death by spokes

I had an interesting noise coming from the rear of the bike recently,
tried to eliminate it but couldn't pinpoint it. I noticed that it
stopped when I stopped pedally and didn't resume when I started again,
just came on randomly. Had to be something to do with the hub but I
couldn't see why, also it was a newish wheel (18mths old and not often
used as I have a fleet of bikes) with sealed bearings and kept in good
maintenance so shouldn't have had any issues yet.
The other day a spoke suddenly broke, no biggy as I had 23 more. When I
stopped to remove the spoke and sort out if I could make it the rest of
the way home I also looked over the rim. Every nipple hole on the drive
side of the rear wheel was cracked!
This was a quality machine-built wheel and had performed well. However
somewhere in the manufacture, and likely because it was a paired spoke
24 hole wheel, the spokes were overtensioned. What had this to do with
the hub noise? I took the freewheel off at home and checked the axle and
cones. I was unable to remove the axle but it was not bent or broken,
the cones still had the original green grease inside and no dirt or
brown grease however the axle turned roughly. Possibly this was the
intermittent noise? Weird.

P.S the rear wheel is probably a write off because of this
overtensioning. Death has spoke'n.
PPS not going to state the manufacturer's name, that's not the point as
there ar plenty of such wheelsets out there.

DD wrote:
the spokes were overtensioned. What had this to do with
the hub noise? I took the freewheel off at home and checked the axle and
cones. I was unable to remove the axle but it was not bent or broken,
the cones still had the original green grease inside and no dirt or
brown grease however the axle turned roughly. Possibly this was the
intermittent noise? Weird.

Somehow in all this I lost the sentence that I believed the cause of the
noise was also via spoke overtensioning, that the hub may have been
warped. Sorry for not making more sense.

DD wrote:

I had an interesting noise coming from the rear of the bike recently,
tried to eliminate it but couldn't pinpoint it. I noticed that it
stopped when I stopped pedally and didn't resume when I started again,
just came on randomly. Had to be something to do with the hub but I
couldn't see why, also it was a newish wheel (18mths old and not often
used as I have a fleet of bikes) with sealed bearings and kept in good
maintenance so shouldn't have had any issues yet.
The other day a spoke suddenly broke, no biggy as I had 23 more. When I
stopped to remove the spoke and sort out if I could make it the rest of
the way home I also looked over the rim. Every nipple hole on the drive
side of the rear wheel was cracked!

is the rim too flexy ?? I think for the low spoke count wheels, the
stiffness of the rim is important - especially for the paired spokes
rims. Because the spokes are so far apart. And when you break a spoke, i
doubt whether you can true the wheel and keep riding.

+ravi

DD Wrote:
DD wrote:
the spokes were overtensioned. What had this to do with
the hub noise? I took the freewheel off at home and checked the axle
and
cones. I was unable to remove the axle but it was not bent or
broken,
the cones still had the original green grease inside and no dirt or
brown grease however the axle turned roughly. Possibly this was the
intermittent noise? Weird.

Somehow in all this I lost the sentence that I believed the cause of
the
noise was also via spoke overtensioning, that the hub may have been
warped. Sorry for not making more sense.
I think you were dealing with two issues:
Rim that was not strong enough to support your weight and forces from
riding. Twelve spokes carried most of the load due to the small number
of spokes in the rear wheel and the higher tension in the drive spokes.
These forces flexed the rim mostly at the drive side spoke nipple
interfaces.
Hub issue is likely another issue, not related to spoke tension. If it
were due to spoke tension you would have had cracking at the spoke/hub
interface.


