These Japanese Engineers Invented $7,900 Bike Wheels

[Keith A]

Have a few extra pennies to spend on some wheels? Then you might want to check these out...
http://www.bloomberg.com/news/articles/2015-03-18/japanese-engineers-reinvent-the-wheel

http://media.gotraffic.net/images/in00qdwKYdRU/v1/1200x-1.jpg

[Dead Man]

The article didn't even give a weight....

[Keith A]

Here's their website...not sure if the specs are there or not.
http://www.gokiso.jp/en/products/wheel.html

Yep, the specs are here...
http://www.gokiso.jp/en/products/wheel.html#pricelist

[ergott]

Except that's the least ideal lacing pattern for a rear wheel.

They have a lot to learn about wheels and basic geometry.

[mtechnica]

They have a lot to learn about wheels and basic geometry.

Right I'm sure these guys don't understand engineering or geometry at all :rolleyes:

[Dead Man]

Wow... 1800g tubular wheelset for $7900.. am I misreading something?

[ergott]

That rear hub lacing isn't one of a well engineered hub and spoke pattern. Sorry.

[Dead Man]

Right I'm sure these guys don't understand engineering or geometry at all :rolleyes:

Apparently not when it comes to bikes. "super climber" right!

[josephr]

Apparently not when it comes to bikes. "super climber" right!

the weight loss comes from the 7900 gram reduction in the wallet!

[Cicli]

They would be cooler of they were Rapha.

[Likes2ridefar]

would love to try them out.

[Dead Man]

would love to try them out.

I'd ride an 1800g wheelset, but you'd have to incentivize it for me somehow. Taking $7900 from me just wouldn't quite meet the threshold.

[Likes2ridefar]

I'd ride an 1800g wheelset, but you'd have to incentivize it for me somehow. Taking $7900 from me just wouldn't quite meet the threshold.

It's been shown again (and again) weight is not as important as aerodynamics or rolling resistance until you meet a certain % grade that is rarely experienced in race situations and doesn't matter in all other conditions.

cut and paste from their site:

GOKISO Wheel is not a "ultra-light wheel".

[Dead Man]

It's been shown again (and again) weight is not as important as aerodynamics or rolling resistance until you meet a certain % grade that is rarely experienced in race situations and doesn't matter in all other conditions.

cut and paste from their site:

GOKISO Wheel is not a "ultra-light wheel".

but they call it "super climber"

[odin99]

light weight. cheap. durable...

not light weight
not cheap
questionable lacing pattern...

they may have missed a few marks.

[thirdgenbird]

Except that's the least ideal lacing pattern for a rear wheel.

They could have done radial on both sides. :)

[Mark McM]

Here's their website...not sure if the specs are there or not.
http://www.gokiso.jp/en/products/wheel.html

Here's my favorite quote from this web page:

You can feel the acceleration even when you stop pedaling.

So, these wheels must incorporate some kind of motor?

[ergott]

Yes, I lied. There are worse patterns. Remember when Zipp did radial drive?

The problem is these engineers hyper-analyzed reducing mechanical drag and didn't look at the entire wheel design.

[Mark McM]

Except that's the least ideal lacing pattern for a rear wheel.

What's the most ideal pattern?

[MattTuck]

Ahh crap. My bike is obsolete now. Guess I need to throw it in the dumpster and start with a new carbon frame and these wheels. :rolleyes:

[Mark McM]

Yes, I lied. There are worse patterns. Remember when Zipp did radial drive?

The problem is these engineers hyper-analyzed reducing mechanical drag and didn't look at the entire wheel design.

What about FSA's triple flange RD-600 wheels?

http://autobus.cyclingnews.com/photos/2005/tech/newarrivals/jun30/fsa_rd-600_wheels13.jpg

[fuzzalow]

What's the most ideal pattern?

Radial on the drive side, crossed inside-pulling spokes on the NDS with a hub that can transfer torque from the cassette carrier through the center of the hub to the driving spoke flange on the NDS.

