Seeking the advice of wheel building gurus

IaninSheffield

Über Member
Location
Sheffield, UK
Having recently attended an informative and enjoyable wheel-building course, I set about my first project to build a dynamo hub front wheel. For a touring bike, the components include a Ryde Sputnik 36-hole 700c rim, SP PV8 hub and Swiss DT competition 2.0-1.8-2.0 spokes with 12mm brass nipples.
I laced up the wheel as we had learned using a 3-cross pattern, began the iterative process of tensioning, adjusting the spoke line, adjusting dishing, both radial and lateral truing and stress relieving. All has gone well apart from one problem I can't seem to resolve - a highly localised (for want of a better word) jink in which the rim pulls sharply and briefly to one side when the wheel is spun in the truing stand. The rest of the rim runs fairly truly, apart from the jink in the vicinity of a single spoke and try as a I might, I can't seem to pull the rim back across by tightening the spoke concerned, either alone or with the other appropriate spokes to either side of it.

I've tried releasing all spoke tension and starting once more from scratch, but unfortunately with the same outcome. I don't know whether it's significant, but the rim joint is a couple of cm away from the localised jink. So, lacking experience, I'm now at a loss what to try and would be really grateful if anyone with greater wisdom and/or experience could suggest things to try.

Many thanks.
 
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Ian H

I am an ancient randonneur, & I stop often for tea
Location
East Devon
What order of magnitude? millimetres? Less than 1mm?
 

JhnBssll

Veteran
Location
Suffolk
My guess would be that the rim wasn't straight before you started. It's not always easy to test, but you can put it against the rim of a (known true) wheel to check it's flush all the way round. Not useful in this case unless you unlace the rim, something I've had to do a few times and it's always frustrating 😖

The other thing to check is whether the whole rim is moving or if it's just on one side which would indicate damage to the rim wall rather than a buckle. Is this a new rim or a repurposed old one?
 
OP
IaninSheffield

IaninSheffield

Über Member
Location
Sheffield, UK
My guess would be that the rim wasn't straight before you started. It's not always easy to test, but you can put it against the rim of a (known true) wheel to check it's flush all the way round. Not useful in this case unless you unlace the rim, something I've had to do a few times and it's always frustrating 😖

The other thing to check is whether the whole rim is moving or if it's just on one side which would indicate damage to the rim wall rather than a buckle. Is this a new rim or a repurposed old one?
Would never have thought to check the rim beforehand. Doh! It was brand new.
I'd prefer not to unlace the rim, but that's a good suggestion and if it has to be, it has to be.
Wonder to what extent this wheel, if it is faulty, will cause problems if I risk running it as it is?
 
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