Cracked Rear Hub

Simonb said:

I noticed a clicking noise coming from my drivetrain this
morning on my commute -- sounded like the indexing had
gone slightly out. Tried adjusting to no avail so decided
to leave it until I got home. I've just taken a look at
the rear hub and there's a crack running almost completely
around it! Obviously it is unrideable, but I have no idea
how this may have happened. Can this be down to normal
wear and tear? It's done about 7000km in the past year.

Un-branded OEM hub BTW.

Simon

I don't quite get what happened - is the crack round the
casing or next to the spokes? And is the axle inside intact?

My old tourer used to eat axles, but always became unridable
when they snapped.

AC

"anonymous coward" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Simonb said:

I noticed a clicking noise coming from my drivetrain
this morning on my commute -- sounded like the indexing
had gone slightly out. Tried adjusting to no avail so
decided to leave it until I got home. I've just taken a
look at the rear hub and there's a crack running almost

completely

Quoted message said:

Quoted message said:

around it! Obviously it is unrideable, but I have no
idea how this may have happened. Can this be down to
normal wear and tear? It's done about 7000km in the
past year.

Un-branded OEM hub BTW.

Simon

I don't quite get what happened - is the crack round
the casing or next to the spokes? And is the axle
inside intact?

My old tourer used to eat axles, but always became
unridable when they snapped.

AC

Sounds like the hub body has fractured, to me. Poor hub,
probably - yes, it does happen sometimes.

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
virus system (grisoft.comgrisoft.comOpen ↗). Version: 6.0.631 /
Virus Database: 404 - Release Date: 17/03/2004

anonymous coward <[email hidden]> wrote
in message news:<[email hidden]>... I
don't quite get what happened - is the crack round the
casing or next to

Quoted message said:

the spokes? And is the axle inside intact?

The crack is around the casing on the cassette side, I
assume the axle is intact. Is it rideable in this state?

Simon

Now I think about it, it can't possibly be rideable!

Silly me.

Simon

Simonb said:

I noticed a clicking noise coming from my drivetrain this
morning on my commute -- sounded like the indexing had
gone slightly out. Tried adjusting to no avail so decided
to leave it until I got home. I've just taken a look at
the rear hub and there's a crack running almost completely
around it! Obviously it is unrideable, but I have no idea
how this may have happened. Can this be down to normal
wear and tear? It's done about 7000km in the past year.

Definitely not /normal/ wear and tear. I would expect any
hub shell to last many tens of thousands of miles. Sorry I
don't know what the cause could be - would be a good
question for rec.bicycles.tech.

It doesn't just happen to cheapo hubs. I noticed someone is
selling modern Campagnolo Chorus hub parts on eBay after
claiming their shell broke, although this is very rare with
these (forged) hubs.

~PB

Simonb said:

Can this be down to normal wear and tear? It's done about
7000km in the past year.

Yes - especially if it's a Hope. Mine went in far less than
7000km (prob more like 4000 tops). I have it on good
authority the failure was down to poor manufactoring
process. Having said that, we have various bikes in the
family (including an often heavily laden tandem) and that
has been the only hub (rest are mostly Shimano) to go in
that manor so far *touch wood*

Chris

Chris Heys said:

Simonb said:

Can this be down to normal wear and tear? It's done about
7000km in the past year.

Yes - especially if it's a Hope. Mine went in far less
than 7000km (prob more like 4000 tops). I have it on good
authority the failure was down to poor manufactoring
process.

I have heard of a Several of cases of disintegrating Hope
hubs, which is slightly worrying as I have them on my #1
commuting bike. Though it's coming up to 14000 km now
without problems [grasps tree]

I've had a Sachs hub lose part of its flange, but this can
probably be attributable to the use of radial spoking on
that wheel.

--

Dave Larrington - legslarry.beerdrinkers.co.uklegslarry.beerdrinkers.co.ukOpen ↗
===========================================================
Editor - British Human Power Club Newsletter
bhpc.org.ukbhpc.org.ukOpen ↗
===========================================================

Dave Larrington said:

Chris Heys said:

Simonb said:

Can this be down to normal wear and tear? It's done
about 7000km in the past year.

Yes - especially if it's a Hope. Mine went in far less
than 7000km (prob more like 4000 tops). I have it on good
authority the failure was down to poor manufactoring
process.

I have heard of a Several of cases of disintegrating Hope
hubs, which is slightly worrying as I have them on my #1
commuting bike. Though it's coming up to 14000 km now
without problems [grasps tree]

The problems occurred with the original ones that had alloy
flanges pressed onto a titanium cylinder in the centre.
Cracks would form in the flanges around the cylinder. The
new one piece Hopes are immune to this.

That said, until earlier this year I was running some of the
original Hopes from 1994 and they were fine. Been through
countless miles of riding and racing. Only changed them as
part of an upgrade to discs.
--
"We take these risks, not to escape from life, but to
prevent life escaping from us." bensales.combensales.comOpen ↗

Quoted message said:

The problems occurred with the original ones that had alloy
flanges pressed onto a titanium cylinder in the centre.
Cracks would form in the flanges around the cylinder. The
new one piece Hopes are immune to this.

My hub was of this type. However, the hub failed accross the
spoke holes part of the flange - realeasing 4 spokes
simulaneously. Further inspection revealed cracks were
almost fully formed in several places, notably around more
spoke holes (both sides) and the point where the alloy
joined with the titanium as mentioned. Couldn't understand
it as the bike was pretty much exclusively used for
commuting.

