Spokes

[andrewbell]

What are the best spokes to use, want them on a set of Ritchey DS Pro Off centre wheels?  What sort of cost am i looking at?

[andrewbell]

*bump*

[javadude]

According to Yellow Saddle, aka Johan Bornman:

 

Butted spokes (Sapim) R7 each. Black spokes cost more

 

That obviously excludes wheel building.

 

http://www.yellowsaddle.co.za

[andrewbell]

thanks, any other information floating around on spokes.

[linnega]

Sapim CX rays are my choice generally.  On the MTB has to be DT Revolutions (cause Sapim don't make the right length?) even if JB whines a bit about how difficult they are to build with.  Never broken a CX Ray spoke.  Broke a few DT Revolutions when I slammed the rear derailleur into the spokes.  After the "rebuild" I had the new spoke break a couple times so sent to JB to build a new rear MTB wheel.  No problems at all with that wheel.

[linnega]

BTW who do you want to build your wheels locallY?

[andrewbell]

not sure, wha is the best material for spokes, do you know anyone in DBN who rebuilds wheels? andrewbell2007-11-11 23:28:49

[bobbie]

oi Andrew... whats up with the spelling today??? what school did you go to???   ("wha is" - "  wheeels? ")

[linnega]

Material is only stainless steel and only from DT or Sapim.  There are other materials, but these are only available from the manufacturers as complete wheels.

 

As for builders, I haven't used anyone local for a while.  There was an old geezer that used to build wheels for the pro teams when Dave Wiseman was a wrench, but I his shop closed.  Used to be next to Peerless Cycles in the bad end of town.  Last set I had built was at Shaun's shop (Power Cycles).  Wheels have been good - still true and strong after 7 years.  Most of the bike shops do build wheels -  but you could just post up to Johan Bornman to build for you in Joburg.

 

[Johan Bornman]

What are the best spokes to use' date=' want them on a set of Ritchey DS Pro Off centre wheels?  What sort of cost am i looking at?[/quote']

 

The best spokes for X application....would be a more appropriate answer but let me try:

 

Spokes come in many shapes and sizes:

1) Straight gauge - same thickness througout

2) Double butted - thick at the ends, thin in the middle.

3) Bladed - round at the ends, flat in the middle.

4) Different materials, galvanised, chromed, stainless.

5) Different colours - silver or black

6) Permutations of the above.

 

Straight gauge spokes have a role to play in cheaper bikes and in situations where a builder quickly has to build up a lot of wheels which don't require much durability. I can't thing of such a situation but perhaps it exists. Straight gauge spokes are easy to build with because they don't twist up as much as butted spokes. However, they break more easily because they are thicker...I know that doesn't make sense but I'll explain.

 

Butted spokes (usually referred to as double-butted) are more durable than staight gauge spokes simply because the shaft is thinner, therefore stretches more than the thicker ends, which means there is less flex there and thus less metal fatigue. Spokes break from metal fatigue, not tension, unless they suck in a jockey or stick or foot.

 

The only spoke material of value to you and I is the special stainless steel used by DT Swiss, Sapim, Wheelsmith and some other obscure companies. They keep this stainless steel alloy secret. It isn't normal stainless, it is very ductile and quite soft, compared to 18/8 stainless.

 

Chromed spokes are used for 8-day races in Belguim where bikes ride around a smoke-filled (cigarettes) indoor track in bright lights. He with the shiniest spokes looks the fastest.

 

Galvanised spokes are used on cheap bikes.

 

Bladed spokes are just flat double-butted spokes and contain less material in the shaft than in the bend or at the threaded area.

 

Good spokes have their threads rolled on, not cut in. This means there was no material removed in the threading process and makes spokes less vulnerable to breaking in the thread's valley.

 

The general limit with bladed spokes is a width of 2.3mm, which is the size of spoke holes in most hubs. The CD-Ray is exactly 2.3mm wide and fits through with a squeeze.

