What causes loose spokes

[dodgeman]

I have been getting that ping-ping noise on occasion and it’s an occasional loose spoke. What exactly causes this? I assume it’s just like and nut and/or bolt that can loosen on its own from vibrations or impacts?

 

[indianajo]

There are real steel spokes that rarely stretch unless the rider is extremely heavy, or jumps curbs, picnic tables, tall rocks or stacks of pallets or whatever. Impact can stretch even good spokes.
I experienced spoke stretch on pedal bikes that cost <$200 at the discount store. I weighed 210 lb at the time and didn't jump anything. From all the loose spoke complaints on some brands of ebike, some <$2000 ebike brands buy these same spokes. Grey metal can contain lead, aluminum, zinc, copper, all sorts of scrap that doesn't have any tensile strength. I have had to re-tension a few very thick spokes on geared hub motors built into a power wheel. These obviously came from *****. The spokes from ***** on my original Yubabike wheels, I have never had to tighten one. So it is not just country of origin that predicts tensile strength.
One brand of real steel spokes I have personally bought is DT Swiss. They were not cheap. They were 14 gauge, not extra thick. They were made in USA. I laced them into a wheel containing a Sturmey-Archer 8 speed IGH. Other people brag about Sapim spokes.
Every time I change a tire I tap around the wheel with the screwdriver listening to spoke tension (pitch). That is how I caught the loose ones. I retighten them to the same pitch, unless a bent rim requires some on one side to be tighter than the other side.

 

[scrambler]

Spokes can loosen with usage.
That can be made worse if they have not been tensioned properly, and or were installed without spokeprep

 

[dodgeman]

My bike is a Trek Verve +3 with 3600 miles on it. The loose spokes has just started happening, 2 have gotten loose. The bike is rated for 300 pounds including the bike and me and the bike are probably 295. I also ride on paved roads mostly but they are pretty rough.

 

[smorgasbord]

Spokes can loosen with usage.
That can be made worse if they have not been torqued properly, and or were installed without spokeprep

To expound on this a bit further, wheel diagnosis is actually pretty complicated. We would like to think our wheels are built like DT Swiss:

But most are probably built with some machines like this:

Or worse.

At any rate, spokes can stretch, the elbows deform, or hitting bumps can deform the rim causing spoke tension to be lost/gained. Park Tool sells a spoke tension device you can use to check your wheels:

I took the cheap way out and bought a cheapie Chinese tension gauge but used Park Tool's web app. For building new wheels, I'd spend the money on the Park, but for checking existing wheels you just want to sure the "relative tension" is consistent among all the spokes on each side.

 

[m@Robertson]

Its also from just plain squishing the rim a touch as it goes over and down the road. A series of pushes and pulls on the spokes that just plain works the nipple a teensy hair so it turns and loosens.

 

[JRA]

After building many wheels over the years that never had spokes break/loosen I would blame it on a poor wheel build to begin with. In fact I don't use a tension gauge although I tried one years ago. There are steps you make while building such as pre-stressing the wheels a few times side to side and having a feel for tension based on experience. Most wheels are machine built and put in the box and if upon receiving them one would go through them they would have less issues. Quality components also make a difference.

 

[smorgasbord]

After building many wheels over the years that never had spokes break/loosen I would blame it on a poor wheel build to begin with. In fact I don't use a tension gauge although I tried one years ago. There are steps you make while building such as pre-stressing the wheels a few times side to side and having a feel for tension based on experience. Most wheels are machine built and put in the box and if upon receiving them one would go through them they would have less issues. Quality components also make a difference.

Yeah, I know the DT Swiss video is long, but near the end they show how the wheels they build are put through a side stress machine as one of the steps. Hand built wheels are the best.

 

[kevinmccune]

Yeah, I know the DT Swiss video is long, but near the end they show how the wheels they build are put through a side stress machine as one of the steps. Hand built wheels are the best.

I like mags.

 

[indianajo]

My bike is a Trek Verve +3 with 3600 miles on it. The loose spokes has just started happening, 2 have gotten loose. The bike is rated for 300 pounds including the bike and me and the bike are probably 295. I also ride on paved roads mostly but they are pretty rough.

Trek certainly shouldn't be buying or shipping garbage. My yubabike has ~12000 miles with no spoke problems on the yuba wheel. The gross weight is up to 330 lb with groceries & ag supplies as cargo.

 

[AHicks]

My bike is a Trek Verve +3 with 3600 miles on it. The loose spokes has just started happening, 2 have gotten loose. The bike is rated for 300 pounds including the bike and me and the bike are probably 295. I also ride on paved roads mostly but they are pretty rough.

You're due for a visit to somebody that's familiar with wheel building. Done properly, that should end your spoke issues IMHO. Don't let some rookie replace or adjust one loose or broken spoke. One of those is indicative of a larger issue.....

Beyond that, how that wheel builder comes up with a solid true build, there's a few ways to do that. Some use a gauge (like me), and some do it by ear (I must be tone deaf). Whatever works for the guy doing it is all I'll say.....

Done right, this should not be an ongoing issue for most of us that don't ride a bike 10k miles a year, or something WAY heavy. I'm 300 by myself, and having no spoke troubles, but I had to learn the above the hard way. Ended up learning how to do it right myself. -Al

 

[PDoz]

My bike is a Trek Verve +3 with 3600 miles on it. The loose spokes has just started happening, 2 have gotten loose. The bike is rated for 300 pounds including the bike and me and the bike are probably 295. I also ride on paved roads mostly but they are pretty rough.

If your wheels are bontranger alloy , they come with a 2 year warranty , carbon come with " lifetime" ( life of bike) . So if you within the specified rider weight limit , and it's under 2 years old, go visit your trek dealer before touching the spokes

 

[Stefan Mikes]

My bike is a Trek Verve +3 with 3600 miles on it. The loose spokes has just started happening, 2 have gotten loose. The bike is rated for 300 pounds including the bike and me and the bike are probably 295. I also ride on paved roads mostly but they are pretty rough.

28 or 32 spokes?

So if you within the specified rider weight limit , and it's under 2 years old, go visit your trek dealer before touching the spokes

This.

 

[TrevorB]

Trek certainly shouldn't be buying or shipping garbage. My yubabike has ~12000 miles with no spoke problems on the yuba wheel. The gross weight is up to 330 lb with groceries & ag supplies as cargo.

With ebike should be tensioning rear wheel every 6 months, especially on cheaper models. Once spokes start breaking really up for rebuild which should result in stronger wheel. I've broken few spokes on my Trek 29 ebike none on higher mileage 27.5" Cube and Moustaches (10,000km). Suspect it is cheaper build quality not larger diameter which is reason Trek breaks spokes.