[45K10]

What about FSA's triple flange RD-600 wheels?

http://autobus.cyclingnews.com/photos/2005/tech/newarrivals/jun30/fsa_rd-600_wheels13.jpg

My ex-wife had a pair of these,
I am glad her and the wheels are gone :banana:

[Likes2ridefar]

What's the most ideal pattern?

there is no ideal pattern.

[Bob Ross]

Is Lightweight/CarbonSports GmbH really doing such a swift business with their Obermeyers or Ünterhausens or whatever-they're-called wheels that someone said "Looks like there's plenty of demand in the marketplace for another set of wheels that cost more than most frames!" ?

[bicycletricycle]

whats exactly is wrong with the lacing pattern?

The reduced tension on the non drive side means the pulling spokes do very little so why not go radial?

[bicycletricycle]

the spherical end caps that automatically adjust for inaccuracies in dropout alignment are interesting.

i wonder if you can feel the suspension in the hub

[RedRider]

Is Lightweight/CarbonSports GmbH really doing such a swift business with their Obermeyers or Ünterhausens or whatever-they're-called wheels that someone said "Looks like there's plenty of demand in the marketplace for another set of wheels that cost more than most frames!" ?

Yes. It's a sliver of the big wheel market but there is a strong demand for these and other high end wheels.

[oldpotatoe]

What's the most ideal pattern?

24spoke, 2 cross right and radial left. Carbon rim....not lookin' to argue but isn't that pretty common with a lot of carbon wheels, that pattern??

Don understand comment either.

[dustyrider]

Aren't we really missing the major issues here? Where's the rotor go for brakes? What about through axles? Didn't they get the memo about the new boost standard!?

[Kirk Pacenti]

I've seen the hubs in person; they are extremely well made. I was particularly drawn to the extra wide drive ring and pawls. The weight didn't bother me too much - from a real world stand point, it simply doesn't matter.

The end caps are an ingenious feature, but I'm dubious of the suspension. And given the cost and the market's demand for all things 'light weight', I think they're just over engineered and for all intents and purposes, un-sellable... at least in the US...

[oldpotatoe]

Radial on the drive side, crossed inside-pulling spokes on the NDS with a hub that can transfer torque from the cassette carrier through the center of the hub to the driving spoke flange on the NDS.

Except outside pulling for 24 2 cross.:eek::cool:d

[sparky33]

These engineers did not 'invent' ridiculously expensive bicycle wheels.

We've had those for some time now.

[Mark McM]

whats exactly is wrong with the lacing pattern?

The reduced tension on the non drive side means the pulling spokes do very little so why not go radial?

As long as the spokes don't completely slacken (tension reduced to zero), the static pre-tension has no effect on how drive loads are divided between drive side and non-drive side spokes. That's a matter of the geometries and relative elasticities of the components.

[Mark McM]

24spoke, 2 cross right and radial left. Carbon rim....not lookin' to argue but isn't that pretty common with a lot of carbon wheels, that pattern??

And the same spoke pattern is used on a lot of wheels with metal rims too - like the Ford Model A. If it was good enough for Henry, it's good enough for me!

http://www.kenrockwell.com/trips/2010-05-nyc/5-31/IMG_7539-yellow-wheels.jpg

[deechee]

really? I thought the part about Sharp's fridge making clear ice cubes far more interesting.

Talk about fluff piece. The guy doesn't even mention what city or prefecture these two live in. Ugh. And the Japanese phone export problem has never been about over-engineering, its about the ridiculous demand for flip phones with physical buttons. Bad analogy.

[bicycletricycle]

When chub hubs were first made they had a section on their website showing the research that led them to the huge flanges, they replaced four pulling spokes on both the drive side and non drive side of a wheel and applied drive load, they could see that the drive side spokes took up almost twice as much load as the non drive. That was on an undished wheel with equal tension.

