Abram Clark's geared giraffe

The Seattle folks went on a Coker ride today. It was John Childs, Tom Jackson, Jeff Sloan, myself, and we were joined by Abram Clark on his 2:1 geared penguin giraffe unicycle with thin 20"x1.125" wheel. I don’t think Abram posts here so I put some photos of Abram’s giraffe and some mpegs of him riding it in THIS GALLERY . One of the videos is of a comparison ride between Abram and Jeff Sloan so you that can see the cadence difference.

Interestingly, at the beginning of our ride, Sabin Arditty was there to meet Dan Heaton for some trials at Gasworks Park. We didn’t know of each other’s rides. They were gone by the time we returned three or so hours later.

Abram’s giraffe is an elegant and lightweight vehicle. He took it offroad a little and freemounted whenever we were off as if there was nothing to it. He let the rest of us try it out at the end of the ride.

A few photos of the Coker ride are HERE IN THIS ALBUM but they are relatively uninteresting except the last three which are of a skateboarder trying to ride Tom Jackson’s Coker. He did succeed for a short ride and we found out that he had ridden a 20" or 24" in the past.

Very cool, thanks Greg. He rides it with such facility! That comparison was really neat. I don’t think there’s anything like that in the gallery. Please give my compliments to Abram.

I failed to mention that on this Coker ride, we started out with a three Coker pileup on Stone Way involving Jeff, JC, and Tom. Abram and I deftly avoided their conspiracy. This was followed by a nice showerburst as we circled Green Lake Park. Close to the end, I had a pedal strike on an 18" curb and went down and took out Jeff Sloan. Jeff caused the initial pileup so he had it coming.

I also got to try out my new Airfoil wheelset. The axle is a full inch wider than the stock model (8.25" vs 7.25") but I didn’t notice the larger effective “Q” until riding it for awhile. I noticed no difference in the responsiveness due to weight differences which didn’t surprise me. I did get to confidently ride down a flight of three or four steps with no protective gear and it was like the stairs were only small bumps with that big wheel. I also did an 18" curb drop.

This will be fun and dangerous when the gear goes on.

It was weird riding behind Abram and seeing him pedal at a slightly slower cadence than the Coker right next to him. The brain doesn’t want to accept it. :slight_smile:

It was a fun urban ride. A little over 19 miles and included some stretches of poor pavement, wavy pavement, gravel dirt trail, a short ride down a grassy hill, rides over bridges with metal plates covering expansion joints, sidewalks, and other sorts of urban challenges. Abram handled it all with that little wheel.

The thinking behind the lightweight skinny wheel is that the lighter wheel will have less momentum which will make it easier to make balance corrections after it is geared to a 40" equivalent. I don’t know how true that is in practice. But that was the plan.

Wow… just… wow! That thing’s cooler than a cucumber in a bowl of habaneros!

Doyaknow what kind of giraffe this was in previous incarnation(s), or is this a totally Frankenstein’ed invention?


Could I also request a seatpost cam on your next ride? Every time I hear of these pileups I’m dying to see the footage… maybe I’ve just been spoiled by Dylan Wallinger’s footage in U2, but until I get my own Coker, I must live vicariously through your seatpost…

Wow. That looks like it has some serious speed potential. Did you have a cyclocomputer on it? Any stats? I could almost imagine it being easier to plan a “tuck and roll dismount” in case of an unforeseen obstacle (speeding deer, marmot, mountain lion, pebble), but that’s just the armchair observation. Did you feel like you were flying? very cool.

–unidaddy

That is a pretty beast (referring to the 'raffe, not Greg). How hard is it to get used to the gearing? Geared up to 40inches would make it only slightly “larger” then a Coker, but how does the loss of the flywheel effect affect how it rides? And lastly, what crank length is being used? They look rather long, but it could just be because they are next to such a small wheel.

Daniel

The legs on the frame are cut down and welded back in place. It looks like it was a Savage giraffe frame, but I’m not sure.

The two pileups were minor and slow speed affairs. It’s more like a game of leap frog than a pileup. Jeff went down at low speed due to wavy pavement. Tom was right behind Jeff and Jeff’s Coker fell right in front of Tom. Tom had to jump from his Coker and leap frog over Jeff’s fallen Coker. Tom’s Coker then fell right in front of me. I had to jump from my Coker and leap frog over Tom’s Coker to avoid riding over it or landing on it. All comedy. No risk of injury (other than ego).

