Loose spokes

TimC said:

My new el-cheapo alexrims wheel has always been a little flexy, but for a few weeks now, has been continually loosening off one spoke in
particular -- I discovered this when the wheel became warped enough to
touch the brakes. The spoke had completely come loose form the
nipple. Tightening that back up brought the wheel back into
almost-true, but it keeps on loosening itself every couple of days or
less.
.

My first suspicion would be spoke wind-up, but I've never seen one quite that bad. Still, it's an easy fix so it won't hurt you much to start there. Fold a piece of tape over the spoke so that it forms a flag, then tighten the nipple. If the spoke starts twisting significantly find yourself a pair of pliers with not too abusive jaws and use them to keep the spoke from turning as you turn the nipple. Or , you can keep track of how the flag pointed when you started turning and then back down on the nipple until the flag is back in its original position after you've tightened it. If that doesn't do the trick find yourself something to use as thread lock. Either the real stuff (in the mild form) or a drop of enamel or some other paint will usually do the trick.

TimC said:

My new el-cheapo alexrims wheel has always been a little flexy, but for a
few weeks now, has been continually loosening off one spoke in particular

Possibly either spoke or nipple is out of spec, but it's more likely a
case of insufficient tension. Threads lock by a very slight elastic
deformation. Too little tension and you won't get that lock, and things'll
move. Machine built wheels are notorious for having too little tension.

Given you're reasonably happy with tweaking nipples (ooo-er guvnor), I'd
get it true, then put a turn or so on to every spoke. You'll probably need
a retrue after that.

Two more things to do - Destress and unwind. Destress the spokes by
massively overtensioning them - get an old crank or a big shifter and use
it to wrap pairs of spokes around each other so the tension is roughly 1.5
times normal on that pair - Sheldon's site has a picture of this process.
Unwind them by putting the wheel on the ground, then putting a wheel on
each side and leaning on it. Rotate and repeat until it stops pinging,
then flip the wheel over to the other side and do the same thing. Check
the true again.

If after that one spoke still gives you grief either replace it or try
loctite.

--
Dave Hughes | [email hidden]
Lithospheric flight paths typically result in extremely high drag
coefficients, often quite a bit in excess of design parameters.
- Rick Dickinson

TimC said:

My new el-cheapo alexrims wheel has always been a little flexy, but
for a few weeks now, has been continually loosening off one spoke in
particular -- I discovered this when the wheel became warped enough to
touch the brakes. The spoke had completely come loose form the
nipple. Tightening that back up brought the wheel back into
almost-true, but it keeps on loosening itself every couple of days or
less.

Would this be related to the relative flexiness of this particular
wheel (same model as the stock wheel on the OCR3, of which I didn't
originally have a problem)? And what is the cause?

Can't see anything obviously wrong with tensions. The tension of the
spokes on the non-drive side is much lower than the drive side (I know
they are meant to be lower, but don't know about "much" lower). Not
even all the way around, but not varying by a large amount.

Dunno. I go ogled, but didn't find an answer.

--
TimC
Confucius say: He who play in root, eventually kill tree.

Hi Tim

Needing to have the rear wheel trued every 2 weeks at LBS is where my problems started.
I have just replaced my rear rim.
The Alex ACE 19 (not DA16 typo in other thread) had 6 spokes in a row start to pull thru the rim and it was obvious as there were cracks and bulges beside the eyelets.

Have replaced it with a Mavic Open Pro. I am VERY happy with it and will get the front replaced soon. Acceleration and fast cornering especially have improved noticeably.

Fortunately Avanti were very good about a waranty claim on a 15 month old bike. They came up with the price of a Mavic A719 and I paid extra for the upgrade to Open Pro as the A719 does not accommodate 25mm tyres or 100psi+ which is my preference.

I suggest a very close inspection of the rim around the spoke holes to see if you are suffering the same problem.
If the wheel is fairly new probably best to take it back to the LBS and have them look at it and perhaps lift the tape to see if any nipples are sunken deeper in the rim.

Dont know if its fact or fiction but heard that there was a problem a while back at the Alex factory where a large number of wheels went thru the machine tensioning process twice and that there have been more failures in this batch than wheels tensioned once as specified. Rumour ?

My previous thoughts on this.
cyclingforums.comt318654.htmlOpen ↗

Hope it gets sorted out quickly.

