Fat Tire Mini Bike Build

[loud1]

I started this build at the beginning of July, 2013 by doing lots of research that revealed little i didn't already know, and a couple of rear tires from a Snapper rear engine rider. Here it is August now and i have the main frame essentially done, I bought front and rear rims and tires for a Yerf-Dog mini bike from BMI Karts, a torque-a-verter, Predator 212cc engine and various other parts to complete the project. I'm using 3/4 black pipe for the frame since i have an abundance of scrap and an HF pipe bender and im using a Linclon weldpac 125 with flux core wire.

I've been doing all of this work during my lunch hour at work so progress is kind of slow, I also have never built a mini bike before or used bent tubing for any weldments either and I have no printed plans, just a vague idea of what i want so I'm venturing into some unfamiliar territory with this project.

Now for the progress pics, enjoy. (there will be more to follow)

 

[mckutzy]

Well that looks good, looks like you have done your homework.

 

[mysteryboy28]

welcome to the forum. looking good so far!

edit your profile to show us where you live. we like to know that kind of stuff. i get all excited when i see someone else is from michigan. lol.

 

[loud1]

welcome to the forum. looking good so far!

edit your profile to show us where you live. we like to know that kind of stuff. i get all excited when i see someone else is from michigan. lol.

Thanks, I've mostly been eyeballing it so far, i did jig it so the two portions of the bottom frame were aligned properly.

Edited my profile.

Brewin, Drinkin.

 

[landuse]

Welcome to the forum!! You have gotten off to a grat start. Keep it up

 

[loud1]

Update

Here is a short update. I have completed assembling the forks so all that's left is the motor mount, handle bars and a few misc brackets for mounting the break, seat and the one fender i have so far.

 

[chris_the_poser]

How big are those tires and how long is your bike? It looks long which there is no problem with that.
There will just be less wheelies that way.

 

[loud1]

How big are those tires and how long is your bike? It looks long which there is no problem with that.
There will just be less wheelies that way.

Tires are 20x7x8 and the length is right at 70". I'm not too worried about wheelies, this is more like a utility bike, but not as ugly as a Tote Gote.

I probably should have changed the angle on the bottom bars to shorten it a bit but this is my first one, I'll change it up for the next one.

 

[loud1]

It's running and moving! Got it up to 30 mph today, Im not sure it will go much faster than that with my big butt on it. It handles great! I love those 20 in tires, I ran it over dirt, sand, really rough stuff, deep gravel, loose gravel and pavement, it handled it all pretty well.

 

[mckutzy]

Looks cool. What do you have for brakes?

 

[loud1]

It has a foot operated band brake right now on the rear, I'm going to switch to a hydraulic when i get more money to throw at it, that band break doesn't work very well.

 

[mckutzy]

Ya you have a bit of tire there to stop. Unless you going to get a full out hydro setup, and idea if your piecing it together is another sprocket. That can be used in a pinch for a disc.
Is there enough room for a disc caliper, that would be my next. I imagine that you were thinking about this when you were building.... swap them out later.

 

[loud1]

That's pretty much exactly what i have planned, I'll modify a sprocket by turning the teeth off on my lathe, the bolt pattern is 2 7/8" and i haven't been able to find a disk with that pattern. Otherwise i have loads of room for the caliper.

I'm going to pick up another trailer fender this weekend and weld those on Monday, I also have to replace my throttle cable, the one on there is too short.

Oh and btw, I love your bike, I kind of have a thing for rat builds.

 

[mckutzy]

Ya a rat build is an acquired taste for some, I just dont have much of a talent for painting and no paint, well just plenty of "red oxide primer" in stock, only on a wet days of course.

 

[loud1]

OK folks, I think it's ready for paint! The rear fender didn't turn out exactly as i wanted but it should work ok. I have a different seat in the works as well as a different break setup but she is essentially done mechanically.

 

[mckutzy]

Looks good.
I would add some braces to the fenders. A brace on the lower end of the front to the fork and the same on the rear, at the far end to the frame.

A not too far ride will most likely shake it right off, potentially causing all kind of problems.

 

[loud1]

Looks good.
I would add some braces to the fenders. A brace on the lower end of the front to the fork and the same on the rear, at the far end to the frame.

A not too far ride will most likely shake it right off, potentially causing all kind of problems.

I would agree but these are 14ga trailer fenders, they don't shake at all, I have run the crap outta this thing trying to get them to move, they are pretty solid. I may put braces on the anyway but for right now they seem to be doing ok.

**edit** By running the crap outta it, I meant there is a 1 mile RR side track, I ran down the middle of that track 4 times. Man does my a$$ hurt!

 

[chris_the_poser]

Let some air out of your tires they should cushion you fairly well I would think. Idk how much good it would do on rail road tracks.

 

[mysteryboy28]

where's the video of this thing in action???

 

[loud1]

where's the video of this thing in action???

I don't think there is a camera lens wide enough to fit my big butt in the picture.

The tires are at 10 psi each, pretty cushy 'cept on the tracks.