Mini Giraffe.

After look at online pics, i have decided to build my own mini giraffe.
Im using pieces of an old bike. I want to put a push- lawnmower tire on
there. Probably be about 10" or so. Might be bigger if that would help.


I am stumped on a sprocket question though. The top sprocket is going to
be the front sprocket of the 20"bike i am using. I got a problem though
with the bottom sprocket. How big should it be? I was going to use the
back sprocket off the bike but it was a multi-speed and all the
sprockets are together as one piece.

Also, how will i attach the bottom sprocket to the lawn mower wheel?

I also need help with the frame. SHould i use the bike frame and chop it
up so i will already have the crank shaft (?) or should i make a custom
frame??

Looks like i got my work cut out for me.

Kelly.


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juggle508 - Extreme UNIcyclist

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Have you considered using a very small children's bike for the wheel? It
seems to me that a lawnmower wheel would be incompatible with the
design? I'm sure you could find a cheap kids bike with a 12" wheel, then
use the bottom sprocket that's already attached. To lock out the
sprocket I've seen where someone welded the sprocket to the axle without
changing anything else on the wheel.

Also, have you seen my prototype home designed giraffe? Maybe you could
make something similar just with a smaller wheel?

As for the gear ratio, for example: on a 10" wheel you would want twice
as big a cog on the cranks then on the wheel so the giraffe would pedal
and balance like a 20" giraffe.

Unless you have access to welding equipment, I would recommend just
using a back half of a regular bike frame; it looks kind of odd, but
works quite well from what I have seen.

Keep us posted on your progress!

~Cameron


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UNIquelyCanadian - 8~)[==)--O

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I would use a wheelbarrow wheel or a handcart wheel.


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loosejello - Amanda gives me sunburn
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I have a photo album at my Yahoo club with photos of a mini giraffe I
built with a 12" bike wheel.

The ratio seems to work the best will have an equivilant to a 20"
tire.

Tire diam/#of cog teeth x #of drive sprocket teeth = 20

without going outside and counting I think the cog is 16 teeth and the
cahin wheel is 24 theeth. I'll let someone else do the arithmatic, but
it is in the 19 3/4" range.

you will also want longer cranks with a giraffe than with the same wheel
equivilant on a standard uni. I like to use 5" or 51/2 one piece
cranksets. on my giraffes.

Al


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al_lieffring - World famous mediocre unicyclist

sola rota Ya'll
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