Pitted axle cones

[D.M. Procida]

I changed the tyre on the front wheel on my bike (Dawes Horizon 2005)
because there was a long slash in it which had every look of being the
kind of thing to let go at 45km/h downhill. It's been like that for
several days, but

Then when I put the wheel back on the bike I noticed some play, and when
I tightened up the axle I noticed that it didn't feel perfectly smooth
when I span the wheel holding the axle between my fingers.

So I had a closer look at the axle, and both cones are lightly pitted -
they look like some tiny lettering has been stamped into them.

How bad does this pitting need to be before the cones/bearings need
replacing?

Daniele

 

[Pete Biggs]

D.M. Procida wrote:
> I changed the tyre on the front wheel on my bike (Dawes Horizon 2005)
> because there was a long slash in it which had every look of being the
> kind of thing to let go at 45km/h downhill. It's been like that for
> several days, but
>
> Then when I put the wheel back on the bike I noticed some play, and
> when I tightened up the axle I noticed that it didn't feel perfectly
> smooth when I span the wheel holding the axle between my fingers.
>
> So I had a closer look at the axle, and both cones are lightly pitted
> - they look like some tiny lettering has been stamped into them.
>
> How bad does this pitting need to be before the cones/bearings need
> replacing?

Ideally the cones should be replaced if there is /any/ visible pitting, but
nothing dangerous willl happen if you continue with them.

Leave in a bit of play if the axle can't be made to turn smoothly otherwise,
if you like.

~PB

 

[Rob Morley]

In article <1hkflno.1j9qqrlo8qpjN%real-not-anti-spam-address@apple-
juice.co.uk>
D.M. Procida <[email protected]> wrote:
> I changed the tyre on the front wheel on my bike (Dawes Horizon 2005)
> because there was a long slash in it which had every look of being the
> kind of thing to let go at 45km/h downhill. It's been like that for
> several days, but
>
> Then when I put the wheel back on the bike I noticed some play, and when
> I tightened up the axle I noticed that it didn't feel perfectly smooth
> when I span the wheel holding the axle between my fingers.
>
> So I had a closer look at the axle, and both cones are lightly pitted -
> they look like some tiny lettering has been stamped into them.
>
> How bad does this pitting need to be before the cones/bearings need
> replacing?
>
If it's actual pitting rather than discoloration of the surface they
should be replaced. If it's a QR hub you should check the bearings for
smoothness with the skewer tightened (pack the end of the axle with
washers or similar so you can check it out of the frame) or you may find
that bearings which feel fine in your hand are overtightened when
attached to the bike. It was possibly failure to do this in the first
place that resulted in excessive wear.