Near instant catastrophic front wheel failure

[dbairaktaris]

On my last ride on the 10th June 2017, while I was riding at around 30 km/h on a flat bitumen surface, my front 3 year old DT Swiss RR 1450 Tricon Wheelset Black Shimano/Sram 10/11Sp, deformed catastrophically over a distance of maybe 5 meters, jammed against the fork and sent me flying over the bike and onto to the hospital.

I am 53 years old, I weigh 89kg, I am 1:83 cm tall, reasonably fit and have been riding accident free for over 30 years. Several spokes are broken although the tyre remains pumped and the hub appears to work fine. New Gatorkins tyres and service was applied to both wheels about two months ago. The riding conditions were 100% visibility, clear skies, 18 degrees Celsius and dry surface. At the point of the incident I had already ridden 32 kms.

DT Swiss suggested that something has come into the wheel/spokes and caused the damage. While I cannot recall the incident myself, nearby witnesses have excluded the possibility of impact.

I am devastated that I cannot explain why and how this happened. I would greatly appreciate any past experiences and suggestions in locating a subject matter expert that will help me understand what happened. My cycling family are also devastated. Please help me to gain the confidence to ride again.

Thank you,

Dimitrios

 

[I like Skol]

Sorry to hear about your accident Dimitrios and I hope you are on the road to recovery and soon out on the road again.
I have just googled the wheels you have/had and the immediate 1st thing I notice is that the front wheel only has 18 spokes. At 90kg you are not heavy but also not lightweight, I myself weigh just a few kilos more than you but would not consider a wheel with less than 28 spokes even for a 'best' bike.
I am not an expert but the logical failure mode that I would suggest is this;

Too few spokes in the wheel resulting in increased stress and premature fatigue failure of 1 spoke.
This is not catastrophic in a 'normal' wheel with 28/32/36 spokes but a wheel with only 18 spokes has just 9 spokes on each side so losing 1 of them is to lose more than 11% of the wheels structure on that side.
The result is increased load on the remaining 8 spokes, but this is not distributed evenly around the wheel and the biggest portion of that additional load will pass to the remaining spokes on either side of the failure.
These spokes are likely just as fatigued as the spoke that already failed so are in no condition to handle the increased load and will snap, the initial failure will cascade around the wheel with the result being a seriously deformed wheel and the accident you experienced.

I have no other evidence to base this hypothesis on other than your weight, the period of use and the spoke count of the failed wheel so I could be wrong. The fact that the wheel had just been serviced should be irrelevant unless they had to true the wheel? Did the wheel require regular trueing because if it did then that may also point to the answer.
I suggest that maybe your choice of wheel was wrong and you might have been better served using a more robust wheel for regular riding and saving the super lightweight wheels for race-day.
Get some new, more robust wheels without worrying about wheel set weight and get back on your bike to enjoy many more worry free miles.

 

[S-Express]

Quote 1

and have been riding accident free for over 30 years

Quote 2

Please help me to gain the confidence to ride again.

See Quote 1.

 

[Fab Foodie]

I would also suggest rider weight/low spoke count is the primary cause.
Am similar weight and only break front spokes on my low spoke count, low weight wheels. Never the higher spoke count rear.

 

[Yellow Saddle]

It is very easy to determine a wheel's reason for failing. It is more difficult to extract exact circumstances from the rider though.

It was a stupid wheel to start off with but it is still possible to see what went on.

Do you still have the wheel? Can you post some photos of the wheel? In particular of the damaged areas. Bends are not as important as metal separations. I want to see if there are cracks in the rim, if the spoke retainers have broken out of the rim and if the spokes broke in fatigue or tension. Did the spokes break at the very ends or did they break in the centre? Can you get a good enough focus on the spoke ends where they broke to post some pictures?

 

[srw]

My Mavic Ksyrium Elite front wheel has 18 spokes, and I've never been as light as 89kg. It's carried me several thousand miles over all sorts of terrain. The OP's DT Swiss wheels are twice the price of my Mavics, so should be built to at least the same standard.

My best guess is that DT Swiss are right, and something has hit the spokes. It could simply be a large stone or a bit of wood.

As for getting confidence back, there's only one way to do that. Get out and ride.

 

[Ian H]

18 spokes makes a racing wheel—one you treat with respect and ride on smooth tarmac. For daily bashing about something more robust/less fancy would be more appropriate. More spokes make catastrophic failure less likely.

 

[Yellow Saddle]

My Mavic Ksyrium Elite front wheel has 18 spokes, and I've never been as light as 89kg. It's carried me several thousand miles over all sorts of terrain.

Several thousand miles is hardly something to marvel at for good wheels.

The OP's DT Swiss wheels are twice the price of my Mavics, so should be built to at least the same standard.

[/QUOTE]

There are two things and only two things that DT Swiss is good at. First, it makes excellent spokes.
Second, it is very, very good at hyping up poor quality products and sell it on as OEM equipment. DT hubs, shocks, suspension forks and rims are mostly poorly designed, overly complicated and over-priced.

My best guess is that DT Swiss are right, and something has hit the spokes. It could simply be a large stone or a bit of wood.

Let's not guess. The OP has asked for help, his side of the bargain is to furnish us with proper information first.

As for getting confidence back, there's only one way to do that. Get out and ride.

And of course fitting appropriate wheels and understanding why the first ones failed.

 

[I like Skol]

My Mavic Ksyrium Elite front wheel has 18 spokes, and I've never been as light as 89kg. It's carried me several thousand miles over all sorts of terrain.

But you may have the light touch of a pixie, never ride faster than 10mph and avoid every irregularity in the road. Your wheel is still a fashion statement for pretend racers unless you actually race on it!

 

[GrumpyGregry]

Is it possible one spoke broke and got tangled?

 

[Yellow Saddle]

Is it possible one spoke broke and got tangled?

No

 

[Fab Foodie]

My Mavic Ksyrium Elite front wheel has 18 spokes, and I've never been as light as 89kg. It's carried me several thousand miles over all sorts of terrain. The OP's DT Swiss wheels are twice the price of my Mavics, so should be built to at least the same standard.

My best guess is that DT Swiss are right, and something has hit the spokes. It could simply be a large stone or a bit of wood.

As for getting confidence back, there's only one way to do that. Get out and ride.

Maybe rim strength is also part of the equation. Your Mavics being stiffer/stronger than his rims or have heftier spokes of course.

 

[Fab Foodie]

But you may have the light touch of a pixie, never ride faster than 10mph and avoid every irregularity in the road. Your wheel is still a fashion statement for pretend racers unless you actually race on it!

What does it matter? Everybody should be able to enjoy whatever wheels they like ...racer or not.

 

[srw]

Maybe rim strength is also part of the equation. Your Mavics being stiffer/stronger than his rims or have heftier spokes of course.

Probably heftier spokes - they're bladed rather wiry. The Mavics defintely aren't racing wheels - Mavic's recommendations are "For a longer longevity of the wheel, Mavic recommends that the total weight supported by the wheels don't exceed 120kg, bike included" - which is not a racing snake weight, it's a reasonably chunky rider with a lightweight bike and a light touring load. And the use is "ASTM CATEGORY 2 : road and offroad with jumps less than 15cm".
https://shop.mavic.com/en-gb/ksyrium-elite-rr0623.html#1028=3283

Yes, one day they'll fail catastrophically, but not yet I hope.

 

[EnPassant]

Mavic's recommendations are "For a longer longevity of the wheel, Mavic recommends ..."

Yes, one day they'll fail catastrophically....

Following the groundbreaking lead of their advertising copywriters.....

With apologies for the necro, not looked in for quite a while.