Stupid question about spoke lengths

[cribbit]

Just built 2 wheels that I carefully measured and put through the online calculator. Both have ~2mm of threads showing.

I'm reading a lot of conflicting opinions on this online. Some people say I'm going to have the wheel explode underneath me. Others say it's totally fine.

So - am I going to die or never notice the difference?

[weisan]

Yes you are going to die, eventually. Everyone does.

No, you will never notice the difference.

[David Kirk]

The issue isn't typically with the spoke but instead it's with the nipple. If the spoke isn't using most (or ideally all) of the nipple threads the nipple can fail.

I'd do a little bit of measuring to be sure that you aren't just using a few threads in the nipple.....failure is a bummer if one nipple breaks and a serious bummer if you hit a bad bump and have a number of them go. I've seen it happen and it never ends well.

dave

[cribbit]

The issue isn't typically with the spoke but instead it's with the nipple. If the spoke isn't using most (or ideally all) of the nipple threads the nipple can fail.

I'd do a little bit of measuring to be sure that you aren't just using a few threads in the nipple.....failure is a bummer if one nipple breaks and a serious bummer if you hit a bad bump and have a number of them go. I've seen it happen and it never ends well.

dave

I'm using more than half. What would you say is the lowest amount of threads you'd go? I'm using DT Swiss double butted spokes with 1cm of threads, in brass DT Swiss nipples.

[marciero]

I'm assuming that you mean the threads are showing on the inner part of the circumference; that is, spokes are too short, rather than too long?

What does it look like on the rim bed side? How far below the tops of the nipples do the spokes end? In addition to the number of threads engaged, I have heard that it is important to engage the top portion of the nipple that is embedded in the rim, so that the spoke penetrates the rim. This seems reasonable- it insures that the load is supported by the unified structure of spoke, nipple, rim. Unless that happens the nipple alone must support the load in that small section. It's not designed to do that. Even if you had lots of threads engaged, which you dont-see below, it can still fail. So you would not want the spoke ending more than about 1mm below the nipple top.

And regarding the number of threads, keep in mind that the threads dont even start until a millimeter or two into the nipple. You have 10mm total, and between the 2mm exposed and 1 or 2 inside the nipple you are giving away a significant amount of that.

Plus, having threads exposed screams "hack job".

[unterhausen]

Yes, nipples break where they mushroom out to hold the rim. I would rebuild those wheels. I hate it when I have to do that, but if you can see threads outside the nipple the spokes are much too short.

[bicycletricycle]

spoke should fill the whole nipple

[peanutgallery]

Rebuild it, and I would take a moment to make sure you're using the right measurements and a worthwhile spoke calculator. Sounds like there is a problem there

[FriarQuade]

Any amount of thread showing at the nipple is too much. In a perfect world they should be flush with the backside of the nipple, especially in an aluminum nipple. This ensures the head that actually holds the load is threaded to the spoke. You're not going to die riding the wheels the way they are but they will have a shorter life and require more maintenance while you have them.

[ultraman6970]

The ops says 2mm of thread showing at the spoke... well... are we talking 2 mm at the bottom of the nipple or are we talking 2 mm of spoke getting exposed at the exit of the nipple???

The 1st one is spoke tad short, the second one is spoke tad long.

Always you can put a longer nipple? Which is cheaper and easier to do thatn swapping the whole set of spokes you know.

Another option is that you have the spokes in the wrong hole at the rim? (just speculating) just check that the left side of the wheel spokes are connected to the left side holes of the rim, well now a days rims pretty much dont have that difference but something like that can make you miss the calculation for 1 or 2 mm.

[oldpotatoe]

Just built 2 wheels that I carefully measured and put through the online calculator. Both have ~2mm of threads showing.

I'm reading a lot of conflicting opinions on this online. Some people say I'm going to have the wheel explode underneath me. Others say it's totally fine.

So - am I going to die or never notice the difference?

So, spokes are somewhere in the vicinity of 4-5mm too short? Spokes should be at outside end of nipple when tensioned, nipples 12mm long, about 2mm showing, spokes have 10mm of threads.....so really short. Did you calc for 2 cross then lace 3 cross?

Like anything with threads that's under tension, if you don't engage the 'proper' amount of threads, it's not as strong as it could/should be. Can you kill a nipple(s) because of this..yup..even brass nipples are not uber 'hard', alloy even softer.

