Hey fellow riders,
Been reading forums for a while and finally had a worthy post, so I joined.
Over the past few weeks a friend and I took the advise of a previous post on here and decided to build our own giraffe. My friend mark works in a welding shop so was able to do the welding work with little time. Long story short, we extended the tail of the BMX bike we used and doubled up two old chains to do the job. The uni's seat measures up at just about 5' 8". We made our only purchase of a set of chain tensioners for 10 bucks and slapped a viscount seat on to replace the hard plastic original one.
Being that this is our first ever giraffe to attempt riding, we decided to skip to the fun and ride it with the original BMX sprocket set, which is 16 teeth on the wheel and 43 teeth on the chain ring. Makes for pretty rugged gearing on a giraffe at 1:2.68 etc. As it is we don't have other sprockets to use, or want to deal with mounting them onto the cranks and wheel.
Just wondering if any of you guys have ever tried anything like this. Every other giraffe I've seen is 1:1 gearing, but the result, although intimidating to say the least, makes for a very fast 20" wheel giraffe that, despite initial impressions, IS RIDEABLE. We both spend about an hour this morning working on it, making it further and further, until mark first (as always) found the rhythm and cruised about 100 yds. out his driveway and up the road. It wasn't till this afternoon that I was able to do the same, but it is definitely exhillerating cruising right along while pedaling quite slowly on our first ever giraffe. I'm new to the forum, so am unfamiliar with how to set up a gallery, but we've got some poor quality videos of the riding that I'll be trying to put up to show off our handywork (err.. hastywork).
Hope this long post didn’t waste anyone’s time. And I’ll let you know if I get anything up for you to look at.
That is so cool! I’m about to build a giraffe of my own. Would love to see some detailed pictures.
As simple as hacking up an old BMX frame and using some imagination. My original idea when we started talking about it was to leave the tail section alone, just modify it to work as a linear fork, thus making it possible to use the same length chain…this wasn’t so however, as mark didn’t think it’d be tall enough that way, which I’m glad for now. he left the downtube attached to the hub and chopped off everything else from it. used the top tube to extend the bottom fork and then welded the vertical tube onto the top of it all to have an adjustable seat height.
Here's a picture of him when we first started attempting to ride. The tail triangle piece was a simple fix....just took the frame pieces that go up to just under the seat, and bent them around (with heat of course) to meet with the straight ones. Hope the picture helps, and let me know if you build one.
Oh, and let it be understood that although the gearing makes for a fun challenge, it's quite lacking in practicality, unless you plan on riding large expanses of smooth paved surfaces at high speeds 5+ ft. above a 20" wheel. We have yet to find out if idling is even possible, as the wheel travels SO FAR with so little pedal input, which means you have VERY LITTLE authority over it, ESPECIALLY with your cranks vertical as they are while idling.
Re: homemade geared giraffe
On Fri, 10 Dec 2004 22:19:01 -0600, “Tunnelrat81” wrote:
>Every other giraffe I’ve seen is 1:1 gearing
Often, giraffes are close to 1:1 gearing but not quite. The slightly
off-unity gear is better for wear.
Yours sounds like a cool project. Several people will want to see your
pictures but new(ish) forum users don’t seem to be allowed to make a
gallery here. You could post pictures in this thread but not video.
That you would have to host elsewhere or ask someone to put it in a
gallery at unicyclist.com for you.
Klaas Bil - Newsgroup Addict
“Deflating pi does not reduce calories, it just concentrates them. - billham”
Do you think it would be ok if I didn’t use a bike fork, but instead took two metal tubes and made a T A LL frame, with a lot of clearance around the wheel , like the ones on miyata, torker, pashley giraffes? I this type of giraffe frame might be more sturdier.
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Shucks, it messed my drawing up, well here’s a detailed picture of the frame.
I’m sure it would be stronger to use a frame like the one pictured, but at that point, you’re basically fabricating the whole frame. If you’ve got the resources, you might as well do it. I think the fork portion of our frame is plenty strong, but any time you have that much length of straight, thin-walled pipe (from the fork up to the seat) you’re in danger of bending from hard falls, simply from the greatly increased leverage.
After the weekend I should be able to get some more detailed pictures of our giraffe up, so far the one is all we have.
Good luck with your fabricating, and be sure and post some pictures if you decide to build one. AND if you are using a BMX bike frame for material, go ahead and try the stock gearing just for fun, its a riot.
How do you stop the freewheel?
About a year or 2 ago I was practicing MIG welding. My first project was the exact same as yours. I used the wheel and frame off of a crappy freewheel bike. I simply welded the gear to the hub, since the whole thing had been free and noone cared to ever salvage it again. I used the bottom bracket and welded it onto the rear triangle at a different angle. I then took a piece of the toptube and welded that between the seattube and the back of the rear triangle to strengthen the whole thing. IT worked well although I never bothered to check chain length so I ended up using a half-link in it. I used stock gearing. It rode weirdly, but wasn’t too bad since it was only about 3’ tall. It’s since rusted over and been cut up for scrap. I haven’t gotten to do any MIG at that shop since then, so I haven’t bothered to rebuild it.
Just like gerble said, we just welded a small bead around the gear to lock it to the hub, allowing the axle to still turn of course, but locking down the freewheel.
I was bored last weekend so i got out the grinder welder and an old bike and made a 7 1/2 ft uno with a 26" wheel and potentialy a 15 speed gear change (it did have 21 gears but when part sheared off inside the hub i had to grind the end off to weld it up inside) i havnt riden it much but already feel that it is too lower gear so this weekend i am going to try and make
it possible to change gear and hopfuly even change gear on the go
if you have any suggestions on how i can do it please post them here… giraffe uni… there is also a pic of me riding my raffie
This is video of me riding a highly geared giraffe with a 26" wheel (pretty fast)
I experimented with gear ratios on giraffes back in 1980 by changing the top chainwheel on my Schwinn Giraffe. I think the size we used the most was 48 teeth on top, to 26 on the bottom, for not quite 2:1. Yes, it was a pain to freemount the cycles (we had two of them), but idling was possible if you took your time about it. I also rode it in formation in a parade once or twice, but that was pretty hard also, being in a line with other giraffe riders stopping and starting.
In 1980 Bradley Bradley and I also rode them in the March of Dimes Superride, 75km for charity. We were the first ones to start and the last to finish, with painful urination and other ailments! Never again on a 20" wheel!
I have ridden a low giraffe with a 20" wheel and a 3:1 gear ratio. The guy had it set up with aero bars and a speedometer. I did not think going fast on it would have been a good idea at all…
James, that was really you?! I find it funny how I keep bumping into you on here. So, how fast were you going in this?
home made giraffe
My first home made uni was a giraffe. I used an old 26 inch coaster brake singe speed bycicle for the frame. I welded the sprocket of a 20 inch rear wheel from a single speed coaster braked “spyder” bike solid to the hub. But… for the crank sproket I found that a sproket off of the rear wheel of another 20" rear wheel would fit almost perfectly over the clamping nut (opposite side of the large crank sproket) of the crank. The clamping nut centered the sproket around the crank pretty well. Then Weld the sproket to the clamping nut assemble the crank and bearings with the bearing cone “nut” like normal. Screw the calmping nut down and seat it pretty well on the bearing cone “nut” then weld the clamping nut to the crank. True you can’t disasemble the thing if your brearings go out, but you’ve had your fun and you can allways build another. This worked pretty well and the uni had a 1:1 ratio.
yey… i luv giraffes…
the first time i learnt (a 5 ft) my trainer held my hand for a bit… then let go… i was doing fine until someone yelled out “Did you teach her how to get off?”