amazing…!!! <3
Shift Lever
The S3X kit came with a shifting lever that is designed to fit in the ends of a handlebar. We were able to make this work with a KH seat brake mount by drilling out the ID a bit. The lever sits a tad too close to the seat handle for comfort, but it did the job and keeps it protected in the event of a bail.
So now you just reach down with your finger, flip left or right, and switch gears!
It would work really nice on a uni with handlebars so that will be the next step.
That’s incredible!
Brilliant! We’d talked about a design like this but it’s great to see it beautifully executed. On a 29er (Coker frame, presumably) you could have 39", 47", 63" gears with the same cog ratios; that would be a serious road machine.
And…
So at about 2am on a Thursday night, everything had come together and I was ready to hit the streets. Or at least, cautiously hit the sidewalks. The goal was to have this built in time for the Vancouver Mini Maker Faire on Sat. June 24th and everything seemed on track.
I love it. brilliantly executed! I could almost see it, and wish I built it… Kudos!
it needs a disc brake.
Tell us more!
How does it ride?
Is there any slop?
How does it compare to the Schlumpf in terms of shifting feel?
How much added weight?
Amazing work!
absolutely beautiful !
Wow! Great job on everything from the 3D model designing through to the machining and assembly. Please keep updating this thread with your progress.
Unbelievable dedication to the sport. Great job. I can’t wait for hear more.
What a beautiful project. You’ve done a lot of really careful work, there. The nice thing about the jackshaft design is that the cogs can be changed if you find that your initial choice of gear ratios is too aggressive. The adapter with the dropouts to hold the three-speed hub could use some radii on the top corners. You will be reaching back there to catch something during a UPD and it looks like it will want to bite your hand.
I think these geared unicycles get easier to ride with larger wheel diameters and especially with heavier wheels.
this is completely mind blowing, I love it !!!
Yes, great execution of this idea! Please give us a detailed review of riding this machine.
You’ve got a BUNCH of interested thread readers, with more to come, I’m sure.
How much does she weigh after all that?
This is a really cool project. I wonder if the brake mounts will be strong enough for the torque from the S3X. I guess you should know before long.
I had thought about using a through axle hub to do this as well. I think with a Nightrider frame, and a 29" wheel you may have enough space to put the jackshaft hub inside the frame. That would be pretty cool.
Post a vid Of it in action!
Brilliant!
Amazing build! Good on you. I can’t wait to see it in action!
Wowsers
Great engineering! cant wait to hear all the hoopla of the finish product.
Good job!
I was looking on a site where they were testing the SX3. In a not very well documented way, they listed the backlash at the hub to be 15 degrees. That’s really big. Are you going to measure the backlash on this set up? I always used the deflection at the pedal axle of a 6", or 150mm, crank. I have listed figures for various hubs that I built from 0.5mm to 1.2mm deflection at a radius of 6" and I think the Schlumpfs measure about the same. As I remember, Pete’s jackshaft builds were better than that. Maybe they seemed better than that because the high friction chain/cog connection damped it so much.
Beautiful work, Justin. If it comes out anything like the electric-assist uni you had at MUni Weekend last year, it’s going to be a winner. The gearing sounds kinda high, but as Harper pointed out, this system allows you to change your cogs at will. And if the end result is to marry that setup with an electric-assist system, the gearing may be just right. Also that will probably help with the momentum issues of the smaller wheel.
Videos please! 
Arg… Justin… so much suspense!
We all want to know how it went, if everything worked as planned, the shifting, the weight, the backlash…
You’re hard on us!
Oh wait… it hasn’t been filmed yet… need a hand filming?