MV Agusta Forum banner

1 - 20 of 113 Posts

·
Registered
Joined
·
479 Posts
Discussion Starter #1
Unless the bike is on display in your living room, stay away from CF sturctural components. Especially wheels, handlebars and brake levers.
 

·
Registered
Joined
·
410 Posts
I'd like the hear the issue w/ CF wheels also. Is there any history of them failing? I just bought some for my Ducati 749R. From everything I've read they are an excellent way to eliminate some unsprung weight.

Steve
 

·
Registered
Joined
·
479 Posts
Discussion Starter #4 (Edited)
Not really as bold as you might imagine.

CF wheels are banned by every racing organization you can think of. F1, MotoGP, the pinnacle of their respective sports, have outlawed them.

Both of these sports used forged magnesium, which outside of possibly beryllium of which the dust is deadly to humans and the material immensely costly, is the best material for a racing wheel.

CF when developing stress cracks are practically undetectable. There is no means of non-destructively testing a CF component. (This is why only MotoGP, where the teams all have big bucks and will scrupulously throw away rotors at their recommended service interval, or after a crash despite no signs of damage), allows carbon rotors. Magnesium/aluminum can be x-rayed, and especially in the case of alumiunum, have significantly more ductility in the material, meaning you have more time to catch cracks.

CF also has to be very well designed to be strong on all load axis. The BST wheel, which I've gone over in detail, has a serious design flaw in how they connect the inner rim spokes to the rim outer. Basically, in their design, all load that is being transferred between the inner and outer goes through resin only where the two are bonded.

If you surf the internet boards, there are several instances of catastrophic failure of these wheels.

Last week, a member of another board I frequent, fireblades.org, had a CF clip on fail catastrophically on the race track. This is not to say metals don't fail, but they're typically a much more forgiving material.
 

·
Registered
Joined
·
8,860 Posts
I don't know much about the structure but I have seen (i believe maybe those very same cf wheels) photos of the cf inner rim completely torn away from the outer.

Trying to find the pictures but don't remember where...

http://www.amaproracing.com/rulebook/05rrrules.pdf

Chapter 1 paragraph A.i.3. Wheels may be replaced with aftermarket parts provided
they are not constructed of carbon fiber or carbon composites.
Maximum rear wheel rim width is 6.25".

Although many don't have problems w/their CF
 

·
Registered
Joined
·
479 Posts
Discussion Starter #6
I also forgot to mention, CF has a limited fatigue life (both the resin and the fibers). So it will eventually crack. BST does not give a service interval for their product.

Here is some reading for you.

A failure on WERA. (cause unknown)

http://forums.13x.com/showthread.php?threadid=63152&perpage=15&highlight=bst&pagenumber=1

A beautiful 998 destroyed, blamed on BST failure. (probably the one you're thinking of admin)

http://www.southbayriders.com/forums/showthread.php?t=10765&highlight=bst+failure

And CF clip on failure.

http://www.fireblades.org/forums/general-discussion/43808-sponsored-aleve.html?highlight=clip+on

I would say the evidence is not ironclad. But I will NEVER use a CF wheel on anything.
 

·
Registered
Joined
·
1,059 Posts
I was at ThunderHill that day. I rode in with the corner workers for lunch and they said the bike cartwheeled. So, who knows? I was also at Pahrump a few years ago when an instructor from Keigwin crashed his RC and we picked up pieces of the magnesium front wheel that shattered. Magnesium is porous and there have been reported problems of wheels losing air. So I stay away from Mg too.

It's interesting that the e-bay auction says the BST wheel is unique in that it is formed as one piece.

I stick to forged aluminum because I think it's safer and it fits my budget. :)

Like you said, the evidence isn't iron clad, but it's enough for me too that I wouldn't go out and spend the extra money on wheels, clip-ons, or levers.

My mountain bike has a carbon frame, carbon seat post, carbon riser, and a carbon bar. I'm not too worried.


PS: Sorry for bastardizing this For Sale thread. Step Toe are you selling these wheels? Are you Martin from MotoWheels?
 

·
Registered
Joined
·
479 Posts
Discussion Starter #9 (Edited)
Yeah, for me it's simple.

On the road, forged aluminum is where it's at. Far more ductile than Mg, lower notch sensitivity (for chunks taken out by potholes and errant tire changers) and just all in all cheaper/more forgiving. 10 Spoke forged Al 'sinis will be on the SPR sooner rather than later. (I also wonder if this why the Tambo came with Al over Mg?)

On the race track, I think Mg is worth the cost/risk for classes that allow aftermarket wheels. I ran them, but kept a real careful eye on them. If I do it again, it will be Marchesini only, they seem to be the best current maker of them.

