rousseau

Yesterday I noticed a pinging sound from the back wheel when I was grinding up hills. Today I'd planned to do a quick recovery ride, but nixed that because both the front and back wheels were pinging, and more loudly at that.

On a hunch, I tightened up the spokes on both wheels. They did indeed seem to be looser than normal, and even before the pinging started I seem to recall having felt that the bumps in the roads felt worse than normal. After tightening the wheels I did a test ride, and the pinging was gone. The sense of diagnostic accomplishment was gratifying.

But only partially, and here's my query: Did I not tighten the spokes enough in the first place? I don't have a spoke tensioner, but I tightened them to what I thought was a reasonable tension. I built this pair of wheels 2,073 kms ago, my first wheel build. Should I expect that the spokes will loosen every 2,000 kms or so as a matter of course?

Yellowbeard

I ran into this problem, too, except my wheel only made it about 30 km. I guess I should still be worried.

I re-dished my rear wheel in the fall and noticed the bike felt weird on my way to archery practice three days later. Heard the pinging on the way home and then realized the weird feeling was a pronounced shimmy. Got off the bike and found the loose spokes. Still unsure why they came loose.

Veloraptor

Pedaling puts reverse forces on the spokes,specially when you are climbing hills or mountains. I would use some locktite on spoke threads if they keep coming loose. If the wheels are pinging then you know the Park Tool Website spokes are too loose.

wmodavis

Low tension in a wheelbuild will result in the spokes loosening further. That is why a tensionmeter is soooo... important especially early in your wheelbuilding career to help you know what the tension is (should be around 100kgf or whatever max the rim manufacturer recommends), and to help you get the feel for the proper tension. A highly tensioned wheel is the best way to achieve a durable and strong wheel. A loosly tensioned wheel is the best way to get trouble. Knowing what the actual tension is worth its weight in gold as assurance that you have done it right. Guessing or seat-of-the-pants tensioning doesn't give that assurance. Locktite on the threads makes you feel secure even with an improperly tensioned wheel - but it's only a feeling!

interested

"pinging" sounds are a diagnostic sound of spokes unwinding. The problem is simply that when you assembled the wheels the spoke began to twist and wind up when you started to tighten the nipples. When you where "grinding uphill" these movement rocked the rims in the lateral plane. This in turn unloaded the spokes and allowed them to untwist at a rapid rate (the pinging sound).

A tensiometer wouldn't have helped you at all regarding spoke wind up, since twisted spokes "feels" as tight as the untwisted spokes. It is likely that you had reasonable tension to begin with, but that the untwisting made the spoke come loose.

Here is a cure:
Avoid spoke wind up to begin with
Lubricate all interfacing parts; nipple, nipple well and spoke threads when assembling a wheel.
When turning the spoke key a 1/2 turn to tighten the nipple, then immediately back off a 1/4 turn in the opposite direction. Off course this is only needed when the spokes starts to become tight.
Use some tape to make flags on a spoke or two so you can visualize the spoke wind up and how backing off helps unwinding it. (some use a marker on the spoke to do the same).
You can take out some spoke wind up by putting lateral pressure on the rim, like pushing the wheel against a hard surface while holding on to the rim, but this is best avoided or done carefully since it can destroy the rim if overdone.

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Regards

interested

No. All bicycle wheels should never have to be touched again after assembly for any normal use. Spokes breaking or coming loose without exterior causes are faults with either the materials (rare) or assembly.

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Regards

rousseau

Yep, I do this.

I do this, too.

The consensus is that I hadn't reached the proper tension with the wheels, it looks like. I guess I'll have to invest in a tensiometer at some point.

interested

Not consensus since I disagree . Pinging sounds are the most likely caused by unwinding spokes, not loose spokes (why should they make such a sound?). The "ping" or "pop" sound comes when the spoke overcome the friction by which it is held fast and "jumps" to its new position.

https://www.myra-simon.com/bike/wheels.html
"This releases the tension on the lower spokes just beneath your hands and lets them unwind if they've got wound up, making a pinging sound"

https://www.crazyrides.com/apps/maste...en.asp?LCID=en
"The second is spoke windup created during tightening, which produces an artificially correct tension level. When wound-up spokes untwist and release their extra tension, they ping the first time the wheel is ridden. In effect, that's the sound of the wheel going out of true."

Spoke untwisting due to wind up when climbing (lateral stress) is also a classic case. Of course there are other causes to why wheels may creak/ping/pop, but the most likely cause to why your spokes suddenly became loose are IMO spoke wind up, not too low tension in it self.

