Broken QR Skewer

displacedaussie

Last Friday I rode in to work as usual and locked up my bike in the cage downstairs. At the end of the day I got my kit on, went downstairs, unlocked the bike and the rear wheel fell out!

Huh? I thought. I looked down and my rear quick release skewer was missing.

WTF?! I thought.

I looked around and there it was, on the ground. The skewer a couple of metres away on the left and the nut a couple of metres away on the right.



Looking at the skewer, it appears to have failed part way along the thread. A fair amount of it is still inside the nut.



So a few things.

1) I hit 60km/hr on my commute on Friday morning. I don't like to think what would have happened if it had completely broken during my ride.

2) For the skewer to have flown so far to the left I guess the skewer is under quite a bit of tension?!

3) I replaced my brake pads on Friday morning which included removing the rear wheel. I didn't notice anything wrong with the skewer (although I suppose I didn't really look). I don't think I tightened it up too much - I'm one of those crazy people that reads the manual and follows instructions - but maybe I did? I didn't do it any different to the way I normally do it.

4) The skewer is from a set of Shimano RS80 wheels I bought in March last year. The wheels (and skewers) had done 9064 km.

5) Is this kind of failure common? Did I do something wrong? Should I have discovered this myself?

hendo9

Is that rust on the skewer or dirt? Rust could have weakened the skewer to the point where it couldn't take the tension anymore? You should periodically remove the skewers and apply a bit of grease to them to prevent rust setting in, especially if you ride on wet, salty roads!

sungod

looks very corroded, maybe it's the angle but judging from the end inside the nut it looks like there might've been a crack there for some time, eventually it failed

if this is one of a set, i'd have a very good look at the other one

fwiw i remove mine completely every now and then and grease them

Anonymous

I tend to take my wheels off when cleaning bike and have made a point of taking skewers out to.
Seems sensible to dry and lube them a bit.

How tight should a skewer be? Is too tight to undo with one finger too tight?
I do them quite firm so that you would have to brace with fore/middle finger and pull with thumb.

Hope you got home OK ;-)

displacedaussie

There's a very tiny amount of discolouration there, but it doesn't look that bad and there's nothing anywhere near where the break happened.

Regularly checking and regreasing my skewers is definitely something i'll be doing regularly from now on, although I'm still not sure if that would have done any good in this case. The matching front skewer looks and feels absolutely fine.

rolf_f

I wouldn't over analyse it. Sometimes stuff breaks - usually it doesn't hurt you when it does. You could check the skewer every week and you still probably wouldn't have spotted this before it happened. If you hadn't noticed it and had ridden the bike with the skewer missing, probably nothing would have happened. Gravity and your weight would likely hold things together without too much drama but any bumps would probably result in obvious drive train noise that would stop you before you managed to dislodge the wheel entirely. It's not coincidence that only the front wheel is protected by tabs to stop the wheel falling out if the skewer is loose.

mercia_man

hendo9 wrote:

Is that rust on the skewer or dirt? Rust could have weakened the skewer to the point where it couldn't take the tension anymore? You should periodically remove the skewers and apply a bit of grease to them to prevent rust setting in, especially if you ride on wet, salty roads!

After my wife's Shimano skewer broke in exactly the same way as this, I regularly remove, check and grease the threads.

racingcondor

I was expecting to see an ultralight, external cam skewer rather than a Shimano or Campag skewer (both have a reputation for being strong and made properly). I guess it's just a case of bad luck and a lesson to clean that rear wheel slightly more often (off the bike so you can check the skewer).