# Looking for feedback on Ritchey WCS wheels



## Nessism

2007 WCS Protocol wheels available from ebay for $400 shipped. 20/24 flat blade spokes and medium low profile rims. I know that Ritchey wheels don't have the best reputation but what say ye?

http://cgi.ebay.com/07-RITCHEY-WCS-...4QQihZ007QQcategoryZ58098QQrdZ1QQcmdZViewItem


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## Lectron

Now with the new hubs I believe they should be OK. 

The spoke failure problem from previous models should also
from what I hear not be an issue anymore


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## Nessism

One thing I like is that they are NOT radial laced. I'm kind of a retro grouch, and an engineer, and radial lacing doesn't make sense to me other than the marginally better lateral stiffness. 

Think I'm going to be ginny pig and order these...


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## rruff

Nessism said:


> radial lacing doesn't make sense to me other than the marginally better lateral stiffness.


Unless they were suffering flange failures, what is the problem with radial?

On second look, I'm not too keen on the narrow flange spacing and the NDS flange being bigger than the DS... what would be the purpose of that?


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## steel515

i have a hub that was raidal spoked. can I use 2 cross?


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## Nessism

rruff said:


> Unless they were suffering flange failures, what is the problem with radial?
> 
> On second look, I'm not too keen on the narrow flange spacing and the NDS flange being bigger than the DS... what would be the purpose of that?


Crossed spoke patterns support the hub better when torque is being transmitted - either power or braking.  

Not sure about the flange differences - marketing maybe.  The narrow flange spacing is Ritchey's way of balancing the tension in the rear spokes - that and the offset rim. I honestly don't know how much difference it all makes in the end. Most likely not much.


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## rruff

Nessism said:


> Crossed spoke patterns support the hub better when torque is being transmitted - either power or braking.


We need crossed spokes to transfer torque, but with rim brakes there is no braking torque... which is why radial laced front wheels are so common.

On a rear wheel it's kind of a mixed bag as far as radial lacing the NDS is concerned. If they are crossed like the DS, then the leading spokes can lose significant tension due to torque and go slack... which is a bad thing. If the NDS flange is smaller or the hub body narrow, then it is less of a concern. On the other hand if those spokes are radial laced then the DS must take all the torque loads. 

What Ritchey did was make the NDS flange *larger* in diameter... and I can't see any point to that at all. I'm not a fan of narrow flange spacing either because it reduces the lateral stiffness of the wheel. That doesn't mean that the wheels are junk though... if the components are good and they are well built they should be ok.


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## steel515

NDS larger in diameter= shorter spokes= stiffer wheel?


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## rruff

steel515 said:


> NDS larger in diameter= shorter spokes= stiffer wheel?


The same effect could be achieved by making the spokes a couple percent larger in cross section... and with probably less weight. If stiffness is your goal then a wider flange spacing is the most sensible approach.


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## Nessism

rruff said:


> We need crossed spokes to transfer torque, but with rim brakes there is no braking torque... which is why radial laced front wheels are so common.
> 
> On a rear wheel it's kind of a mixed bag as far as radial lacing the NDS is concerned. If they are crossed like the DS, then the leading spokes can lose significant tension due to torque and go slack... which is a bad thing. If the NDS flange is smaller or the hub body narrow, then it is less of a concern. On the other hand if those spokes are radial laced then the DS must take all the torque loads.
> 
> What Ritchey did was make the NDS flange *larger* in diameter... and I can't see any point to that at all. I'm not a fan of narrow flange spacing either because it reduces the lateral stiffness of the wheel. That doesn't mean that the wheels are junk though... if the components are good and they are well built they should be ok.


No torque in front wheel? Brake pads slow the rim which in part transfers the change in angular rotation through the spokes..hub...entire bike. Major torque.


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## rruff

There essentially no torque transfered from the hub to the rim... torque is transfered along the circumference of the rim only, and the spokes do not have to carry this. With a disk brake the spokes have to transfer 100% of the torque.


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## Lab Worker

rruff said:


> If stiffness is your goal then a wider flange spacing is the most sensible approach.


This is diffcult to do on a rear wheel because of the limitations of the freehub. Moving the NDS flange outwards will increase lateral stiffness, however it also reduces the spoke tension on these NDS spokes. It's a double edged sward.

