Spokes coming loose

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Spokes coming loose

Postby msg » Wed May 09, 2012 9:13 pm

What is the best way to stop the spokes on my bike from coming loose. Twice now the some spokes on the front wheel have become so loose that they have almost fallen out. It is about 3-4 spokes opposite from each other. Do you just tighten them up and use some loctight on them or is there a bigger issue here.
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by BNA » Wed May 09, 2012 10:09 pm

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Re: Spokes coming loose

Postby rkelsen » Wed May 09, 2012 10:09 pm

What tyre pressures are you running?
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Re: Spokes coming loose

Postby rustychisel » Thu May 10, 2012 1:46 am

uneven spoke tension. You don't say what wheel, what spoke configuration, which can be a critical factor, but the simple answer is you need to address the issue with a 'whole wheel' view rather than individual spokes.
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Re: Spokes coming loose

Postby msg » Thu May 10, 2012 6:05 am

It is the front wheel, runnnung 100psi, 32 spoke, 700c, brand new in febuary, each time it haqs happened it has gone back to the lbs that it was bought from. They have retensioned all the spokes and retrued it. Then a couple a hundred kms later the spokes are loose again
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Re: Spokes coming loose

Postby rkelsen » Thu May 10, 2012 10:21 am

Are you running 23mm tyres?

I don't think it's tensioned properly.
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Re: Spokes coming loose

Postby jacks1071 » Thu May 10, 2012 10:31 am

Uneven and/or insufficient spoke tension would be the likely culprit.

Once the wheel is built up properly you can apply some locktite, that should only be required with a radially laced wheel though. If you have a 2 or 3 cross on the spokes the locktite shouldn't be required if the wheel is built and tensioned properly.
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Re: Spokes coming loose

Postby rustychisel » Thu May 10, 2012 10:32 am

It needs a rebuild. Slackening all spokes off then retensioning and STRESS RELIEVE before final truing. For more on this consult Sheldon Brown or Jobst Brandt, or one of the excellent wheelbuilders who inhabit this forum. Lazy LBS monkeys are more likely to use loctite on nipples, which neither addresses the poor build quality nor helps when you need to have it retrued down the track.
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Re: Spokes coming loose

Postby WestcoastPete » Fri Mar 15, 2013 12:11 am

Buried thread hijack!

I have a situation on my mate's bike where ALL of the spokes on his rear wheel are coming loose. He bought it over saying he had a buckle, and when I touched a spoke, it felt so loose that I thought it was broken. It turns out that they were pretty much all like that. Weird. Anyway, I unthreaded all of the spokes to equal-ish loose tenions, like when lacing up a new wheel, then retensioned it in my truing stand, using my tension gauge to ensure that things were reasonably equal (dished wheel, so tighter on the RHS than the LHS). Stress relieved as usual. Apparently it only lasted a few days, and now he's dropped it back over and the spokes are so loose, they could almost fall out. So loose!

My intention is to retrue it again, probably using linseed oil to help prevent loosening, but I'm not convinced this will hold. I can't understand why a perfectly good, well tensioned wheel would unthread like this. Does anyone have any ideas?

Let me outline the situation:

- The bike is a few years old, well used, and has never had a problem like this before
- It's 32h, 3-cross, 9sp cassette, machine built, from a Giant CRX 3
- I've learned recently that the bike was on the roof of a car, facing backwards, and - you can see what's going to happen here huh - driven into something in a car park. Nothing too dramatic apparently, but this was about a month before my mate noticed a buckle. There is no evidence of damage to the bike or the rim. I can't see how this is related.

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Re: Spokes coming loose

Postby Baalzamon » Fri Mar 15, 2013 12:41 am

How did you stress relieve?
I typically wind up a spoke twice as much as I intend then back off to what I intended increasing the spoke tension that way
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Re: Spokes coming loose

Postby biker jk » Fri Mar 15, 2013 8:59 am

What spoke tension did you get to on the drive side? For a 32 hole box section rim (such as a Mavic Open Pro) you should have 95-105kgf. If the spoke tension is sufficiently high and you stress relieve then no thread locker is needed.
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Re: Spokes coming loose

Postby WestcoastPete » Fri Mar 15, 2013 11:12 am

I had about 110Kfg to 130Kfg on the drive side. I stress relieved by overtensioning and then winding back. I also used the Jobst Brandt "strong grasp midspan of spoke pairs" method, and a hammer handle used as a light lever. This has worked for me every other time.

