Spoke Failure?

[DeltaOscar]

I've been riding this set of Bianchi Levitation wheels for 4 years.

I recently had them re-spoked. Yesterday after about 400kms of riding since the rebuild the rear wheel developed a wobble which very quickly became too serious to carry on riding. I checked the spokes and 8 of them had no tension whatsoever. The rim was moving laterally a good half inch in both directions.

So?

Why no problem until the rebuild?

And

What to do about it?

Any advice? Thanks

 

[JPW#]

If I were you I would take the wheel back to the wheel builder to "true" or to rebuild the wheel. 

[Johan Bornman]

I won't take the wheel back to the builder since he did a poor job in the first place.

 

The wheels had just-just enough tension to survive 400kms but gradually the nipples unscrewed, one by one as the they are directly above the road and in the load-affected zone and thus slightly slacker than the rest.

 

 

[AndreZA]

JB, could the spokes have wound up and as he was travelling it was releasing?

 

 

[Johan Bornman]

JB' date=' could the spokes have wound up and as he was travelling it was releasing?

 

 

[/quote']

 

No.

 

Spokes cannot tighten themselves and cannot wind themselves up.

 

However, spokes can loosen and can unwind if they were wound up to start off with.

 

A wheelbuilder that doesn't understand the relationship between torsion and spoke diameter builds wheels that wind themselves down like a clock.

 

Nipples are prevented from unscrewing not with locknuts, linseed concoctions, loctite or peanut butter. They're prevented from unscrewing through tension in the spoke. High spoke tension causes high thread ramp friction. That's the good stuff.

 

 

 

 

[DeltaOscar]

Thanks JB

 

It is with the 'wheelbuilder' now, who is recommending spoke freeze.

 

It sounds a bit dubious to me.......

 

Can you recommend anyone in CT who can do a proper job?

 

As I said these wheels lasted about 7000kms before this, so I don't beleive there is anything inherently wrong with them.

Just need someone to take care of them who knows what they are doing.

 

Cheers 

[DeltaOscar]

Oh yes...

Any chance the hub or the rim could have been damaged?

I'd imagine they were both taking loads in directions they weren't designed to?

[AndreZA]

However' date=' spokes can loosen and can unwind if they were wound up to start off with.

 

[/quote']

 

that is what I meant, thanks

 

 

[Johan Bornman]

I suggest you PM Straatvark and see if he can do the job for you. He's a good wheelbuilder and understands the issues at play.

 

Get your "wheelbuilder" to immediately cease putting gum on the spokes. The next sod will just have to remove it and it is a finicky job.

 

Nothing is damaged, although the spokes could be dodgy now, they've been subjected to undue metal fatigue due to the low tension.

 

 

[Johan Bornman]

However' date=' spokes can loosen and can unwind if they were wound up to start off with.

 

[/quote']

 

that is what I meant, thanks

 

 

 

Sorry, I misread the question.