home made mini bike project

[kohler321]

this is my "home made" mini bike all of the info on it is in the video. Let me know what you think.

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

 

[mike75925]

you may be able to leave your gearing where it is if you put a semi restrictive muffler/pipe on. you are losing almost all of your bottom end by running that short of exhaust (recommended straight exhaust is 12"). you can go with smaller diameter or way longer with some bends. since you made the frame so well, any thoughts to running the dirtbike rear wheel? if it is a 4 bolt pattern, a gokart/mini sprocket may mount right up. are those the original lowers on the forks? the tubes look extra long for them. will you be getting a tav and/or suping the motor up?

 

[kohler321]

Ya, i know i am losing torque without having any kind of exhaust, but i am still am wanting 6:1 just for better drive ability. It will be used mostly off road, and by the time the clutch is fully engaged, i am already going a bit faster than i want, plus i am barely ever going to use the top end that is capable with this bike, so i figure i might as well take advantage of some more low end power. Also, i might eventually put on a billet rod, gx160 head, and some stiffer springs, don't need much more power but want to be able to rev it up a bit.

Thanks for the response/input by the way.

 

[mike75925]

chain tensioner?

 

[kohler321]

I haven't had to put one on yet, just used the adjustability of the engine and rear end to set chain tension. I will probably put one on when i change to 6:1 though.

 

[kohler321]

Well i switched my drive ratio to 5.4:1. I have yet to drive it though, just did a couple launches and it is quite responsive. Also, I decided to make a chain tensioned as suggested. it uses an idler sprocket it is spring loaded so it auto adjusts the chain tension. This way i don't have to adjust the motor and wheel to set the chain tension. Here is a picture.

 

[devino246]

you put the tensioner on the wrong side of the chain. You need it on the bottom

 

[kohler321]

Fixed the tensioner so it puts tension on the bottom of the chain, and am in the process of putting a gx160 head and flywheel for advanced timing and higher compression.

 

[kohler321]

I have gotten the gx160 head and flywheel on, and will post pics of the fixed chain tensioned tonight. Also, i took it for a run on some a loose gravel road, and still managed to muster 69.7KM/h or 43.3MPH. I think i will be able to get into the high 70's low 80's (KM/h) when i get this thing on a real road.:arf: Also am putting on a fuel tank that makes it look more like a motor bike as well as some actual foot pegs.

 

[kohler321]

here is a pic of the new chain tensioner set up.

 

[mike75925]

looks good