another coker on ebay

FYI: There’s a used coker on eBay.


Whoever is posting that unicycle obviously knows about unicycles. He showed a top view to show the trueness of the wheel, a side view to see the whole thing, and a closeup of the airseat conversion to show that it’s the real deal.
I wish I wasn’t leaving for the Peace Corps next year. I’d love to have a Coker, but I’m going to have to wait three more years… :frowning:

Here’s a direct link to the ebay auction without the friggin redirect through the adfarm mediaplex tracker:
ebay: Coker 36" Unicycle w/ airseat conversion

Sorry about the tiny URL (aka “friggin redirect”).

Jeez. Dude, have I disrespected you?

I was complaining about the redirect. They’re on my block list so the redirect there does not work for me. There is no need to bounce through to get to an ebay auction.

Darn that tinyurl guy! :wink:

It’s not the tinyurl redirect that is the problem, other than the fact that if there was no need to hide the second redirect through then there would be no need for the tinyurl link.

tinyurl redirects to which finally redirects to ebay. There’s no need for that. There is no need to hide a link to an ebay auction in a referrer link or an ad link. There is no need to post sneaky links here.

Here’s the link that tinyurl redirects to:

Click on it if you want. It will take you to the ebay auction. It doesn’t work for me because I’ve got mediaplex in my block list.

Sorry. :wink:

If you didnt just look at the pictures :smiley: you would have saw this.

This guy really does know about unicycles and what’s going on in the unicycle world.

Unfortunately a geared unicycle is no replacement for a Coker. The geared unicycles, like Blue Shift, don’t ride very well. They are nothing like riding in cruise control on a Coker. Yeah, the geared unicycles can be fast, but that comes at a big cost in control. A geared unicycle will not replace a Coker. The Coker still rules for many distance riding tasks where the geared unicycles will prove to be unsuitable. He really should keep the Coker and get the geared unicycle as a supplemental unicycle.

Unfortunately I’m thinking along exactly the same lines as the seller. - lighter, smaller Uni with the speed advantage of a Coker. the main disadvantages I see are the loss of rolling momentum, lower sitting height. I don’t understand why there would be less control with a good hub. could you explain please?

Having significant experience with both, I agree. I wouldn’t say that a geared unicycle doesn’t ride very well. With experience, I think you can get reasonably used to it.

…However, it is no replacement for a Coker. On the geared uni, a small lapse in focus gives you an abrupt UPD, and when you do UPD, you hit the pavement hard and fast. A UPD on a coker is much more graceful (and less likely).

With a geared 26", a skillfull person can turn on a dime, but on a coker, the turns are much easier, almost like carving.

That being said, I’m very interested in what a geared 36" is like

I have ridden Greg Harper’s Blue Shift a couple of times. Not a lot, but enough to learn what the thing is like. Blue Shift is a geared up 29er.

The forwards and backwards balance is more tricky than on a standard unicycle. The balance envelope seems to shrink more than it ought to given the virtual wheel size and the crank length. It required constant focus and attention while riding. You have to pay attention to your riding much more so than you do on a normal unicycle. It is much much more difficult to recover from bumps and unexpected undulations in the pavement than it is on a standard unicycle. Little bumps that would be no problem on a standard unicycle can, and will, cause a UPD.

On a flat smooth bike trail the geared unicycle is a dream. Fun and fast. A real thrill on what otherwise would be an uneventful ride on a Coker. I rode the Blue Shift along a river bike trail and had a smile on my face the whole time, (except for the times of sheer terror when I thought I was going to loose it and crash).

On an urban hilly ride the Blue Shift is completely different. The Blue Shift does not climb very well at all. Very difficult to maintain momentum going up a hill. Very difficult to maintain balance while going up a hill. These are hills that are trivial on a Coker, but I found quite challenging on Blue Shift. This ride also included riding on sidewalks with driveway cutout and curb cutouts. Those cutouts are trivial on a Coker, but quite challenging on the Blue Shift. I had several UPDs just trying to ride across driveway cutouts. There were also intersections where the pavement was not even. The pavement gets worn and wavy in old intersections. Trying to ride across those waves was very difficult. I had a couple of UPDs because of that wavy pavement.

On the flats the geared unicycle is fun fun fun. On hills the geared unicycle sucks sucks sucks when in high gear. On uneven pavement the geared unicycle is challenging to control. It’s not unicycle nirvana. It has faults.

I don’t view the geared unicycle as a replacement for a Coker. There are places where the Coker is much more forgiving and much more appropriate. The geared unicycle is a supplemental unicycle for use in addition to a Coker. I’d rather have a Coker first and a geared unicycle second. The Coker is much more practical for cruising. For example, the Coker is great for riding on dirt roads and smooth dirt paths. The geared unicycle would be totally inappropriate in that terrain.