Luckily I didn't fall off and the rear wheel stayed intact
long enough to get home...just!

Chris

Chris Heys said:

Quoted message said:

The problems occurred with the original ones that had
alloy flanges pressed onto a titanium cylinder in the
centre. Cracks would form in the flanges around the
cylinder. The new one piece Hopes are immune to this.

My hub was of this type. However, the hub failed accross
the spoke holes part of the flange - realeasing 4 spokes
simulaneously. Further inspection revealed cracks were
almost fully formed in several places, notably around more
spoke holes (both sides) and the point where the alloy
joined with the titanium as mentioned. Couldn't understand
it as the bike was pretty much exclusively used for
commuting.

I've only seen failures like that where either:

- the spokes where incredibly over-tensioned,
- the wheel was laced radially.

But that's beside the by, Hope realised it was a design
failure and changed them.
--
"We take these risks, not to escape from life, but to
prevent life escaping from us." bensales.combensales.comOpen ↗

"Pete Biggs" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Simonb said:

I noticed a clicking noise coming from my drivetrain
this morning on my commute -- sounded like the indexing
had gone slightly out. Tried adjusting to no avail so
decided to leave it until I got home. I've just taken a
look at the rear hub and there's a crack running almost
completely around it! Obviously it is unrideable, but I
have no idea how this may have happened. Can this be
down to normal wear and tear? It's done about 7000km in
the past year.

Definitely not /normal/ wear and tear. I would expect any
hub shell to last many tens of thousands of miles. Sorry I
don't know what the cause could be - would be a good
question for rec.bicycles.tech.

It doesn't just happen to cheapo hubs. I noticed someone
is selling modern Campagnolo Chorus hub parts on eBay
after claiming their shell broke, although this is very
rare with these (forged) hubs.

~PB

I've seen plenty of Campag hubs break, including Record
models, and including Nuovo Record, etc. (I.e., it's not a
"new" problem.) However, all the Campag hubs I've seen fail
have broken across the spoke holes. This is made much more
likely when building a radial wheel - neither Campag nor
Shimano will guarantee hubs built this way. However, I've
seen 3X wheels go the same way.

I think there are tw possible causes for this problem:
misaligned rear ends, or simply a poorly cast/forged hub.
It's not normal wear or tear by the most obvious
definition, IMO.

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
virus system (grisoft.comgrisoft.comOpen ↗). Version: 6.0.634 /
Virus Database: 406 - Release Date: 18/03/2004

"BenS" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Dave Larrington said:

Chris Heys said:

On Wed, 17 Mar 2004 23:06:39 -0000, "Simonb"
<[email hidden]> wrote:

> Can this be down to normal wear and tear? It's done
> about 7000km in the past year.

Yes - especially if it's a Hope. Mine went in far less
than 7000km (prob more like 4000 tops). I have it on
good authority the failure was down to poor
manufactoring process.

I have heard of a Several of cases of disintegrating Hope
hubs, which is slightly worrying as I have them on my #1
commuting bike. Though it's coming up to 14000 km now
without problems [grasps tree]

The problems occurred with the original ones that had
alloy flanges pressed onto a titanium cylinder in the
centre. Cracks would form in the flanges around the
cylinder. The new one piece Hopes are immune to this.

That said, until earlier this year I was running some of
the original Hopes from 1994 and they were fine. Been
through countless miles of riding and racing. Only changed
them as part of an upgrade to discs.
--
"We take these risks, not to escape from life, but to
prevent life escaping from us." bensales.combensales.comOpen ↗

The ealiest Hope hubs, with the three-piece construction,
were fine - that's why your '94 hubs have survived. Around
that date, however, problems began; there was no obvious
change to the design, but I've always assumed that they
changed the material used in some way (i.e. dfifferent
alloy). It seemed that almost every hub they produced failed
within a matter of months. Hope replaced them without
quibble, but I ended up having to rebuild a hell of a lot of
wheels FOC! They then modified the three-piece design by
increasing the outside diameter of the flanges, whilst
mainting the PCD of the spoke holes. This seemed to fix the
problem. Before very long, they brought out the one-piece
design; this is largely problem free, as far as I'm aware -
although *no* hub is indestructable.

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
virus system (grisoft.comgrisoft.comOpen ↗). Version: 6.0.634 /
Virus Database: 406 - Release Date: 18/03/2004

FYI, Here's a photo of the hub in question:

widerworld.co.ukcracked hub.jpgOpen ↗

(the crack ends on the other side about 2/3 the way round)

Simon

"Simonb" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

FYI, Here's a photo of the hub in question:

widerworld.co.ukcracked hub.jpgOpen ↗

(the crack ends on the other side about 2/3 the way round)

Simon

Ouch! Definitely one for your friendly wheelbuilder... :-)

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
virus system (grisoft.comgrisoft.comOpen ↗). Version: 6.0.634 /
Virus Database: 406 - Release Date: 18/03/2004

[email hidden] schreef ...

<about Hope hubs >

Quoted message said:

Before very long, they brought out the one-piece design;
this is largely problem free, as far as I'm aware -
although *no* hub is indestructable.

True, but our Chris King rear hub comes very close to
that ideal!

--
Regards, Marten