In my research the most effective way to increase lateral stiffness is to use a spoke with a larger cross-section. Bladed spokes like the CX-Ray and Aerolite weigh about the same as Revolutions or Lasers, however the round spokes significantly increase lateral stiffness.


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## rruff

Lab Worker said:


> In my research the most effective way to increase lateral stiffness is to use a spoke with a larger cross-section. Bladed spokes like the CX-Ray and Aerolite weigh about the same as Revolutions or Lasers, however the round spokes significantly increase lateral stiffness.


Did you measure this? The cross sectional area of all these spokes is the same, so their stiffness will be the same. 

Increasing the bracing angle is the best approach up to a point. The lateral stiffness actually increases at a faster rate than the tension drops. The DS spacing is stuck at ~18-19mm because of the cluster, and it seems that ~36mm is the sweet spot for the NDS... so you end up with a 2:1 ratio of tension on the back wheel. Even with the low NDS tension the wheel will still take a bigger lateral load before those spokes go slack compared to a narrow flanged hub. If you don't put enough tension in the wheel, then you will have problems with the NDS spokes going slack due to radial loads. If you use a shallow rim that can't take high tension it is a good idea to use an OC rim, but a stronger rim should be able to take 120-130kg on the NDS, and 60-65kg on the NDS seems to be enough for most people... if the spoke counts are properly selected.


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## Nessism

In the Ritchey catalog there is a background diagram that shows the rear hub flange spacing at 46mm. Dura Ace 9 speed rear flange spacing is 54mm by comparison. 

One question: the tall flange on the NDS increases the bracing angle no?


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## rruff

Nessism said:


> One question: the tall flange on the NDS increases the bracing angle no?


Yes, but if increasing the bracing angle (lateral stiffness) is your aim, then why not just move the NDS flange over a little? Seems like it would be lighter overall and avoid potential issues with the NDS spokes going slack from torque.


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## Lab Worker

rruff said:


> Did you measure this? The cross sectional area of all these spokes is the same, so their stiffness will be the same.


Yes, I measured this. A few months ago I built a test jig to find out what the importance of spoke type, spoke lacing pattern, hub flange width, and rim type were on lateral stiffness. The jig holds the wheel very securely by the axle and uses a digital strain gauge to apply a load to one side of the rim. The deflection is measured to 0.01mm by a DTI.

The cross-section (not cross-sectional area) of an Aerolite and Revolution is not the same. The Revolutions I've tested are the 2.0/1.5mm/2.0mm variety, whereas the Aerolites are only 0.9mm wide (in cross section). Since spokes are effectively columns under tension I think the spokes second-moment of area (I-value) around its two axis which would affect stiffness.



rruff said:


> Increasing the bracing angle is the best approach up to a point. The lateral stiffness actually increases at a faster rate than the tension drops. The DS spacing is stuck at ~18-19mm because of the cluster, and it seems that ~36mm is the sweet spot for the NDS... so you end up with a 2:1 ratio of tension on the back wheel. Even with the low NDS tension the wheel will still take a bigger lateral load before those spokes go slack compared to a narrow flanged hub. If you don't put enough tension in the wheel, then you will have problems with the NDS spokes going slack due to radial loads. If you use a shallow rim that can't take high tension it is a good idea to use an OC rim, but a stronger rim should be able to take 120-130kg on the NDS, and 60-65kg on the NDS seems to be enough for most people... if the spoke counts are properly selected.


The problem (as you say) is that by moving the NDS flange outwards the spoke tension on the NDS side drops. This is fine until a point*, but if you continue past this point then the NDS spokes are so slack that (1) they need a mechanical retainer to stop the spokes unwinding, (2) they become so slack in the wheel that lateral stiffness actually decreases.**

*This point varies depending on the other factors in a wheel.

** I'm not 100% sure about this, but the data I have indicates this trend. To test it accurately I would have to machine a hub which has the NDS flange spaced out further than the industry norm. This only applies to rear wheels where the DS flange spacing is fixed at ~19mm....on a front wheel where the flanges are symmetrical the data shows that the wider the flange spacing the stiffer the wheel (which is what we all expect)


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## rruff

That looks like a very cool rig! Have you published your results anywhere... or would you like to post them here?