Cheers
Hugh

you can get 'Pro Lock' nipples that have Loctite already in them

531Aussie said:

you can get 'Pro Lock' nipples that have Loctite already in them

My wife has a very bad sore throat and I haven't slept well because of it
(she has slept much worse), so my eyes aren't too focussed this morning.

I read "Pro, nipples, Lotte". Oops, sorry Lotte.

Theo

On 2006-03-17, Random Data (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

Two more things to do - Destress and unwind. Destress the spokes by
massively overtensioning them - get an old crank or a big shifter and use
it to wrap pairs of spokes around each other so the tension is roughly 1.5
times normal on that pair - Sheldon's site has a picture of this process.
Unwind them by putting the wheel on the ground, then putting a wheel on
each side and leaning on it. Rotate and repeat until it stops pinging,
then flip the wheel over to the other side and do the same thing. Check
the true again.

Hrm. I don't quite grok your explanation, and I don't grok Sheldon's
picture. I *used* to have a mechanical mind, dammit (but then again,
I used to have a mind that liked computers).

I've currently got the wheel sitting at the shop, and they agree it's
an "interesting" wheel. The non-drive side spokes seem to be
massively undertensioned.

Yesterday on the BR, a second spoke had worked its way loose. Within
about 2 minutes of me fixing that one, the original trouble maker came
loose -- and entire 2 minutes to go from completely tight to
completely loose!

Later on, when heading home, a spoke broke.

The stock alexrim wheels were great, this one seems to be a lemon.

--
TimC
Stapp's (of Murphy's law fame) Law: the universal aptitude for
ineptitude makes any human accomplishment an incredible miracle.

TimC said:

Hrm. I don't quite grok your explanation, and I don't grok Sheldon's
picture. I *used* to have a mechanical mind, dammit (but then again, I
used to have a mind that liked computers).

Hear that, Sheldon? He's dissin' your artwork!

The idea is that you want to make the spokes "longer" than they should be.
You want to (temporarily) put silly high tension on to get rid of any
weird stresses that the spokes have due to the manufacturing process.
Brandt explains it a lot better, and I think if you google "Brandt spoke
stress" you should be able to find sme info. yarchive.net or .org comes to
mind, but I must get around to importing my bookmarks....

Anyway, to tension the spokes you stick a large lever in the point where
two spokes cross (the rim-most cross on a standard 3cross build) and use
it to twist the spokes around each other. So you push the spoke that
crosses to the inside "out" and the spoke that crosses on the inside
"in". You've then got curved spokes where they were straight, so tension
goes up. The lever is so that you can move the spokes more than you
otherwise could.

The second part is the way to alleviate spoke wind-up. That's where
there's enough friction between the various interfaces that their is a
rotational tension on the spoke - you wind on a turn of tension, but it's
trying to unwind itself by about a quarter turn. By *detensioning* the
spoke - say by deflecting the rim slightly toward it - you reduce the
friction and let the spoke unwind itself. If you've ever jumped on a newly
trued or built wheel and heard it ping, you've heard the spokes unwinding.
Generally doesn't make a huge difference, but it's annoying.

Quoted message said:

I've currently got the wheel sitting at the shop, and they agree it's an
"interesting" wheel. The non-drive side spokes seem to be massively
undertensioned.

Hey, maybe I'm not full of [censored]! It could also be related to the incidents
HughMann was talking about.

--
Dave Hughes | [email hidden]
Thus leading us to the obvious conclusion that all software should look
like a nipple. - Eric the Read

On 2006-03-18, HughMann (aka Bruce)
was almost, but not quite, entirely unlike tea:

Quoted message said:

Fortunately Avanti were very good about a waranty claim on a 15 month
old bike. They came up with the price of a Mavic A719 and I paid extra
for the upgrade to Open Pro as the A719 does not accommodate 25mm tyres
or 100psi+ which is my preference.

Yay Peter Moore!

He replaced every single one of my spokes with higher specced DT
spokes. $20 (SAIT, no wrong froup) for the spokes, rebuild, truing,
the lot.

I've found that competant LBS I was looking for. Learnt my lesson now
-- don't go to the big chains, whatever you do. The more shiny the
shop, the less trustworthy (mostly).

--
TimC
A bug in the code is worth two in the documentation. --unknown