OK so I am thinking of making a 32" unicycle. I have a broken 36" rim I am going to mod but the problem is that nobody makes a 32" tire.
My idea is to use spiderwire fishing line wrapped a crap-load of times for each bead (1/2 spool per bead). I tie the ends and work in some bow string wax in them to keep the strings together and make it easier to manage. I would then sew them into a two ply nylon carcass (threads at 45˚) and soak it all in rubber cement. Once the rubber cement it soaked in I would take it out taking off the excess cement.
I would then mount the tire on the rim with a 29er tube in it before it is dry and let it take its shape around the inflated tube.
I would try to get the tread off a 29er tire in a continuous loop and stretch it over the tire allowing it to bond to the rubber cement in the casing.
I know that the whole tire will sort of collapse when it has no air pressure since it is built in and on stretched rubber but I don’t think that this should be a problem if it is inflated. I plan on putting some Stans sealant tin the tube since it won’t have a huge amount of puncture protection and the tube will probably end up as part of the sidewall. (would that remove friction giving it a tubeless like feel?)
I will probably try this in 26" first to see it if works but do you guys see any obvious flaws in my plan? Anything you would do different? I have never done anything like this before as i have never had the need (right like I NEED a 32" unicycle) and does anyone have any suggestions for the donor tire. I would probably want something with small knobbies. This would be used for commuting and some XC riding.
Rotating the tire with the tube being part of the sidewalls might be a problem but I will tackle it when it seems necessary.
If it works I might also make a lightweight 36er tire this way.
OK, so you just earned the “Hardcore” award for today…
Right off the top of my head I’m thinking that rubber cement is going to have almost zero shear resistance to the kind of loads you’re contemplating. “Shoe Goo” is the same stuff for “fixing” worn-out sneaker soles and it NEVER works, always peels off no matter how you prepare the surface.
There’s a tire retreading factory here in my town, and I’ve seen their setup. Heat and pressure are involved. I’m not sure about the composition of the rubber or what they use to bind the bulk tread strip to the tire “skin.” I can ask, if you want. Maybe there’d be a way to “blend” a chunk of another tire into a 26 or 29er? Hmmm.
OK, so not to be all negative…somewhere in my technical library I have an 1899 book on “motocycles” – cars, eh? – that showed a cross-section of a pneumatic tire. I’ll see if I can look it up tonight. I don’t know what research you’ve done but you might mouse around a little for tire designs in old books. Somebody had to make them before Dunlop and Goodyear got going.
This time of year, remember to put the winter air in the tire, or you’ll have problems with the tread wearing off in the cold.
You could go with a hard tire like on a Penny-Farthing, I guess…different rim design (narrower). Those tires usually come in a strip, hard rubber with an embedded wire running inside. Trim the strip to just shorter than (pi)(diameter) and then use the tails of the wire to torque it on. Bugger of a rough ride, though.
I didn’t break it, the guy who crashed into my parked truck with it inside did. It is the Nimbus SE rim that I bought from Levi. It out of round and has a big crack on the third spoke hole from the seam. I plan to cut the rim a spoke hole and a half from there and re-bend it making a 32" 32h rim. I will have to wait until Koxx releases their 32h hub to build it up or I could botch something together with a regular hub for the mean time.
Anybody have any other suggestions instead of rubber cement? The nylon cloth would be providing all the structure, the rubber cement would just be keeping things together. It would be basically like an uncured rubber on the exposed sidewall but should bond well to the tube and tread (I think). The most important part for the glue is to keep the tread on. I can’t really heat cure anything since I have a camping stove and a toaster oven…
I have thought of the combining two tires idea but you would still need a new bead and it would be hard to connect the two tires in a strong and smooth feeling way. I think making a whole new casing would be easier to get a good result.
I have looked around on the internet but basically nobody does this. a few places hand make sew up tires but this seems simpler to me. The most helpful site I have found is the Schwable Tech Info page
I might try to figure out a way to add a puncture protection strip too.
It will probably be a while before I start this project. I would like to find a job first and maybe an apartment but I have gotten sort of used to living in a vehicle.
oh and really not interested in solid tires but thanks for the suggestion.
IMHO, it’s the only real barrior to a different size
I think a 44 would sell a lot better then a 32, but no matter. There are a lot of vid’s about tire construction. You need to come up with serious $ to get the pressure mold-oven thing together to bake the tire rubber into the bead and plys.
A tube for a 44 could be easily patched together from a couple 36 tubes. Rims welded up in back yards, spokes cut a different length. It is all so easy, more or less. Even the tire is easy, all it takes is money, there is nothing that needs to be learned, uni tires are extremely low tech. Not a back yard endeavor by any stretch though. If you had the $ to pay for 10,000 screwy sized uni tires, you could have them in a month IMHO. Just call Coker tire Co ! They would love to help I am sure. They have done more for uni riding by making that tire then the Beadles did for religion or the pope did for music. A new tire size takes the act of an economic god. My impression is that the fab start up costs are high, and yet there is no other way. You can’t bake a serious tire for low $, I think, because tire making machines-molds-ovens-pollution controls etc. are very expensive.
Having written that, I am amazed that there is more then one brand of 36 tire. That gives me some hope that development of larger uni tires will continue.
