium wheels you are basically paying for aesthetics. You are buying something that looks cool and that may or may not offer a true performance advantage and possibly a very marginal one at best which makes the return on the investment pretty low.
 

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Any idea what that max number of tire changes might be?

My wheels once saw Canadian Superbike racing action on Steve Crevier's VTR1000 and have already been re-powdercoated one time by the previous owner so I am really concerned about what could lie beneath.

Fingers are crossed that they will be perfect and last me a very long time!!!!
 

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I know of no failures of any brand with the forged aluminum models. It may have happened somewhere, but I am unaware and being in the industry as I am I usually have a pretty good feel for most issues of importance in this sport.

Having said that, when you buy forged aluminum wheels instead of the much lighter forged magnesium wheels you are basically paying for aesthetics. You are buying something that looks cool and that may or may not offer a true performance advantage and possibly a very marginal one at best which makes the return on the investment pretty low.
So Mike I think a 2.5 # loss of reciprocating mass in the front and a 3 # loss in the rear is a true performance advantage.
And they will last forever.

All you need to do is ride back to back and I swaped my tires also no doubt a huge change in feel.

Not just defending my purchase,as I had a chance to trade around for a used set of mags + $500.00 from wings but the whole time thinking about it and not knowing the history of the rims I would have been testing them just like J.J. is doing and it was a gamble,at the time I purchased the NEW aluminum ones the price of magnesium had skyrocketed.

lighter is better and there is nowhere on the machine that matters more than the wheels. (I WANT a 3.5# loss in front and a 6 # loss in the rear) You've got my C.C. # send me some mags !!!

JUST KIDDING !!! ( I'll be lucky if I can get the hangars on this pay day !)
 

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Depends on what brand they are and the deal you got I suppose...

I've seen some aftermarket wheels literally weigh more than the OEM wheels they replaced.

Where the weight is placed is equally as important. You could have a lighter weight wheel with a heavier outer rim weight that would create more gyroscopic effect than a heavier wheel that had more weight towards the hub and less on the outer rim.
 

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lighter is better and there is nowhere on the machine that matters more than the wheels.
Significantly lighten the flywheel on a Ducati 916/996/998 track bike (or remove it from a VTR250 :D ) and you will have an entirely new appreciation of weight reduction that far surpasses anything you have experienced with wheels.
 

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Depends on what brand they are and the deal you got I suppose...

I've seen some aftermarket wheels literally weigh more than the OEM wheels they replaced.

Where the weight is placed is equally as important. You could have a lighter weight wheel with a heavier outer rim weight that would create more gyroscopic effect than a heavier wheel that had more weight towards the hub and less on the outer rim.
Excellent point !

Marchis' (forged aluminum) I got them from you guys under 2K and marchi (forged mags) were on the table for trade;)

You know I scrutinize every used part I put on the machine !
 

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Significantly lighten the flywheel on a Ducati 916/996/998 track bike (or remove it from a VTR250 :D ) and you will have an entirely new appreciation of weight reduction that far surpasses anything you have experienced with wheels.
I was thinking in terms of handeling,but I suppose with an engine spooling-up quicker and less gyro it would make a drastic charachteristic change to the handeling :rolleyes:

I actually added flywheel weight to my cr500 so it would grip:twocents
 

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I was thinking in terms of handeling,but I suppose with an engine spooling-up quicker and less gyro it would make a drastic charachteristic change to the handeling :rolleyes:

I actually added flywheel weight to my cr500 so it would grip:twocents

I experienced the same problem with the RC51 with a lightened flywheel in that it would just spin up everywhere, but on the Duc's it's golden and a much more drastically noticeable change to the bike not only in terms of power delivery, but also how you have to ride the bike at pace to make it work.

On the VTR250 removing the flywheel altogether gives you lightning quick revs out of the bike and of course it doesn't have enough hp to be a traction problem so you just get this stupid fast little machine that goes like a raped ape.
 

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Yep, my buddy jetfxr decieded to leave the flywheel alone on his 51 build from similar information and it steers with the throttle tube pridictably he describes slide and countersteer after his build with a giant shit eating grin on his face !!!


OOPS wrong pic. I beleive he's looking for his bike key !!!
 

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