Hot answers tagged

10

There is one major cause of this problem and it is putting a 1.8mm aka 15ga spoke in a 2.0mm/14ga nipple. This mismatch will screw together and hold under some tension, but then slip. It is easy to test. Obtain a known 15ga nipple. If it can screw on to your spokes at all, it confirms the problem. The same thing could happen with a 2mm spoke in a 2.3mm ...


10

The grooves/enlargement shown at the hub are all normal. The path to a wheel that doesn't break spokes is use premium quality spokes (DT, Sapim, and Wheelsmith are the usual poster children), set their line properly at the rim and hub, and stress relieve them properly during building. Fatigue breakages are almost universally the result of one or more of ...


8

Another common cause for spoke breakage at the J bend is low spoke tension, or preload. As you ride, the bike momentarily "hangs" from the topmost spokes on the rim. Because its a dynamic changing system, this load hands off to the next spokes around quickly. So every wheel revolution, a spoke is pulled tighter and then relaxed. If the spoke is ...


8

Using a high quality spoke key that engages on 4 sides (and fits properly) usually avoids this problem, even with coloured alu nipples.


7

Spokes typically break due to fatigue failure. Steel has a material property called the fatigue limit, which is the level of stress it can experience repeatedly without weakening. As long as the stress on the material does not exceed the fatigue limit, it is not weakened. If the material exceeds its fatigue limit, tiny cracks form, and repeated cyclic ...


7

I agree with Daniel’s comment, I’ve had success with using vice grips to hold spikes myself. Be careful not to use excessive force to prevent crushing the spoke. It may help to add a small “flag” made of tape to each spoke to help visualize spoke vs nipple rotation. Matt’s suggestion of using penetrating oil and heat is a good idea, provided you removed the ...


7

In Roger Musson's book Professional Guide to Wheel Building 7th Edition, https://www.wheelpro.co.uk/wheelbuilding/book.php this is covered in brief (for a dished rear wheel): The wheel can support more load before the left spokes go slack by making the right side spokes stiffer than the left and this is accomplished by using thicker (stiffer) spokes on the ...


7

Kilograms force. It is tension equal to a weight of that many kilograms pulling on the spoke under earth gravity.


6

I believe DT has a blanket recommendation of 1200Nm for all their rims, or 122 kg-f. You could email them to corroborate but that number should be safe. Use the tensiometer chart for the thin section of your spokes. By the same token, always position the tensiometer such that you're isolating a thin segment for measurement. If you had any of the thick ...


6

I recommend you take the bike to a bike shop and let them deal with this. Yes, you can get individual spokes, but they need to be exactly the right length, which is determined by the specific hub and rim you've got, and the lacing pattern. You probably do not need to rebuild the wheel with all-new spokes, but if you do, it will probably be cheaper to buy a ...


6

The main reason for reducing spoke count is to improve aerodynamics. This usually goes along with a deeper-section rim, which makes up for the strength lost with the missing spokes. Generally when there are fewer spokes, each spoke is at a higher tension, although that's not always the case. Highly tensioned spokes are more likely to be pushed past their ...


4

Spokes generally break when they are not tensioned enough, because they can then cycle from being taut and being loose as the wheel rolls, and because of this they fatigue and fail. Specifically, as the wheel rolls on the ground, when a spoke is pointing up, away from the ground, it does not carry any of the bike and rider weight and is tensioned, but when ...


4

Having done something similar myself last year, beware of damage to other spokes. I didn't break any at the time, but 2 snapped within 3km of each other, 150km later, and when I removed the cassette I could see that all the drive side outer spokes has chunks or of them. This was presumably where the chain ended up after smashing the plastic disc. A new rear ...


4

No this may not be correct. The Wikipedia sizes (0, 1, 2, 3) are Park Tool specific sizes. Park Tool SW-1 is 3.30mm. Whether or not your multitool uses the same numbering as Park Tool is anyone's guess. My understanding is that DT Swiss nipples all use 3.23mm (Park Tool SW-0, black tool). Of course your bicycle may have some other nipples than DT Swiss. If ...


4

The hub holes are elongated a little bit but I would not be concerned. It seems to me a pretty typical amount of deformation. I would reuse the hub but I would re-lace the hub with the same pattern. It's hard to say why the spokes failed but unless it happens repeatedly I would chalk it up to poor quality or defective spokes, or spokes that got unevenly ...


