What do unicyclists want from a geared hub?

Unicycles and Equipment
1

I’m starting this thread as a result of some pms I received concerning this thread-

“The ‘schlumpf’ experience- to a non user”

The person who sent the pm was giving some general advice concerning geared unicycles, but also mentioned that they were reluctant to post the opinions on the public thread as they felt that they may get ‘jumped on’.

I think the gist was that they felt that expressing some, what they considered to be, valid criticisms of the schlumpf geared hub, would be met by responses implying that the fault lay not with the hub, but would instead suggest that the sole fault lay with the rider, for not sticking out the learning curve.

And, somewhat worse than that, they felt that previous attempts to discuss geared unicycle variations, such as a non-shiftable geared hub e.g. tended to be met with ridicule.

And, most surprising of all, to me, was a claim that many purchasers of schlumpf hubs just never got to the point where they could use them properly, and, put them up for sale, also, that many schlumpf owners simply used them in one mode, having given up on mastering foot shifting.

That last one, in particular, came as a surprise to me, as I was not aware of it, despite many years of reading this board.

The picture painted was that of the geared hub being the province of an elite group of riders, with those who had tried, and failed, to master the hub, tending to be somewhat quiet, fearing criticism by the one’s who’d succeeded in taming the hub, or, perhaps themselves taking on the notion that they had somehow ‘failed’.

The reason I started the above thread is because, firstly, I’m interested in riders experiences of geared hubs, and, because I was quite fascinated by the ‘Huni-rex” different approach i.e. a one geared (geared up) chain drive.

It soon became apparent that the Huni-rex was not for me, but, I felt that if a different design came out that eliminated the hunis faults (such as it’s crank length restrictions) I would actually be interested in getting one, even though it’s a non-shiftable single gear.

I also think there might be a place for a shiftable hub that’s not foot shiftable (‘on the fly’).

So I’m just floating these ideas and wondering what other unicyclists would like to see in a hub.

For example, how high a priority are things like simplicity, ease of maintenance etc.

What portion of unicyclists would sacrifice shiftability if it meant a hub that could be maintained and repaired by the user?

Would some welcome a 2 gear hub that wasn’t shiftable ‘on the fly’, but required a dismount to shift?

And, most important of all, are there unicyclists who don’t aspire to be numbered amongst the ‘elite’ i.e. are unwilling to put in the many, many hours necessary to become competent on a schlumpf, but would still like some kind of geared hub to be commercially available.

2

I don’t own a geared hub, I haven’t even mounted one, but I do have interest. What I want:

  • Affordability - well duh, who wants to spend more money?
  • Availability - what if I do want one? Wait 6 months or more for the opportunity or hope a used one becomes available.
  • Reliability - I've read enough comments (really only takes one, two anecdotal experiences seals it, the guard is now perpetually up) where a geared hub has broken and going back to the availability bullet, 6 months to a year to get the $texas investment fixed. The possibility of waiting a whole year to fix a broken hub is incredibly off-putting.

Sacrificing the ability to change gears might kindle more interest if it translated into addressing those 3 items mentioned above. Even more interested should it retain the ability to shift, just not on the fly.

Another factor, again tied to those three things. I’ve never ridden a geared uni. There’s always the fear that I’ll invest the $2K, wait the 9 months, and end up not liking it. Sure, I need to go to one of these meetups and hope that someone 1) has one and 2) lets people test it out, just saying that by and large it’s a big investment in both time and money on something that may or may not suit people’s needs; the simple act of attaining a geared hub seems to carry lots of risk.

3

I think with any internally geared hub, there’s unlikely to ever be one that’s user-repairable?

I know with bikes with internal geared hubs (e.g. sturmley-archer) it’s not really feasible for the average rider to tinker with it in the way they can with deraillers. The 3 gear sturmley archer is considered as a hub that is less prone to issues than a derailler, but, when it goes, it’s usually a case of having to get a new one.

I’ve just realised, it would be good from the start to get the terminology straight, to facilitate a discussion free of confusion- presumably the schlumpf hub type would be an internal-geared hub, or just ‘geared hub’, whereas the Huni-rex type which use an external chain wouldn’t be referred to as a ‘geared-hub’?

