Could you make a Rohloff unicycle?

Just wondering after seeing one or two clowns going painfully slowly along the main roads on their unicycles.

A unicycle would be REALLY hard to ride with the freewheel that is built into a Rohloff!!!

Rachel

You’d need to take the freewheel out first but yes, in theory you could (assuming that running it fixed wouldn’t trash the gears) though obviously it’d affect the balancing as you change gears.

Just trying to imagine where to fit the twist grip – wherever it is, it’s going to look very wrong changing gear…

don’t sturmey archer do a 3 speed fixed?

Two speed unicycles http://www.krisholm.com/khu/kh-schlumpf only £1100

not sure I’d trust a crank arm attached to the hub and axle with a quick release?

Much discussion of geared unis on the uni forums. At some point I’m sure I’ll get myself a Schlumpf one, but as z1ppy points out they’re rather pricey and at the moment my income is somewhat limited!

The trouble with converting an existing hub (apart from the issue with the freewheel) is the need to put a crank axle through the middle with a conventional installation. Somebody did come up with a solution to that and made a uni with a CV nuvinci hub http://www.unicyclist.com/forums/showthread.php?t=92919
here’s his previous work with a SA S3X
http://www.unicyclist.com/forums/showthread.php?t=89581
interesting idea, but rather cumbersome and probably no cheaper unless you have the skills and time to DIY.

As for where to put the shifter, lots of serious unicyclists already use handlebars and/or under saddle mounted brake levers. Though the shift buttons for a Schlumpf geared uni hub are mounted on the ends of the wheel/crank axle and you shift with your heels.

You’d need to take the freewheel out first but yes, in theory you could (assuming that running it fixed wouldn’t trash the gears)

The trouble is, as discussed on those threads I linked, “taking the freewheel out” is far from straightforward, and even if you do, you still have the issue of “neutral” between gears which would result in a fall with a conventional hub.

not sure I’d trust a crank arm attached to the hub and axle with a quick release?

Eh? Why would you need to have a QR?

Gears would allow for much higher speeds, this could be problematic, no?

And could you not have a freewheel if you have a brake? It’d take some finesse to stop without being thrown flat on your face, of course.

I’ve got a feeling I’ve seen a Rohloff unicycle somewhere – I think it had the Rohloff as an intermediate drive in a chain system, a bit like a “Kangaroo” ordinary.

Or I might have imagined it 🙂

I’ve got one of those Schlumpf 2-speed unicycles in the shop. People who can ride unicycles have had a go, and no-one’s mastered changing gear on the move yet…

Eh? Why would you need to have a QR?

I was being slightly jokey but most hubs only have at best an M6 bolt to hold them into a frame. If you’re plannign on attaching a pair of crank arms to the end of the hub axle then a QR/smallish nut would be needed, no?

I’ve got one of those Schlumpf 2-speed unicycles in the shop. People who can ride unicycles have had a go, and no-one’s mastered changing gear on the move yet…

Wow – that’s a pretty specialist thing to have in a shop. What shop is that, and do you have other unis?

I understand changing gear on the move takes a bit of practice, but given it takes a week or two for most people just to learn to ride 50m on a uni, we’re used to not being able to do things instantly.

If you’re plannign on attaching a pair of crank arms to the end of the hub axle then a QR/smallish nut would be needed, no?

A complete redesign of the hub is needed to put a separate crank axle (capable of taking the torque) through the middle! Hence why it’s far from straightforward.

Gears would allow for much higher speeds, this could be problematic, no?

Yes. UPDs (UnPlanned Dismounts) are a fact of life with riding unis. Normally you’re not going faster than you can run, so you just run it out, but having gears (or a 36″ wheel) changes that. Hence you need to have good confidence you’re not going to have a UPD – I’ve not actually had one during normal road riding for ages, but it would still be a case of working up the confidence in going faster. Control at speed isn’t of itself a problem – like bikes, unis get more stable the faster you go.

And could you not have a freewheel if you have a brake? It’d take some finesse to stop without being thrown flat on your face, of course.

Not really, no. You rely on back pressure on the pedals for control even when you’re not actively trying to brake. As mentioned above, people do use brakes on unis (I’m thinking of getting one for off-roading soon as I’m now doing downhills which are hard work on the legs otherwise), and like everything else on a uni it’s just a case of practice.

Wow – that’s a pretty specialist thing to have in a shop. What shop is that, and do you have other unis?

http://www.kinetics-online.co.uk – I only have specialist things in the shop, a 2-speed unicycle is relatively normal for me 🙂

No other unis, though – tempted to get a Surly one…

Boo – nowhere near me, and I can’t think of an excuse to visit Glasgow 🙁

BTW though, what size wheel is your Schlumpf uni?

A complete redesign of the hub is needed to put a separate crank axle (capable of taking the torque) through the middle

as I said, a QR’s not really up to the job then 😉

BTW though, what size wheel is your Schlumpf uni?

24″ – it’s a pretty old one, using the frame Schlumpf made – I think he’s just making the hubs now.

Ah – a bit smaller wheel that I’d want. Not the one which went on ebay by any chance?

I don’t suppose you know if the frame would take a bigger wheel – I understand some of the Schlumpf frames were adjustable, but not really sure what that means? Also how much are you selling for – I’m assuming (maybe incorrectly) it might be a bit cheaper than a more recent one?

I hadn’t actually considered selling it 🙂 Yeah, I know, I haven’t quite worked out the point of a bike shop. I’ve had it from new.

It is adjustable – basically its just tubes clamped together, a bit like an old pair of suspension forks – but I don’t think there’s enough adjustment there to go to 26″.

I hadn’t actually considered selling it Yeah, I know, I haven’t quite worked out the point of a bike shop. I’ve had it from new.

Oh 😳 – I kind of misunderstood the bit about it being in your shop!

Thanks for the info – in that case I’m glad I didn’t go for the 24er on ebay (though still kicking myself about missing out on the Schlumpf 29er which went on unicyclist.com classifieds)

Oh yeah, I theoretically get stuff to sell it, I just get kinda attached to some things and forget to sell them 🙂