tie me eccentric kangaroo down, sport

many years ago i saw a picture on john foss’s web site of a kangaroo unicycle with an eccentric wheel,

and now i have a spare 24" uni frame and hub that i want to do something interesting with,

i thought about lacing the wheel myself but when i tried to find out how it was done i realised that it was a bit (well extremly) more complex than i had thought

i decied to treat my self by getting the old uni wheel rebuilt with a 20" eccentric wheel, so i went down to the bike shop and asked to speak to the man who builds the wheels,
unfortunatly (and unsuprisingly too) he had never build an eccentric wheel before. but he had been thinking about it for a while.
he’s agreed to do it if i can find out what the hell he’s suposed to do.

so does any body out there have any experience in eccentric wheels?
it’ll probably be all greek to me but as long as the wheelbuilder understands then i’tll be fine.

thanks.

UMX aka evil ewan

citizen_smith@hotmailOBSCURED.com
(your know the deal, there isn’t realy a domain called
hotmailOBSCURED.com)

this one does’nt even look like it has spokes,maybe the owner will see this and say how he made it

kangoro.gif

Re: tie me eccentric kangaroo down, sport

In article <jagur.4511z@timelimit.unicyclist.com>, jagur <jagur.4511z@timelimit.unicyclist.com> wrote:
>
> this one does’nt even look like it has spokes,maybe
> the owner will see this and say how he made it

it is posible to do it with spokes, i belive that unicycle factory make them but i’ts a long way from scotland.

i’d entertain the posibility of using metal plate “spokes” like the uni in the picture but i’t looks like it’d be just as dificult to build.

UMX aka evil ewan

citizen_smith@hotmailOBSCURED.com
(your know the deal, there isn’t realy a domain called
hotmailOBSCURED.com)

maybe its just a wooden disc jammed into the rim,and then use screws in the spoke nipple holes to make it stay in there.

i think a 48 holed rim with 48 screws drivin into the wood disc would be fine

Re: tie me eccentric kangaroo down, sport

In article <jagur.4557z@timelimit.unicyclist.com>, jagur <jagur.4557z@timelimit.unicyclist.com> wrote:
>
> maybe its just a wooden disc jammed into the
> rim,and then use screws in the spoke nipple holes to make it stay in
> there.
>
> i think a 48 holed rim with 48 screws drivin into
> the wood disc would be fine

sorry, i was talking cross purposes, i hadn’t actually looked at the link yet, now i understand. i though you meant the one in john foss’s garrage pages.

this would be annother option, i suppose, but i realy like the idea of spokes, it’ll look more weird just for being made of regular unicycle parts.

and spokes would be easiry for me, i just need to pay the person who builds it.

the offset on the uni in your pictures is huge i was thinking of using a 4" offset (i.e. a 20" wheel in a 24" frame) it must make it incridibly dificult to ride any distance on it.

who’s ridden one of these beasts? is it more dificult that it seems?

UMX aka evil ewan

citizen_smith@hotmailOBSCURED.com
(your know the deal, there isn’t realy a domain called
hotmailOBSCURED.com)

spokes would look nice to,but i cant see it being easy to cross lace them(serious math)without frustration.now,radial lacing(spoke comes straight out from hub)would be easier but that would sacrfice lateral strength.

The way to do it would be to get a wheel builder from your local cycle shop (store) to take up the challenge. All cycle spokes come with a long threaded section at the end, and when they build a normal wheel, they lace it loosely, then tighten and adjust it, then they cut the spare off the ends. I reckon any competent wheelbuilder would enjoy the challenge.

The degree of eccentricity need not be that great. On a 20 inch wheel, setting the hub only one inch off centre will mean that the height of the unicycle will change by two inches during a complete revolution of the wheel. That would be enough to produce the humorous and challenging effects desired, whilst making the unicycle rideable. Remember that you will need to lift your entire weight and the weight of the forks/seat tube/seat by the two inches each revolution of the wheel.

Re: tie me eccentric kangaroo down, sport

In article <jagur.45b0a@timelimit.unicyclist.com>, jagur <jagur.45b0a@timelimit.unicyclist.com> wrote:
>
> spokes would look nice to,but i cant see it being
> easy to cross lace them(serious math)without frustration.now,radial
> lacing(spoke comes straight out from hub)would be easier but that would
> sacrfice lateral stregnth.
>
>
> –
> jagur - Random Member
>
> “they’re using a bounty hunter named Jango Fett,to create a clone army”
>
>
> ------------------------------------------------------------------------
> jagur’s Profile: http://www.unicyclist.com/profile/502
> View this thread: http://www.unicyclist.com/thread/17888
>

all the pictures of eccentric wheels (on bikes) seem to be radial or one cross, it’s had to seem from pictures, maybe radial is the way to go, its only a 20" wheel i’m thinking about, but then that would mean that it wouldn’t realy put up with me riding it
with any degree of energy. i’d settle for one cross spoking though.

