Mavic R-SYS front wheel safety recall

[familyguy]

It sure looks like Mavic are trying to explain this away when it cant be explained away (in my non-lawyer opinion).

Hub damage? When the spokes fail in compression like that, there's no force against the hub, and there'd be no damage to the hub. The spokes of this wheel are designed to work in compression, not tension, as Mavic have repeatedly stated. If the spoke cracks at the bottom of the wheel (while in compression), then rotates to the top of the wheel and is tensioned (not its normal force resistant state), it will break, will it not? Next downward rotation its going to pop. Thereby pushing the wheels downwards, with no force on the hub, and immediately putting all the top spokes into tension and failing suddenly.

attached with this letter is a picture taken by a photographer at the scene of the accident. One can see the significant section of the tire which has separated from the rim of the wheel.

Could also have happened when the wheel impacted below the fork crown. Ditto the sheared off valve stem.

There are several key facts which may indicate that the cause of the accident was not the failure of the Mavic wheel.

There's a few if's in that response. And a couple of things just seem out of order in terms of the event timeline.

Jim

[Aushiker]

G'day

More input from Mavic at Road.cc

Regards
Andrew

[trailgumby]

Might not be just the front with a problem. See here. Seems that when one goes, the rest go out in sympathy. Is that scary or what? Mavic can keep its carbon spokes, I think. Kevlar tethers seem to be remarkably useless.

[twizzle]

G'day

More input from Mavic at Road.cc

Regards
Andrew

I think Mavic should shut up. Every time they open their mouths they set off my !! BAN ME NOW FOR SWEARING !! detector. Next they will be saying it's the fault of the riders - if they didn't ride on the wheels, they wouldn't break.

[im_no_pro]

“When carbon breaks it falls apart, unlike steel or aluminium and that can be shocking. The cause is the same, but it has a psychological impact” the Mavic spokesman told us.

The message is that in the wrong circumstances all wheels break, but while carbon wheel might not break any more often than the non-carbon variety (they may even break less) when they break they are more likely to… really break. Although we can't help feeling that a wheel that falls apart is likely to have more than a pychological impact on the person riding it.

My bold - Stating the obvious really

Interesting to note Mavic's original comments re: supposed hub damage if the wheel was at fault, is it just me or would that be mainly the case if you were riding upright in a straight line, not around a corner as was the case?? Im no lawyer, and definately not an engineer, but it all smells funny to me. At the end of the day, Mavic's problem is that I am a (potential) customer. Regardless of what the engineers say, I would not be purchasing these wheels. And if they continue to spit this sort of drivel when they are confronted with a product issue, it is unlikely that I will be buying Mavic products full stop.

[Aushiker]

At the end of the day, Mavic's problem is that I am a (potential) customer. Regardless of what the engineers say, I would not be purchasing these wheels.

That is the key issue here I suspect. Interesting they also make comments about testing and engineering and hence implication that this is good, yet the rims where recalled ... seems a contradiction to me.

Regards
Andrew

[Aushiker]

G'day

Bike Snob NYC has the answer and the explanation ....



Regards
Andrew

[Aushiker]

It looks like Grays Online got a hold of some Mavic R-SYS wheels and put them on the market in May 2012. Product Safety Recalls Australia got on to it and they have now been recalled. If you picked up a cheap Mavic R-SYS wheel from Grays Online you might want to have a chat to them.

Regards
Andrew

[Dimis]

Ouch...!

Are the mavic r-sys SLRs an issue also?
I was about to drop $1800 on them upgrading from the ksyriums SLRs which sold with my other bike.

Thoughts?

Thx

[GeoffInBrisbane]

They are supposed to be fixed now. I know plenty of riders won't touch them, for reasons outlined in this thread, but my R-Sys SLs are two years old and have never needed so much as a true... Disclaimer being I'm about 65kg and not one for breaking equipment. Haven't heard of any failures in a long time, either. Not sure if anybody else has?

Would have thought that if this had continued to be a problem, Mavic would've killed off the wheels and been busy fighting legal actions, but I might be wrong...

[barefoot]

Any structure that relies on long thin members (such as spokes) loaded in compression is fundamentally flawed.

Long thin members fail by in compression by buckling.

The engineering mechanics of buckling are well known. Essentially, to resist buckling, your member needs stiffness. For a cylinder or tube, increased stiffness comes by increasing diameter. So, for a compression-spoked wheel, it becomes a question of how thick a spoke you need to get the buckling resistance you want. And for a road bike wheel, this immediately becomes a trade-off against aerodynamics, because it's much harder to push a thick tube through air than it is to push a thin wire through air.

What trade-off are you comfortable with between aerodynamics and keeping your teeth?

A far better solution is to use very slim spokes for vastly improved aerodynamics, and load them in tension to eliminate the buckling failure mode altogether.

[im_no_pro]

There's every chance the current ones are a vast improvement over the 2010 model. In staying that, you could give me a set of brand new ones and I would glady accept them. But only for use on the wind trainer.

As for buying them, not a chance in hell. That may be an emotional decision rather than a rational one, but I dont care.

[Dimis]

There's every chance the current ones are a vast improvement over the 2010 model. In staying that, you could give me a set of brand new ones and I would glady accept them. But only for use on the wind trainer.

As for buying them, not a chance in hell. That may be an emotional decision rather than a rational one, but I dont care.

Yeah, but they're all black, and so very good-looking, and they match my kit oh so well...

[ldrcycles]

There have been failures of the supposedly fixed R-Sys wheels (there's some pattern of coloured stripes on the spokes to tell them apart), personally I wouldn't even think about touching them.

[GeoffInBrisbane]

As far as I had heard, the only one fixed on that failed was the one mentioned upthread which Mavic blamed on damage sustained in an accident (to widespread cynicism). Have you heard of any others? I ask not out of an attempt to rubbish your statement, but out of self interest (in my teeth)...

[ldrcycles]

Yea I've seen from memory pics of about half a dozen different post recall R-Sys breakages, in forums about the place (wouldn't have a clue where, it's been a good 2 years or so since I saw them).

[Rich-Ti]

You could crush the spokes of the old version between your fingers if you have a strong pinch. The new version won't crack even with an almighty squeeze of a set of pliers.

I weigh almost 85kg and my R-SYS SLRs have been good for 3yrs now. A very good 'almost-all-rounder' wheel I find (except fast, flat riding - they're not what you might call 'aero' at all!), especially with the Exalith brake surface.

That said, if I were to replace them it'd be for the Ksyrium SLR - cheaper, not a lot of weight difference, slightly more aero front wheels (not that it really matters) and only carbon spokes on the non-drive side rear.

Just a damn shame they don't do the Ksyrium in a tubular version any more...