Even if I hadn't done these things properly, I can't see why EVERY spoke would come loose, especially this loose. That's the main thing that I'm finding confusing.
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Re: Spokes coming loose

Postby biker jk » Fri Mar 15, 2013 5:57 pm

WestcoastPete wrote:I had about 110Kfg to 130Kfg on the drive side. I stress relieved by overtensioning and then winding back. I also used the Jobst Brandt "strong grasp midspan of spoke pairs" method, and a hammer handle used as a light lever. This has worked for me every other time.

Even if I hadn't done these things properly, I can't see why EVERY spoke would come loose, especially this loose. That's the main thing that I'm finding confusing.


Well clearly you had sufficient tension. As such, the only other potential cause could be a defect in the rim (cracking, brake track worn thin) such that the wheel isn't rigid under load and allows the spokes to lose tension and they unwind. Also, if the rim is compromised and you inflate the tyres this could also make the spokes go lose.
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Re: Spokes coming loose

Postby rkelsen » Sat Mar 16, 2013 9:26 am

WestcoastPete wrote:My intention is to retrue it again, probably using linseed oil to help prevent loosening, but I'm not convinced this will hold.

Soft Loctite might help.

I keep banging on about the same thing, but what tyre pressures is your mate running, and how much does he weigh?

This was also a recurring problem for me. It happened on 3 different [machine-built (hey - i'm a tightwad)] rear wheels. My problem turned out to be excessive tyre pressure, as evidenced by the fact that 22,000km after lowering my tyre pressures the problem hasn't resurfaced.

Nowadays I run 90psi on the roady with 23mm tyres and 45psi on the commuter which has 32mm tyres.
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Re: Spokes coming loose

Postby kukamunga » Sat Mar 16, 2013 10:01 am

Loctite 290 is low-strength (green?) and high-wicking and recommended for nipples post-building/tensioning. Available through Bike Box (Schwalbe).

Linseed Oil is highly discouraged as a lubricant or otherwise in wheelbuilding by the ex-WheelCraft (Dirtworks) DT wheelbuilder. Graphite powder with fork oil or Tri Flow is highly recommended

Otherwise, it sounds like new rim time
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Re: Spokes coming loose

Postby WestcoastPete » Fri Mar 29, 2013 3:43 pm

I think we've actually found a reason for this problem!

So my mate brought the bike back with it's super-loose spokes and I retrued it again. I didn't add any threadlocking type stuff for a few reasons, the least of which being that I couldn't rationalise why it was needed. He came and picked it up today, and when I was going through it with him, he squeezed the brake lever (v-brakes) and the rear wheel deformed to the left. "Do that again!" I said. Sure enough, the right brake pad pushed the whole rim over to the left when he squeezed the lever. This action presumeably removes all of the tension from the non-drive side spokes and they gradually work themselves loose. It fits in with the rest of the story of how the bike was driven into one of those carpark things while it was mounted on the roof of a car a month or so before the initial problem became evident, and it had been trouble free for years prior. The frame doesn't look obviously bent, but the wheel certainly didn't sit in the dropouts perfectly; it was only out by a millimetre or less, but it was enough for it to be offset in the frame.

For now, he'll ride it and I'll keep my eye out for a replacement frame. He'll try to lay off the rear brake, but that freaks him out a bit, despite my encouragement. He's also found that he really enjoyed riding the old road bike I leant him, and is kinda interested in something that stretches him out a bit more, so we'll look at a new bike as an option as well.
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Re: Spokes coming loose

Postby drubie » Fri Mar 29, 2013 8:21 pm

You should adjust the v brakes so they are centred on the rim. Its quite easy. I think I'd be running a string line through the rear dropouts and checking the frame alignment.
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Re: Spokes coming loose

Postby WestcoastPete » Sat Mar 30, 2013 10:50 am

drubie wrote:You should adjust the v brakes so they are centred on the rim. Its quite easy. I think I'd be running a string line through the rear dropouts and checking the frame alignment.


I did attempt to do this, but the guy had to go and I couldn't adjust it far enough without changing the washer setup and maybe the spring tension in the brake. We discussed the string method too, to confirm or suspicions, as well as dropout alignment tools, but I'm pretty confident in the diagnosis.

The frame is aluminium, so not really a cold set candidate. I'll keep an eye out for a replacement frame for now.

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