Open letter to Greg Harper

After composing a Private Message to Greg Harper, the text of which appears below, I decided instead to post it here for all (I hope) to enjoy. But first, some background information…

The context:

Greg recently attended a meeting of the New York Unicycle Club. I had the wonderful opportunity to meet Greg for the first time. Also present was the Harper-geared Coker (with a Dave Stockton wheel), owned by Kris Holm and on loan to Andrew (HardcoreCokerRider). As I’m sure you already know, this Coker has a internally-geared hub invented and built by Greg. The gear ratio is one point five. Each pedal revolution takes you well over 14 feet.

I had the opportunity to ride this amazing machine, but I didn’t ride it until after Greg left the meeting. This was my first experience with a geared unicycle. I hadn’t even read anything about any of the geared unicycles (and still haven’t).

Mentioned below in what was intended to be a Private Message is the fact that Greg mis-mounted when he first rode my Coker. I can’t make the details of this acrobatic mount public without also attesting to the fact that Greg is an excellent unicyclist, which I saw with my very own eyes. He simply tried hopping onto a strange Coker with very long cranks and the seat too low; an act which sent him over the Coker, landing on his hands (and his shin on my pedal).

Lastly, keep in mind that riding the geared Coker took many attempts, requiring my full and utter concentration. For about 45 minutes. Toward the end, I could hit-or-miss free-mount and I could ride moderate distances. At least to me, it’s that different. It took all the concentration of my entire being (which perhaps caused… my problem).

Here is my message to Greg…


Let me see if I can feel bad about the blood on your pedal (not pedals, I only shin raked one of them)…no; it’s not working for me. I do recommend that you raise the seat on your Coker so that those other than leprechauns can ride it. I would say that “I feel your pain” about losing your ability to ride a standard Coker but I’m the one with scabs on his shins. I considered litigation but dreaded the bad taste it would leave in the mouths of the unicycling community.

It was a real treat getting to meet (or, in some cases, reaquaint myself) with all you folks. I wish I would have witnessed you riding der Uber Coker which, as you saw, I mounted much more easily than your Coker made for midgets. I don’t know if you rode the Schlumpf 29er’s that were there but, if so, it would be interesting to know how you feel about the stability of geared unicycles as wheel size (and mass) increases.

As to how to get one, simply steal it from Andrew at the next meet. He would be easily distracted by a cleverly planted magazine with a flashy picture of a helicopter on the cover.

Thanks for the AWESOME letter. You know how much I like that under-utilized word. This puts a perspective on matters well worth bearing in mind.

At the recent CMW, Ben Unruh whipped out his midget coker with 125’s and amazingly I freemounted first try and rode a few feet. By the second try i was able to fly around th parkinglot, but it was more like riding an ultimate wheel since I was literally 12" above the saddle.

Now I HAVE TO try the geared coker, although, I really don’t plan on buyng a coker anytime soon.

I have had the pleasure of riding a geared up Harper-hub Coker - with 170mm cranks. It was great. I didn’t quite just jump on and ride it the first time, but it didn’t take long to get used to it. Then we were all cursing Beau who just mounted and rode. But we didn’t notice any problems going back to regular Cokers afterward. Here’s a video of Beau riding it.

We did an 8 mile ride that day with Mike Scalisi riding his geared up Coker and there was a time that he and I were out in front, out-distancing everyone because we were going 14mph or so. I looked over at his legs and they were barely spinning! He was laughing at the coolness of it.

Anyway, I’ve said this before, but THANK-YOU Greg for starting this round of innovation that will lead to a new level in unicycling long distances. These are the good 'ol days!


Beau looks good on it for a first ride. He didn’t wind it up very fast but he’s immortal and fearless and will eventually outdo all of us (that he has not already surpassed.)

You are certainly welcome. It has been nice to see it unfold. Thanks for participating and helping to generate interest.

You might notice that at the bottom of his pedal stroke, his toes are pointing downward. I’m sure if the seat-post was sized appropriately he would have been much faster.

