Redesigning the cassette hub

[fiamme red]

Interesting:

http://www.mountainflyermagazine.com/view.php/kappius-components-broken-carbon.html

http://road.cc/content/news/52734-kappius-components-death-freehub

[keevon]

I'm surprised there hasn't been more discussion about this...

http://www.mountainflyermagazine.com/img/upimages/eddie_clark/2012/EClark_2012_Kappius_DSC_4714.jpg

Tough to say exactly how it works, but it almost looks like an adaptation of the screw-on freewheel. Only this time around, it's optimized for the large void space created by SRAM hollow cassettes.

I would imagine that the pawl assembly fits onto splines on the hub shell:
http://www.kappiuscomponents.com/wp-content/uploads/2011/10/4726813861.jpg

The cassette - with special adapter installed inside - fits onto the outer splines of the drive ring. There's a bearing pressed into the skinny end of the cassette that supports the axle.

Interesting that they use rare-earth magnets for pawl engagement, although I guess that means that the toothed drive ring has to be steel. Given how large it is, I wonder how many grams it adds to the hub.

Cool concept. The engagement seems to be the biggest advantage. Although I'm concerned about the fact that the cassette plays an integral role in hub support... might get pricy to replace a worn-out cassette that also includes half of the hub bearings.

[Jaq]

Read both articles. I freely admit to not knowing enough about to realize that bearing placement on rear hubs is a problem. Is it? My Record 8 speeds worked flawlessly for 13 years until the drive-side cone got rough. I bought all NOS cups & cones, but ended up only swapping out the drive-side cone and tossing in new bearings and the hub's flawless again.

Seems like a solution in search of a problem, and a very expensive one at that. Still, if it saves a few grams and sounds like the Wheel of Fortune every time it coasts, someone'll buy.

[fiamme red]

I wonder whether 240 points of engagement would give any advantage in the real world (except making more noise).

Am I missing something because I use Shimano hubs with only 16 points of engagement, as opposed to Chris King with 72?

[jonnyBgood]

Kallius was in our shop last month and we were talking about his hubs as I had asked him "Why more paws?"

He simlpely said "Well..quicker engagement!"

Like others have posted it seems as if we are trying to fix a problem that is not there.

[ergott]

http://www.concept64.fr/Pieces_Velos_sur_mesure/Bienvenue.html

http://img442.imageshack.us/img442/1893/shapeimage21.png
http://img269.imageshack.us/img269/4494/shapeimage2w.png
http://img141.imageshack.us/img141/4092/k720copie.jpg

[cmg]

not sure where the benefits are? still transfer of load happens at the same location. the real benefit if they could reduce the number cogs, go to internal shifts on some gear ratios and move the cassette side flange further to the right. would allow the building of a stiffer wheel.

[ergott]

not sure where the benefits are? still transfer of load happens at the same location. the real benefit if they could reduce the number cogs, go to internal shifts on some gear ratios and move the cassette side flange further to the right. would allow the building of a stiffer wheel.

Larger bearings, better placement.

[ultraman6970]

noticed the difference or time to react in the engagement system between different brands and models but from what I have seen the secret is in the how many teeth the ratchet has, the pawls is only a detail IMO, u can put 3 or 4 pawls with more ratchet teeth and will engage quicker. He is putting more ratchet teeth because the diameter is larger, so it should engage quicker.

I dont know if the larger ratchet system will act as the cane creek hub system did with the spokes, if the thing tend to do that then the wheel will be easier to move IMO.

There was another guy with another project with hubs but can't remember what was Hmmm...

Hope the best to the guys :)

[old_fat_and_slow]

Looks very interesting, and appears to be a good concept.

However, dang!!!..... them prices are very scary. Gee, and I thought DT 190's were pricey.

[fiamme red]

The hub designer left a comment here:

http://road.cc/content/news/52734-kappius-components-death-freehub

"Wide wheel bearings are good. Big flanges are good. But one of the biggest pleasures of riding my hub is the quick engagement. Especially in low gear on my mountain bike, and while cyclocross racing where you start and stop pedaling a bunch."

[Chance]

I would imagine that the pawl assembly fits onto splines on the hub shell:
http://www.kappiuscomponents.com/wp-content/uploads/2011/10/4726813861.jpg

The cassette - with special adapter installed inside - fits onto the outer splines of the drive ring. There's a bearing pressed into the skinny end of the cassette that supports the axle.

Interesting that they use rare-earth magnets for pawl engagement, although I guess that means that the toothed drive ring has to be steel. Given how large it is, I wonder how many grams it adds to the hub.

