pocket bike upgrade, 43cc to 196cc

[robbie]

Make sure you add a brace to the spot where the shock absorber attaches to the bike frame, otherwise the forward component of the push from the shock absorber will bend the frame.

 

[Bluethunder3320]

yeah i just thought of that.

 

[robbie]

Your swing arm shock absorber mount would have been better if attached at the back, near the axle, with the hoop leaning forward in line with the shock absorber. Lightweight vertical braces on either side would complete the design. Since you placed it vertically, you may want to add a little bit of a brace back to the axle area, but it may be good enough as it is.

My main concern was the marginal strength found in the designs of these dinky-bikes as they come from the factory. I know this because my Chinese bike project ended up with a lot of gussets and braces welded on to make up for the "just good enough" design in the original bike. I cut a lot of sheet metal triangles from an old mower discharge chute and welded them on to fix failed joints. It worked great.

Make sure you watch out for the thing that was the biggest issue on my bike: joints that are designed so the force pulls the two pipes apart rather than pushing them together. For instance, suppose you attach a shock mount to the bike by welding a tube on top of the main top frame tubes. This will cause the wheel to push up on the shock absorber, lifting the shock mounting tube off the top of the frame tubes. This will cause the tube to rip around the welds. Always make the forces push the tubes together so the welds are squeezed instead of stretched.

Or if you want to sound like an engineer, build your bike so the joints that carry the most force are in compression instead of tension. This is easy to do when you design a frame, but when you start hacking up a Chinese bike and welding a bunch of crap on (like I did, and like you are doing now) you sometimes surprise yourself with a ripped weld after you go over a big bump, and then you smack your forehead and say "wow, I should have made that a compression load."

 

[Bluethunder3320]

great info!!!! thanks!!!!!! i will definitely add 2 pieces to brace it. pics when i do that.

 

[Bluethunder3320]

Forgot one chain # I got but for my harbor freight engine I got one of these clutches for my bar stool that I am building

http://www.bmikarts.com/item/41-Tooth-3-4-Bore-Clutch-400941-3161

Tractor Supply Store wanted double the price.

i think it will be #35 chain since i already have roller chain and my friend has a hillard clutch for $25. i have that same clutch on my go kart and baja warrior tho thanks.

also look on ebay sometimes they are even cheaper. i got one for $20 once.

 

[Clayton]

That pocket bike is getting a littler more than just a 6.5hp engine...I like it!

 

[Ghanem]

Hi man I liked your baja but i was wondering ohm much did it cost you and how many cc is the Engine??

I want to buy that one in the link so what do you thinkhttp://www.northerntool.com/shop/tools/product_200465664_200465664

 

[Bluethunder3320]

Hi man I liked your baja but i was wondering ohm much did it cost you and how many cc is the Engine??

I want to buy that one in the link so what do you thinkhttp://www.northerntool.com/shop/tools/product_200465664_200465664

i paid $275 for it in working condition, starts first pull.

mine has a 196cc honda clone 6.5hp with a baja sticker on it...

i am going to change the gear ratio since its geared for like, hill climbs, so ill get about 30mph.


check your craigslist first....

 

[Clayton]

Blue, if you bypass the gov you will get the same effect, with the same torque. That way you can still pop wheelies and lay black marks all over the pavement.

 

[Bluethunder3320]

Blue, if you bypass the gov you will get the same effect, with the same torque. That way you can still pop wheelies and lay black marks all over the pavement.

yeah but sometimes that makes the engine go boom....

 

[Ghanem]

from where did you bought it?

 

[Bluethunder3320]

i got it on craigslist. apparently there were 2 girls that owned one each, then they got quads. their dad somehow gave them away for free. one of the bikes was totally falling apart and the other i got for $275 in good condition.

 

[Ghanem]

ok so it is used i will buy a new one

Thanks

 

[Bluethunder3320]

where you located? look on craigslist first though you never know. you might find a steal and save a ton of money and invest into a TAV2 and make it badass for less than a cost of a new one.

 

[Ghanem]

I am from in the united arab emirates

 

[Bluethunder3320]

oh. im not sure if there is a craigslist or something there.

 

[migel101]

oh. im not sure if there is a craigslist or something there.

lol

 

[Bluethunder3320]

yeah so tomorrow ill continue working on it. gotta figure out what to do for a seat and stuff.

 

[Bluethunder3320]

coming along GREAT.

 

[Clayton]

That bike looks awesome, just gotta see it finished. I am sure it will be loads of fun.