Question of the day: HED Ardennes + vs. HED Belgium +

[kppolich]

Is there a difference between the Ardennes + and Belgium + rims? If so, what?

[Luwabra]

factory built - ardennes

custom built - belgium

specs are the same im like 99.9% sure anyway

[stien]

Agree with the above. Decals. I personally wouldn't bother with the current stock HED hubs, matte finish. Glossy ones were way better.

[Mark McM]

And unfortunately, the Black version (textured and treated brake tracks) is only available on the Ardennes (pre-built wheels), not on individual rims.

[dddd]

Pre-built wheels will often exploit the added stiffness of straight-pull spokes (and related hub architecture) to utilize a lower spoke count.

This to decrease weight and improve aerodynamics without incurring any flex or reliability issues.

I've built with Belgium rims to utilize a Powertap hub and went with 28 of the superlight spokes and tension up at 140kg for racing weight riders. The rims are a pleasure to build with, but galling of the nipples in the rim sockets sets in over 140kg in my experience.

[Mark McM]

Pre-built wheels will often exploit the added stiffness of straight-pull spokes (and related hub architecture) to utilize a lower spoke count.

This to decrease weight and improve aerodynamics without incurring any flex or reliability issues.

Straight pull spokes do nothing to improve wheel stiffness. Wheel stiffness is primarily a variable of rim stiffness, flange offset, and spoke thickness. In fact, the design of many straight pull hubs results in a reduction in effective flange offset, potentially resulting in reduced wheel stiffness.*


*The reason that some wheels with straight pull spokes use radial lacing on the drive side is to maintain maximum flange offset - this is especially true for those wheels that use fat aluminum spokes, where a crossing the drive side spokes would result in a reduced drive side effective flange offset.

[moobikes]

There was something about the rims on the FR models being a lighter extrusion but they are no longer marketing the FR series.

It's possible the rims on the Black series are lighter than the rest. The Black wheelset is a couple ounces lighter than the SL wheels but spokes and hubs are the same. Only the rims are different.

Other than those two the rest of the range have the same rims as the Belgium +.

Is there a difference between the Ardennes + and Belgium + rims? If so, what?

[Mark McM]

It's possible the rims on the Black series are lighter than the rest. The Black wheelset is a couple ounces lighter than the SL wheels but spokes and hubs are the same. Only the rims are different.

Actually, the weight difference is primarily from different hubs on each wheelset. The Black series wheels have a carbon body front hub and a straight pull spoke rear hub. The non-Black wheels have an aluminum body front hub and a standard elbow spoke rear hub. The difference in rim weight is probably just a few grams due to the difference in machining. The Black series wheels also come with titanium skewers (steel skewers for the standard wheel), but that's probably not included in the weight numbers.

[PaMtbRider]

The ardennes at one time could be had with rims that were scandium. They were marginally lighter than the C2 rim you could buy. I don't think they are available anymore and all rims are the same.

[moobikes]

The hubs and spokes on the SL and the Black wheelsets are the same.


Actually, the weight difference is primarily from different hubs on each wheelset. The Black series wheels have a carbon body front hub and a straight pull spoke rear hub. The non-Black wheels have an aluminum body front hub and a standard elbow spoke rear hub. The difference in rim weight is probably just a few grams due to the difference in machining. The Black series wheels also come with titanium skewers (steel skewers for the standard wheel), but that's probably not included in the weight numbers.

[dddd]

Straight pull spokes do nothing to improve wheel stiffness. Wheel stiffness is primarily a variable of rim stiffness, flange offset, and spoke thickness. In fact, the design of many straight pull hubs results in a reduction in effective flange offset, potentially resulting in reduced wheel stiffness.*


*The reason that some wheels with straight pull spokes use radial lacing on the drive side is to maintain maximum flange offset - this is especially true for those wheels that use fat aluminum spokes, where a crossing the drive side spokes would result in a reduced drive side effective flange offset.

Believe that if you want, but it's not universally true. In fact, the entire spoke and flange interface is more flexible with j-bend spokes, and positioning the spoke heads for optimal spoke bracing need not be compromised at all by the use of straight-pull spokes, since there is plenty of room at the flange. It's the spoke-to-derailer contact vicinity that is what defines the maximum driveside spoke bracing angle (for best rim support and for best spoke tension of the non-drive spokes), but straight-pull spokes do nothing to compromise this.
Just because SOME wheels using straight-pull spokes do a poor job with positioning the spoke heads, this is not a necessary fault of such hubs when well-designed. Even my Roval aero wheels from the early 1980s had their straight-pull driveside spokes in an optimal position for use with freewheels of the day, though used radial spoking on the non-drive side and 2:1 spoking because the rim extrusions were commendably stiff, not because of any inferiority of flange placement of spoke-bracing angle.

There is of course a good reason why virtually all of the highest-performing wheelsets use straight-pull spokes, while their down-market imitators save cost by compromising structural efficiency (stiffness contribution per spoke) with j-bend spokes.

There will always be controversy regarding the best spoke type, since some wheel builders and suppliers are using one type of spoke or the other. Many if not most brands of wheels today offer both types of spokes however, with straight-pull spokes appearing in their lightest and highest-performing wheelsets.

