I’ve robbed enough ideas from various guni threads to want to make something that goes wicked fast without the great bother of making a huge wheel (although a huge wheel would get some looks from passers by). Anywho, I’m making a “short” giraffe with small crank axles just above both sides of the hub axle (using gears on both sides). My quandary, though, lies in wheel size. I can see the aesthetic appeal in using a 20" (looks cool going wicked fast), however I also am aware that 24"+ wheels roll over bumps better resulting in less UPDs. I dunno, form or function?
I am also toying with the idea of putting the crank axles below the hub axle (I know…another ripped off idea;) )
Not that I’ve tried this but… A 24" might be a little less skittish, and additionally might lend itself well to being a really fast cross country Muni. That could be interesting…
i’d definatly go for a 24", you dont wanna be going wicked fast into a decent sized crack on a 20" and lose your front teeth.
cranks below the axle would make for worse turning circles i would imagine, but i can’t be sure on that. i say just make something, and if it screws up, make it again :P.
Right on. I really needed to decide. My bits from UDC just arrived (in a “AmeriChicken” box lol), and I’m off to the welder/ machinist to get him to turn me some axles, so these iseas are awsome!
thanks
j
wow you’re really getting into this design and making thing, thats awesome! you’ve actually bought parts and are going to pay somebody to do it!! you’re my hero!, i usuallyjust cut up old bikes and weld them together myself the dodgey way, but you, sir, are amazing
I’m into it for about $150 thus far. It suprised me. All those bits and bobs add up. I have all the parts except the crank axles and the wheel and tire. I’m hoping the axles will be pretty cheap considering this machinist is a buddy… and owes me a favor. I got bearing holders and a seat post. 80 bucks for 3 little things!(including shipping duties etc.)
I built something just like you’re describing. I used a 26 inch wheel because of the tire and rim selection–and I had some lying around.
They are a lot of fun, and you really can go fast on them. I used 175mm cranks on mine because I live around very steep hills (I’m in the mountains) and I really don’t have any problem riding mine up hills.
The bigger your wheel, the comfier your ride. Also, (and bear in mind this is half my own experience and half reading the forum) I hear that longer cranks are nicer on gunis.
I would definitely recommend getting your crank length nice and comfortable for your particular needs, and then deciding on the gear ratio you want with your wheel. You should be able to run any crank size you like, however bear in mind that for a giraffe you’re going to need leverage to mount it, so longer cranks and lower gear ratios will make it far easier to get on.
If I were you I’d probably be looking into a 24 or 26 with an mtb tire on it, something to soak up the bumps a bit more. good luck!
ah yes. george ahs long since graduated from iowa state(where those vids were hosted) and they’ve taken down his webspace. not sure how oten he reads these forums anymore, but that guni was a senior mechanical design project.
machinist to get him to turn me some axles, so these iseas are awsome!
I can’t SEE it. The link in his thread doesn’t work. I need to see how its done correctly!