Proper Mg wheel usage includes blasting off the paint and carefully inspecting them every year according to Carrol Smith. But most people, myself included, don't really do that. I do have a friend who does...incidentally he's had two different Mg wheel failures over a long racing career...
 

·
Registered
Joined
·
479 Posts
Discussion Starter #10
Gladio said:
PS: Sorry for bastardizing this For Sale thread. Step Toe are you selling these wheels? Are you Martin from MotoWheels?
Oh man, I hope not! I read that e-bay ad and thought StepToe was just showing them.

Heh, I'd planned to order my wheels from MotoWheels when the time came too. I wonder if it's going to take a few extra weeks? :toothless
 

·
Registered
Joined
·
1,059 Posts
luvtolean said:
Oh man, I hope not! I read that e-bay ad and thought StepToe was just showing them.

Heh, I'd planned to order my wheels from MotoWheels when the time came too. I wonder if it's going to take a few extra weeks? :toothless
I did, and it took mine like 5 months. :(

PS: Did you do the Grattan day with Fireblades two years ago?
 

·
Registered
Joined
·
479 Posts
Discussion Starter #12
Nope, 3. The only one I made it out for was 2002.

I might try for this year, but there's lots of things vying for my time and money right now.
 

·
Registered
Joined
·
1,073 Posts
Jack, according to Step Toe's profile, he is from Aus.

On the topic of BST, I have 3 sets of BST on various bikes for the past 3 years without any problem. 2 years ago, I crashed my ZX-10R with BST wheels over 130mph out of Spring Mountain Motorsport Ranch's T8. I am still running the same wheels today. Raced with the same wheels last year in WERA West Formula 1 Nv and ranked 5th in the class.

Maybe I am lucky, who knows. However, I am very wary of people opinions based on anecdotal stories from this and that. Everyone is entitle to his/her opinion and I can certainly respect that, afterall, it's your money to spend wherever you wish. It just get my blood boils, when people push their opinions as facts.
 

·
Registered
Joined
·
410 Posts
Well, now I'm thoroughly freaked out about my CF wheels. I did get the DOT rated ones, if that makes any difference to their durability. Having just crashed my Yamaha Raptor 700R quad yesterday (you can see the cool video of it at www.cullenaz.com), I am not looking forward to another get off any time soon. :bash:

Steve
 

·
Registered
Joined
·
1,073 Posts
BTW, I also race with CF handlebars and yes, I am aware of the Yanagawa's incident at Laguna Seca that took Doug Chandler out of the race. (I had a chance to speak to Doug recently about that incident. What I got was a chuckle out of him. He seems to think that was an isolate and rare instant.)

If you ever handle one, you will understand why a properly made CF handlebar is very unlikely to fail.
 

·
Registered
Joined
·
1,073 Posts
sgcullen said:
Well, now I'm thoroughly freaked out about my CF wheels. I did get the DOT rated ones, if that makes any difference to their durability. Having just crashed my Yamaha Raptor 700R quad yesterday (you can see the cool video of it at www.cullenaz.com), I am not looking forward to another get off any time soon. :bash:

Steve
Nice place there, Steve! I wouldn't be too worry, just keep an eye on the wheels.

BTW, Pfeifer asked me to relay a message to you thru Andy Ruhl that he would like to get in contact with you.
 

·
Registered
Joined
·
479 Posts
Discussion Starter #17 (Edited)
ARCHILLE said:
However, I am very wary of people opinions based on anecdotal stories from this and that. Everyone is entitle to his/her opinion and I can certainly respect that, afterall, it's your money to spend wherever you wish. It just get my blood boils, when people push their opinions as facts.
I said it was anecdotal. What's interesting about your post is that WERA is allowing them, didn't know that.

ARCHILLE said:
If you ever handle one, you will understand why a properly made CF handlebar is very unlikely to fail.
Tell that to "tornado bait" in the thread I posted who just beat the hell out of bike and body when his snapped off.


My training and experience with these materials and carbon fiber, is what leads me to the ultimate conclusion, you don't structural components made of the stuff.

Maybe I need to put an "IMO" before every sentence?
 

·
Registered
Joined
·
1,073 Posts
luvtolean said:
I said it was anecdotal. What's interesting about your post is that WERA is allowing them, didn't know that.
... :smoking:

Tell that to "tornado bait" in the thread I posted who just beat the hell out of bike and body when his snapped off.
I am not trying to tell you whether you should or shouldn't use it, luv. What I am telling you is my experience with them. There are failures in everything in life and circumstances conspire to increase the likely-hood of such events. :)
 

·
Registered
Joined
·
479 Posts
Discussion Starter #19
But...but, I want to argue. :cross:

Cool man, I'm glad they're working out for you guys. Insanely light, and very pretty for sure.

Just not for me. :)
 
1 - 20 of 113 Posts
Top