[Mark McM]

Believe that if you want, but it's not universally true. In fact, the entire spoke and flange interface is more flexible with j-bend spokes, and positioning the spoke heads for optimal spoke bracing need not be compromised at all by the use of straight-pull spokes, since there is plenty of room at the flange. It's the spoke-to-derailer contact vicinity that is what defines the maximum driveside spoke bracing angle (for best rim support and for best spoke tension of the non-drive spokes), but straight-pull spokes do nothing to compromise this.

I didn't say all straight pull hubs have non-optimal bracing angles, just that some do. I agree that spoke/derailleur interference is the limit for bracing angle. But some (not all) straight pull hubs hubs place half the spokes at a meaningful distance inboard of this limit.

I don't know why you believe that the spoke flange interface is more flexible with j-bend spokes. Well seated (and stress relieved) j-bend spokes have very little flex at the elbows - measurements have shown that the majority of spoke flex is along the length of the shaft (which makes sense, since the shaft is a much longer, and often thinner, portion of the spoke). I have seen a number of wheel stiffness data (such as in the Damon Rinard test (http://www.sheldonbrown.com/rinard/wheel/data.htm)), and I haven't seen anything to indicate that straight pull spokes make for stiffer wheels. (For me, its not a matter of 'believe that if you want', its about facts and evidence.)


There is of course a good reason why virtually all of the highest-performing wheelsets use straight-pull spokes, while their down-market imitators save cost by compromising structural efficiency (stiffness contribution per spoke) with j-bend spokes.

Oh? And what is that reason? As far as I can tell, straight pull spokes are primarliy used as a product differentiator. Is there any data that shows that straight pull spokes build stronger, 'more efficient' wheels? Straight pull hubs can shave maybe 10 or 20 grams, but at the expense of needing application specific, and often proprietary, components. There are far more important factors in wheel stiffness and durability than the shape of the spoke end.

[Mzilliox]

But is anyone selling a set?

[Andy sti]

But is anyone selling a set?

But you want colored hubs... :)

[Mzilliox]

But you want colored hubs... :)

haha, you are right, after stewing i sent an email to Mr Ergott, and colored hubs are in my future.... FINALLY!

[dddd]

I didn't say all straight pull hubs have non-optimal bracing angles, just that some do. I agree that spoke/derailleur interference is the limit for bracing angle. But some (not all) straight pull hubs hubs place half the spokes at a meaningful distance inboard of this limit.

I don't know why you believe that the spoke flange interface is more flexible with j-bend spokes. Well seated (and stress relieved) j-bend spokes have very little flex at the elbows - measurements have shown that the majority of spoke flex is along the length of the shaft (which makes sense, since the shaft is a much longer, and often thinner, portion of the spoke). I have seen a number of wheel stiffness data (such as in the Damon Rinard test (http://www.sheldonbrown.com/rinard/wheel/data.htm)), and I haven't seen anything to indicate that straight pull spokes make for stiffer wheels. (For me, its not a matter of 'believe that if you want', its about facts and evidence.)


You're right about some wheels having the spokes too far inboard, I think Mavic comes to mind, but still others have copied their approach of having big gaps between crossing spokes and I guess those are the ones you were referring to.

The fact that bent spokes break at the bend suggests some additional flexing at that location, as well as less-than-optimal stress distribution across the cross section of the spoke. The higher-end wheels usually rely on fewer spokes, so both the stiffness and fatigue resistance are paramount in assuring reliability of the entire wheel.

I note that high-mileage and/or heavily weighted Ksyrium wheels not-uncommonly fail at the rim, and some fail at the hub "flange", but in both cases it is along the load path of sub-optimally angled driveside spokes that these wheels meet their maker. So these might be a good example of what you were saying(?).

[Mark McM]

The fact that bent spokes break at the bend suggests some additional flexing at that location, as well as less-than-optimal stress distribution across the cross section of the spoke. The higher-end wheels usually rely on fewer spokes, so both the stiffness and fatigue resistance are paramount in assuring reliability of the entire wheel.

Yes, fatigue failures at the elbows does indicate that there are concentrations of stress and strain at the elbows (strain being the elastic deformation per unit length). However, because the area of high strain is very small, it does not result in a significant flexing of the spoke. The flex of a component is the gross elastic deformation, and is a product of the strain times the length/size of the component. An excessive strain that is highly localized to a small portion of a component does not result in a significant change in total flex.

To give you an idea of the total flex in a spoke: The elbow of a spoke is only a very small part of the spoke, just a millimeter or two, while the spoke may be up to 300 mm long. So most of the flex (elastic stretch) of a spoke occurs in the long straight portion. This is particularly so for spokes with thin cross-sections (such as DT Revolutions of Sapim CX-Rays), which increases the strain in the shaft of the spoke. For thin spokes, the elastic stretch just due to static tension can be more than a millimeter (which is why wheel builder frequently subtract a millimeter from spoke length calculations when using thin spokes in high tension applications). The extra flex due to strain concentrations in the elbow will only be a very small fraction of a millimeter, and therefore only very small percentage of the total flex.

(Of course, a properly built wheel will have the elbows stress-relieved and well seated into the hub flange. This minimizes stress and strain concentrations in the elbow, and can virtually eliminate spoke breakages at the elbow.)

[kppolich]

So they are the same rims, one is hand built, one factory?
factory built - ardennes

custom built - belgium

[tumbler]

So they are the same rims, one is hand built, one factory?

I believe that is the gist of it.