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Regards

rousseau

Thing is, two things:

1. This wasn't a one-time pinging sound on my short ride yesterday, it was constant. While I certainly understand the logic you quote in your post, by that logic it seems my spokes should have completely unravelled by the end of my ride. My (admittedly somewhat uneducated) guess is that the three or four spokes giving forth with a syncopated symphony of pinging were loose enough that the friction of the nipples against the eyelet produced the sound with each pass of the wheel. Does that sound reasonable?

2. I do indeed use the flag method for monitoring spoke windup while tightening spokes, a lesson I learned because my first attempt at wheel-building resulted in mucho pinging within the first five seconds of the initial ride (and no subsequent pinging--a very different scenario from my current situation).

Somehow my spokes came loose over 2,000 kms. As far as I can tell the best reasoning for this would be that I hadn't tightened them to the proper tension in the first place.

Al1943

Loose spokes ping whether unwinding or not.
Any change in spoke tension effects lateral true, radial true, and dish; maybe a little, maybe a lot.
Spokes can loosen for a number of reasons including insufficient tension, poor spoke/nipple fit, rough roads, and cracking in the rim adjacent to the nipple.
A tensiometer is very good to use but not essential.
Check for cracks in the rims near the spokes. These are fatal to the wheel.

Al

Panthers007

I would have someone who builds wheels look - with a tension-meter - at wheels thay do this. And have them brought to proper tension and stressed.

conspiratemus

Spokes that are too loose do indeed ping, even when not unwinding, but the OP is right: it's a different ping from the creaky ping of turning nipples. We were on a supported tour last year and met another couple with a brand-new tandem whose rear wheel pinged continually. I palpated around his wheel and realized one spoke was completely slack and the one next to it on the same side was way too tight, (which is why the 40h rim didn't wobble -- yet.) Since we had just met and they had no reason to trust that I knew what I was talking about, none of the four of us wanted me to get out my spoke wrench and winkle away at their wheel. So he eventually approached the tour leader, who did exactly that, tightening the loose spokes -- there were more than one -- and balancing the tension. Quiet wheel for the rest of the tour.

rousseau

I should add that I lately did several 15-minute trips over jarring, uneven sidewalk, and that I'm not exactly, shall we say, built like Michael Rasmussen. Unless anyone stops me, I'm going to surmise that insufficient tension combined with rides over terrain that would do Paris-Roubaix proud have served to loosen my wheels to the point of pinging.

P.S. I used to live in Hamilton.

vredstein

It is interesting that these wheels started pinging after much use. But if the pinging is indeed individual spokes loosening, it's a chain reaction.
All spokes are under their individual tensions. Builders try to get them as even as possible, but there's always some difference. All the spokes have a different amount of friction between the nipple and the spokes threads, and between the nipple and the eyelet.
Let's say you purposefully built a 32-spoke wheel with all the spokes under tentioned, but all the spokes pretty much under equal tension. You build this wheel applying locktite to 29 nipples, no lube at all to one nipple, grease to one nipple, and oil to one nipple, I'd think that that oiled nipple would be the first to come loose, followed by the greased nipple, followed by the unlubed nipple.
On a wheel like yours, where all nipples are lubed, they still aren't all lubed exactly the same, they all have a tiny difference in the amount of friction on the spoke threads and the nipple/eyelet interface. So the one with the least friction will probably loosen first. I'd think this would put more stress on the rest of the spokes, causing a spoke with a little less friction than the others to loosen. And so the chain reaction goes on. This affect is magnified on an undertensioned wheel. This could explain why you hear multiple "pingings".
They say you learn more from your mistakes than your successes. I have a spare rim, hub, and tension meter, so I just might build a wheel like the one I described and see what happens.

rousseau

Sounds like an interesting experiment. I hope you keep us posted.

Further to truing, I'm getting a bit tired of using a square piece of tape as a flag for monitoring spoke-winding, as after a short while it loses its adhesiveness and I have to press it harder against the spoke with my thumb to make it stick. Yeah, I know, my grandparents survived the Communist Revolution in Russia and escaped to Canada by the skin of their teeth, so it's not really a hard life I lead, but still...would anyone have any better ideas for a spoke-wind indicator?

vredstein

Alligator clip.

rousseau

Hey, neat!

rogerstg

I give the spokes a swipe with a sharpie to get a reference mark. When done I just wipe it off with alcohol.