Author Topic: Spoke tension  (Read 1955 times)

ourclarioncall

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Spoke tension
« on: February 17, 2022, 05:43:20 pm »
I find it hard to understand how on day a 32 spoke wheel

Breaking one spoke can throw the wheel out of alignment

I understand the concept I think as with guitars you have the tension from 6 strings . One string snaps and it throws the rest off. So the whole system is a balance and they share the tension

But I doubt on a 32 string guitar snapping 1 string would make any noticeable difference as there are much more strings to share the load

I appreciate that guitars are different to wheels but just letting you in on my thought process 👍

Danneaux

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Re: Spoke tension
« Reply #1 on: February 17, 2022, 05:59:27 pm »
Quote
I find it hard to understand how...Breaking one spoke can throw the wheel out of alignment

This may help your understanding...  :)
https://www.rivbike.com/pages/broken-spokes-and-their-wobbly-wheels#:~:text=The%20left%2D%20and%20right%2Dside,balance%20and%20causes%20a%20wobble.

Best,

Dan.

ourclarioncall

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Re: Spoke tension
« Reply #2 on: February 17, 2022, 08:42:51 pm »
Quote
I find it hard to understand how...Breaking one spoke can throw the wheel out of alignment

This may help your understanding...  :)
https://www.rivbike.com/pages/broken-spokes-and-their-wobbly-wheels#:~:text=The%20left%2D%20and%20right%2Dside,balance%20and%20causes%20a%20wobble.

Best,

Dan.

Thanks Dan

Yeah makes a bit more sense now . I’m visualising the tension on both sides of the wheel . So when one side breaks and let’s go , I can understand how that would change things in that area of the rime

PH

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Re: Spoke tension
« Reply #3 on: February 17, 2022, 09:17:05 pm »
Breaking one spoke can throw the wheel out of alignment
It does, but not necessarily by much.  Sometimes just letting the brake out a bit is enough, if not it's usually possible to true it up by adjusting the spokes around it as a temporary fix - I say temporary, I did this for a workmate who put the chain into the spokes on the way to work, I thought that would get him home, two years later he was still riding it!

ourclarioncall

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Re: Spoke tension
« Reply #4 on: February 21, 2022, 07:21:29 pm »
Breaking one spoke can throw the wheel out of alignment
It does, but not necessarily by much.  Sometimes just letting the brake out a bit is enough, if not it's usually possible to true it up by adjusting the spokes around it as a temporary fix - I say temporary, I did this for a workmate who put the chain into the spokes on the way to work, I thought that would get him home, two years later he was still riding it!

So when you tighten a spoke , is the spoke pulling the rim in the direction of the side the spoke is on?

Sorry if my question is confusing

If I tighten spokes that that are on the left side of the wheel, thin will that pull the rim towards the left ?

PH

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Re: Spoke tension
« Reply #5 on: February 21, 2022, 07:45:42 pm »
If I tighten spokes that that are on the left side of the wheel, thin will that pull the rim towards the left ?
Yes, but you're also trying to even it out, so a little tighter on the left and let the right ones out a bit, 1/4 turn at a time for each, 2 spokes either side ought to be enough, find an old wheel and see how you get on.  Being a master wheel builder is a skill, but getting a wheel round and rideable just takes a bit of practice.

Moronic

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Re: Spoke tension
« Reply #6 on: February 23, 2022, 09:11:19 am »

So when you tighten a spoke , is the spoke pulling the rim in the direction of the side the spoke is on?

Sorry if my question is confusing

If I tighten spokes that that are on the left side of the wheel, thin will that pull the rim towards the left ?

Yes and it is important to remember that the rim relies on even spoke tension to remain circular. The rim is malleable concentrically as well as laterally. As observed above, it's an art.

I'm thoroughly impressed by the balance and resilience of the wheels in my Thorn. I imagine they will benefit from occasional maintenance, and I've got some research to do on finding someone I'd trust with them. I certainly won't be getting in there myself.
Bongs For Steve: a lyrical novel about smoking and friendship. https://www.amazon.com.au/Bongs-Steve-I-J-Baker-ebook/dp/B0B2BRTKM2

PH

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Re: Spoke tension
« Reply #7 on: February 24, 2022, 04:21:12 pm »
I imagine they will benefit from occasional maintenance, and I've got some research to do on finding someone I'd trust with them. I certainly won't be getting in there myself.
Well built wheels shouldn't require any adjustment to spokes and tensions for their life.  My SJS built Mercury rear wheel is a couple of years older than the bike, so at least 7 years, the spokes haven't been touched. I pop it into the wheelstand when I'm doing a service to check true and give the spokes a ping to hear if there's any tension difference (There's an app to judge that precisely, but you can hear any significant difference) At the same time I'm looking for cracks or corrosion around the spoke holes,  and if the bike is going to see any winter riding on salted roads I'll dribble a bit of ACF-50 in there (Or any other corrosion inhibitor) That's it.
The art of wheelbuilding is to get the spokes tight enough that they don't fatigue, without overly stressing the rim. Easier than it sounds, as that's quite a narrow window and not all wheeelbuilders agree which to prioritise.  Right choice of components helps and non dished wheels, like a Rohloff, do make it simpler.  Get that right, and the lifetime of spokes and rim, if you can avoid corrosion and wear from breaking, it pretty much infinite.  The exception is damage, though even then a good wheel can take a lot, the wheel in the accident that wrote off my original Mercury's fork is still round and true! though the hub makes a horrible noise so it's not in use. OTOH they don't like a sideways impact, I've had a wheel bend almost in half from a much more minor collision at right angles. 
Machine built wheels are a different story, both wheels on my E-bike needed re-truing after a couple of thousand miles and the cheap hybrid I used for deliveries before it broke two spokes in a year.
« Last Edit: February 24, 2022, 04:23:14 pm by PH »

Moronic

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Re: Spoke tension
« Reply #8 on: February 25, 2022, 12:39:55 am »
Thanks PH. Best news I've heard in a while.  :D
Bongs For Steve: a lyrical novel about smoking and friendship. https://www.amazon.com.au/Bongs-Steve-I-J-Baker-ebook/dp/B0B2BRTKM2

ourclarioncall

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Re: Spoke tension
« Reply #9 on: February 25, 2022, 01:10:46 pm »
Thanks PH

That was very Helpful insight 👍