Hub cone nuts. Why do they crack?

I have cracked both the cone nuts on my rear hub after only 90 miles!

I re-spaced the 120mm hub to 130mm by putting 5mm spacers behind the nuts and then tightening them (just a little) with cone spanners. Now they've died.

Does anyone know where these are available as spares? The hubs are Novatec branded.

I have had this problem too, your lbs should stock spares.

I've also cracked my nuts but will discuss on a different type of forum altogether.

is the frame actually 130 spaced or is it a little smaller and putting a lot of pressure on the nuts?

edit: they crack because they are a harder steel to actually grip. thus making them a little more brittle. if they were softer they wouldn't break as often (its pretty common), but at the same time they also wouldn't bite in to your dropouts to hold your wheel in place.

because....
cheap metal
bad thread on axle
dirt on threads on axle
too much force
wrong tool
erm, a combo of the above?

is the frame actually 130 spaced or is it a little smaller and putting a lot of pressure on the nuts?

edit: they crack because they are a harder steel to actually grip. thus making them a little more brittle. if they were softer they wouldn't break as often (its pretty common), but at the same time they also wouldn't bite in to your dropouts to hold your wheel in place.

Good info. Thanks.

It's is a 130 spaced frame and not pinching much. Being an old road frame the dropouts don't have the large flat area of track ends. Perhaps this is focusing the pressure a bit.

because....
cheap metals
bad thread on axle
dirt on threads on axle
too much force
wrong tool
erm, a combo of the above?

I used a cone spanner and didn't go nuts (ehem) with it. Might have over done it tightening the track nuts though.

I have had this problem too, your lbs should stock spares.

I'll pay them a visit. Time off the bike though! Very frustrating at this time of year.

Cheers for the comments/help.

I bought my fave mechanic at my LBS a packet of custard cremes. He pinched the nuts off an old hub that was knocking around in the workshop (Shimano XT I think). So now I'm sorted.

Biscuits make the world go round.

damn straight.
bike mechanics care not for money, so long as you keep their exotic tea/coffee/biscuit/cake/cheese fridges topped up, they are happy.