4

To clarify… I really wouldn’t look for a geared hub I could tinker with and fix myself. At the same time I don’t want to have to pack up a geared hub, put in on a boat, and twiddle my thumbs for 9 months while I wait for it to make the return boat trip every time something goes wrong.

So in short, hopefully I can send it somewhere to be fixed, and hopefully that somewhere is relatively local.

5

Me neither. But the only alternative I can think of, would be a geared hub that’s repairable by a bike shop technician? Which I think is pretty unlikely, given that most bike shops won’t even attempt to repair bike geared hubs.

That would suggest that, for you, some form of chain drive hub would be the best option? That would be straightforward to tinker with, and, once established, would also probably be cheaper than an intenally geared hub.

No current design is shiftable, but, presumably, in theory, could a derailler type mechanism be used?

6

The ubiquitous PM triangle (fast, cheap, good, pick two) comes to mind. You can get a cheap hub, but you’ll get what you pay for. There’s a reason the Schlumpf costs what it does…

Ever looked inside the transmission case of a typical passenger car? It’s loads more complicated than our unicycle’s transmission, yet there are kids with not much more than a HS diploma working on these things.

Of course, it will take an entire supply chain to make user repair even possible… unless Schlumpf uses off-the-shelf parts to make his hubs, he’d have to do even more work to make spares available worldwide. That’s a tall order for a hub that doesn’t see widespread use.

This has been discussed many times over on this site. I could be wrong, but no one has yet designed a tensioning mechanism that would work bi-directionally.

7

Well, when I bought mine, I basically wanted a single unicycle that can do it all. However, the expense, added weight, increased complexity and maintenance, lower reliability (i.e. risk of a spa trip to the Alps), and gear ratio that didn’t quite fit my needs in either a 26 or 29 wheel, combined with me lacking sufficient time and stamina to do the all-day epic mixed muni rides I had fantasized about, added up to the downs outweighing the ups for me, so I sold it. I don’t feel that I sold it because I failed to master it; to the contrary I didn’t actually find it that hard to “master” shifting, even on trails. Granted I didn’t hold on to it super long (about a year), but that’s because once I decided it wasn’t for me, I figured I’d be better off selling it sooner rather than later so the resale value didn’t slip too much.

I do feel that the Schlumpf hubs are only for the elite in one sense: you have to have the ability and willingness to put up a big chunk of change just to find out if it will work for your riding style and terrain. Yes, there are those that are lucky enough to try one first, but I don’t think you really know whether it’s for you until you’ve ridden one for a while, and certainly not until after you’ve become pretty comfortable with shifting.

I suspect there are more people who are quiet about owning one and not loving it, than those who bought one and won’t admit they can’t ride it. A guni is like any other uni, anyone who is willing to put in the time and effort will be able to learn to ride it. Most people who shell out the cash for a Schlumpf will also put in enough effort to be able to shift.

The Schlumpf hub is an amazing creation, and they serve some riders very well. But that doesn’t mean they’re for everyone, just like different riders do better with different wheel and crank sizes. I’m glad I bought one, but for me it was also the right decision to sell it.

8

Is it too much to ask for a fixed gear hub that doesn’t shift? I wish i could go faster when riding street, but a larger wheel just doesn’t offer the same options as a smaller trials wheel. I wanna be abe to keep up with Bmx riders while also being able to keep my riding technical. I hear the schlumpf hubs are extremely heavy as well, so a unshiftable hub would simplify the design and lighten the load. This is also something that would make crank-rolling tricks on flat much more smooth and interesting due to the length of the push. Crankflips may be tougher, but a fixed-gear unshiftable hub would open up SO many possibilities.

9

Is that the main difficulty then? If someone invented a tension mechanism, is a derailleur 2 gear a possibility?

10

I think a one geared unicycle would be a good idea too.

The other thread discussion the Huni-rex chain drive concept-

http://www.unicycle.uk.com/26-huni-rex-unicycle-black.html

and, though the huni has considerable downsides, especially concerning pedal strikes and crank length restrictions, I can’t help feeling that it should be possible to change the design and end up with something practical.

For example, have the crank axle level with the hub, either in front or behind, thus eliminating the above issues.

The great advantage of the chain approach is that it’s mechanically a lot simpler, and easy to repair/modify.