I’m very surprised that Jeff wasn’t able to implement the “Moses Dismount” since he was riding directly behind me when I invented it. Thought he would have gone to school on that one for sure…

Or perhaps he chose to take all of you out at low speed just to demonstrate his phenomenal cosmic power.

Just because I couldn’t make the ride doesn’t mean you should ignore my sig line. “Tailgate at your own risk”…it’s an idea whose time has come.

Abram Clark himself

First of all, I do post on this forum, though admittedly quite rarely.

I have no idea. It had been sitting around for a long time, and wasn’t getting
ridden. The only remaining original component is the frame, and as JC says, that
was cut down too. Actually the chain is original too.

It takes a couple tries before you get used to it. Greg, Tom J, and Jeff all
managed to ride it after a couple mount attempts, but it takes some practice to
get used to the smaller wheel. It’s much easier to stop, and accelerate quickly,
but small bumps are far more noticeable of course. It’s pretty twitchy,
especially going up hills.

Yes, they are long cranks. Here are some stats:

170mm cranks
46 tooth Rocket chain ring
23 tooth Soma track cog
Suzue track hub

There are some pictures of putting it together here:

http://abram.atypedigital.com/2005/photos/projects/giraffe/

There are links to pictures of putting the frame together, and then there is
another link to a few pictures of putting the rest of the components together.

-Abram

My ego wasn’t bruised at all. I enjoyed getting some practice in rapid controlled dismount. Today I got to try it twice. The first, behind Jeff. He was trying to ride some very wavy pavement and lost it. Even though he was three feet to the right, his unicycle landed right in front of me. I abandoned my vehicle a few inches before contact, choosing a nice place to step.
The second rcd came as Greg was turning off the Ballard bridge. Somehow he turned a little left before the 180deg right and scraped his pedal and flew off his uni, leaving it parked in the narrow exit. I decided it dismount, but I could probably have gone around it. I wimped out and dismounted.
Abram’s uni is truly amazing. The cranks are a little bit higher than the Coker, but with longer cranks, I ride it a little lower than the Coker. I managed to ride it around at the end of the ride, once I found a railing to start out on. I’m not sure how he does the freemount so well, I never even noticed him mounting during our ride.
The ride is very twitchy. You have to hold on to the seat to keep the back/forward, side-to-side motion down. Turning isn’t too easy. I don’t think I managed a 180. Still it seems you could pick it up pretty quickly.
I found it easiest to mount with a ledge or wall, and JC’s shoulder worked too.

Yeah, watching Tom Jackson ride a rail skinny like that on a geared giraffe was truly amazing.

Steve DeKoekkoek has a penguin giraffe geared to 2:1 with a 20" wheel also but the wheel is wider and heavier. I’m trying hard (with my antique mind) to remember that Steve’s was easier to ride at slower speeds and that might be because the wheel was not so sensitive to surface irregularities. Abram’s was easy to start and stop and even stillstand.

Re: Abram Clark’s geared giraffe

slight correction. that looks like a 20x1 1/8th tyre.

a rim that fits that size has a larger ERD than a rim that fits a 20x1.125

the tire on that Giraffe would not fit on a standard 20" rim like most freestyle uni’s use for example.

shame shame, converting those wonderful fractions into decimals can be tricky when it comes to rim sizes and tires to mount on them.

the popular size 20" ERD is 406

the fractional 20" size has a greater ERD of 451

schools out…:wink:

thanx for sticking the pics and the videos in the gallery
and congratulations on managing to miss the freemount in each and every video

what kind of freemount does he use?
foot-up-on-the-wheel or something closer to a ‘Coker-mount’?

I’ve never understood the difference in tire sizes between things like1-1/8 and 1.125. I know that the 24x1-3/4 (Schwinn) is much different than the 24x1.75 but I would think them to be the same. Their standards, I guess.

You’re welcome. Abram does a static mount in which he just jumps up higher than usual. I think he presently has a clamp ring on the lower cog so running jump and roll back mounts may tend to loosen it.

is that your voice doing the commentary to some of the clips greg?

Yes. For some reason, my mouth is the one right by the microphone.