After ebike conversion, has anyone had a higher rate of broken spokes or bent wheels?

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mike killay

Esteemed Pedelecer
Feb 17, 2011
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14 gauge (1.9mm diameter): 740 lbs, 336kgf to break it in the middle.
But spokes never break in the middle. They either break at the J bend or at the end of the thread.
Spokes work in extension (tensile) and usually break in compression, that's their weakness. If your spokes are loosened, you'll break them.
I don't understand how a spoke can get into compression.
It is pushing against a hole in the rim and will just push up into the inner tube.
 

Woosh

Trade Member
May 19, 2012
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wooshbikes.co.uk
I don't understand how a spoke can get into compression.
It is pushing against a hole in the rim and will just push up into the inner tube.
the angle of the spoke entering the hole in the rim is such that the nipple usually is stuck solid in the hole.
When you go over a pothole, your loosened spoke will go into compression.
This situation happens far more often with thicker e-bike spokes, 13 gauge instead of 14.
 

Eray

Finding my (electric) wheels
Sep 12, 2020
14
0
Hi,
I have 4 broken spoke now. I couldnt find the size/measurement. Is there anyone help me? The wheel is 26” and the motor is 500w bafang.
Sorry to disturb the topic, I didnt want to start a new one.
Thank a lot in advance
 

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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
After 4 spokes break, it's clear that something is wrong with your spokes or the wheel-build. It's time to respoke the wheel. I'd use 14g spokes. I normally get mine from this guy, but postage has jumped significantly, so probably time to find a UK supplier:

Yours are breaking at the nipple end. I'd say they were loose and you ran your bike like that without checking them until it was too late.
 
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Eray

Finding my (electric) wheels
Sep 12, 2020
14
0
After 4 spokes break, it's clear that something is wrong with your spokes or the wheel-build. It's time to respoke the wheel. I'd use 14g spokes. I normally get mine from this guy, but postage has jumped significantly, so probably time to find a UK supplier:

Yours are breaking at the nipple end. I'd say they were loose and you ran your bike like that without checking them until it was too late.
Thanks a lot for your answer
Yes, as you said I never checked before. I guess somehow the wheel center has been moved.
So what I will do is to change all of them as you recommend but I dont know the length and the thickness of the spoke. Or as you said “14g” is enough information to buy?
Thanks a lot
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,920
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West Sx RH
Ryan build wheels /Ryan for spokes, I whole heartedly agree with Wheezyrider. I use Ryan for all my spoke needs.
14g = 2mm spokes a bit more flexible then 13g/2.3mm spokes.

To ideally get the correct spoke length one need to measure the rim erd (effective rim dia) and then input the results in a spoke calculator. If erd is not known then one needs to accurately measure the rim internal measurement and then add approx 4mm for the thickness of the rim material. Using a spoke calc one inputs all the relevant info needed to get the spoke lengths.

Alternately one can take a gamble and remove a good spoke to measure it.

If you have never built a wheel up then you have learning curve ahead of you, after a few tries it gets easier.
 
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vfr400

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Jun 12, 2011
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You can measure the spokes you already have. Their length will be correct. measure from the middle of the elbow to the end of the spoke - one with a thread, not a broken one.
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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If you are going to the trouble of replacing all the spokes, you might want to think about getting a decent new rim at the same time.
I always use the cheapest rims I can find. I never had a problem with one. I've seen problems on other bikes, like rims worn through by the rim brakes, and I've seen rims with cracks around the spokes on expensive rims and also on bikes with 12g spokes.
 
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Eray

Finding my (electric) wheels
Sep 12, 2020
14
0
Ryan build wheels /Ryan for spokes, I whole heartedly agree with Wheezyrider. I use Ryan for all my spoke needs.
14g = 2mm spokes a bit more flexible then 13g/2.3mm spokes.

To ideally get the correct spoke length one need to measure the rim erd (effective rim dia) and then input the results in a spoke calculator. If erd is not known then one needs to accurately measure the rim internal measurement and then add approx 4mm for the thickness of the rim material. Using a spoke calc one inputs all the relevant info needed to get the spoke lengths.

Alternately one can take a gamble and remove a good spoke to measure it.

If you have never built a wheel up then you have learning curve ahead of you, after a few tries it gets easier.
You helped me a lot. Thanks a lot for your time
I have one last question. I learnt the size from the seller which are 217mm and 219mm. I will buy them from ryanspokes but should I order anything else? Like nipples? Or when I order spokes, nipples are icluded?
Thanks again
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Double check that nipples are part of the order, if not you will ideally want new ones.
The shorter spokes will be for the drive/rhs as the rim will be dished over to that side to centralise the wheel in the drop outs. I don't bother with different size spokes and buy one size.

A couple of utube videos on wheel lacing as it is easier to lace form scratch then try one at a time, the trueing up of wheel can be done in the drop outs. One can use a cable tie wrapped and cut so a tail acts as a pointer on the rim edge to allow for final trueing.
How to Lace a Wheel - Three cross pattern - YouTube
Without the bullshit. How to build a 36 spoke wheel. - YouTube
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
It looks like you got 117 spokes. Your old one doesn't look like 217. As I said before. you should take one of your good spokes and measure it from the middle of the elbow to the ned of the thread.

Assuming that whoever gave you the sizes of 217 and 219 was correct. you should choose the middle or upper value because it's more dificult to build with spokes that are too short. There's a bit of tolerance on the spokes being longer than what you need, but not shorter. I'd have chosen 219mm, or 220mm if the seller only stocked standard sizes.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Make sure you haven't made an error ordering ?
Looking at the black spoke it looks about 197mm but as it isn't actually on the tape we can't be sure certainly no where near the 217/219 you mentioned.

Start again remove a good spoke from the LH & RHS measure them properly and order them properly.

Whom did you order from ?
 
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Eray

Finding my (electric) wheels
Sep 12, 2020
14
0
Make sure you haven't made an error ordering ?
Looking at the black spoke it looks about 197mm but as it isn't actually on the tape we can't be sure certainly no where near the 217/219 you mentioned.

Start again remove a good spoke from the LH & RHS measure them properly and order them properly.

Whom did you order from ?
I ordered from ryan spokes. I double checked of course before I write here and the ryanspokes :) I ordered 217mm.
the one I have, black one, is 211mm but looks 5-6mm is missing screw side.
Anyway today I will take of the wheel and try to find a place to built it right away. I am working as a food delivery courier and loosing money of I cant work.
I found https://www.bicyclewheelbuilder.co.uk
I hope they are kind enough to fix my wheel today
Thanks everyone for your time, help and support
You all great
 
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Deleted member 33385

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I hate fat shaming, I've always cycled between pudgy and fit... I hated being fat, so recently did my Doctor - therefore I took to extreme measures to avoid the need for statins and started intermittent fasting for five days a week: one big meal a day, and ate whatever the hell I wanted on weekends. Overall, the weekly calorie count reduction was enough to lose me two stones gradually over 6 months so far. I still have a stone and a half to go, before the NHS BMI calculator shows relative clear:

https://www.nhs.uk/live-well/healthy-weight/bmi-calculator/

...I don't recommend this intermittent fasting thing to everyone, particularly diabetics. Ask your doc first, I didn't. When it comes to extending range on pedelecs, losing every little helps...
 
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Yak

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Mar 20, 2020
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I’m intermittent fasting and cycling too, after a health scare, down from 143 to 120 so far (since last March). In my defense I was 117kg when I was super fit - just gym/weights/labouring then, not cycling, so aiming for sub 100kg at my age/sport, maybe another 18months. I think that still puts me at obese, which would be wrong. And yeah, you really notice every kg lost on the bike.