 

Bladed spokes are generally of a high quality and the extra cold working required to hammer them flat makes them stronger...but unfortunately only in the place where spokes don't break - the shaft. Since the J-bends and threads are the same as on butted spokes and that's the achilles heel, they're just as strong as butted spokes.

 

The longevity of a good spoke is determined not by the manufacuting process, but by the wheelbuilder's skill and understanding of the problem at hand.

 

Bladed spokes are very expensive and stock in SA is virtually non-existent. Some of the wheel importers bring sizes in to suit their wheels  (and they replace millions of them because they don't understand wheelbuilding), but these sizes don't fit what you and I want to do - build different wheels from random components.

 

Bladed spokes are easy to build with because they're easy to hold and prevent twist. Twist is bad because spokes will untwist themselves and come loose. Spokes are prevented from unscrewing by neutral torque, high tension and something called thread ramp tension. NEVER LOCTITE!

 

DT Revolution and SAPIM laser spokes are special case double butted spokes. They're still 2mm thick at the two ends, but extra thin (1.5mm) in the shank. Laser's are hen's teeth. Revo's are freely available.

 

Linnega says I complain and whine when people ask for wheels built with Revo's, but that is just to prepare them for the extra cost involved. It helps justify my case. These spokes are more expensive than other spokes and are very hard to build with. They twist. Why do they twist and why does it matter?

 

A piece of wire's resistance to torque increases/decreases with the square of it's diameter. Therefore, a spoke half as thin, will twist four times easier. This is the problem with Revo's they twise when you bring then up to tension. Since they're so smooth, you can't hold them and if you hold them with something like a vice-grip, they still slip and cut a small circular scratch right around, which acts as a stress riser and amputates the spoke at the precise moment you are far from home. Therefore you cannot hold them and the only way to get the twist out is to overshoot and back-up.

 

They're also expensive to buy - sometimes up to three times as much as normal spokes. They do however build into nice durable wheels if the customer doesn't spec' some silly design.

 

Black, and silver spokes are a purely costmetic issue as they're identical. Naturally, black costs much, much more.

 

Spokes don't care if your rims are offset or not.

 

 

That was Spokes 101.

 

Regards

JB

 

 

Johan Bornman2007-11-12 01:33:53

[andrewbell]

what difference does rounded and bladed spoke make to ones ride quality?

[ORCA]

what difference does rounded and bladed spoke make to ones ride quality?

 

 

 

none

[linnega]

I don't believe there will be any perceivable difference (or even measurable) in either aerodynamics or ride quality.  The bladed spokes from Sapim are more durable according to tests done by Sapim  (the Sapim CX-Rays are used on Campagnolo wheels):

http://www.sapim.be/content/themes/img/Fatigue-test2.jpg

[AndreZA]

Yous must listens to JB. He spokes the truf.

 

 

[Johan Bornman]

Linnega is right. There is no difference in ride quality. You can't feel what spokes are in a wheel. Also, you can't feel whether they have high or low tension. Only after the point where spokes become slack at the load affected zone (the two or three spokes at the bottom of the wheel), then you can feel any difference.

But to get back to the point of that very interesting little graph of SAPIM's where they show that their most expensive (coincidence?) spoke is also their most durable. It is true for the way they rigged the test jig. Since those spokes are cold-forged (fancy word for hammered) into that flat shape, they are very strong. However, the bladed area is not the area that gets stressed, it is the elbow and threads. Therefore the very expensive CX-Rays are not really stronger, because they'll fail at places where the testers chose not to test.

 

As for the aerodynamics of a bladed spoke....spokes trail each other and rtide in each others' slipstreams. A bladed spoke only has a marginally better aerodynamic profile than a flat one. I think the expense makes them impractical. Also, if you own a set of bladed spoke wheels and round wheels, you'll know that it is much nicer to handle the round spokes  when washing, handling and repairing. The bladed spokes are sharp and uncomfortable to handle.

 

JB