Project 79cc predator build bmx

Hello all this is my first build and I welcome all feed back.
i wanted to build a box bike with something different.
so here goes.
I have decided to use a mongoose frame it had the best angles for the build.

 

[Imthegrt1]

Thanks zoom bike ...
For the speech but I figure some sights are that way no biggie I did ask for people to be truthful with me. And give there 2 cents thought.
Lucky for I'm just an old fart I just trying realize me child hood lol,and don't get upset.

 

[butre]

that wheel barely fits, are you sure it won't scrub the frame any time something flexes?

 

[Imthegrt1]

Yea it's close front wheel either grind down on frame or put smaller tire on front back is good plenty of room

 

[butre]

I'd rake it out personally. bmx frames are twitchy and some rake will add clearance and slow the steering

 

[keatonx]

Increasing the rake will make it even twitcher. It'll provide more centering force when the bike is still and vertical, but it fights the self- correcting effect of the headtube angle by reducing trail. I think you meant increase the headtube angle.

And don't worry imthegrt1 your not the only person putting a big engine in a BMX



160cc fitchel and sachs rotary engine from the 60s. Going to drive the wheel through the dirt bike gearbox under it. Made 8hp, stock

 

[Imthegrt1]

Increasing the rake will make it even twitcher. It'll provide more centering force when the bike is still and vertical, but it fights the self- correcting effect of the headtube angle by reducing trail. I think you meant increase the headtube angle.

And don't worry imthegrt1 your not the only person putting a big engine in a BMX

View attachment 54400

160cc fitchel and sachs rotary engine from the 60s. Going to drive the wheel through the dirt bike gearbox under it. Made 8hp, stock

Sweet have you started a thread let will be keeping an eye on you

 

[butre]

I've got a bmx getting tractor tires and a predator 212 that burns oil in the near future

 

[KCvale]

Thanks zoom bike ...
For the speech but I figure some sights are that way no biggie I did ask for people to be truthful with me. And give there 2 cents thought.
Lucky for I'm just an old fart I just trying realize me child hood lol,and don't get upset.

Thanks grt1,
You did ask for any and all input so I gave my idea's and I'm glad you didn't take me to be offensive, weld on fellow old guy and I look forward to seeing how your experience is beyond the fun of building it ;-}

 

[Imthegrt1]

So motor mount welded on and fit great . Lined up perfect goin good so far.

 

[Imthegrt1]

So jackshaft bearings and collars came in going with a 3/4 shaft
Got the rear sprocket on and the clutch on