Lab Worker said:


> Since spokes are effectively columns under tension I think the spokes second-moment of area (I-value) around its two axis which would affect stiffness.


Compared to the axial stiffness, the bending stiffness of a spoke is super tiny. It resembles a thread more than a column. Look at how much force it takes to bend a spoke sideways a couple mm and compare this to the amount of force necessary to stretch a spoke along it's length. I don't see how the difference in bending stiffness of the spokes could have a measurable effect on the lateral stiffness of the wheel.



> they become so slack in the wheel that lateral stiffness actually decreases.


Yes, we must keep the spokes from going slack because that is when the stiffness goes way down.


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## Lab Worker

rruff said:


> That looks like a very cool rig! Have you published your results anywhere... or would you like to post them here?


I haven't published results yet. As you can imagine there are a lot of variables: considering only one rim you have to look at 1) spoke type (of which I've tried to consider three: DT Comp, DT Revo, DT Aerolite), 2) spoke lacing pattern (of which I've tried to consider radial, 2x and 3x) and 3) hub type (of which I've tried to keep as constant as possible). My data still has holes in it, once it's complete I'll share the results.

I will say that I've tested a few 'factory' wheels, and most of these are not particularly stiff, despite all the acronyms in the marketing blurb ;-)



rruff said:


> Look at how much force it takes to bend a spoke sideways a couple mm and compare this to the amount of force necessary to stretch a spoke along it's length.
> 
> I don't see how the difference in bending stiffness of the spokes could have a measurable effect on the lateral stiffness of the wheel.


I agree with what you're saying in theory, however the data doesn't reflect this. With the same rim and hub a wheel laced with Revolutions is laterally stiffer than one laced with CX-Rays.

The difference in bending forces is HUGE though. Look at when you use a tension meter; bladed spokes will deflect around twice as much as a round spoke when under the same tension.

More research is needed


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## rruff

Lab Worker said:


> The difference in bending forces is HUGE though. Look at when you use a tension meter; bladed spokes will deflect around twice as much as a round spoke when under the same tension.


The difference in bending stiffness *is* large... but it is still the difference between two insignificantly small numbers compared to the axial stiffness. Have you ever used an FSA tensiometer? It works on the principal that the deflection is *independant* (almost) on the bending stiffness of the spoke. In other words the spoke acts like a thread.


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## Lab Worker

rruff said:


> Have you ever used an FSA tensiometer? It works on the principal that the deflection is *independant* (almost) on the bending stiffness of the spoke. In other words the spoke acts like a thread.


No, I haven't but I would like to. I thought it worked on the same principle as other spoke tension meters: support the spoke, apply a lateral load and measure deflection. How is the FSA different?


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## rruff

It is the same... but only the FSA measures and supports at the same side of the spoke. The others support on one side and measure from the other, so spoke thickness must be accounted for. But in either method the bending stiffness of the spoke is not a major contributor.


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## Lab Worker

rruff said:


> It is the same... but only the FSA measures and supports at the same side of the spoke. The others support on one side and measure from the other, so spoke thickness must be accounted for. But in either method the bending stiffness of the spoke is not a major contributor.


How does the FSA support the spoke and apply load from the same side? Without supporting the other side of the spoke would it not push itself away from the spoke?

I think that the second moment of area ('I' value) is what a tension meter is pushing 'against'. I just approximated the shape of an Aerolite and calculated the I value about the two axis: around the 'long' axis, the way a tension meter measures, the I value is about 1/6th of the 'short' axis, and just under 1/2 of a round 1.5mm diameter spoke like a Revolution. I can post the calcs if you'd like to check them?

This is a pretty good thread-hijack :blush2:


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## rruff

Lab Worker said:


> How does the FSA support the spoke and apply load from the same side? Without supporting the other side of the spoke would it not push itself away from the spoke?


The support and measurement are on the same side. A load is applied on the other side of the spoke, and pushes the spoke against the dial gauge. 

I know that the "I" values are very different... but that isn't what the tensiometer is measuring. A tensiometer is trying to measure tension in the spoke, and to a close approximation we can assume the the bending stiffness of the spoke is insignificant. If we know the force being applied at the midpoint between the supports, and we know the deflection, then the tension can be calculated via a force balance.

