Apparently this is not uncommon; the nut is of a softer metal than the axle, the reasoning being that damage to the axle is a lot more complicated to fix than just replacing the nut. Fair enough.
But typically this turns into a bigger problem than it first appears. I go straight to ebay and order 3 of what I think are what I need. I also check with one of the local bike shops to see if they have one in their parts bin. They don't. So, my bike's kaput because of a nut costing 99p...The ebay order arrives - and they don't fit...It's also a bit confusing because they're called left hand axle nuts, as in for the left (non-drive) side. This gives the impression (at least to me) that they won't fit the right hand (drive) side which is what I needed. So you have to email and phone these people to confirm that you're buying the right thing. They're suitable for both sides :-)
The one on the right is the right one... |
Now, I'm learning all the time and I've learnt that the nuts and bolts for bikes are specifically for bikes and have to be bought from a bike shop; you cannot simply just go into a hardware/DIY store and buy replacements even though they might look the same. For example, the near universal 15mm wheel nuts have a specific screwthread for bikes - my local hardware store told me when I tried to buy some there.
Which has taught me to be prepared and to ensure that I have at least 2 of everything before I actually need it...