--
daveornee

On Sat, 12 Nov 2005 17:48:19 +0800, DD wrote:

I had an interesting noise coming from the rear of the bike recently,
tried to eliminate it but couldn't pinpoint it. I noticed that it
stopped when I stopped pedally and didn't resume when I started again,
just came on randomly. Had to be something to do with the hub but I
couldn't see why, also it was a newish wheel (18mths old and not often
used as I have a fleet of bikes) with sealed bearings and kept in good
maintenance so shouldn't have had any issues yet.
The other day a spoke suddenly broke, no biggy as I had 23 more. When I
stopped to remove the spoke and sort out if I could make it the rest of
the way home I also looked over the rim. Every nipple hole on the drive
side of the rear wheel was cracked!
This was a quality machine-built wheel and had performed well. However
somewhere in the manufacture, and likely because it was a paired spoke
24 hole wheel, the spokes were overtensioned. [snip]

Yet another reason why old hands tend to favor 32 as the minimum
number of spokes to have in a wheel that's intended for long-term use.


--
Typoes are a feature, not a bug.
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Words processed in a facility that contains nuts.

DD wrote:
I had an interesting noise coming from the rear of the bike recently,
tried to eliminate it but couldn't pinpoint it. I noticed that it
stopped when I stopped pedally and didn't resume when I started again,
just came on randomly. Had to be something to do with the hub but I
couldn't see why, also it was a newish wheel (18mths old and not often
used as I have a fleet of bikes) with sealed bearings and kept in good
maintenance so shouldn't have had any issues yet.
The other day a spoke suddenly broke, no biggy as I had 23 more. When I
stopped to remove the spoke and sort out if I could make it the rest of
the way home I also looked over the rim. Every nipple hole on the drive
side of the rear wheel was cracked!

interesting. did you get this wheel out of the box or had it been
"prepared" by your lbs? from what i can see, a lot of shops feel it's
necessary to "help" pre-built wheels by increasing spoke tension -
presumably following the misconceptions that tension should be "as high
as the rim can bear" and that increasing spoke tension increases wheel
strength.

if you have the wheel rebuilt, make sure you do your homework on the
manufacturer's spoke tension spec [call or website] and ensure your lbs
doesn't feel compelled to "help" your new wheel with tension in excess
of that. buy a $60 tensiometer and check it yourself if necessary. if
you buy a new wheel, same rules apply. personally, i won't buy one of
those branded pre-built wheel unless it's still in the box, unopened.
i've had no problems from the ones that remain untouched.

This was a quality machine-built wheel and had performed well. However
somewhere in the manufacture, and likely because it was a paired spoke
24 hole wheel, the spokes were overtensioned. What had this to do with
the hub noise? I took the freewheel off at home and checked the axle and
cones. I was unable to remove the axle but it was not bent or broken,
the cones still had the original green grease inside and no dirt or
brown grease however the axle turned roughly. Possibly this was the
intermittent noise? Weird.

P.S the rear wheel is probably a write off because of this
overtensioning. Death has spoke'n.
PPS not going to state the manufacturer's name, that's not the point as
there ar plenty of such wheelsets out there.

DD wrote:
I had an interesting noise coming from the rear of the bike recently,
tried to eliminate it but couldn't pinpoint it. I noticed that it
stopped when I stopped pedally and didn't resume when I started again,
just came on randomly. Had to be something to do with the hub but I
couldn't see why,

If you couldn't see why it had to do with the hub, maybe it wasn't the
hub? I've heard cracked rums make noise...

also it was a newish wheel (18mths old and not often
used as I have a fleet of bikes) with sealed bearings and kept in good
maintenance so shouldn't have had any issues yet.

Any guess on the mileage on this wheel?

The other day a spoke suddenly broke, no biggy as I had 23 more. When I
stopped to remove the spoke and sort out if I could make it the rest of
the way home I also looked over the rim. Every nipple hole on the drive
side of the rear wheel was cracked!
This was a quality machine-built wheel and had performed well. However
somewhere in the manufacture, and likely because it was a paired spoke
24 hole wheel, the spokes were overtensioned.

How do you know? Not trying to sound snotty - but there might have been
other causes for the cracks.

P.S the rear wheel is probably a write off

With cracks, the rim is certainly dead.

because of this overtensioning. Death has spoke'n.

.... or other cause for rim cracks...

What did the dealer say?

wrote:


If you couldn't see why it had to do with the hub, maybe it wasn't the
hub? I've heard cracked rums make noise...

Well, cracked rummies do moan and sing a lot.