I always thought that was strange

the huge flanges seemed to solve this



I think that the static pre tension does matter. When drive load is applied the pulling spokes increase in tension deflecting the detensioned non pulling spokes in an attempt to provide the straightest path for the load to travel. The drive spokes have less ability to deflect because their static position is closer to the maximum deflection they will see under load and thus are able to efficiently transfer drive load at a lower power level keeping the non drive from doing as much work.

that makes no sense but is how i always imagined it.

i am not an engineer

:)

[bicycletricycle]

i think those are 1 cross

And the same spoke pattern is used on a lot of wheels with metal rims too - like the Ford Model A. If it was good enough for Henry, it's good enough for me!

http://www.kenrockwell.com/trips/2010-05-nyc/5-31/IMG_7539-yellow-wheels.jpg

[Mark McM]

When chub hubs were first made they had a section on their website showing the research that led them to the huge flanges, they replaced four pulling spokes on both the drive side and non drive side of a wheel and applied drive load, they could see that the drive side spokes took up almost twice as much load as the non drive. That was on an undished wheel with equal tension.

I always thought that was strange

the huge flanges seemed to solve this

The biggest difference between the drive side and non-drive side spokes is the load path - the torque is applied from the freehub to the drive side of the hub, and nearly directly to the drive side spokes. For the non-drive side, it has to pass through the hub spool before it gets to the non-drive side spokes. So if the hub spool can twist, even just a little bit, less of the torque will be passed to the non-drive side spokes.



I think that the static pre tension does matter. When drive load is applied the pulling spokes increase in tension deflecting the detensioned non pulling spokes in an attempt to provide the straightest path for the load to travel. The drive spokes have less ability to deflect because their static position is closer to the maximum deflection they will see under load and thus are able to efficiently transfer drive load at a lower power level keeping the non drive from doing as much work.

that makes no sense but is how i always imagined it.

i am not an engineer

:)

Metal behaves in a linearly elastic way, so the relative response will be same, regardless of their initial load. Consider a simple spring scale:

http://cdn.xump.com/Newton-Spring-Scale-5N-500A.jpg

If the 1 gram graduations are 1 mm apart, that means that for every additional gram of load you add, the spring stretches an addition millimeter. Say you wanted to measure 200 gram of salami, and your weighing pan weighed 100 grams. After hanging the pan, the spring would be stretched 100 mm. Add 200 grams of salami (300 grams total), and the total stretch would be 300 mm. The 100 grams/first 100 mm is the 'preload' and the next 200 grams/200 mm is the 'working load'

What if the pan weighed 300 grams instead? Then the total stretch would be 500 mm - 300 mm for the work 'preload', plus 200 mm for the 'working load'. In other words, the reaction for the 'working load' is the same, regardless of the 'preload'

The same holds true for spokes - the preload doesn't affect the response to the working load.

[bicycletricycle]

the elasticity of steel as evidenced by the spring in a scale is relevant but not directly applicable? A wheel system is much more complicated than a simple scale.

The chub hub experiment seems to prove the direct load path reason for drive side spokes doing more work. I just don't believe that hub shell twist is a factor in anything but the most ridiculously light hubs

On the ride home, if we had the same wheel , one with 2x drive and radial non and the other built the opposite , I think the wheel using the lower tensioned non drive crossed spokes would twist the hub more before transferring the load to the rim.

In the opposite case the higher tensioned crossed spokes would transmit the drive force more readily reducing the amount of hub twist.

If both sides were crossed than surely the same would be true, the crossed drive spokes would transmit the load before the hub could twist enough to "Engage" the non drive spokes.

To me this doesn't have anything to do with the spokes ability to transmit the load but their opportunity to do so.

Either way, the direct load path seems to prefer the drive side out of shear proximity, making the drive side the best place to cross the spokes regardless of the disparity in tension.

[ergott]

So if the hub spool can twist, even just a little bit, less of the torque will be passed to the non-drive side spokes.


Less, but not zero. Also, that hub shell looks fairly oversized. It should transmit a good deal of torque from the non drive side flange.

If that's the case, why not make both sides 2X? Radial heads in reduces lateral stiffness and also reduces the hubs ability to transmit torque.

Another point. With radial on the left side the nipples are more likely to back off the spoke threads. I've seen far more wheels in my days go out of true because of this than anything else. Crossed spokes have the spokes leaving the rim at an angle and are less likely to go slack. If you reduce the center to left distance enough to have significant tension to avoid this issue you further reduce lateral stiffness in the wheel.

[Grant McLean]

Either way, the direct load path seems to prefer the drive side out of shear proximity, making the drive side the best place to cross the spokes regardless of the disparity in tension.