It may not 'fail', probably won't but can ya get stranded even a couple of nipples fail because of this, sure can

As for No, you will never notice the difference..ahh, the stuff of 'juniors' who build wheels, not 'wheelbuilders'...You'll notice if ya kill a nipple or 2...

Use this, measure the ERD yourself, measure the hubs yourself(flange diameter and center to flange)don't take online sites for granted:)

If you are going to do a wheelbuild, do it right..I can calc and cut proper spokes for you, BTW..if I have accurate numbers.

https://leonard.io/edd/

[unterhausen]

The ops says 2mm of thread showing at the spoke... well... are we talking 2 mm at the bottom of the nipple or are we talking 2 mm of spoke getting exposed at the exit of the nipple???
It has been a while since I screwed up and got spokes that were too long, but 2mm of threads showing inside the nipple because the spokes are too long is on the borderline of running out of threads and bottoming out the nipple. That's still a pretty big mistake and I would rebuild. I know it's $45
or something like that unless you can talk someone into cutting the same spokes again. Of course, that's not an option if the spokes are too short.

I had some bad wheelsmith spokes where the head would pop off, and that is a horrible feeling on a ride. Rebuilt with DT spokes and I'm much happier knowing that I have spokes from a company with quality control. The time lost rebuilding the wheel is nothing in comparison to having to wait for an uber.

[Dasarbule]

A picture is worth a thousand words

[ultraman6970]

Definitely tad long is better than too short.

[Black Dog]

It has been a while since I screwed up and got spokes that were too long, but 2mm of threads showing inside the nipple because the spokes are too long is on the borderline of running out of threads and bottoming out the nipple. That's still a pretty big mistake and I would rebuild. I know it's $45
or something like that unless you can talk someone into cutting the same spokes again. Of course, that's not an option if the spokes are too short.

I had some bad wheelsmith spokes where the head would pop off, and that is a horrible feeling on a ride. Rebuilt with DT spokes and I'm much happier knowing that I have spokes from a company with quality control. The time lost rebuilding the wheel is nothing in comparison to having to wait for an uber.

Or an ambulance.

[Mark McM]

Or an ambulance.

I've seen a lot of broken spokes, and I've seen a lot of crashes, but I can't recall seeing a crash caused by a broken spoke.

Once, a rider ran his front QR into my rear wheel (at least I think that's what happened), causing 6 out of 20 rear spokes to snap. This caused the tire to rub against the stays, but my bike kept rolling until I came to a stop. (I replaced the broken spokes, plus 7 others that got damaged in the same incident, and I'm still riding that wheel today).

[unterhausen]

this crash apparently happened because the other rider's qr took out a batch of spokes https://youtu.be/GaQJB_bWA4c

[jtbadge]

this crash apparently happened because the other rider's qr took out a batch of spokes https://youtu.be/GaQJB_bWA4c

riding aerobars in traffic, smart

[unterhausen]

youth (and speed) are wasted on the young

[Mark McM]

this crash apparently happened because the other rider's qr took out a batch of spokes https://youtu.be/GaQJB_bWA4c

I agree that breaking a large number of spokes (particularly front spokes) could cause a crash. In the video above, 4 out 8 spoke on one side of the wheel were broken (or 4 out of 16 total spokes), and yet the wheel did not collapse and the rider was able to slow the bike down substantially. My original comment was that I've never seen a crash caused by a single broken spoke.

[Black Dog]

I agree that breaking a large number of spokes (particularly front spokes) could cause a crash. In the video above, 4 out 8 spoke on one side of the wheel were broken (or 4 out of 16 total spokes), and yet the wheel did not collapse and the rider was able to slow the bike down substantially. My original comment was that I've never seen a crash caused by a single broken spoke.

I agree about the low likely hood of a broken spoke causing a crash due to catastrophic failure but I have seen a fistful of crashes due to a single a few spoke breaking that caused wheel lockup (rear wheel) that induced a skid the laid the rider down. This is especially the case in low spoke (high tension) wheels and frames with little wheel/tire clearance. To qualify this, I have been riding for over 30 years and have more than a few miles on the odometer. I have also seen wheels loose over 1/3 their spokes and still not fail.