All that said, I do want a geared 29er. It is fun and offerers a riding experience that the Coker does not. But it will not be instead of my Coker. My Coker will still get more riding time than the geared uni.

I know we are getting further and further off topic, but…
For all you who have ridden the geared uni, do you think it would be easier to ride if it used a smaller wheel? A wide, slick 24 perhaps? I’d imagine you’d lose a lot of speed, but it’s more compact and if it’s easier to control, might be more practical for getting between classes or short commutes.

Why is Blue Shift so hard to ride in less then optimal conditions? Is it just because it’s geared up and your mind has trouble dealing with it? Is it slop in the gearing? Is it the lack of the flywheel effect because of the lighter smaller wheel?

I’d like to think that a geared uni would one day be able to do the job of a Coker. Maybe not with the current gearing technology, but some time in the future.

I don’t know. It would be interesting if someone did an analysis of the physics to try and answer that question. There have been some physics papers describing how it is possible to ride a unicycle. It would be interesting if that same style of analysis was done to figure out what’s different between a standard unicycle and a geared unicycle.

When you ride a geared unicycle it definitely feels like something is different in the physics of riding the thing. I don’t know what it is or why it is. My theory is that the forces on the torque arm of the geared hub have some sort of affect on the balance. The torque are is attached to the frame when the hub is geared up. The harder you pedal the more force there will be on the torque arm. I don’t know if the force on the torque arm is enough to affect how the unicycle rides, but it might be. Sudden changes in torque, for example when trying to recover from a bump, could also have an effect. When climbing there is also more torque, and that could be why climbing with the geared unicycle feels so strange and balance is more difficult.

Maybe someone could make a Segway style unicycle to compare the geared hub. Make a Segway style unicycle with a geared hub and compare the balance corrections needed with the same Segway style unicycle made with a non-geared hub.

you reallywouldnt believe how big a coker is until you have ridden one

I’m not sure if it would be easier on a smaller wheel. I’ve only ridden one size (26") so I can’t compare. I think I’ve heard others mention otherwise. I’d be interested in what Kris Holm has to say about this since he has a geared 36er.

I think the thing that makes the geared uni harder to ride is that small changes are amplified. Small bumps act like larger bumps.

…on the hill climbing, the seat/frame wants to full forward when you try to stand up going uphill. This makes it harder.

I don’t think the difficulties have much to do with slop or the flywheel effect. I think it really has to do with the amplification effect. This is why I wonder if a 36er might actually be easier since that wheel size is already good at smoothing out irregularities.

I also don’t think better gearing technology will help much. Even if you completely eliminated slop and the gearing was completely smooth, the fundamental behaviour of the cycle would not be drastically altered.

Yes, that is what I noticed too. I think that may be because of the torque arm, but I’m not sure. The torque arm is pushing the frame forward. Normally when you climb you try to get in front of the unicycle and lean a little bit forward. You can’t do that on the geared unicycle because it wants to dump you off the front when you do that. When climbing with the geared uni you can’t lean as far forward which makes climbing much more difficult.

Re: another coker on ebay

On Fri, 5 Nov 2004 15:45:20 -0600, “john_childs” wrote:

>I don’t know. It would be interesting if someone did an analysis of the
>physics to try and answer that question. There have been some physics
>papers describing how it is possible to ride a unicycle. It would be
>interesting if that same style of analysis was done to figure out what’s
>different between a standard unicycle and a geared unicycle.

I’m not sure if I’m up to it but I might one day give that a go. I’m
on Schlumpf’s list of people interested in their geared 29’er.

>My theory is that the forces on the torque arm of the
>geared hub have some sort of affect on the balance.

That might well be it. If it is, it’s probably becoming easier with
more riding experience. As in that you anticipate the frame to tend to
fall forward if you torque more.

Analogue: I normally pull my seat handle with my left hand (if I pull
at all, that is). That tends to tilt the unicycle backward but I
automatically compensate and don’t even notice. If I on occasion
(variety is the spice of life) pull with my right hand, I am (to some
degree) taken by surprise by the uni ‘falling’ backward. The automatic
reaction is not yet as engrained there, but it would undoubtedly
become with more practice. Same I think with the torque arm reactions.
You would compensate automatically once you have unconsciously figured
out the reaction pattern.

Klaas Bil - Newsgroup Addict

I figure it’s pretty clear that offroad unicycling is a stupid thing to do - joemarshall