Why not? I have a broken 36" rim, It is useless right now and I can hopefully make something cool out of it instead of throwing it away. (and building an ultimate would be too easy :))
haha, I am a homeless guy living in my vehicle. I am not going to be spending major coin on this. This is a low tech do it yourself kind of project. Definitely not going into the business of off sized unicycle building.
On Nov 26, 10:49 am, saskatchewanian
<saskatchewan...@NoEmail.Message.Poster.at.Unicyclist.com> wrote:
> OK so I am thinking of making a 32" unicycle. I have a broken 36" rim I
> am going to mod but the problem is that nobody makes a 32" tire.
>
> My idea is to use spiderwire fishing line wrapped a crap-load of times
> for each bead (1/2 spool per bead). I tie the ends and work in some bow
> string wax in them to keep the strings together and make it easier to
> manage. I would then sew them into a two ply nylon carcass (threads at
> 45˚) and soak it all in rubber cement. Once the rubber cement it
> soaked in I would take it out taking off the excess cement.
>
> I would then mount the tire on the rim with a 29er tube in it before it
> is dry and let it take its shape around the inflated tube.
>
> I would try to get the tread off a 29er tire in a continuous loop and
> stretch it over the tire allowing it to bond to the rubber cement in the
> casing.
>
> I know that the whole tire will sort of collapse when it has no air
> pressure since it is built in and on stretched rubber but I don’t think
> that this should be a problem if it is inflated. I plan on putting some
> Stans sealant tin the tube since it won’t have a huge amount of puncture
> protection and the tube will probably end up as part of the sidewall.
> (would that remove friction giving it a tubeless like feel?)
>
> I will probably try this in 26" first to see it if works but do you
> guys see any obvious flaws in my plan? Anything you would do different?
> I have never done anything like this before as i have never had the need
> (right like I NEED a 32" unicycle) and does anyone have any suggestions
> for the donor tire. I would probably want something with small knobbies.
> This would be used for commuting and some XC riding.
>
> Rotating the tire with the tube being part of the sidewalls might be a
> problem but I will tackle it when it seems necessary.
>
> If it works I might also make a lightweight 36er tire this way.
>
> Peace
>
> ERIC
>
> –
> saskatchewanian
> ------------------------------------------------------------------------
> saskatchewanian’s Profile:http://www.unicyclist.com/profile/14180
> View this thread:http://www.unicyclist.com/thread/74505
>
> Posted Via Usenet.com Premium Usenet Newsgroup Services
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> http://www.usenet.com
Wow that looks perfect. I didn’t know you could get rubbers that would vulcanize at room temperature. And it is not that expensive. I will just have to figure out how to get it into Canada (anyone in Mane want to lend me their address?)
This is about making tubulars (to be sewn up and glued to a rim), not clinchers (with beads and a seperate tube).
this is not exactly what you’re planning on doing, i know, but i think it might be helpful. particularly that part about laying the cords and binding them together (with latex). it doesn’t say much about the tread, though, but it at least seems that for a lightweight road tire, you don’t really need high pressure molds or anything.
to be frank, this is an extremely ambitious project, but i would really like to see you do it. good luck!
No, man, I meant “hardcore” for wanting to build yer own tire. Leaves those people building frames in the dust. We all assume the uni mantra is “Ride, Fix, Ride, Fix, Repeat.”
I’ve seen a lotta really amazing things in here. That’d be another one. Think of the story. “There I was, down and flat halfway between Regina and Swift Current. Lookin’ around in the ditch I found the tread off a semi tire, a ball of tangled fishing line, a pack of matches and a half-full jar of Gorilla Glue…”
I started work on my 26" test tire. Using a 24" tire and tube to simulate the 29er parts for the 32" tire.
I peeled the tread off the casing on the tire. I started off trying to ‘skin’ the tire like you would a deer but the casing really wasn’t very cut resistant and I only had about 1mm of leeway before cutting through the tread. Basically I had painfully slow progress for the first 5 or so cm and I think that all the old traders back home would deny knowing me if they saw my attempt to skin the tire.
I got a bit wiser and started pulling threads with my pliers. Then I realized that I could just peel the tread off the casing if done in the right direction and having the sidewall cut down to but not through the casing.
I learnt a bit about the tire construction through the deconstruction process. There is zero stitching in the casing, even where the ends join to make a loop. I think I am going to follow their example and trust the glue/rubber to hold everything together.
I could not find any nylon fabric or RTV butyl rubber so I ended up getting polyester and contact cement instead. what the hey, it is more of a test on concept than materials anyway.
I was going to prep the material and make the casing yesterday but it started to sleet. Sleet turned to snow and now rain. Once it dries up I will give it a try. My biggest concern at the moment is that the tread from the 24" tire is not as stretchy as I thought it would be. Maybe a lighter weight donor tire would work better.
I thought of this thread whan I saw this bit on monocycles recently. If you look closely at Ben Wilson’s cycle, you can see a Schwalbe Marathon sidewall logo. . . so is this some photoshop bit of hijinx?? or is there really a schwalbe 48"?? tire out there??
Maybe unicyclists aren’t the first to crack the “making one big tire out of two smaller ones” construction DNA??
looks like two tires joined. It looks to me like there is a join near where his hands are in the pic. There is also two logos on the side. I wonder what he did with the bead and if he can feel the connections when he rides on smooth surfaces.
