I do not want to get into a “heels or ankles” discussion, but I started with using the heels, until I recently found out that it is easier to shift with the padding of the shoe which is just below the ankle.
That’s way more complicated than it needs to be, you really just need to make the gears on surrounding the main gear larger, and make the main gear smaller. that way all you’re changing is the diameter, not the construction of the entire hub assembly.
darkoman drive system solves all problems, put it on an 09 torker and you have what you all are looking for!!
a unicycle hub has to be simpler than a bicycle hub w/ the same amount of gears considering that neither can really slip either direction w/ the exception of a ratchet system for the chain cog on a bicycle.
Nice animation of all 3 planetary configurations here.
Then scroll down one page.
http://www.youtube.com/watch?v=SQ-oxRSMlGg
This unicycle was build by some one in germany.
It’s not mine.
I have riden it at the unicon 14.
The gear ratio is a lot higher than a schlumpf hub.
What is “darkoman drive system”? My searches came up empty as far as drive systems are concerned.
That must be jogi’s 1:2.5 ratio unicycle. Unfortunately it was broken some months ago, and it was a fixed ratio (no gear shifting)
I was going to add to this thread to say that I have some pretty decent photos of the hub internals… but those photos (well, top 4 anyway) are mine. Oh well.
Just to comment on the freewheeling aspect of a gear change; there is a short moment when the wheel rotates independently of the hub. Theoretically, this is for a maximum of 1/12th of a revolution, and often much shorter, although a couple of times I swear it has gone on longer. You don’t need to freewheel for very long at all for it to feel like a lifetime though!
STM
Why do all of you disassemble your hubs? Just for curiosity and for taking some photos? Or is there are real business case behind?
Don’t get me wrong, I really appreciate that pictures. But I would never ever take my hub apart, just so see what it looks like from interior.
Are you aware that disassembling the hub kills warranty?
I do not think that people really disassembled their hubs. Some photos look like they came from Florian - but I may be wrong.
Florian had a set of hub internals at Ride the Lobster, which is where the pictures came from. When you saw them, it was pretty obvious how it works, but it is hard to describe how the shifty rod bits go across.
Joe
Considering that I made two significant errors, such that my gears were operating in reverse and that my “high gear” was really a low gear and vice versa, I’d certainly say it was more complicated than I expected. :o
Still though, I don’t think making the planet gears larger than the sun gear will have the desired result. You still have to take into account the ring gear. In the Schlumpf set up, if all you did was make the planet gears larger than the sun gear, they would rotate less than once for a rotation of the planet carrier, but that <1 rotation would be added to the full rotation of the carrier, thereby turning the ring gear (Schlumpf’s output) 1+<1 rotations.
It looks like the shifter slides a dual ringed clutch along the crank spindle, and that the pegged teeth on either side of that clutch are spring loaded against each other. Their engagement being staggered on each side, so that when shifting one side is disengaged, and the other side’s pegs are compressed, after enough of a rotation (that small coasting section) these pegs reach their corresponding notches and pop out, engaging the new side. The spring tension in the shifter itself would have to be greater than that in the combined pegs to prevent them from shifting the clutch back.
STM,
Thanks for taking the Schlumpf hub pics at RTL. Whenever I see great unicycle pics like those I collect them for the archive for just such a discussion. Now that I know they’re yours I’ll give you credit next time. I didn’t mean to take the wind out of your sales. Credit where it’s due.
Geoff
I think that’s exactly how it works. I spent some time looking at the pics today and came to the same conclusion - considering that, it was quite an amount of nonsense what I wrote in post #3 :o
Exactly, that’ right
i got a question why is it that this geared hub http://www.sjscycles.co.uk/product.asp?pf_id=19009&src=froogleUS¤cy=USD
only 129$ as the uni one is around 1500? what makes this hub so inferior and the other one SOOO much better?
The hub you cite is not inferior.
1.) The operation of the hub is entirely different.
2.) The hub is not required to withstand the transient torque of direct drive.
3.) The cog is driven rather than the axle.
4.) The hub freewheels rather than operate in fixed mode.
5.) The tolerances required are much less restrictive.
6.) The strength requirements are much less demanding.
7.) The market for that hub is at least two orders of magnitude larger.
Using the SEARCH feature in this forum would help you explore this independently.
That’s because he misspelled it. The name is DAKOROMAN, and a search under that will yield better results.
The Dakoroman Drive System represents a light-year leap in unicycling hub design, rendering Schlumpf and all earlier geared hub systems obsolete. The design is so far ahead of its time, most RSU denizens fall short of the intellect needed to absorb it conceptually.
There are many threads which discuss the DDS, but this one is representative.
I believe reprah was able to complete a working prototype in his garage, although the residual energy shorted out much of his home’s electrical system.
Thanks! That helped. It’s interesting.
How hard is it to change the outside bearings (the ones that the frame clamps onto)? And are they prone to more wear than normal fixed Uni ones?