Mavic has been doing the radial drive spokes on some models of Ksyrium
for about 10 years. The bracing and orientation of the flanges seem to
be chosen to give more spoke clearance on the drive side for the derailleur.

http://www.bikebug.com/images/Mavic%20Ksyrium%20SLS%20large%20E.jpg

[oldpotatoe]

Less, but not zero. Also, that hub shell looks fairly oversized. It should transmit a good deal of torque from the non drive side flange.

If that's the case, why not make both sides 2X? Radial heads in reduces lateral stiffness and also reduces the hubs ability to transmit torque.

Another point. With radial on the left side the nipples are more likely to back off the spoke threads. I've seen far more wheels in my days go out of true because of this than anything else. Crossed spokes have the spokes leaving the rim at an angle and are less likely to go slack. If you reduce the center to left distance enough to have significant tension to avoid this issue you further reduce lateral stiffness in the wheel.

Ohh, I get it and I agree. I don't do 'goofy' lacing, radial NDS on any wheels I build either but the 24 2 cross right, radial left, radial front 20..is almost a standard on a lot of wheelsouttaboxes. I think radial anything is the stuff of weak wheelbuilders.

[Pastashop]

the elasticity of steel as evidenced by the spring in a scale is relevant but not directly applicable? A wheel system is much more complicated than a simple scale.



The chub hub experiment seems to prove the direct load path reason for drive side spokes doing more work. I just don't believe that hub shell twist is a factor in anything but the most ridiculously light hubs



On the ride home, if we had the same wheel , one with 2x drive and radial non and the other built the opposite , I think the wheel using the lower tensioned non drive crossed spokes would twist the hub more before transferring the load to the rim.



In the opposite case the higher tensioned crossed spokes would transmit the drive force more readily reducing the amount of hub twist.



If both sides were crossed than surely the same would be true, the crossed drive spokes would transmit the load before the hub could twist enough to "Engage" the non drive spokes.



To me this doesn't have anything to do with the spokes ability to transmit the load but their opportunity to do so.



Either way, the direct load path seems to prefer the drive side out of shear proximity, making the drive side the best place to cross the spokes regardless of the disparity in tension.


The drive side "pulling" spokes will experience a higher peak tension than the drive side non-pulling spikes. But the actual work they do during the power stroke is about the same as the other spokes, because the system behaves exactly as Mark McM explained, in its elastic regime. We can be confident that it is in its elastic regime, because the spoke and rim and eyelet and nipple and hub flange deformations (after the wheel is stress relieved) are very tiny, the components are metal, and therefore nearly 100% elastic.

Incidentally, the above (elastic, cyclic elongation/contraction) also means that the output pedaling energy that makes it to the hub is returned (i.e. not lost to heat) during the non-power strike portion of the cycle. The only place any waste heat is generated (causing parasitic energy loss) really goes is into the tire. But compared to the energy loss in the tire due to the squishing of it by the ground, that's negligible.

[ergott]

The bracing and orientation of the flanges seem to be chosen to give more spoke clearance on the drive side for the derailleur.


Except that the flange placement isn't the limiting factor for derailleur clearance. You can have a right flange far enough from center to have spokes rub the derailleur before anything else hits.

Go measure the distance between a derailleur and the spokes and see just how much room for improvement there is with the Mavics.

[ultraman6970]

I believe was here where I saw those hubs like 2 years ago, their concept is nice, stiffer axle, more bearings than anybody, wonder if they can be accelerated as quick as nice as lose balls hubs.

But for 10.000 bucks is better to have a dinner ticket with Ms. Ozawa included.

[oldpotatoe]

Mavic has been doing the radial drive spokes on some models of Ksyrium
for about 10 years. The bracing and orientation of the flanges seem to
be chosen to give more spoke clearance on the drive side for the derailleur.

http://www.bikebug.com/images/Mavic%20Ksyrium%20SLS%20large%20E.jpg

Some Mavic guy told me it was cuz crossing those big, fat aluminum spokes would compromise clearance between them and rear der.

[Pastashop]

Some Mavic guy told me it was cuz crossing those big, fat aluminum spokes would compromise clearance between them and rear der.


