What is the Schlumpf of the future?

Based on my forum searches, the most recent Schlumpf hubs were released early in 2008. That wasn’t all that long ago, but it still gets me thinking…

What improvements might be in the next Schlumpf (or other) geared unicycle hub?

3 speeds? How would you shift that?
low gear? Is this desired?
hand shifter?
weight improvements?
strength improvements?

Is there any new Schlumpf development happening right now?

on the new hubs unicycle.com is now printed on the case.

What I’d like to see is:

  • Greater reliability
  • No-brainer shifting mechanism
  • Gearing up to about 90 gear-inches on a 700c/29" wheel
  • Smaller gradations in gearing (either CVT, or more gears)

Gearing down would have limited usefulness, although I would have used it in the uphill race at UNICON.

All of these things are quite difficult engineering problems, so don’t expect to see them soon.

Last year with my previous engineering school we worked on a project with a toroidal CVT (continuous variable transmission) but stopped because too heavy, and would have required a complete reengineering for a uni. So I came back on the way of pinion gear.

My idea is a 3 gears hub based on a 29"/125mm uni with a epicyclic train : a lower gear to have something close to a 24"/150mm for off-road, a direct drive 1:1 and a higher gear equivalent to a 36"/110mm for road.

No more ankle gear shift but a cable shifting system with a MTB gear shifter on the T-bar handle

I have done a sectional drawing which is fine but need to go more into details now. May be will go in production in the future …

Didier

I still think that for Uni CVT is the way to go. I am ready to lose efficiency to get something “smooth” that will suffer less with the sudden small forward/backward movement changes involved in uni. And yes I need gear down because uphills are spoiling a lot of Muni joy :smiley:

My wish list still involves the variable transmission(CVT) failing that I would like to see a three speed hub where you could match the overall gearing to suit your choice of wheel size ,cranks and terrain.I have made a fixed geared uni previously http://www.unicyclist.com/forums/showpost.php?p=955157&postcount=1and given the right amount of imagination and drive I plan to make a geared uni in the future.I think the CVT is only possible if high tech industry get involved and given the obscurity of unicycling that doesn’t look likely at this stage,I think the best we can hope for is to adapt idea’s developed for other machines.The “de-vinci hub” came very close.

I’m pretty happy with what I have. IMHO, no need to make it more complex or heavy. Not sure that I could even make use of a whole host of gears?

However, one big improvement would be an easier and more reliable shifting mechanism i.e. move away from the ankle shift (though it is a lot of fun!) and towards a more mountain bike like cable shifting mechanism.

A $400 hub!!

More than any sort of technological improvement, I would love to see the hub become more affordable. You could dream of a new hub with more gears or lighter or whatever but it is not of very much use if only very few people can afford it.

Teddy

I too would like to see the cost come down, but not at the expense of quality. As has already been discussed on this forum (under various other threads) the cost is unlikely to come down a whole lot because this is such a niche sport that investing in a more automated industrial production process would not be worth while to Florian and/or others. I think the consensus was that if a way could be found to make this hub, and other things using the same parts (i.e. bicycle bottom brackets / hubs) then you might be talking since such items would appeal to a wider market. So for now we’re limited to these hubs being made by hand which is indeed expensive, but also worth every penny IMHO. (Yes I’ve had to sacrifice a bit to afford one myself).

hub sleeve idea

Just some thoughts…

Wouldn’t it be cool if hub internals could slide out of a “hub shell” and then slide into another “hub shell” on a different uni?

I’m interested in getting a Schlumpf at some point, but there’s always the debate over which wheel size to go with. If I could have a 24", 26", and 29" uni in my garage, and one Schlumpf to ride them all, that would be cool. Yes… I’d be Lord of the Schlumpf! :p:D

Each uni would need to be outfitted with a compatible “hub shell”, and at least one crank arm would need to be removed, but that’s fairly easy to do before a ride, while the alternative wheel build is certainly not!

Feasible? Practical? Desired?

In my opinion, either the cost must go down, or the reliability must go up.
Speaking as someone who hasn’t bitten the bearing yet, the price is pretty high, but I’d feel like it was worth it if:

  • I had a high level of confidence that I wouldn't be tearing it out and shipping it back a few times per year
  • The price was such that it would be reasonable to have a backup.

I’d love to see a 1:1 / 3:2 / (9:4? 3:1?) 3-way combination.

A hand shifter would be cool! :sunglasses: Though the heel shifter in so unique. :roll_eyes:

I would seriously consider buying a 24" muni with a granny gear. I think I like the 24" better than the 20" for muni.(never rode a schlumpf 20") But with a smaller gear those hills might be easier to climb.

I think it’s unlikely that adding two pounds of weight and a sloppy mechanism is going to make hills easier to climb, even if the gear is lower.

On the cost issue, is there a way to expand the market? Right now these highly specialized hubs are sold to a few unicycle fanatics. Could the same mechanism be adapted to specialized mountain bikes or road bikes? If so that might increase the market by 10-fold and bring some economy of scale.

I admit that I do not see another plausible use for these geared unicycle hubs, but if there was one it might make a difference.

Scott

Florian made a bike bottom bracket before he made a unicycle hub. But that doesn’t help us with the cost, because he still makes them by hand in Switzerland. The way to cut the cost is to make them in China, which requires lowering your workmanship standards.

They said that about Honda

Cheap Jap crap. They will never make anything good.

Taiwan isn’t so far removed from mainland China, in culture and ambition. Lot’s of top end uni parts are made in Taiwan, so China will not lag far behind.

I see no hope of a 3 speed, without a new invention, that I am not seeing on the horizon. The planetary gear setup on the current 2 speed hubs doesn’t have a place to fit a third gear.

If uni riding, and the demand for geared hubs gets a big increase, a Torker quality sort of product, likely made first in Taiwan, and then in China, will appear.

The planetary gear set is unpatentable, having been used in boats for more than 100 years. If the market grows large enough , other players are free to make new stuff.

My drawing shows this is possible to fit 3 gears (0,724 / 1 / 1,38) with just 1 planetary gear in the standard 100mm bearing centre - centre, but based on a complete different design from Schlumpf current one.

Shimano Nexus 7 is an excellent (cable-operated) planetary gear hub. Nice for a shortened giraffe chain-drive set up. Just have to learn to cope with freewheeling and using braking to control dropping off the back.
http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/0/nexus/product.-code-SG-7R46.-type-.html


The only thing id like to see at new schlumpfs hub is to do a lighter hub (maybe made of titan?). Just because its so heavy, i own 2 wheel-sets, one with s-hub and one without it . I also have some problems with shifting on technical terrain because sometimes i automaticly shift to lower or higher speed (its because of my feet position on pedals), thatwhy i think handle shifting would be ok.-but i dont have any problems with shifting when i want to shift.

Few weeks ago i emailed to the manufacturers of the CVT NuVinci if they have plans to develop or were already developing a CVT hub for unicycle application. Their reply was negative.

CVT would be in my limited knowledge of unicycles a perfect fit. Going down gear it is an excellent feature and the option to fit a gear at almost unlimited gear position (within the range of the CVT) is just fantastic.

Maybe in the near future we may be able the get more than one gear hub.