Also, while I was swapping wheels, Beau also gave my non-geared coker wheel a spin ultimate style. I think Nathan was video of that too.

The amazing part about this video is how much practice Beau had before I took it. Like about 1 try and 5 seconds. 36" Ultimate wheeling


arent there only 4 or 5 of those hubs floating around? they’re really really rare…

That’s really amazing that Beau could ride that on his first try! I’ve never rode a Coker before, but I’d really like to. I wouldn’t have imagined it to be soo difficult, but it looks like he’s really struggling in those videos!

waits for ECMW


The first video is Beau riding a coker geared up 1:1.5. So its a virtual 54". Lots of other people tried it that day, and most people took quite a bit of time to be able to ride it at all. Beau did it pretty much his first try with a seat post that way way too high.

The second video was him riding a coker with no seat or frame (aka an incredible wheel). I think I’ve only heard of one other person riding a 36" incredible wheel, and this is harder since it has a higher Q factor due to the cranks sticking out a bit.

A regular coker with the seat post adjusted correctly isn’t really that hard, but that’s definitely not what you’re seeing here.


After riding with Harper for almost 3 years now I have come to realize Greg never does anything by accident.

That “fall” you described is a classic Harper Pratfall. In fact, he once tried a pratfall that he considered “lame” so he broke his leg just to convince everyone it was real fall.

Don’t be fooled.

                                                       You squealer.

I think there are precisely two. That’s why I’m so thrilled to have this totally RARE and AWESOME opportunity.

Cokers are a beast and are really fun to ride. When you FIRST start riding one, the size and the weight and the speed and the height and the inertia really hit you. But we are talking about a geared Coker here. All of those factors are multiplied.

That’s GOOD news because it means I’m normal. I’m truly amazed that Beau could ride it right away.

I had “forgotten” my initial reaction to that event (which I am now remembering clearly). I was thinking… “What’s he DOING? Why is he doing that (sailing over my unicycle)? Maybe it’s some experiment, but what’s the PURPOSE?” I didn’t think it polite to ask.

der Uber Coker UPDATE:

I met with Andrew (HardcoreCokerRider) today in “the city” (a.k.a. New York City) for another ride on the geared Coker.

It took many attempts to mount it before I could ride it. But having ridden it once before, progress was much quicker this time. The type of mount where you walk behind it and jump on is the best mount, because it gives you a bit of momentum. But if you mount and lean too far forward, you will fall off the front, because you cannot accelerate quickly enough to match the lean. If you stomp down on the pedal, you will fall off because the pedal will not respond much. You have to mount into a mostly vertical position, then sloooowly accelerate (the word finesse comes to mind). This was the key bit of advice from Andrew that helped me get it moving. As my familiarity and confidence increased, I did find that I could pull up on the seat and accelerate much more forcefully and quickly. But initially, it’s best not to rush.

At first, my riding wasn’t smooth at all – I would keep speeding up and slowing down, while trying to settle down in the seat and relax. Sometimes, I would UPD before ever really sitting down. Gradually, I got much more smooth and relaxed, but not totally. Turning, even a wide 180 degree turn, still gives me problems.

Eventually, I tried a static mount (grabbing the wheel) and NAILED it on my first attempt. But that was the only time I could do it. We were pretty tired at that point, because before taking out der Uber Coker, Andrew introduced me to his style of Coker riding – which took us both on an insane journey through the streets of New York City, dodging cabs and pedestrians and potholes (on regular Cokers). I was focused on staying alive and trying to keep up with Andrew. Being my first time, he had to keep waiting for me whenever I got “stuck”. Once, he squeezed between a parked car and the corner of an SUV – I had to walk the Coker between… and it barely, barely fit. Often, to pass the time while waiting for me, he would zoom around, carving his signature turns around pedestrians and cars. Anyway, that’s why we were tired by the time we rode der Uber Coker. It’s best to be at your best when piloting a geared Coker (or a helicopter, I’m told).