I suspect they do this to avoid any contact between Al spokes. Al doesn't have a stress / fatigue limit like steel does, so any amount of force would cause it to weaken a little bit. Given the number of stress cycles that a wheel undergoes, a relatively thin, braced spoke made of Al would be prone to failing much sooner than a steel spoke.

[Mark McM]

the elasticity of steel as evidenced by the spring in a scale is relevant but not directly applicable? A wheel system is much more complicated than a simple scale.

It's still an elastic structure, so it will still behave linearly. Damon Rinard (an engineer who has designed bikes for many companies, including Trek, Cervelo and Cannondale) has published data from a set of stiffness testing on a wide range of wheels (see the test and results here (http://www.sheldonbrown.com/rinard/wheel/index.htm)). One of his tests involved testing the lateral stiffness of a wheel with varying amounts of spoke static tension. Here's what he found:

1. Does stiffness vary with spoke tension?
Some believe that a wheel built with tighter spokes is stiffer. It is not. Wheel stiffness does not vary significantly with spoke tension unless a spoke becomes totally slack.
I measured the deflection of Wheel #2 while gradually loosening the spokes in quarter turn increments. The wheel did not display any significant change in stiffness until the spokes were so loose some became totally slack.



The chub hub experiment seems to prove the direct load path reason for drive side spokes doing more work. I just don't believe that hub shell twist is a factor in anything but the most ridiculously light hubs

On the ride home, if we had the same wheel , one with 2x drive and radial non and the other built the opposite , I think the wheel using the lower tensioned non drive crossed spokes would twist the hub more before transferring the load to the rim.

In the opposite case the higher tensioned crossed spokes would transmit the drive force more readily reducing the amount of hub twist.

If both sides were crossed than surely the same would be true, the crossed drive spokes would transmit the load before the hub could twist enough to "Engage" the non drive spokes.

To me this doesn't have anything to do with the spokes ability to transmit the load but their opportunity to do so.

Again, because the structure is linearly elastic, and because the load distribution is dependent only on the relative elasticity of the members, the static pretension will play no role in distributing loads around the structure.

The distribution of torque between the two sides of the wheel was covered in the "The Bicycle Wheel" by Jobst Brandt, the bible of wheel operation and mechanics (pdf copy here (poehali.net/attach/Bicycle_Wheel_-_Jobst_Brandt.pdf)). Below is what he wrote on the subject (note: the book was written before freehubs were common, and most rear hubs had narrow shafts between the flanges):

TORSIONAL STIFFNESS OF THE REAR HUB
Torque transmission is more than adequate in hubs used today. Therefore, the
following discussion is of more theoretical than practical interest.
Some torque from the right side of the hub is transmitted through the hub shaft
to the opposite flange (see Equation 5 in Part III). The torsional stiffness of this
shaft determines how much torque will be transmitted. The shafts of most
aluminum alloy rear hubs are relatively weak and have a torsional stiffness of
about 30 Nm per degree of twist. This is considerably less than the torque
stiffness of the crossed spokes, but it is enough to transmit thirteen percent of
the torque in a tangentially spoked small-flange hub. In a large-flange hub only
seven percent of the torque is transmitted through the shaft because, in
comparison with the small-flange hub, the effective spoke stiffness is much
greater. In a high-low-flange hub, with a right flange larger than the left flange,
nearly all torque is transmitted by the spokes on the right side of the wheel.
Some hubs with large-diameter shafts have such a high torsional stiffness that
torque is distributed almost equally to both sides of the wheel. This design
feature makes small-flange hubs as stiff torsionally as conventional large-flange
hubs. Track-racing hubs, that accommodate only a single sprocket rather than
multiple sprockets, have their flanges so widely spaced that their shafts transmit
less than five percent of the driving torque to the left side of the wheel (see
Equation 6 in Part III).