Cool concept. The engagement seems to be the biggest advantage. Although I'm concerned about the fact that the cassette plays an integral role in hub support... might get pricy to replace a worn-out cassette that also includes half of the hub bearings.
It is very interesting. On rough count there seems to be about 60 teeth, with 4 positions of engagement out of 8 pawls -- phased for different timing. That apparently gives them the 240 engagement combinations per revolution. What is most curious is that they seem to be spaced for engagement in groups of two but not across from each other so loads are symmetrical. If that’s the case, would love to know why it was done that way. Pictures can make things look different that they are.

Just a guess that lack of space for springs led to magnets.

[torquer]

Larger bearings, better placement.
http://sheldonbrown.com/images/k7hub.gif
Sheldon Brown's cutaway shows the bearings almost at the outside end of the freehub, about where they are on this new cog carrier. And the outside diameter is limited by having to fit inside an 11-tooth cog, just like with the Shimano.
So for $999, you get "quicker engagement"? I'll admit to limited MTB experience, but is slow engagement a problem anyone has run up against?
Has it ever cost anyone a win (or as much as a place) in a race?

[Andrewlcox]

I contacted Kappius and nearly the whole hub minus bearing assembly (ceramic balls from USA) is made and assembled in the USA with some very special equipment. I like that!

Andy

[DRietz]

http://sheldonbrown.com/images/k7hub.gif
Sheldon Brown's cutaway shows the bearings almost at the outside end of the freehub, about where they are on this new cog carrier. And the outside diameter is limited by having to fit inside an 11-tooth cog, just like with the Shimano.
So for $999, you get "quicker engagement"? I'll admit to limited MTB experience, but is slow engagement a problem anyone has run up against?
Has it ever cost anyone a win (or as much as a place) in a race?

The bearing assembly in Sheldon's photo is an outdated cassette hub.

Almost all modern cassette hubs have four sealed bearings throughout the length of the hub. Two on either end of the hub shell that support the axle, and two within the freehub body to support its rotation. Flanges with a wider offset do build a more laterally robust wheel.

And yes, high engagement is very important in technical mountain biking. In an extreme case, it could mean the difference between making the right move or falling onto a cactus...or off a ledge. :p But, in actuality, it could mean the difference between seconds during a cross country race. Whether or not that's worth a grand to you... Well, that's your decision.

I'm fine with my Chris King rear hub. Certainly enough engagement points for me and still made in the US. Comparable weight, too.

[bicycletricycle]

i like magnetic "springs", thumbs down on the special cassettes. those hubs are going to get super heavy when they fill with mud.

[Chance]

Almost all modern cassette hubs have four sealed bearings throughout the length of the hub. Two on either end of the hub shell that support the axle, and two within the freehub body to support its rotation. Flanges with a wider offset do build a more laterally robust wheel.
Agree, although it's hard for me to tell from the posted pictures how the flanges can be further apart when location, for the greatest part, is limited by clearance from largest cog to spokes. Also as to bearing locations, some of the "wheel's" deflection must be coming from the axle flexing under load, not so much from the hub which is much larger in diameter. Test data would be very valuable to see if the design performs a lot better or not.

[torquer]

The bearing assembly in Sheldon's photo is an outdated cassette hub.

Almost all modern cassette hubs have four sealed bearings throughout the length of the hub. Two on either end of the hub shell that support the axle, and two within the freehub body to support its rotation. Flanges with a wider offset do build a more laterally robust wheel.
Last time I trust that Sheldon guy!
But seriously, why this apparent step backward (from wider bearing support to narrower)?

And yes, high engagement is very important in technical mountain biking. In an extreme case, it could mean the difference between making the right move or falling onto a cactus...or off a ledge. :p
Like I said, I've never turned a MTB crank in anger. Add cactus spines to the mix, doubt that's going to change anytime soon.

[mjb266]

My initial thoughts:
You are really only using two seemingly narrow pawls at a time. Not the 18 and 72 simultaneous engagement points peers use

Magnets may draw in junk and hold onto it

The torque applied to the cassette would try to twist the shell/cassette interface and you'd get play or creaking. Seems you need a bearing there , maybe a big one like king uses at that point.

Are those holes in the hub shell??? What function could that serve beyond just looks?

[DRietz]

Last time I trust that Sheldon guy!
But seriously, why this apparent step backward (from wider bearing support to narrower)?

Beats me. Cheaper to manufacture? It may have left the building when cassettes got to be 9 and 10 speed, as in a longer freehub body and too much flex in the axle when the bearings were spread that far apart?

In case anyone is interested, I think these hubs are certainly cool. However, would I spend $1300+ on them?

:bike:

[rockdude]

I race against Kappus on a regularly and have seen these in action. They look pretty cool and he is damn fast on them. I think more engagement is needed in MTB and possibly cross.