11

What I woud like to see is a jackshaft design combined with a schlumpf-like shifting mechanism. Shift on the fly between direct drive and chain drive.

I would design the system to work with tomicogs top and bottom for easy interchangeability and gear ratios from .64 underdrive to 1.56 overdrive with small steps between using various cogs. If you could get cogs larger than 20 tooth made the range would be much larger.

It would be cheeper to make, easier to work on, and more flexible in setup, plus you won’t get bearing slip.

Having said all that I just purchased my second Schlumpf.

12

It depends on the gearing you use and what you use it for.

On a 29" Schlumpf/125mm cranks, I almost always stick with high gear when riding on the road. It’s very fast and light, and probably the closest thing a Schlumpf gets to the ‘feel’ of a road bike, even if you ride it single speed.

On a 36" Schlumpf, you have to shift. It needs to be shifted out of low gear into high gear to accelerate out of a freemount.

In terms of shiftability, I’ve seen people who can barely shift (or stop each time) enjoy their Schlumpf hub just as much. And then there are people who can shift every half revolution.

I’m somewhere in between, but even if it is something everybody can shift easily (eg with thumb shifters), it’s a big jump between the two gears, and it still rides like a slow heavy bike with two gears. I don’t think I would enjoy it just from being able to shift like, say Chuck or Scott.

For the record, it wasn’t me PM’ing onewheeldave. It’s sad that people feel they can’t say something on the boards for fear of being ‘jumped on’. I put my opinions for all to critique, as you can see in the thread he was referring to :slight_smile:

13

It’s a significant difficulty.

The forces involved in maneuvers such as mounting and braking can be quite large. This requires a strong tension mechanism, otherwise the backlash in the chain would consume some of the applied force, and the rider would suffer the effects.

At the same time, a derailleur mechanism relies on some amount of play in the chain to switch gears without significant effort. With a very strong tensioning mechanism, switching gears will be quite difficult, both in terms of stress on the chain, and on the derailleur mechanism.

Between a rock and a hard place, we are.

14

People shouldn’t be afraid of having opinions. Others will jump or not; so what? We are all not supposed to want the same things from our unicycle experience. This gets us a wonderful variety of unicycles, as well as activities to do with them.

The Schlumpf is the no-compromises version of a durable, shiftable 2-speed hub. All the things an “elite” rider might lust for, while still being realistic enough to be buildable. Not necessarily cheap, though. Too bad its maker had to live in one of the world’s more expensive countries…

A non-shifting hub or drivetrain would be cheaper, and probably easier to repair, but also have riding limitations (no low gear).

I still suck at shifting, but I don’t mind the challenge; it’s one of the reasons riding geared appeals to me. If I didn’t like things that are hard, I’d be zooming around on a 27-speed 2-wheeler. That said, if I could purchase an add-on lever shift mechanism for my existing uni, I probably would.

Also I wouldn’t mind too much a design that requires stopping to shift. For casual riding it’s fine, but it would be terrible for any kind of racing. Also, the smaller the wheel, the less desirable it would probably be. It’s easier to foot-shift on smaller wheels.

A cycle like the Huni-Rex would be improved by putting the wheel axle either at the bottom, or behind the crank axle. Bottom would probably make for a stronger and lighter frame, but the other configuration might be interesting to ride.

I like Sask’s idea of a shiftable jack-shaft system. It would be mechanically much simpler than a Schlumpf, but it might be hard to keep the weight from getting up there.

You can also gear up a simple giraffe. Make it low to improve usefulness, and you can even switch out the sprockets to change the gear. But not on a ride, unless you want to carry the tools and parts necessary. I used to do that with my Schwinn Giraffe, but changing the gear involved taking apart the bottom bracket, and changing chain length.

What about the 2-way derailleur idea? It might be an idea that just hasn’t had much attention paid to it, since bikes don’t need such a thing. Seems to me all you would need would be a lockout mechanism on your chain tensioner. It would be fixed in place while riding, and unlocked for the shift. Completing the shift, the tensioner would be locked into a new position; one that applied the same amount of tension, but at the new position. It seems “totally doable”, but again may suffer weight penalties if it can’t be done elegantly.

…Or is it too little? You mentioned using one for riding technical. This might work well on a 20" wheel, but you may find it too sluggish to be useful. Got to try it out. I think I’ve only ridden a geared up 20" once (not counting giraffes), and that one was geared to 40" equivalent. This made it really sluggish.

