What do unicyclists want from a geared hub?

Is that jump from 24 to 34 from one cog to an adjacent one? Or, are there intervening cogs to act as ‘steps’ in between?

Personally, i find changing pedals from one hole to anther fairly easy: anything involving moving a chain from one cog to another is likely to be a fairly ‘dirty’ procedure, due to the oil/dirt on the chain- just as with doing it on a bike.

That’s between adjacent cogs. If you’re after the total range from one end of the cassette to the other, then the latest SRAM XX1 has a 10-42 cassette!

I don’t find changing gears on a bike at all dirty, and there’s no reason why shifting a chain should involve you getting dirty, even if it’s a very manual thing - I was thinking of something like the original derailleurs used on bikes which involved undoing the QR to remove chain tension and shifting the chain between cogs using a lever with a fork on the end. Not something you want to do whilst riding a uni, but very quick once dismounted. If you want to forgo the added complication, then just carry a little hook to move the chain from one cog to another, and carry it clipped under your saddle.

I honestly think the multi cog and chain tensioner solution might be a goer provided we can solve the problem of the amount of force the tensioner needs to withstand (I think some sort of mechanical ratchet system might be sufficient). If only I had the facilities to actually try out such an idea, but it has to be a little bit simpler than the 3-speed uni somebody on here built…

Have you not seen Pete Perron’s machines from a few years back? Here’s one thread about one of them. Works really well for a single-speed geared machine, much better design than the hunirex IMO. You can change the gear ratio fairly easily by swapping sprockets around.

As for shiftable-but-you-have-to-dismount-and-fiddle-with-stuff systems, that’s what Harper’s epicyclic hub (“blue shift”) was like, before the Schlumpf design added the foot shift idea. You had to get off, remove a bolt on the torque arm and reattach it to a different place.

What do I want from a geared hub? Most of my unicycling is xc, and sometimes it would be nice to be able to shift up and slow the cadence down on easy sections, but I just don’t think I’d use it enough to justify the cost. That’s not a dig at Schlumpf at all - making something for such a small market is bound to be expensive - but it’s enough to put me off buying one. If there was a multi-speed, light, reliable, less expensive option I’d be tempted, but I can’t see that happening in our small market. They need to be precisely made because of the need to eliminate gear slop as much as possible (not so necessary on a bike) and the need to be able to drive in both directions (most multi-speed bike hub gears rely on ratchets and one-way clutches to work, and could not be made to drive both ways just by locking the freewheel, and even the ones that do drive both ways like the Sturmey 3-speed fixed are very sloppy).

That sort of thing would work in theory, bit like an auto-adjusting car clutch or drum brake mechanism. If you had a cable to release the ratchet on the tensioner, then shift with a simple “fork” type mechanism like you mentioned, then allow the ratchet to re-engage to stop the tensioner folding up on back-pressure. That would work as long as it didn’t all tangle itself up while the ratchet was disengaged during shifting - you’d have to make sure you were pretty stable before doing it, unless the tensioner spring could be set stiff enough to allow slight corrections without disaster!

If that sort of thing worked it could be built into a giraffe/penguin or a jackshaft-type uni.

Bah, missed edit time. Here’s a dodgy sketch… Bit like an Osgear - in fact you could just have a manual cable tensioner like an Osgear.

ratchet.jpg

+1

It wasn’t what I thought it would be and I couldn’t use it the way I had planned, so I sold it sooner to avoid loosing more money.

For me it was a better choice to learn how to ride a big wheel off road, also I now have a 32" which is a nice alternative to having too big (36) or too small (29).

I also want a downshift hub and a hub with a smaller step, and I’d be willing and able to pay for them, but I’m probably the odd one out on that plan :roll_eyes:

As to the flaming, yeah, non users and “failed users” get a lot of grief for not finding the Schlumpf love. So maybe the Schlmpf lovers could keep something in mind: Unicyclists on the whole are not the kind of personalities who give up on things easilly; we ride unicycles which by their nature are very challenging to learn, so it’s not very accurate judgement.

What would I like out of a geared hub? My point of view comes from a KH-Schlumpf owner and user with over 3 years experience.

Obviously the ‘ideal’ answer would be a full set of gearing like you’d see in a bicycle. Realistically however, I’d be happy with 3 gears: normal 1:1, a 1:.5-.75 for climbing and the traditional 1:1.5 the KH-Schlumpf has right now. While others have complained about the large step up in gearing I’ve found it to be quite useful for the type of riding I do. However I could see why some would think that a gear perhaps 2/3 the way in between would be good but if I could only have two gears I like having the bigger step for my 24" (and soon to be 26") wheel.

Cost. Obviously it would be great if it were a bit less expensive. Folks like to point out that for the price of a GUni you could buy a whole fleet of non-geared unicycles. This is definitely true, however with a GUni I DON’T NEED A FLEET OF UNICYCLES! I’m perfectly happy with just riding my single GUni that does well across the board; from trials to riding XC and more technical trails to riding 100 miles at a time on paved paths. It rocks! So cost isn’t as much a big deal as one might think though it is a very scary and risky BIG step to the uninitiated.

