Tech DA 9000 C50, cracked.

Mar 10, 2014
468
144
73
Funabashi, Chiba
#1
Crash yesterday morning, rather spectacular for what it was. Stopped traffic for a while since concerned citizens were concerned for my well-being. Daijobu?? Daijobu?? Yeah yeah yeah. Thank you. This conversation happened a lot.

Positives were, only I was involved, my helmet did its job and that was the difference between serious hospital type stuff and not. Bones somehow held up. Skin, not so much.

The bad, front end pretty mangled and a crack in the carbon part of my front wheel.

Got the front end sorted out at the bike shop yesterday, the lingering issue is with the wheel.

They said it will cost 70% of the cost of the wheel to get it fixed by shimano, or they could order the part and install it for a fraction less.

This is the first time anything like this has happened to me with wheels.

My question is, should I just ride it and hope for the best or get it fixed? Seems to be working fine, went for a ride today with no problems.

Thanks i. Advance for any advice.
 

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theBlob

Bokeh master
Sep 28, 2011
2,863
1,450
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...
#2
Front wheel? I'd be getting it fixed, unless it's one of those wheels that have the carbon just for show and all the structural strength is in the underlying aluminum. Then I would be glueing it together.

But I certainly would be letting a pro decide for me what was the best course of action.

Sorry to hear about your crash and glad it seems it was not more serious.
 

leicaman

Maximum Pace
Sep 20, 2012
2,512
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Asakadai, Saitama
#3
When you crash and die, you can't use the money you saved by not fixing the wheel so you might as well spent the money now, thus avoiding the crashing and dying part.
 
Likes: TCC
Mar 10, 2014
468
144
73
Funabashi, Chiba
#5
Front wheel? I'd be getting it fixed, unless it's one of those wheels that have the carbon just for show and all the structural strength is in the underlying aluminum. Then I would be glueing it together.
.
Actually. This is what my question was about - I was wondering of anyone knew about these wheels, whether the carbon actually did anything or if it was "just for show". I would base my decision to fix or not fix on that point really.
 

andywood

Maximum Pace
Apr 8, 2008
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Niigata
#7
Post some pictures and rim details.

If it is an accident waiting to happen, I'd say best to spend 100% on a new wheel than 70% getting it fixed.

Also, Shimano Japan has excellent customer service (regardless of where you bought the product) for items broken under ordinary use. When I cracked a crank arm I sent it in on Friday and had a new crankset by Monday (similar story with levers). So, it's a longshot but if you could somehow explain it as wheel failure...

Andy

www.jyonnobitime.com/time
 
Mar 10, 2014
468
144
73
Funabashi, Chiba
#9
Post some pictures and rim details.

If it is an accident waiting to happen, I'd say best to spend 100% on a new wheel than 70% getting it fixed.

Also, Shimano Japan has excellent customer service (regardless of where you bought the product) for items broken under ordinary use. When I cracked a crank arm I sent it in on Friday and had a new crankset by Monday (similar story with levers). So, it's a longshot but if you could somehow explain it as wheel failure...

Andy

www.jyonnobitime.com/time
There should be a pic in the original post?
 

Sikochi

Maximum Pace
Sep 13, 2010
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Kochi
#11
They said it will cost 70% of the cost of the wheel to get it fixed by shimano, or they could order the part and install it for a fraction less.
I`m confused. I understand the 70% via Shimano; fixed probably means a new wheel less a large percentage of the retail mark-up, but as for the shop, what part will they order and install? Are they saying the carbon isn`t structural???
 

AlanW

Maximum Pace
Jan 30, 2007
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Tokyo
#12
The carbon on DA wheels is structural. The alloy rim is not strong enough alone. I'd definitely get it fixed (new rim/spokes) or possibly a new wheel which might be the same price if you look around.
AW.
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
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#13
Yeah, those C50 rims use an internal nipple seated up against the inside of the carbon. This is more like a full carbon rim, than most aluminium / carbon mixes (the Mavic Cosmic Carbone rims which are a carbon / aluminium mix have the nipples seating on the aluminium section, for example), with the aluminium part 'merely' acting as a replacement braking track and tyre mount system, rather than part of the spoke system.

As it is so integral to the design (it is the wheel, rather than a glued on skirt which only gives aerodynamic advantages), you are going to need a new rim.

So, erm, how did you actually do this? Did you ride as hard as you could at a 20cm high kerb with a sharp edge?
 
Mar 10, 2014
468
144
73
Funabashi, Chiba
#15
The carbon on DA wheels is structural. The alloy rim is not strong enough alone. I'd definitely get it fixed (new rim/spokes) or possibly a new wheel which might be the same price if you look around.
AW.
Yeah, those C50 rims use an internal nipple seated up against the inside of the carbon. This is more like a full carbon rim, than most aluminium / carbon mixes (the Mavic Cosmic Carbone rims which are a carbon / aluminium mix have the nipples seating on the aluminium section, for example), with the aluminium part 'merely' acting as a replacement braking track and tyre mount system, rather than part of the spoke system.

As it is so integral to the design (it is the wheel, rather than a glued on skirt which only gives aerodynamic advantages), you are going to need a new rim.

So, erm, how did you actually do this? Did you ride as hard as you could at a 20cm high kerb with a sharp edge?
Thanks again for this very helpful information/advice. I've decided to take the wheel in and get it fixed/replaced thanks to the fine responses in this thread.

The crash itself... Hard to remember the details but I mostly remember it was very quick and violent - there were several forces working all at once. And the sounds. Really gross crashing and slamming of me and my bike sounds.

"ride as hard as you could at a 20cm high kerb with a sharp edge?" - not so far off this, I think.

I like to minimize the difference in speed between me and other moving things on the road if I can; I've always thought the larger the difference in speed the more dangerous, in principle.

My mistake was following a car a little too close maybe, and being half asleep, morning traffic so not so fast, probably under 30km/h. Got caught in a strong rut I didn't see and it just took the bike, from there I don't really remember but I must have been whipped at a curb and one of those lumpy residential walls (what I crashed into hard with my head and shoulder I'm pretty sure) and then I was on the ground listening to one of my lenses skitter away on the pavement.

Guess I'm lucky I didn't get torqued the opposite way into oncoming traffic.

New front wheel for 73,000 yen here. How much did they quote for the fix?
Wow that's a fantastic price, the lowest anywhere I think. Would have gone for it but the guy told me there's a kanji there that says "sold out". Bummer.

The fix price is about that, give or take a few K including tax.
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
1,291
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#19
http://www.wiggle.co.uk/shimano-dura-ace-9000-c50-clincher-front-wheel-2014/

80990yen with free delivery.

(Edit; the crack is around the valve hole and not the nipple area...)

@armmewitharmony Looking again at the photo you posted, there are two interesting things here with the rim.

-The crack appears to start at the valve hole, and spread down.
-There does not appear to be any damage at all to the metal part of the rim.

If you had ridden into something, hard enough to crack carbon, you would definitely have at least a bit of a ding on the metal part of the rim, which would be the first part to make contact with whatever it was you hit.

So, I reckon the damage is more likely to have been something catching on the valve, and yanking it really hard to the side, which cause the crack. Did your tyre puncture when you had the crash, and did you notice the valve was damaged?

I suppose it could have been the wheel slipping down a slot / hole in the road and twisting, causing the crack, but again, there is no real visible damage to the metal.

The spokes seem to be fine too...

When you spin the wheel, is it straight? And pushing the valve with your fingers, can you get the crack in the carbon to open up? (Don't push it too hard!)