Jesse James chopper bicycle.

[Dougthewelder]

so i'm starting a new project now that my go kart is running good.

here is a short video of what i'm working on. this is my first project like this with a bike so suggestions are welcome! thanks!

http://www.youtube.com/watch?v=RPtljd9cmlI

what do you guys think about this for a back tire?

http://cgi.ebay.com/ebaymotors/ws/e...witem=&sspagename=STRK:MEWAX:IT#ht_648wt_1165

 

[bigfootrules31]

$180 for a tyre?????? thats the biggest ripoff iv ever seen.

 

[Dougthewelder]

well it comes with the axle the hub the sprocket the brake pads and caliper and the rim and tire. if i were to try to get all those parts i would be looking at about the same cost i think...

 

[anderkart]

Maybe I got this all wrong here but It seems like a wide rear tire with more of a rounded tread profile would turn much better. The tread on that one seems to be pretty flat across so as you leaned the bike way over to enter a high speed corner the rear of the bike would suddenly raise up and you'd only be riding on the much smaller contact patch of the treads outer edge. I actualy prefer the way flat tread-ed tires like this look over a rounded design, but it just seems that tread thats more rounded off would have way more predictable turning characteristics. (especially when you factor in the major tracking differences these front/rear widths will result in while leaning the bike way over around fast corners) I dont know, meyby you can just run low enough tire pressure where the tires tread flexes enough to stay mostly flat to the road surface.

Maybe theres a way to figure it out but I couldnt find an overal tire height measurement on that ad to get an idea how it would compare to your front. I think It looks cool to have the front a bit taller than the rear on something like this but too much of a diference might end up looking kinda dumb.

 

[Dougthewelder]

good thoughts anderkart! i had the same thoughts and totally agree with you. i did a Google search on this tire type and size and found these pics. to me the size looks about right. as for the turning at high speeds, this tire will not be as good like you said, but i think this bike will ultimately be for looking cool and riding around the neighborhood so i think it would be just fine.

http://www.crazy-8-ball.com/pictures/vtwinmini/205-50-10 tire on chopper from rear.JPG

http://www.crazy-8-ball.com/pictures/vtwinmini/black vtwin 8.JPG

i took a little time and did a more or less to scale mock up.

By vitamaxx at 2009-11-04

i think it looks good what do you think?

 

[anderkart]

Yeah I understand about building for looks over performance but it is nice to have both when possible.

Wow, nice mock up. I was picturing that rear might be a whole lot shorter than your front but those seem to look pretty good together. I started riding Harley's in the late 70's before the whole super wide rear tire craze got goin and quite honestly I think they look silly. (but what do i know, I'm just a grumpy old fart...

 

[Dougthewelder]

well the tire is about 18" tall and about 7" wide so its not "super wide" but yea i guess it does have that kind of look to it. when i first started seeing bikes that had those wide back tires i thought they looked cool so i guess its just a preference thing.

on a different note i'm excited about this things performance. it will have the same engine and torque converter as my go kart, and my go kart is plenty fast. my go kart will go about 45mph and has great climbing power and low end acceleration. the gearing on it is a 8 tooth on the torque converter side and a 70 tooth on the axle.
this bike will be much less heavy and the ratio will be a 10 tooth on the converter side and a 54 tooth on the wheel. also the wheel will be bigger around. i think this bike will go 55 mph when its done. i will post videos and such of course when i make more progress!

 

[anderkart]

I agree, the whole extra wide rear tire thing is a total preference thing. I'll just bet the next upcoming generation will come up with some new trends most guys your age think are kinda silly too.

Anywho... cool project man, I'll be following your thread for updates.

 

[Dougthewelder]

well iv made some progress. i finished converting the fake gas tank that came with the bike into a real gas tank, it is kinda small though.

also i might have messed something up today. i was wondering why i couldn't get my clones to idle nice and low like the flathead on my mini bike when i remembered the compression release on the cam in these clone engines. i thought to my self, self i bet once the engine gets under a set rpm the compression release is keeping the exhaust valve from closing all the way thus killing the engine. then i thought hmmm older engines didn't have those and i am still able to start them... anyway I took it off the cam shaft, and now OMG its hard to turn over lol... i hope i don't break the pull start starting this thing now (or pull my arm out of joint )

here is a video of the gas tank and some new parts i just got in.

http://www.youtube.com/watch?v=1EBCQQ2MGMc

 

[brendonv]

I reckon it needs more rake. Looks more like a trike or bobber. Give it mega rake and it will look sick.

 

[anderkart]

Lookin good man.

So, does your clone idle good now?

 

[Dougthewelder]

well as far as the idle goes i'm waiting to fire it up again until i get it on the bike so when i get it started again ill let you guys know if it was worth it removing the compression release.

here are some pics of the work i did on it today. its not welded up yet, i just set it up to get an idea what it will look like.

 

[brendonv]

Looks sweet.

 

[Dougthewelder]

ok so i was just doing a bit of math. i found that my tire will have to turn 1112 times to go a mile. and if i assume about 4000 max rpms out of my stock clone here is what i found.

the sprocket on the TAV2 is a 12 tooth so 4000 x 12 is 48,000 teeth per minuet (tpm)

i will be running a jack shaft with 13 tooth and 18 tooth sprockets respectively

so 48000/13 is 3692 rpm on the jack shaft

3692 x 18 is 66,456 (tpm) off the jack shaft

66456/60 is 1,107 rpm of the rear sprocket and tire

now to convert this to mpH i will multiply 1,107 x 60 and we get 66,456 (RPH) revolutions per hour.

now to find the actual speed we divide the RPH by the number of revolutions the wheel need to turn to go 1 mile. 66,456/1112 is 59MPH

**** that quite fast lol, and the TAV2 can achieve a 10% overdrive so 59 x 1.10 = 64.9 mph

now i don't think it will actually go quite this fast (maybe down a big hill ) but i think this thing is going to haul ***. if i were using a normal centrifugal clutch i don't think this ratio would have any take off power at all but because of the TAV i believe it will still get "ok" take off power.

should be fun!

 

[brendonv]

U gotta take into account that u will be sitting on it so that adds to rolling resistance. Then there is air resistance which takes off like 10% anyway. So all up, ur looking at about 45mph. I doubt u will go that fast but point is, it has some ballz.

 

[Dougthewelder]

well the proof is in the pudding as they say. i think it may do 50mph though because my mini bike with a 5hp brigs can do an easy 45mph and it would go faster if that wasn't where the rpms maxed out at.

i can't wait to get this thing done and test it!

 

[Smurph]

50mph is real close to 80% of 59. To think that air and weight will only take 20% is a good estimate considering it won't be as heavy, and will have quite a bit lower of a coefficient of drag than a go kart. I bet you'll see 50mph.

 

[brendonv]

Are u really gonna do 50mph on that bike though? I wouldnt want to push that front bike wheel or the metal that much. Lets just say "its fast enough" XD.

 

[freakboy]

Nice man but only one sujestion add some more rake and imo it would look better

 

[Dougthewelder]

well i think 50mph will feel ok on this bike. really if you go down a big enough hill on a bike you get close to those speeds just pedaling, it feels fast for sure but i think the bike will be ok. the rear tire is rated for highway speeds so its ok. the front tire seems good but i think this will be the bike that i use a helmet on if it really does go 50mph.

as far as changing the angle of the front forks, for now i like the look of this bike. maybe that can be a future project.

thanks for the input guys. its fun to have a group of people that are interested in these sort of things. some people i tell them i'm converting a kids bike into a motorcycle and they just look at me like i'm crazy.