The best news… I could ride my Coker almost immediately after riding the geared Coker. I could adjust back to my “ordinary” Coker almost right away this time (although I’m afraid to jump mount… and it hasn’t ever felt totally right since riding the geared Coker). One more tool in my toolbox… my brain knows how to switch back and forth now. It’s been a long time since I’ve had trouble adjusting to different wheel sizes, and now this includes a virtual 54" wheel.

Question: How does riding the geared Coker compare to riding a regular Coker with short cranks (say, 102’s)? Der Uber Coker at rest is lesson in inertia. It takes a LOT to get it moving. How similar is this to short cranks? If I practice with short cranks, will it improve my ability to ride der Uber Coker? Or the other way around: Now that I can ride a unicycle whose cranks don’t give you much torque vis-à-vis “wheel size”, will this experience translate to an ability to ride a Coker with very short cranks? (by the way, 175s are “normal” for me and 140s are “short” – I could successfully ride 125s last year, but I took them off because they were too crazy for me at the time.) That good riders initially have trouble with the geared Coker tells me it’s much more than an issue of torque that causes the difficulty. But lack of torque must be the biggest factor, I think.

Also, we shot some video. I will post it soon – after I fix my computer problems. And we are planning another Uber ride soon.

Thanks for reading about this mediocre rider’s experience with… der Uber Coker.

So hardcorecokerrider Andrew DIDN’T fall off of the face of the earth then?

I have to admit… that would be a pretty sure-fire technique – but now that I’m wise to it, it will no longer work. A nice pic of a Coker rider dropping into a half-pipe… that would probably do it!

Not yet… just been overwhelmed with work, flying lessons, and other commitments. I’ve gradually been doing some more Coker riding lately when I can… beyond my normal commuting around NYC and attending Unatics meeting. I had the good fortune to ride with uni57 (Dave Lowell) through the streets of NYC and over the Williamsburg Bridge recently. I hope to get to a skatepark again soon… after quite a long absence.

After several members of the NYUC took der Uber for a spin at the last club meeting, some of the hex screws on the hub loosened - bringing our fun on der Uber to a screaching halt. Tonight I took the wheel off so that I could tighten the screws up, then I put the wheel back on and promptly took der Uber for a test spin. The machine is back to being tight and riding fantastic. I was in pretty good form today on der Uber, with my turns getting sharper and more banked and my slow speed maneuvering also improving… so I figured I’d try riding backwards. I made a few attempts at it, with my best effort getting me almost 3 revolutions. I had given up after the first few times I tried it when I had first received the machine because it seemed impossible, but now it feels like it’s definitely doable - though frightening. I’m glad I tried it again after taking a long break from attempting it.

Which screws were these? There are 5 small ones that hold the torque arm onto the hub. There are 3 large ones that hold the hub together. There are 6 small ones from the opposite side that hold a bearing block in place.

Without searching on this topic I can name a number of people who have done this before, including myself, Peter Bier, Kris Holm and Andrew Carter. When Peter and I rode our Coker wheels as ultimates we had 125mm cranks which I’m sure makes it harder than with 150s or 170s - just mounting with short cranks is a challenge!

It was the 5 small ones that hold the torque arm onto the hub… but only 3 of the 5 loosened up. I believe (but I’m not 100% sure) the looseness of those screw resulted in there being more play (slop) when I moved the cranks. After I tightended up the loose screws, it seemed like it was back to the minimal amount of play that it had previosly (the way it was when I got it back from you). Have you or Kris or any other Uber riders ever had any of the screws loosen up on you?

I have learned that for a machine, such as der Uber, that has sophisticated engineering (and a greater number of moving parts, nuts, screws, etc.)… it is wise to do a preflight (oops… “preride” - well maybe preflight is appropriate, since it does feel like your “flying” on that thing - and postflight inspection, just like you would before and after you fly an aircraft). You certainly don’t want any unexpected mechanical difficulties at cruising speed on der Uber!

Yes. I’ve tightened those on uni.5 and BlueShift. It doesn’t hurt anything but it does make the backlash seem greater. LocTite may be the answer for those.