Wheelbuilding

[S.Giles]

Fatigue life is not measured in units of time but in cycles. Approximately the same as wheel revolutions. This life is typically in the tens of millions of revolutions.

Let's hope there's at least some spoke-to-spoke variation in spoke fatigue life!

 

[Yellow Saddle]

variation

Let's hope there's at least some spoke-to-spoke variation in spoke fatigue life!

Quite a lot too and believe it or not, someone did his Phd on exactly that topic.

 

[S.Giles]

...believe it or not, someone did his Phd on exactly that topic.

Sounds like the kind of project Professor Piehead would take on. Follow the link to see his test on bicycle crash helmets.

 

[winjim]

This is utter nonsense. The coating on black spokes is an oxide coating and the process only affects the surface layer of molecules. it does not affect the spokes at all. The reason your bike shop only stocks silver spokes is because of the high cost of black spokes. They are up to 40% more expensive and wheelbuilders without their own spoke threading machines have a stockholding problem. In order to be competitive, you have to keep about sixty lengths in four styles and in two colours. Do the math. The easy answer to the problem is to only stock silver, in even (or odd) number lengths in straight gauge only. The with a little BS and some cheating (selling customers rubbish straight gauge spokes), you run your business slightly more profitably.

Well they're certainly DT double butted so no worries there, and I'm not too precious about the colour. Bike shop man must build some black ones though, as he had them on display in the window!

 

[winjim]

Time to get busy!

 

[winjim]

Today's work so far. Both radial and lateral trueness appear to be maybe about half a millimetre out. Spokes pretty evenly tensioned. Dish is spot on. Just needs a few final tweaks and tensioning up. Pretty pleased with it so far

I've a feeling the rear might be a different story

 

[Smokin Joe]

View attachment 83251
Today's work so far. Both radial and lateral trueness appear to be maybe about half a millimetre out. Spokes pretty evenly tensioned. Dish is spot on. Just needs a few final tweaks and tensioning up. Pretty pleased with it so far

I've a feeling the rear might be a different story

Rear wheels are just as easy to true as fronts, they may be dished but all the same building techniques apply.

 

[winjim]

The completed set, and not looking too bad even if I say so myself . For the weight weenies out there, they are 823g front and 934g rear sans skewers, which is an improvement on the wheels they're replacing which were 937g front and 1049g rear, and that's with four extra spokes per wheel which should keep them sturdy. I suppose I could have got the weight down by using lightweight spokes, but as it was my first build I wanted to keep things simple. Now to try and find some time to ride the things...

New skill learned, bike mechanic status - level up!

 

[winjim]

Well today I finally (finally!) got to ride my new wheels . It was just a short blast out to Strines and back as it's a bank holiday and I had to get to the garden centre but still... They have the tyres on from the old wheels which are a pair of crappy Vittoria Zaffiros. I kept these on so I could make a direct comparison without changing too many variables, and also because they've plenty of life left so there's no point replacing them until I need to. When I do I'll probably treat them to something nice like an open Corsa or Pave .

So how do they compare? I'd love to regale you with tales of how they "spin up quickly", or have a wonderfully "low rolling resistance", or indeed extoll the virtues of their "vertical compliance and lateral stiffness" but I can't! What I can say is that I noticed no difference at all between them and my old wheels. Now there could be several reasons for this:

• Family situation means that I haven't been riding that much recently and my fitness has suffered. It's difficult to make a comparison between equipment when it's been so long since I've ridden, and any major performance change will be due to my lack of fitness.
• I am far from being a pro cyclist and my senses are just not attuned to the subtle nuances of equipment upgrades.
  
• My old wheels were actually pretty good anyway and the new ones are just rather similar. Or the new ones are pretty average.
  
• The performance benefits of new wheels have been massively overstated by the cycling industry and all this marketing talk is just a load of old bobbins.

What I will tell you is that there was no pinging or tinkling sound from the spokes, so I think i had all the spokes tightened properly, and the wheels are just as true now as they were when I set off. In fact this did provide a performance advantage, I was confident in their trueness so was able to set my brake pads much closer to the rim, meaning better braking performance and more confidence in the descents.

All in all I'm really happy with the wheels and dead chuffed that I managed to learn a new skill and build them myself. Thanks to everyone who's contributed to this thread and encouraged me / given advice.

 

[Yellow Saddle]

The performance benefits of new wheels have been massively overstated by the cycling industry and all this marketing talk is just a load of old bobbins.
What I will tell you is that there was no pinging or tinkling sound from the spokes, so I think i had all the spokes tightened properly, and the wheels are just as true now as they were when I set off. In fact this did provide a performance advantage, I was confident in their trueness so was able to set my brake pads much closer to the rim, meaning better braking performance and more confidence in the descents.

All in all I'm really happy with the wheels and dead chuffed that I managed to learn a new skill and build them myself. Thanks to everyone who's contributed to this thread and encouraged me / given advice.

Good one. Building your own wheels is a very satisfying activity.

I salute your honesty. There is no noticeable difference and the highlighted bit in your quote says it all.
Then, there is something to be said for wheels that like a close encounter with brake pads and stay that way.
Enjoy them.

 

[Smurfy]

This is utter nonsense. The coating on black spokes is an oxide coating and the process only affects the surface layer of molecules. it does not affect the spokes at all.

The anodising treatment used on aluminium is also an oxide coating, and anodising is known to reduce fatigue life.

 

[Smurfy]

I'd love to regale you with tales of how they "spin up quickly", or have a wonderfully "low rolling resistance", or indeed extoll the virtues of their "vertical compliance and lateral stiffness" but I can't! What I can say is that I noticed no difference at all between them and my old wheels.

Totally the wrong answer! You'll never be a reviewer for a cycling mag!

 

[Yellow Saddle]

The anodising treatment used on aluminium is also an oxide coating, and anodising is known to reduce fatigue life.

And?

 

[Smurfy]

And?

You claimed that surface oxide coatings can't affect the fatigue performance of the underlying metal.

This is utter nonsense. The coating on black spokes is an oxide coating and the process only affects the surface layer of molecules. it does not affect the spokes at all.

So I've given you an example of an oxide coating that reduces fatigue life. It seems quite possible that the same fatigue damage mechanisms could apply to black oxide coatings on stainless spokes, thereby reducing the fatigue life.

 

[Yellow Saddle]

You claimed that surface oxide coatings can't affect the fatigue performance of the underlying metal.

So I've given you an example of an oxide coating that reduces fatigue life. It seems quite possible that the same fatigue damage mechanisms could apply to black oxide coatings on stainless spokes, thereby reducing the fatigue life.

Well, they're not the same. There are oxides and oxides. For instance, aluminium oxide that occurs naturally on aluminium, is self-arresting. If you polish a piece of aluminium, it becomes shiny as chrome but very quickly, within minutes, the top layer oxidises and self-arrests. The layer does not penetrate and remains extremely thin, but most importantly on top. In other words, it is a true coating.
Anodising on the other hand is also an oxide, but a form of ceramic, containing Nitride. This does not form on top of the substrate but penetrates to one half its thickness. Because this is hard and inflexible, it creates stress risers and propagates cracks when the item is stressed.
The oxide coating on spokes sits on top and isn't a hard glassy substance.

Black spokes suffer no fatigue problems over and above what silver spokes suffer from. This can be proven chemically and experimentally.