Complexity/Dependability. While I did have an immediate problem with my first KH-Schlumpf hub that failed almost immediately I’ve had no issues with my current, newer (though not the newest) hub that I’ve been using for over 3 years now. Technology and complexity comes at a cost and risk but that is true the world over in all sorts of areas. To me the risk is worth it.

Shifting. I’d definitely love to have a way to do without the feet shifting. While it’s become second nature to me now there are still times when I can’t seem to shift fast enough; especially on trails. With a hand shifting mechanism I think one could better take advantage of quickly changing trail conditions to better maximize the high gear mode where available. The foot shifting is sometimes too slow and you risk missing a shift all together.

That’s all I can think of now. I’m also interested in possible jack-shift or other hybrid gearing technologies if they can be done in a way that doesn’t make the unicycle weigh a ton.

Whilst gear slop can be annoying, it’s the least of the reasons for precision.

If a bicycle gear fails, it’s usually not a big deal. If a unicycle gear locks up or goes into freewheel, you have potential for massive injury.

It must never fail whilst riding.

Good point.

I’m working my way through that one now- thanks for the link :slight_smile:

Seems very, very heavy though.

I’ll doi a search on the blue shift as well- I do vaguely remember threads on that, but back then I wasn’t as interestd in geared unis as I am now.

What happened to the blue shift?

Having looked through a few threads I get the impression it worked pretty well?

Just wondering why no one put it, or something similar into production.

Haha, for such a serious discussion, I think we should all keep in mind that this is the opinion that probably 99.9% of people hold for all unicycles. :slight_smile:

My wife is really, really short. So short that I believe riding a 24" would be a stretch (haha). She recently learned to ride and has expressed frustration with the speed of her trials uni. I kicked around the idea that one possible solution for her would be to put a schlumpf in her trials. Gear up to be able to keep pace with me.

Way, way smaller! I think buyers who give up (or buy for people who give up) may run around 50% or more. It would be an interesting statistic to know.

You mean shiftable, right? Otherwise your feet would really get a workout on the way down!

But we understand Florian’s hub is meant to be the elite, deluxe version. Of course it is built for the racers and pioneers. That said, yes, the vast majority of people won’t ever race.

My idea is meant for a shift-on-the-fly version. The locking out of the tensioner would be part of the mechanism that moves the chain (or cogs). Now featured on a napkin sketch, courtesy of Rob. :slight_smile:

That’s exactly what I’d use a second one for, but am similarly held back by the cost…

Harper made several attempts at finding a manufacturer for it in Asia. Unfortunately, none of the prototypes that were produced were in the ballpark of the kind of precision and realiability we got with even the first generation of Schlumpf hubs. I am still hoping someone else will take on the idea, and offer a similar product; perhaps a non-shifting one.

Last I heard I think Ryan Atkins had it.

Also the other Harper Epicyclic I think was sold by Jack Halpern at Unicon 12, and from memory Gilby bought it.

I hoped it’s kept in good condition for historical purposes. It looked pretty sad when I saw it in Unicon 12.

I still have the second of the two prototypes I machined myself and it’s in splendid shape. The Gilbertson’s had the first one at some time but I don’t know if that’s still the case. I offered to replace the mild steel axle with a hardened stainless version like the one I now have but they didn’t express any interest in it.

As John wrote, I contracted with a Chinese company to make user serviceable, stationary shifting units but they never produced a reliable prototype. By then, Florian had produced his shift-on-the-fly version. If I were to try again, I would reduce the size of several components and check with US job shops to produce a batch. I also have Steve Howard’s frame design used for Blue Shift.

Perhaps start a thread titled ‘bring back the blue shfit’ or something similar?

It’s been a few years since the blue shift was news on the thread, perhaps a lot of new unicyclists (some of whom may have technical abilities or contacts) simply aren’t aware it ever existed.

Perhaps part of the reason it didn’t get followed up was the appearance, and success, of the schlumpf: now it’s becoming apparent that the schlumpf is, perhaps, a hub for the elite, and, as is clear just from this one thread, there are unicyclists would there who would like other geared options to be available, such as a non-shiftable hub- maybe a blue-shift style hub could be an option.

After all, the Huni-rex has gone into production, and, I’m guessing, a well built blue-shift hub would have more appeal than the Huni?

The question is, what would be the advantage over other options. Would it be possible to sell it for significantly less money than a Schlumpf? Along with possible reliability advantages, that’s about the only USP I can see it having - otherwise you have all the disadvantages of a Schlumpf without the advantage of on-the-fly shifting.

I wonder if a Blue-Shift type hub would be significantly cheaper to produce than the Schlumpf though. Slightly fewer parts I suppose, but it’s not THAT different a machine really. If it was only a little bit cheaper I reckon most people would still go for the Schlumpf with the bonus of on-the-fly shifting.

I think the jackshaft design is a more feasible low cost geared solution than an epicyclic hub. Far easier to make, less complicated, possible for the user to change the ratio by swapping sprockets, no slop. And I reckon it would be lighter than an epicyclic - I don’t know why you thought it looked heavy. The cons would be the need for a special frame (unless the jackshaft could be mounted on a bearing-holder bracket a bit like the disc brake mounts) and removing the wheel would be more hassle.

It thought the finished unicycled weighed 28lbs? Maybe I misread it?