The weight of a Shlumpf hub would have a pretty big impact on a small wheel. A non-shifting version, all things being equal, would definitely be simpler (and cheaper), but the weight savings might be a pretty small percentage.

No it doesn’t.
But I suppose you might say you need the low gear to do it quickly. I’m lazy, so I freemount in high gear all the time. I originally learned that skill with my 48:28 giraffe back in the day. :slight_smile:

I don’t know. Unless I’m missing something (I probably am), developing something like I described above sounds like it might be simpler than the complexities of the Schlumpf hub.

15

Sure the Schlumpf hub is not perfect, but if Florian weren’t dedicated to making this product for a very, very niche market, we wouldn’t even be having this discussion. Face it, this is not a mass market item. Just saying. Geared uni’s are an oddball thing that I am glad to have the opportunity to partake of. I am sure there are lots of folks who get a Schlumpf and decide it is not for them, or find it too hard to handle. No shame in that. Probably a smaller percentage than those who buy uni’s and never learn to ride them. :slight_smile:

16

They can create another account on this site to post their opinions if they don’t want it attached to their normal account.

17

I want a geared DOWN hub for Muni
(I almost always walk up …)

18

I didn’t imply they were afraid of having an opinion- neither do i believe that they were afraid of having an opinion.

I don’t even think they were afraid of the reaction of others.

I suspect that, rather, they were concerned that raising the issues may provoke a hostile/flaming discussion, and, some people just don’t enjoy arguments, even though they like discussions.

They could. But it’s somewhat inconvenient, and, the person concerned may feel they’re being a little ‘sneaky’ if they did that.

Essentially, they chose the other option, that of keeping quiet about it on the board. However, during a discussion with me, it occurred to me to ask them why they weren’t posting their opinions on the board, and it became apparent that they didn’t want to, as they felt it could lead to a more argumentative discussion than they were comfortable with.

Whereas I, tend to post whatever I want on here, I’m quite adept at anticipating when discussions may turn hostile, and heading it off (I frequent some boards where there’s far, far more argumentatitive posting/trolling than here), and, in the worst case scenario of someone having a go at me, I can look after myself.

19

Not a limitation to those of us who want a non-shifting geared hub though :slight_smile:

Whereas I ride a uni cos it’s easier than a bike in many ways, especially the maintenance and repairs which personally, I find especially gruelling on bikes.

Bear in mind though, that the vast majority of unicyclists don’t race, and, of the ones who do, the portion who participate in races where a geared hub is necessary, are even smaller.

There’s a huge number of ‘non-elite’ unicyclists out there, many of who just like riding around, some of who would like, if it were available, a ‘non-elite’ hub.

I initially liked the fact that the crank axis was below the hub, as it means less height to fall in UPDs, but, having realised it limits the cranks to 125mm or smaller, I’d also be inclined to position it in fornt/above/behind the wheel axle.
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What’s a jack-shaft system?

Interesting- it hadn’t occured to me that the 2 gear derailleur could be non-shiftable on-the-fly, and, altered during a dismount.

One concern though- there’s a limit to the difference in the two cogs with derailleurs i.e. the ‘jump’ needs to be relatively small. Maybe it would be so small as to be able to acheive the same equivalent gear change via the much simpler means of a 2-hole crank that we already have?

I don’t think the majority are going to want a geared up 20" :slight_smile: For general outdoor riding it’s going to be a 24x3/26/29- a geared up 20" would be nothing more than a novelty and pretty useless for riding outdoors.

20

Not necessarily - not if you have something which you can’t shift on the fly - ie 2 cogs and a lockable chain tensioner (ie only called a “derailleur” out of convenience as it’s not actually that at all). In any case, you can have a decent sized jump even with a traditional derailleur - for example Shimano’s Megarange cassettes have a jump from 24 to 34 teeth, which isn’t too far off the difference in gear ratios of a Schlumpf. You could just as well argue that you might as well have a 150/100 2 hole crank as use a Schlumpf, but I doubt many people would feel that short cranks provide the same experience as gearing (and switching pedals over is always going to be a more time-consuming process than even the most manual method of switching a chain between 2 cogs).