UMX aka evil ewan

citizen_smith@hotmailOBSCURED.com
(your know the deal, there isn’t realy a domain called
hotmailOBSCURED.com)

Re: tie me eccentric kangaroo down, sport

In article <Mikefule.45dsb@timelimit.unicyclist.com>, Mikefule <Mikefule.45dsb@timelimit.unicyclist.com> wrote:
>
> The way to do it would be to get a wheel builder from your local cycle
> shop (store) to take up the challenge. All cycle spokes come with a
> long threaded section at the end, and when they build a normal wheel,
> they lace it loosely, then tighten and adjust it, then they cut the
> spare off the ends. I reckon any competent wheelbuilder would enjoy the
> challenge.
>

thats pretty much what i’m going to do, but i want to gain as much info as posible to make sure that i don’t spend a fortune on his time doing it pureley trial and error, he is keen to take up the challenge but didn’t realy know where to start.

> The degree of eccentricity need not be that great. On a 20 inch wheel,
> setting the hub only one inch off centre will mean that the height of
> the unicycle will change by two inches during a complete revolution of
> the wheel. That would be enough to produce the humorous and challenging
> effects desired, whilst making the unicycle rideable. Remember that you
> will need to lift your entire weight and the weight of the forks/seat
> tube/seat by the two inches each revolution of the wheel.

did i say 4", sorry i meant 2" i just hadn’t realy thought about the mechanics of it that closely.

the ideal i’ve got in my head is that it fits into the 24" frame that i have handy,

i suppose that i’ll have to try a few diffent set of cranks too

UMX aka evil ewan

citizen_smith@hotmailOBSCURED.com
(your know the deal, there isn’t realy a domain called
hotmailOBSCURED.com)

Re: tie me eccentric kangaroo down, sport

On Sat, 4 May 2002 18:53:12 +0000 (UTC),
citizen_smith@hotmailOBSCURED.com wrote:

>who’s ridden one of these beasts? is it more dificult that it seems?

I’ve tried one, 24" wheel with moderate offset, axle 2 or 3 inches off
the wheel centre. I was level 1 at the time but found it actually
surprisingly easy to ride. Not good for speed though because of
spontaneous jumping. Weird to get back to your normal wheel
immediately after it: couldn’t ride it because my reflexes were
biased!

Klaas Bil

“To trigger/fool/saturate/overload Echelon, the following has been picked automagically from a database:”
“BVD, ISPE, Nerd”

Re: Re: tie me eccentric kangaroo down, sport

Was that cycle eccentric AND a kangaroo?

(Klass Bil and an Eccentric Kangaroo walk into a bar,

Bartender: Hey buddy, you look all screwed up.

E.K.: You’d look like this too if you had to carry him on your sholders!

Bartender: I wasn’t talking to you…)

Christopher

I think that the number of different spoke lengths for an n spoked rim and hub would be n/2 for any style lacing (radial up to m cross) and that they are not to difficult to calculate. All of the leading spokes from one side are equal in length to the trailing spokes of the other side. The leading and trailing spokes on one side all differ in length, though.

The problem with an eccentric spoked wheel would be tensioning and truing. Axial variations can be easily adjusted in a truing frame with flat reference edges. Radially it would be very difficult to adjust accurately although with the final product it should be unimportant or, perhaps, unnoticeable. The two adjustments interact unfortunately.

The final product would also be tensioned in a highly unbalanced manner with weird stresses to say the least.

Re: tie me eccentric kangaroo down, sport

On Sat, 4 May 2002 21:23:22 -0500, rhysling
<rhysling.45rwm@timelimit.unicyclist.com> wrote:

>Klaas Bil wrote:
>> * I was level 1 at the time but found it actually
>> surprisingly easy to ride. *
>
>Was that cycle eccentric AND a kangaroo?

Sorry, no it was an ostrich.

Klaas Bil

“To trigger/fool/saturate/overload Echelon, the following has been picked automagically from a database:”
“TA SAS, burhop, GEOS”

Re: tie me eccentric kangaroo down, sport

<citizen_smith@hotmailOBSCURED.com> wrote in message
news:ab0o9b$g2n$1@knossos.btinternet.com
> i decied to treat my self by getting the old uni wheel rebuilt with a 20"
eccentric wheel, so i went down to the bike shop and asked to speak to the
man who builds the wheels,
> unfortunatly (and unsuprisingly too) he had never build an eccentric wheel
before. but he had been thinking about it for a while.
> he’s agreed to do it if i can find out what the hell he’s suposed to do.
>
> so does any body out there have any experience in eccentric wheels?
> it’ll probably be all greek to me but as long as the wheelbuilder
understands then i’tll be fine.

I’ve never done it myself, but it seems to me a good way to do this would be
to:-

get some extra long spokes (like at least 3 inches or so longer than what
you need for a normal 20" wheel), these won’t actually get used, just used
for measuring.

lace the wheel as normal, the spokes will be sticking miles out of the rim.

Move the hub to where you want it to be (2 inches offset from centre) and
turn it round to tighten up the spokes as much as you can.

Now mark each of the spokes where they go into the rim with a marker pen and
measure where you’ve marked on all the spokes. You’ll need to pay attention
to the order of the spokes round the wheel and where they came out of the
hub.

Now get some spokes of length a mm or so longer than each of the
measurements and lace the wheel with these in the right place using the same
lacing pattern and hopefully you’ll have a wheel with the right offset.

Although I don’t know much about this, it’s just an idea.

Joe