4

Get one of the spokes out ans measure its length. It is a primitive method, but by far the simplest one. Less accurately, you could try to measure it on the wheel and account for the hidden part in the nipple, but I would not recommend it.


3

Yes, it’s normal for spoke tension to decrease when the tire is inflated. First of all I’d use much more tension and try to get it more even. Currently you have about 30% difference between slackest and tautest spoke, which is a lot (I’d aim for ~10%, but I’m a perfectionist in that regard). 540N on the slackest rear spoke before you’ve even inflated the ...


3

Honestly its not a lot of work to take a spoke off and measure it properly. Get several spare spokes, and note down the length for next time. If you measure a non-drive side spoke off the rear wheel (they're easier to get off, remember the driveside ones are slightly shorter, by about 1~2mm but many rear wheels can get away with the same length. Another ...


3

There are a bunch of spoke-length calculators online (here's one). This tells you what your spoke length should be, not what it is. You'll need to have exact measurements for the current hub and rim, although the calculator I linked to has a database of measurements you can look up.


3

It sounds as if the holes in your hub are close to the 2mm size of the spoke. This is fairly common, and the way I deal with it is to slightly bend the spoke while I'm lacing it. The goal is to get the J bend to be slightly more than 90 degrees, but normally what you actually get is a slight bend about 5mm past that. It will be hard to do that once you have ...


3

Internal rim width difference would change the tire profile, and thus volume as well as the direction force is put on the casing, which could have a significant effect on how/how well it dampens vibration. A difference in the volume of the rim well is also going to change the air volume of the "tire" (tube) which will have an effect. Side note: ...


3

To answer this question, you need some measurements. The rim ERD, from the Ryde website. The centre-to flange (left and right) measurements of the hub and the spoke hole circle diameter. These you may need to measure yourself as they are not always published. This information is then entered into software (or a website) that performs the spoke length ...


3

Yes, it's normal and you correctly understand why. Some straight pull hubs can create more variance in bracing angle per side than a j-bend hub would. Other straight-pull designs (Velomax/Easton comes to mind) put the spokes in a straight line, creating the least of this variance possible. On a j-bend hub, there is also some amount of this effect. But, it's ...


2

How much tension did you put on them? Since they broke at the rim, was it the nipple which broke or really the spoke? In any case you probably had insufficient tension on the non-drive side spokes¹. You should go as high as possible. This means tensioning the drive side spokes up to the maximum allowed tension (usually 1200N) and then truing and dishing the ...


2

Lots of good answers here. Generally higher tension is better. Equal tension between spokes is also important. I bought a tensiometer from eBay for $30 and it got my wheel much rounder and truer than my previous attempts. Maybe if you're really experienced, you won't need to consult it often, but it really helped me. I saw on park tools website that you want ...


2

A bit late getting onto this, but I am looking at exactly the same problem. It is like under high pressure (110psi in my case) the inner tube is pressed out through the spoke hole and I guess becomes so thin it bursts. It cannot be a spoke puncture as the tape is still ok with no signs of being punctured. I have ordered high pressure 120psi rim tapes and ...


2

I've laced my wheels without a physical crossing for years, for the simple reason that I use sound to judge spoke tension. With a musical ear, it's quite easy to build a wheel with very even spoke tension, but it requires that every spoke can vibrate on its own. You can't tune spokes when they touch. Building a wheel with even spoke tension and interlacing ...


2

Because I was riding without truing the wheel This. When the wheel went from true to not true, some spokes lost tension while others gained tension. Otherwise the wheel would have remained true. And uneven spoke tension is the recipe for broken spokes. That said, jumping curbs is generally not the toughest thing spokes have to endure. That title goes to ...


2

If you still have the old spoke and both/all its parts then that can be used for measuring the length. If that's not possible, as per Daniel's comment, then remove the next spoke that goes to the same side of the hub as the broken spoke - this is important on the rear wheel because the two sides can vary by several millimetres. If you're buying one spoke, ...


2

Sure you can replace spokes yourself. You will need the correct spokes and a spoke key that fits your nipples. You also need a way to remove your freewheel. However a rim that permits the spoke nipple to pull through the metal sounds extremely sketchy. I would not ride that rim. Your rear mech is stuffed. It will never work right again, so other than ...


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