Note that if bending stiffness can be ignored in a tensiometer, it can even more easily be ignored in a wheel, because the spoke is much longer than the test section of the tensiometer.


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## Lab Worker

rruff said:


> The support and measurement are on the same side. A load is applied on the other side of the spoke, and pushes the spoke against the dial gauge.


Got it, thanks. I understand what you mean about removing the spoke width from the equation.



rruff said:


> Note that if bending stiffness can be ignored in a tensiometer, it can even more easily be ignored in a wheel, because the spoke is much longer than the test section of the tensiometer.


But I don't think we can ignore bending stiffness: If we did ignore it then all spokes under a tension of 1000N would register the same deflection on a tension meter....which they don't. A spoke like the Aerolite will meausre about 4 times the deflection of a straight-guage 2.0mm Champion.


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## rruff

It can be (and is) ignored with the FSA unit because you don't have to compensate for the thickness of the spoke. 

FSA does supply 3 curves to cover the range of all available spoke bending stiffness, but they are all close to each other. For instance for a tension of 100kg, the corresponding deflection is:

2.0-2.3mm dia spoke = .34mm
0.9-1.8mm dia spoke = .37mm
1.8x5.2mm Al spoke = .34mm

So I don't know where you are getting a 4x deflection ratio... it is more like a 10% difference max.


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## CycleMonkey

Any of you fellers know of a hub that's got a wider NDS than 36mm?

rruff, where did you get your FSA tensiometer? I thought Quality had them, but I just checked and it's not listed. It's not listed on the FSA site either for that matter.

Neil


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## Lab Worker

CycleMonkey said:


> Any of you fellers know of a hub that's got a wider NDS than 36mm?


I've got some hubs where the flange is somewhere around 42mm. They were purchased as samples to build to carbon rims, however it was one step above impossible to build a decent wheel from them. The only way I managed to have tension on both sides was to lace DS radial and NDS 2 cross. The rims had a 1000N max tension which is why it was so difficult.


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## CycleMonkey

Are they readily available? Brand? I'm looking for options for triplet lacing. Ligero alluded to something a few weeks back, but no details.

Neil


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## Lab Worker

CycleMonkey said:


> Are they readily available? Brand? I'm looking for options for triplet lacing. Ligero alluded to something a few weeks back, but no details.
> 
> Neil


They were available but a model change has made them obsolete.

The flange really was too far off centerline: the spokes sat so far into clear air that drag would be huge, and clearance issues would arise on some frames.

I don't think these would be whatever Ligero was hinting at.

I've pm-d you the details.

Tristan


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## rruff

CycleMonkey said:


> rruff, where did you get your FSA tensiometer? I thought Quality had them, but I just checked and it's not listed. It's not listed on the FSA site either for that matter.


I got mine via BTI. There was a guy selling them on ebay awhile back too.

About the triplet hubs, having the NDS flange spaced way over is a good thing. Maybe the spokes are out in the wind a bit more, but also remember that there are only half as many.


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## CycleMonkey

The wind reaching those spokes has a crank arm, seatstay, chainstay, and maybe a lower leg in front of it anyway.

The Zipp website makes it sound as if the number of spokes doesn't have much effect on wheel wind drag. After one spoke "chops" up the air, the next ones should pass through much more easily, right???


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## rruff

Don't believe everything you read. The number of spokes has a measurable effect looking at Tours data, and so does the spoke shape and size. It seems to be less pronounced than the effect of rim depth, and there is so much scatter that it is hard to pin a number on it. 

I'd love to see a series of tests done to isolate that factor...


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## kramerrides

Nessism said:


> Think I'm going to be ginny pig and order these...



Any update on this, Nessism?


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## Sandy Z

*Death of a Hub*

You all seem very interested in wheels and wheel forces. Today, my friend and I were just riding along on our 2006 Ritchey Protocol wheelsets. Suddenly, a spoke on my friends radially-laced front wheel pulled out a hunk of the front hub flange. We have not yet located the hub debris.

This is a scarey type of failure. We were on a downhill so twisty and steep we were going very slowly. If this had happened at speed, he would have been launched (lunched?)

Thoughts about possible causes? Ritchey says this is a rare type of failure. No impact immediately preceeding the event. No other damage apparent. Ever heard of this type of failure?

Thanks


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