Front axle snap, design flaw?

The old euro zoke fork axle(my '05) has the same outer diameter and dimensions, but it is thicker overall, and has at least 10 mm overlap inside. It also has the hex end (big allen style). inner diameter is ~19 mm
 
Anyone else think that there is a large amount of rust and scale on those parts, for a newish '09? Is it something in the dirt there in Sweden that may be attacking the metal causing the fatigue?
 
Mine measures 48.12 mm from the outer edge to the ridge at the ID reduction on the inside of the axel. Its also very clean, not a spot of rust. It will not keep me up tonight. FWIW, that bike with the broken axel has a lot of rust on the fork hardware.
 
I'm somewhat surprised they did not use a single bore diameter all the way through, but I guess weight is the reason. From the cutaway pic if one did want to put some stock in that area it would take some extra machining, but still perfectly doable I'd think.

That area just looks to carry a lot of stress because of the machining and it is thin. I'm guessing if one had their forks tweaked out of alignment and bound up (without even action) for any period of time it would cause additional stress on it.
 
One thing you don't know is the type of steel, treatment, etc. What looks scary may not be so once you know the whole story. I like to know all the facts before passing judgement.
 
Did an 09 use a wave rotor? The wheel in the photo has the old style rotor? Not to say it could have been changed out....just thinking out loud.
 
I forwarded this thread to the factory and the response was that they had never had a claim (meaning notice) before of a broken axle. They also said they would look at the '09 axles in stock to see if there was a change or problem.
On the point that these bikes should take a big jump.....please remember these are woods bikes and not meant to be jumped over hugh jumps without modifying the suspension. Moderate jumping....yes. MX triples.....no.
Clay
 
If I may clarify, what Clay means is that the chassis itself is not a limitation in MX, its the soft suspension that will transmit huge forces to bike and body when bottomed on a big landing.

This is the first known case of a failure like this, out of thousands, since at least '07 as my axel is the same based on my measurement. That statistic seems pretty good to me.
 
Looking at the pics. Does it seem like there is too much space between the fork and the axle/bearing spacer?
Mine has about 5mm.
 
GMP said:
If I may clarify, what Clay means is that the chassis itself is not a limitation in MX, its the soft suspension that will transmit huge forces to bike and body when bottomed on a big landing.

This is the first known case of a failure like this, out of thousands, since at least '07 as my axel is the same based on my measurement. That statistic seems pretty good to me.
Click to expand...

Yeah.....that's what I meant! LOL! Thanks Glenn! :)
 
Just to be safe, I'm going to hold off on the slow, lazy no-handed backflip over "The One Twenty". I'll just single through there like I usuallly do. :p

It actually really freaked me out the first time somebody tripled through there while I was singling the third one. Always good to hold a predictable line I guess.:eek:
There's very little run up to the first jump. I have no idea how they carry enough speed to triple that thing.

*********

I am of course a slow and unsophisticated boob. But I do find that the WP forks and Ohlins shock seem quite at home on the MX track with a few clicks here and there. I'll be at Rocky Hill tomorrow.
http://www.ctmotocross.com/

track photos are of an old layout before The One Twenty.

-dean
2001 xc300 a.k.a. Spanish Fly
 
The heavy red rust on the pinch bolts, fork shield, and axle is strange to me. Did you leave any accumulated road salt/splash on your bike during the winter season? The salt is very corrosive.

While the axle geometry could be improved, I speculate that the heavy corrosion probably contributed more to this failure than the geometry did.
 
MattR said:
the heavy corrosion probably contributed more to this failure than the geometry did.
Click to expand...

It's possible the corrosive liquid got trapped at the joint between the axle and the wheel spacer.

Must do a lot of riding in an old iron ore mine.
 
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