Super-light trials unicycle - How I became a “function first” weight weenie.

Well the body stood up, but the pins were gone, well most of them.

hmmm, Max, after reading this from you, i’m kind of confused.
please explain.

oh, and as for the frame goes, i’d love to get the CAD drawings. please send them to me at: ryana@rogers.com

Thanks,

-Ryan

I used to try, but I no longer bother beacuse A. I cant consistently at all, and B. it ruins the equipment too fast, im on my fourth pair of pedals since july and I think I already bent them.

Oh, forgot I should mention the worthy tries:

  1. Azonic Fusion Mags, death by pin loss on concrete (which happened to be at the metrodome, directly after a twins game ended wiith police walking by and not caring at all)
  2. Primo Super tenderizers, bent on a 4.5’ drop, deceided to sell and try to upgrade.
  3. Ringlè Zuzu’s: died after the first week, bent em on another 4.5’er.
    4.Odessey Twisted PC: Held up great, but not enough traction when I needed it.
  4. Odessey Twisted Pro: Bent on the second ride, I have to say Im suprised how fast they went.

To make this post useful, Im going to recommend you try the Twisted PC’s if you want it light. they’ll also hold up for awhile and not hurt the pocket book too much.

Re: Super-light trials unicycle - How I became a “function first” weight weenie.

Over the last 7 months, I’ve discovered this:

One unicycle, generic: 15 lbs give or take a few. Modifications: Sun Rhyno Lite rim due to stock rim being bent FUBAR.

My big ass going on a diet: Starting weight: 260. Current weight: 180.

Foods eliminated: excess sugar, carbohydrates, fat, and alcoholic beverages.

The unicycle hops and drops much better now.

(Great job on lightening the uni, by the way. I agree with Harper, your aluminum welds are world-class)

John

I assume there is a reason for this, but I don’t know what it is. In a quest for overall lightness, I wold consider the seat post intergral to the frame design. In fact, if you don’t need seat adjustment (as I don’t on my Freestyle uni), why not simply weld the seat plate to the top of the frame?

Or conversely, keep the seat tube minimally short, just enough to securely hold the seat post, and let the narrower seat post (also should be made of 6061) cover the rest of the long distance. That was how I did it on my old track unicycle, which had a steel frame but an aluminum seat post.

But for a max. lightness cycle, I would run the seat tube all the way up, and eliminate the seat post entirely.

The polished aluminum looks great! How will it hold up against oxidation and corrosion?

I think the main reason the the seat tube running all the way up to the seat on the Wyganowski frame is that the clamp will not get in the way for tricks like seat in front freehand, or standup backward wheelwalk, or that type of thing. For trials though, I think it’s a strength thing.

Heres an example of my dads Funi, plate welded straight to the tube:

The goal is to minimize weight and at the same time maximize strength within the constraints of the finished product. These two requirements generally conflict. Having a seat post tube and a seatpost inside running the length of it is somewhat redundant. One of the tube lengths should be shortened as much as possible to reduce weight. In order to take this to the limit, the unicycle should be sized for one person so that no adjustment range is necessary. Now, which piece of tubing should be discarded? If the seatpost tube is minimized, there will be a weak joint where the short seatpost tube meets the long seatpost and the clamp and that joint will be toward the center of the frame. Although lightweight this is more or less the ideal place to put a joint in order to WEAKEN the frame. On the other hand, if the seatpost tube is brought all the way up to the seat, the joint is eliminated entirely in the limit or it is at least placed as far away from the center of the frame as possible. Picture placing the two frames with their seatposts so that the bearing holders on are one beam and the top of the seatpost is on another beam. Now, jump on the center of the two frames. Which one do you think will break?

This makes sense even though the joint is in an inappropriate location. A great deal of weight has been shed by using an aluminum seatpost instead of steel.

This of course makes sense as long as NO variation in seat height, tilt, or rotation will ever be required.

Harper pretty well covered all this, but here are my responses:

I definitely wanted some adjustment in seat height. The lowest my saddle will ever be positioned is during trials type riding. Because I don’t have a dedicated freestyle uni, I wanted to be able to set the saddle higher than I would for trials. The weight penalty for this adjustment is minimal and to me outweighed by the benefits of adjustment (36 grams for a seat clamp and soon to be only 50 grams or so for a seat post). As Harper mentioned, I shed a good deal of weight by going to an aluminum seat post, my 16" steel seat post weighed in at 390 grams.

Additionally, I have caught my knees/thighs on other seat post clamps enough to appreciate the benefits of a high seat clamp location.

Finally, running the larger diameter tubing all the way to the seat is stronger than running it only half way or less. The larger tubing has better bending and twisting moments than a smaller diameter tube having the same wall thickness (.058" in this case). Because I am running pretty thin wall tubing all over on the frame, this strength difference was definitely a consideration.

On the subject of stiffness, thus far everything has proved to be very stiff. I can flex the carbon fiber base, but not the handle. The frame has proved to be both laterally and torsionally stiff.

The “Mothers Mag and Al Polish” canister claims that the product both cleans and protects aluminum. I haven’t had everything together long enough to know, but I think a regular quick buffing/polishing will help maintain the shine. I should mention that the polish is pretty inexpensive, only $4 for a canister at NAPA.