two-geared uni

On Tue, 19 Oct 2004 07:01:47 GMT, (Frank Bonsch) wrote:

>I don´t know. The 2.35" Big Apple is really fat. The 28" geometry
>should be the same as the 20" which is shown on Schlumpf´s webpage. So
>it could fit but it´ll be very narrow.

I emailed with Schlumpf and Florian let me know that the development
is proceeding well. The 28" frame is indeed designed for the 2.35" Big
Apple.

Their website is current in that:
* Prices are not yet known.
* They hope to deliver a first small series in late December.

Klaas Bil - Newsgroup Addict
--
"I (...) made it without dying, which means mere mortals can do it. - John Foss"

[oxfordrider]

Does anyone have an idea what shipping and VAT will be? It's got to be a killer.

[semach.the.monkey]

Originally Posted by john_childs

I don't think many people are going to be shifting on the fly with that hub. It would be extremely tricky.

I tried a bike with a Speed-Drive at the Seattle Bike Show. It worked. I had to coast while clicking the shifter knob with my heel. You can't coast on a unicycle (well, in the same way you coast on a bike) so shifting on the fly will be quite tricky.

On the unicycle I think the most practical way to shift on the fly will be to do a still stand, tap the shift knob with your heel, and then ride away. Not exactly a true shift on the fly motion.

I'm sure some people will try and succeed in a true shifting on the fly without stopping. Just for fun, try riding a Coker and giving the dust cap on the crank a good strong tap with your heel as you're riding. Not easy to do. Then after you manage to tap the shift knob you have to deal with the sudden change in gearing. Whoa there!

For me, I view the shift mechanism on the Schlumph hub as something that I would use after dismounting. Dismount, shift, re-mount, and ride away. No tools necessary. Very quick and easy. Easier and more convenient than shifting on Harper's hub. With Harper's hub you have to remove a bolt, move the torque lever to a different position, then replace the bolt. Not as convenient. Shifting Harper's hub is something like a 30-60 second operation. Shifting the Schlumph hub is something like a 1 second operation.

Yes, ok, I know it's a 4 year old thread... but isn't it nice sometimes to look back at yesteryear and see what our outlook of the future was back then

Just out of interest, is there anyone that has a Schlumpf hub that doesn't shift on the fly?

STM - remembering when computers would never need more than 640K of memory

[tholub]

Originally Posted by semach.the.monkey

Just out of interest, is there anyone that has a Schlumpf hub that doesn't shift on the fly?

Shifting on the fly is still quite tricky. The KH/Schlumpf is slightly easier to shift than the original Schlumpf was, but it's still tricky to both hit the button and adjust for the change in gearing--especially in those situations where one might want to shift, such as when going from riding fast in the high gear to climbing a hill slowly in the low gear.

For me right now, the average amount of time lost in shifting on the fly is probably similar to the amount of time lost by dismounting, shifting and remounting. I need to improve that, though, for RTL.

[vivalargo]

I've got a 24 geared uni and only have limited use with it - first trail is happening tomorrow. So far, fiddling on the street, I haven't gotten used to slipping my foot back on the pedals (using 165 cranks) to be able to hit the button shifter with my heel. Or maybe it's learning to be accurate. Usually takees me five of six revolutions to get it. I suspect this will become (hopfully) automatic after a few dozen rides but I don't yet know. It's seems pretty tricky, but not moreso than playing a guitar or shooting a free throw. Also, smoothly handling the transition from geared mode to 1:1 feels radically bizarre, and I find myself lurching for the first few strokes.

This is gonna take time to master . . . It almost feels like a new activity.

JL

[johnfoss]

After reading the accounts of some more experienced shifters, instead of trying to "click my heel" as it passes the button, I'm gradually moving my heel inward to try to slide over the button as it passes. This has seemed to work on the few tries I've done, for a smoother transition. But it leaves me worrying about two details:

- Will this put too much side pressure on the button mechanism, with possible damage?
- Will this tend to leave me somewhere in the middle, and not fully engaged in either gear?

A discussion on this might be better in a different thread though...

[mscalisi]

Originally Posted by johnfoss

- Will this tend to leave me somewhere in the middle, and not fully engaged in either gear?

I had this happen on one occasion.It scares me just a little that a "freewheel mode" is possible.

[unisk8r]

Florian did redesign his road hub to have 50% less potential free play between shifts. I use the term 'potential', because it depends on exactly where in the pedalling circle the shifter engages. If it is a few degrees ahead of the pin engagement, you'll never feel it. If it is 1 degree after, then you have the potential for 29 degrees of free play, but the odds of that actually happening are slim (winking to Ken L.). As vivalargo suggests, this is an entirely new skill to learn, but it can become second nature with practice.

[siafirede]

I haven't gone into a "freewheel" mode before, but I shift the way that John described and sometimes when I am not applying a lot of pressure and going downhill, if I shift to high gear it will take a few pedal rotations in low gear before the high gear engages.

Whenever I move my foot in to shift, I always assume that I hit the button and I expect a gear shift to happen at some point (even if I have already rotated the pedals a few times). After a few rotations I will know that I did not hit the button enough and I will try again.

I find shifting to low gear actually easier than shifting to high gear. It engages exactly as I expect all the time when going to low gear and seems like the cranks travel less to engage.

I am at the point now where shifting really isn't difficult though, but I am still cautious every time I do it.

[johnfoss]

Interesting. I sometimes get that 30 degrees or so of freewheeling on the downshift, but haven't noticed it on the upshift. And I don't know about slim odds on that free space, I seem to hit it at least 25% of shifts, but I haven't spent as much time working on shifting as I have on just riding...

BTW mine (Robert Allen's) is assembled with the gold button on the right. Click the right-hand button for upshift. Is it possible to assemble the uni with the hub the wrong way? Or would that automatically put your pedals on the wrong sides?

[chuckaeronut]

I think that what's happening when you shift and it freewheels for what seems like longer than 30 degrees is that you'll have shifted, and the hub will be freewheeling normally, but the speed of your spin closely matches the new speed that the cranks will be going once the hub engages. What I mean is that maybe the hub and cranks are spinning together immediately during a shift, so that it feels like the hub went into the magical freewheeling mode. This happened to me a few times, but now, whenever I shift, I make sure to always give the cranks a good fast "pressureless" spin (not hard, just fast) during the freewheel to get it to engage immediately. Since I started doing that, the hub has never freewheeled on me for more than, say, half a second.

[skilewis74]

Originally Posted by johnfoss

Is it possible to assemble the uni with the hub the wrong way? Or would that automatically put your pedals on the wrong sides?

If you preffer the upshift button on the left, flip both the wheel and cranks. So that the wheel is now "backwards" and the "left crank is on the right" (in relation to how everything was before).