Rear Hub and Cassette Design Question...

Discuss light weight issues concerning road bikes & parts.
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by etownfwd

I'm surprised that none of the wheel, hub, and engineering gurus here have posted about the mild hype that the Kappius Evolution hubs got at Sea Otter.


See here or here

Maybe I'm just drinking the marketing kool-aid, but -to me- the design seems novel. While the stuff seems pretty stiff and light (but what can you tell from pictures?), the idea of having to get your cassette through Kappius seems a bit much.

This brings me to my two questions for those with the brains:

1. Does this hub make sense for making a stonger, stiffer, and lighter wheel or more of a solution in search of a problem?
2. Would it be overkill for Road use?


by Weenie

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by Estelja

I like the idea of utilizing this unused space to make things stronger but I would like to see someone use it to finally perfect a silent roller clutch. A freehub with as many pawls as the Kappius is going to be ungodly noisy when coasting.

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by Valbrona

All hubs (road included) will be like that one day.

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by yeaitsdave

I feel like it has to be a stiffer wheel build, with the bearings being pushed outward... its a cool concept, I'd like to see how it works.

Phill P
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by Phill P

It is a clever design- and the weights aren't too bad. Very heavily built too

211 for the rear hub is ok for a MTB hub. I'm sure you could do lighter but as I said its very heavily built and should be a strong hub and wheel. The cassette then weighs 25grams more than standard, so the rear hub is really 236grams which is not super light.
Front hubs, while not part of the design concept are 110-115grams. Ok for disc hub again, but for the price you could get something lighter. Again it is built to make a very strong hub and wheel.

Id be interested to see what weights he could do if the hubs weren't built with such huge dimensions.

$1000 (USD?) for a rear hub and cassette :shock: $299 for a front hub :shock:
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by TTP

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by bm0p700f

While iot looks like a good idea price is really against it. Given the problems that Kappus illustrate are not catistrophic can the high price really be justifed ubless you really like the design and you have alot of cash to splash. I like the design but I don't the cash. I'm half way there.

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by WMW

Rear hubs have been stupid ever since cassettes took over from freewheels. I don't understand why the cassettes were not stepped down in diameter like the freewheels. Shimano patented a scheme to bring the DS bearings farther out, but no one else could use it... so all other designs had to have a large cantilever. Unless you wanted to make your own cassettes you were greatly constrained by the industry standards.

I don't know the details, but I hear Alchemy's new rear hub will have an extended DS hubshell and bearing... *and* fit standard cassettes.
formerly rruff...

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by oysters

This looks really good, I like the concept.

Would be good if they could do more than just rebuilding SRAM cassettes (though I understand why they've done that to begin with). I don't like the gear ratios, 11 teeth on a cog is not very efficient! Seeing as though they are hell bent on efficiency, why not go the whole way and build efficient cassettes that start at say 13, 14 or 15 teeth at the small end? No one really makes them any more, unless you are willing to build the cassette yourself from multiple cassettes and/or individual cogs. On my dream bike (when it happens, when I'm no longer an impoverished postgraduate student), I'd happily pay these guys two or three times as much for the cassette if they could do custom ratios.

Hopefully they will get enough takers for them to continue development. I think this could be a real industry shakeup.

Be very interesting to see if there are real world reliability differences. How about stiffness/strength tests vs the current standard? How much weight from rims and spokes could be saved due to the increased theoretical strength from the greater flange diameters, and like less twist from the hub?

If they are pushing the envelope this much, why not also build the hub with straight pull spokes in mind? Clearly, those willing to fork out for this hub, won't be concerned by either cost or, say, readily available parts (compatible spokes) when riding on tours etc. Heck, if this hub was that stiff and strong, I'd use it touring the third world, with straight pull spokes and just carry a few spares in my seat tube. Would save me carrying a spare freehub body (weight=lots), the freehub on this should never die. Also save weight on tools for getting cassettes off (around 30g).

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by gilesharrison

I believe Hope was working on something very similar to this a couple of years ago. Don't know if anything came of it though.

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by bm0p700f

Oysters: Shimano do new 14-2XT cassettes. There is an ultegra one.

I personally am very happy with my 52/39T with 12-21T cassette and I am now finding I want an 11T small sproket or a 53T outer as at 38-40mph I am spinning past 110 rpm.

So I am glad they are doing a 11t cassette. Shame I can't afford it. I still think the price is a bit steep but the effort that they put in reflects that I suppose.

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by oysters

Thinking more about it, it might be a reasonable amount of engineering to convert other cassettes to this freehub design. The cassette pretty much needs to be cnc'd from one main piece to be able to mount it to their cone. I guess that isn't beyond the ability of these guys and they are probably thinking about it. If they cnc'd the cone into the cassette it would probably be lighter/stronger. But my god that would be expensive...

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by oysters

Seeing as though they are milling away at the red/xx cassette in order to fit it to the domed freehub, I wonder if its possible for them to mill off the front 11t (or maybe even the 12 too) cog at the same time, then put extra large cogs at the back. With that, you could take say an 11-23 red cassette, take off the 11 and 12, add on say 25 and 27 or 28, giving a 13-27/28 (13,14,15,16,17,19,21,23,25,27/28). Gives closer cog spacing where its needed. Not sure how they would pin the cogs to the back of the original cassette, but I'm sure these guys have it in them.

The way Russ Kappius talked about the hub on one of his videos, he's expecting them to last forever. Sounds good to me.

These hubs are now on and they've been building MTB wheels with them.

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by oysters

I just realised that the 11t and 12t are seperate cogs (was hard to tell so had to go to youtube videos to work it out). So could easily leave them out and just machine a different plug end thingo (the Kappius version of a lock ring) to hold the cassette on the axel against the 13t cog.

Shimano make quite a range of cogs from 17 right through to 28 for dura ace (and also up to 30t with ultegra 6700), which are pinned onto spiders. These could easily be unpinned, and then repinned onto a spider that could either be machined in to the Kappius freehub dome, or to a seperate spider that is then pinned to the highest cog on the 23 of the powerdome cassette, then the seperate spider gets pinned to the Kappius dome (probably the easier option).

Kappius, if you are listening and keen to give this a shot, I'm an impoverished postgrad science student and can't really afford new bike stuff right now, but I'll happily shell out the biscuits ($$$) for the parts (hub, red 11-23 cassette, 6700 or 7900 cassette or at least the last spider with the cogs needed) for you to give this a shot, then test it for you :-)

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by Franklin

Lovely, but the 240s and Shimano hubs he rags upon are way cheaper and virtually problem free.

So there we have it; a superior design, but the current solutions are good enough and well entrenched.

by Weenie

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