Author Topic: Spokes tension check  (Read 2463 times)

mel0

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Spokes tension check
« on: July 30, 2022, 10:18:35 am »
Hi guys, Iím riding my Ogre/Rohloff since a year and I couldnít be more happy.
I read on the Rohloff manual to check spokes tension regularly. Never done but the wheel still look good.
What do you guys suggest? Should I send the wheel to who have built the it or any good wheel builder can do the job? I would be happy to avoid delivery.
Any recommendations in London and surrounding?

Cheers guys

mickeg

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Re: Spokes tension check
« Reply #1 on: July 30, 2022, 11:53:50 am »
Any competent wheel builder will be able to check spoke tension.  To check it properly, they need to know the exact diameter of the spokes.  Some shops do not have a precision caliper to measure the spoke diameter, if you know what brand and model spokes are, you should tell them that.

When I built up my Rohloff wheel, I had a friend that had access to a spoke gauge test the tension, that was nine years ago.  I have not had it checked since.  I have never broken a spoke on any wheel that I built.

PH

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Re: Spokes tension check
« Reply #2 on: July 30, 2022, 12:08:11 pm »
Wheels that have been well built, with the components appropriate for their intended usage, should stay round, true and with even spoke tension for their lifetime.  There's nothing in normal usage that should change those parameters.  It is of course always a good idea to check these things, but it's something you can (IMO should) be able to do yourself, I do it at least annually for all my wheels, I can't remember when any wheel needed more than a check.  My Mercury one was last rebuilt, by SJS, in 2014 and is still perfect.
Round and true are simple enough, with the tyres off and the bike in a stable stand or upside down - create some fixed points (I use thick zip ties) that almost touch the rim and turn it watching that the gap remains constant (I consider 2mm variation to be acceptable, some are more fussy)  If your wheel is round and true, it's very likely the spoke tension will also be even, though it's still worth checking.
Squeezing pairs together will show any that are a long way out, but it isn't precise enough (For me anyway) to accurately spot any differences.  A better gauge is to pluck them with your fingernail, most people can hear if the tension is uneven. I'm not one of them and even if I was I'd still like that sound converted into numbers.  If you have an iPhone, there's an app for that, I'll link below, there may be android versions, I haven't looked. It is incredibly consistent, it accurately measures the tone even if your pluck varies. I also have an expensive Park Spoke Tension meter and the app does a better job.   
If the wheel is round, true and the spoke tension even, that's it, job done.  I suppose it's theoretically possible for all the spokes to be wrong by exactly the same amount, but if it wasn't built that way the odds are probably greater than winning the lottery twice in a row.
If you do find any issue, then it's time to call the experts, but if that were the case then for me that wouldn't be those who originally built it.
Just on a general point, for longevity, even spoke tension is more important than round and true, within reason obviously. Some variation is acceptable, sometimes inevitable, but I'd sacrifice a little trueness for getting that tension right.

Youtube demo of the app
https://www.youtube.com/watch?v=ChFIIe0aPb4

If you want to take your understanding a little further, I can recommend this E-book:
 https://www.wheelpro.co.uk/wheelbuilding/book.php

If you want to take that understanding a lot further, there's the book - The Bicycle Wheel by Jobst Brandt, which I have but admit to never having thoroughly read!

« Last Edit: July 30, 2022, 12:23:33 pm by PH »

JohnR

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Re: Spokes tension check
« Reply #3 on: July 30, 2022, 04:49:37 pm »
Up-ending the bike and spinning each wheel enables a simple visual check that the wheel has no lateral wobble or has gone oval. Also tapping each spoke in turn with a metal object (eg medium sized Allan key) will reveal if there are serious problems with the tension. They should all sound fairly similar but it's unlikely they will all have exactly the same tension.

That's probably enough for most people unless about to embark on a long expedition. I'd interpret Rohloff's guidance as "regularly check your bike for problems".

About 2/3rds of the way along the LEJOG last year I noticed that my front wheel had some lateral wobble and identified that one spoke was loose. As this didn't cause problems (one advantage of disc brakes) I deferred investigation until I got home when I discovered that a nipple had broken.

geocycle

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Re: Spokes tension check
« Reply #4 on: July 30, 2022, 05:19:42 pm »
Well thanks to this thread I discovered a loose spoke! I never check my spokes on my SJS wheels as they have never changed the very few times Iíve looked, but reading this on a wet day peeked my interest. Sure enough one spoke on the rohloff was rattling and very loose. The rim was still perfect but good to sort it.
 

mickeg

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Re: Spokes tension check
« Reply #5 on: July 31, 2022, 01:17:47 am »
I have mentioned this before on this forum, I was riding a on gravel/cobble road that was really rough, somehow a rock got thrown up into my spokes and jammed against the frame, I felt something go clunk but kept riding.  A few miles later my rear rim brake was rubbing on the rim a bit, but by now I had been on teh bike for over 12 hours and I just wanted to make it to the campground.

After a 14 hour day, I decided the next day would be a sightseeing and recovery day with no travel.  Looked at my rear wheel.  That one spoke had a clear bend to it.  See photo.  I had spare spokes and I was afraid that the spoke threads had stripped out of the nipple threads, the spoke was loose.  But I really did not want to pull the tire off, rim tape off to replace the spoke, so I tried to tighten it up.  And the nipple worked just fine.  Tightened up the spoke and trued the wheel.  Later at home, I replaced that spoke, but that spoke and nipple rode many trouble free miles before I replaced it.

When I saw that bend in the spoke, my first thought was - wow, my flange did not crack at the spoke hole !!!  My second thought was that there must be a crack in the rim, but there was not.

mel0

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Re: Spokes tension check
« Reply #6 on: August 07, 2022, 07:00:29 pm »
Thanks guys!