Uni-engineering!

Holy cow! I just joined this list and I can’t believe the SHIT-COOL stuff you guys are doing!

Gearing, shifting, building your own frames, seats rolling right on the wheel, the possibilities are ENDLESS!

Besides the incredible moves now being performed (by amazingly talented riders) in freeriding and muni, what really intrigues me is the discussion around the gearing for high speed, and how unicycling may be at a crossroads.

I want to propose an idea, a principle that might help. It seems that Q-factor is a limit for high-speed riding, even on a geared uni. What about counterweights? Would a flat counterweight to the mass of the pedal reduce or eliminate q-factor?

Again, I’m a newby. Has this been discussed?

See attachment…

I dunno about q factor… I thought it was the angle the cranks stuck out from the hub?

That looks like it would do something to how riding worked, but I’m not sure what the affect would be.

Another Paul, Paul Royle ( i think) has already came up with this, its main application was for hocky, as the wheel tends to go much faster than normal playing hocky. it was meant to stop the wheel shake from the weight of the cranks and pedal. he only mentioned it to me once and i dont think hes posted about it, and im not sure if hes done anything about designing/making anything either, he might reply if he reads this thread,

iain

I have thought about counterweights, as you mentioned, many years ago. I think the theory will work. The downside, of course, is all the weight you’d have to add to the unicycle. I have always assumed the extra weight would more than cancel out any performance gains you’d get from a straighter line.

The extra weight and something fairly massive swinging aroung to clip your ankle every once in a while. Ouch!!

And Q-factor is the distance the pedals are from the centerline of the wheel. A wide hub and cranks that angle out from the hub equals a high Q-factor. Narrow hub and parallel cranks equals a low Q-factor. In theory the closer your feet are together (like when you’re walking) the better. But, narrow hubs mean weaker wheels, so there’s always a trade-off. Bicyclists are always looking for a low Q-factor for reduced knee and ankle stress.

I was thinking of this the other day; this could be a cheap way to have more than one crank length on a single unicycle; have 125mm on one side and 170mm on the other (or whatever)! If you keep the Q-factor low it probably would be OK for leg clearance, and you could work it out so that when you’re on the shorter side, at least, the weight of the pedal would more or less balance out the weight of the longer side of the crank.

counterweight.png

Oh, I like this idea. Could this also be done with weights on the rim itself? That would stay out of the way no matter what.
Plus then you could use those nice machines for car tires :slight_smile:

I like the idea of having it on the rim, and with direct drive, there will always be alignment. But how can you get it to fit with the spokes?

e39m5

I believe the addition of an Escher Bracket to each crank could allow for an “adjustable-q-factor”…

Id like to look at that diagram but its making me dizzy. I think you messed up drawing a line somewhere.

e39m5

The Escher drawing!

That’s great.

Imagine if that drawing actually made it to the shop floor!

Hahaha, “Escher Bracket”…I love it!

I just found out what Escher is. Now thats something to remember.

e39m5

I did a little research and haven’t found the exact origin of the "Trichotometric Indicator Support " but I’m pretty sure it wasn’t an Escher piece.

It was first widely featured by Mad Magazine (as well as several other print media) in the mid 60’s. I remember seeing this figure in a copy of Mad from the late 80’s (since Mad loves to re-print it’s own material over, and over, and over) and have been fascinated by it ever since…

Escher may have nothing to do with the figures in the above diagram, but his name was the first in my mind when I saw the image.