The Missing Link: A 32" unicycle, à la Walmart and UDC

Unicycles and Equipment
41

If Nimbus made a 32" Stealth 2 rim and the prototype 36er MTB tire was made for the 32", that would be a very winning combo.

For me, a 36" is a great XC muni as long as the uphills are reasonable. I don’t have problems doing technical downhill on the 36", but long out of the seat climbs on tech terrain are exhausting and can leave me wishing for a lower gear (smaller wheel). Last weekend I chose the 32 for a long intermediate single track climb and it was hard but doable with a few rests. That same climb on the 36 would have been fun and hard; and probably required some walking, but then on the 29 I would have been “spinning out” and it would have been “boring”.

The 32" has a place, the issue is convincing the mfgs that folks will buy it “in addition” to the 29 and 36. The bright side to the 32 is that it’s faster than the 29 without being as “swing heavy” as the 36, so more agile while still riding like a big wheel.

There is a difference, about the same as going from a 26 to a 29, so if you have ridden those wheels, you know what I’m saying, so just project that difference from a 29 to a 32 or even down from a 36 to a 32.

I’ll have my 32 with me at the California Munifest so folks can try it out, hopefully I’ll have the frankentire done by then…

It is so cool that there are now four 32" unis in the world :slight_smile:

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To me it felt pretty much the same as the 29, just went faster and was slightly harder on very steep hills. Next project will be to schlumpf it :slight_smile:

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Hey Ben, is my “shrunken wheel” in that count? Does anyone know the BSD for the Walmart rims/tires yet? I wonder if they would fit my (700mm) rim.

44

Make that five :wink:

I’m going to measure the rim along the bead seat when I pull the tire this weekend during frankentire fest, so I’ll post those results.

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I am going to schlumpf it :smiley: Any idea how i could calculate the spokelenght? I thought about 6 spokes and then 2 "emty holes.

46

the existing spokes are about 315, it might be worth trying them??

47

Picked up my 32" Maxxis Advantage Frankentire at the shoe repair shop, they stitched between the knobbies and down the sidewall, currently drying from a liberal application of liquid rubber that I painted onto the seams and joints, should be ready to mount for tonight’s romp in the woods :0

Pictures to follow…I’m soooo excited :stuck_out_tongue:

If this thing stays together, I’m making a 2.25 Ardent next!

http://www.maxxis.com/Bicycle/Mountain/ADvantage.aspx
26X2.10 ( 52/53-559 ) Black, 120tpi, FOLDABLE, 555gm, DUAL 65 eXC/Silkworm

Finished weight is less that 700gm :astonished:

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that is SWEET! do you want to let me barrow it :wink:

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Step One: The big cut or as I thought at the time, “the big committment”. I did a simple 2" overlap, this was a tense moment :astonished:

Step Two: Grind and prep for gluing, not so bad if you have got a dremel and a razor knife, maybe twenty minutes worth of grinding and smoothing, the easy part

Step Three: Figuring out the bead diameter. I glued one side and let it set up, then I used the original tire and a bunch of binder clips, lined it up and went for it!

Step Four: The final glue up using Barge contact cement, highly recommended. I tried vulcanizing tire glue first and it did not work. Barge was excellent, easy to work with, even allowed some fine adjusting. Note: Use the tires “lines” to get the sidewalls straight; mucho importante!

Step Five: The shoe repair guy sewed my treads and saves me hours of pain and suffering, he went up and down the sidewallsbetween the knobbies, and along the beads. This is the shot from inside, total cost $20

Step Six: Applyied rubber armor over the seam and threads, this is some good stuff, kinda like a fibrous shoe goo, designed to protect leather boot toes, also works for frankentires

The weigh-in, drum roll…yes folks, that is the correct weight :slight_smile:

Final product after the first big ride, two thumbs up!!

No complaints, this is a great riding wheel, well worth the effort, the tire worked very nice, much better than the stock tire. The Maxxis Advantage Silkworm is a racing tire, so kinda soft in the sidewall for tech muni, so my next tire project will be an Ardent 2.4, then I’ll use the Advantage as my back up tire.