If the Chub hub has more even right/left torque distribution, it is because it has a very fat shaft, not because of the flange size or spoke tension.

http://digitalhippie.net/wp-content/uploads/2009/04/chub_hub_black.jpg

[Mark McM]

Another point. With radial on the left side the nipples are more likely to back off the spoke threads. I've seen far more wheels in my days go out of true because of this than anything else. Crossed spokes have the spokes leaving the rim at an angle and are less likely to go slack. If you reduce the center to left distance enough to have significant tension to avoid this issue you further reduce lateral stiffness in the wheel.

Interestingly, Sheldon Brown wrote just the opposite about half-radial wheels on his web page on wheel building (http://sheldonbrown.com/wheelbuild.html):

A spoked wheel relies on having all of the spokes in constant tension. A highly-dished rear wheel starts with very light tension on the left side spokes. The torque of hard pedaling combined with cyclical weight loading can cause the left-side "leading" spokes occasionally to go completely slack.
Repeated cycles of tension and slackness cause these spokes to fatigue at the bends, and ultimately break.
With half-radial spoking, the amount of dish is very slightly less to begin with if you run the radial spokes up along the inside of the flange ("heads out.") In addition, since there are no left-side "leading" spokes, no amount of torque on the hub can reduce the tension on any of the left-side spokes. In fact, if you have an old wheel that has been breaking left-side spokes, "half rebuilding" the wheel into a half radial will solve the problem once and for all.

Which of these two affects is more significant is likely to depend on a number of factors, including number of spokes, spoke length, and right/left tension differential.

In any case, nipples only unscrew when spokes go completely slack. There are several other methods that can help mitigate non-drive side spoke slackening:

1) Using thinner, more elastic spokes will increase their static "stretch", so the wheel has to be deflected more to completely slacken the spokes. Campagnolo has used this method on some of their wheels, calling it "Differential Spokes".

2) Using a triplet pattern can increase the spoke tension on the non-drive size spokes, decreasing the likelihood of them completely slackening. This system is used by a number of wheel manufacterers.

[Mark McM]

I suspect they do this to avoid any contact between Al spokes. Al doesn't have a stress / fatigue limit like steel does, so any amount of force would cause it to weaken a little bit. Given the number of stress cycles that a wheel undergoes, a relatively thin, braced spoke made of Al would be prone to failing much sooner than a steel spoke.

I think Mavic laces their aluminum drive side spokes radially to maximumize affective bracing angle with aluminum spokes. Aluminum spokes are already much fatter than steel spokes. In addition, crossing the spokes effectively doubles the spoke width at the crossing point (and maybe adding additional space to keep the spokes from touching each other). Since the crossing point is very close to where the derailler cage approaches the spokes, to avoid derailleur/spoke interference, Mavic could either eliminate the crossing by lacing the spokes radially, or move the drive flange inboard (reducing the bracing angle). They chose to lace the spokes radially, and then used a hub with a fat enough shaft to transmit torque loads to the non-drive spokes.

[ergott]

In any case, nipples only unscrew when spokes go completely slack. There are several other methods that can help mitigate non-drive side spoke slackening:

1) Using thinner, more elastic spokes will increase their static "stretch", so the wheel has to be deflected more to completely slacken the spokes. Campagnolo has used this method on some of their wheels, calling it "Differential Spokes".

2) Using a triplet pattern can increase the spoke tension on the non-drive size spokes, decreasing the likelihood of them completely slackening. This system is used by a number of wheel manufacterers.

A crossed pattern is less likely to go slack because it's paired with another spoke instead of a direct line to the rim. The spoke it's crossed with will allow it to deflect more before it can go slack due to this.

[Mark McM]

A crossed pattern is less likely to go slack because it's paired with another spoke instead of a direct line to the rim. The spoke it's crossed with will allow it to deflect more before it can go slack due to this.

This affect can be seen in the data from tests of strain gauge instrumented wheels in the Henri Gavin paper referenced in in a different thread (link here (http://www.duke.edu/~hpgavin/papers/HPGavin-Wheel-Paper.pdf)). Figure 11 shows the strain in an individual spoke as the wheel rotates under load. Load transfers between the cross spokes can be seen as ripples in the spoke strain graph. However, note that the peak strain for radial, 2X, 3X and 4X varies only a small amount - roughly only 5%. This is a relative small affect, and variables (such as flange spacing, spoke thickness) which will have much larger affects.