The tire dimensions are fairly close to the stated dimension of 2.1", which worked out to be 3/8" taller and wider than the stock tire. There is a slight hump at the joints which can be seen when I spin the tire. I shaved the center knobby slightly right at the seam, so the hump is <1/8" and not noticeable when riding. I had a sllight stretching of the rubber at the center line of the tread, but no noticeable stretching at the sidewall.

I pumped it up to 40psi and it held fine, backed it down to 25psi for tonight’s trail riding which felt about right for the tire “design”.

If you are on the fence about doing this project for yourself, don’t be, the wheel is plenty strong for muni and franketire build is easy. It feels like a tall 29er, easier to throw around than a 36er, but faster than a 29er.

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That looks great Ben! Congrats on your first frankenbaby!

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Awesome! That looks great :smiley: What do you think the 2.4’’ wire bead model would be like as a 26’’ muni tyre? I hear it is WIDE and the tread pattern looks good.

52

Oh, Ben…

… you’ve created a lovely mutant monster, that even looks potentially ridable by mere mortals. And must be fast/fun fun/fast too.

Nice work on Project-32!

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Wire bead won’t work, you can stitch the metal, so then it would only be glue holding it together, which would probably separate.

I was thinking of an Ardent 2.25, but I have a couple Ardent 2.4s, so I’ll probably use what I have on hand.

My next one may be a butt joint with a “patch” of casing tying the ends together from the inside, that would reduce the hump and smooth out the sidewall, also stitching across the joint would be cleaner.

I have enough left over carcass from the Advantage that I might use that for the Ardent so it sews easier and weighs less. I wish I had time to build another tire this week, but I leave for Moab on Sunday :slight_smile:

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How much heavier would this type of tyre be for a 36?

I know the new light weight tyre is on the way. But if these hold together and are as light as they seem. Might be a sensible option

Foss tube and 2 racing ralphs might make for a much more nimble 36er

Has this been done already?

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Not to distract from the 32ers but yup, it’s been done.

56

Yeah, Eric has been there already.

But personally, being as I have ridden an RR 2.4 29er and I am riding a comparable Maxxis tire, I don’t believe a lightweight tire is a good choice because the sidewall is just not sufficient to support our weight.

The prototype 36er tire I’m riding now is ~1500gm, 300-400gm lighter than a Nightrider. I think this tire has a good balance of weight, durability, and flexibility. I would not like this tire as much if it were lighter as it would probably be insufficient for off road use. For on road high pressure use, a 1000gm skinny tire is probably doable, but once you add knobbies, abrasion resistance, etc…you have a heavier tire, which is what accounts for the 1500gm off road tire.

So yeah, there is such a thing as having a tire that is too lightweight.

Also, these Frankentires, they are not as durable as a ready built tire, so there is a greater liklihood that they will fail dramatically; ie split apart and jam in the frame, so riding one off road at low speeds is one thing, riding them on thasphalt at a high rate of speed is probably a bad idea.

I measured my prototype 36" tire this morning and it is now, with a couple months of regular use, a full 2.5" wide and 2.25" tall. It is a big tire for a 36er.

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You didn’t read what I wrote properly!

“Awesome! That looks great What do you think the 2.4’’ wire bead model would be like as a 26’’ muni tyre? I hear it is WIDE and the tread pattern looks good.”

I did not mean use the tyre to make frankentyre! I was asking you what the 2.4, 26’’ Advantage would be like as a muni tyre for a 26’’ unicycle :wink:

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Oh, you mean as a regular “buy off the wall” stock tire…well the Advantage is a nice tire, I don’t know that it’s any better or worse than the Ardent, Maxxis uses the same casings between tires and changes the tread pattern.

The Sillkworm sidewall is like a Racing Ralph Evo, so for racing only, not very sturdy, and prone to cutting, so I don’t think it’s good muni material.

The Advantage tread pattern is a little more “open” than the Ardent, so if you like that style it might suit your needs.

I compared them side by side just now and the Advantage has a solid line of outside knobbies vs the Ardent having a “in and out” pattern along the outside edge. I’d never thought about it before, but the solid edge may be what makes the Hans Dampf and Intense such nice riding tires…

Personally, I find the Ardent 2.4 to be a great tire, only surpassed by the Hans Dampf, but if you can get the heavier duty Advantage in a 2.4, you should try it.

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Geared one

I successfully “schlumpfed” it :smiley: Here it is:

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Looks great. How it rides?