2x2 Build

W

wardog

Member
#1
#1
Hi everyone,
This will be the build log for my 2x2 project.
I love tinkering and have completed a few big projects in the past including a 4x4 buggy, but this will be my first 2 wheeled project. In fact I have only ridden a mini bike once and crashed almost immediately...... but I'll figure it out.

On to the tech.
Here is what I have so far:

1984 Honda atc125m for the engine/trans
25x13-9 Duro hf243 4 ply tires on 9x9 wheels
1000 lb capacity trailer hubs/spindles
6" Airheart discs and mechanical calipers
Tractor PTO overrunning coupler
1" keyed U-joint
Buttload of sprockets, bearings, chain, and keyed shafting

The Plan:
I will fabricate the frame from scratch, and there will be no suspension, only tire flex and a sprung seat. The forks and rear "arm" will be single sided. Inboard brakes. And of course a winch and snorkle. This thing is being built extra heavy duty for extreme abuse.... 1" shafting and #50 chain!

Pics:

Good running donor. Electric start 4 speed with hi/low range.




Wrinkly tires.....had to use the lighter fluid bead setting technique.


25x13-9 compared to 22x11-8 from the three wheeler.


Tractor pto overrunning coupler to allow the front wheel to go faster than the rear in a turn. I plan on cutting it down and welding on a sprocket.
 
W

wardog

Member
#6
#6
The three-wheeler was stupid fast in high range..... at least 45 or 50 mph so I wanted to gear it down slightly just to use all the gears and take as much stress off the clutch as possible. The original sprocket ratio on the trike was 3.43:1 (14 tooth to 48 tooth). I am running 1:1 to the jackshaft, then 4.3:1 to the wheels, but also stepping up to a 25" tire. If the ratio needs adjusting I will swap the jackshaft sprocket.
 
W

wardog

Member
#9
#9
I am thinking about widening the wheels before I am committed to the current width. They are 9" x 9" and the tire sidewall protrudes much further than the rim when mounted, so I am thinking widen them 4" or 6" for softer ride and more floatation. I will only be running a couple pounds of air pressure in the tires, so I am somewhat concerned about popping the tire off the bead. If that becomes an issue I will just tube the tires.

What do y'all think? Would a 25x13-9 tire work on a wheel that has been widened to 15"?
 
jeep2003

jeep2003

#10
#10
I think 4 or 6" wider is too much maybe 3 or 4 to keep it in range but its hard to say without seeing it in person. I dont think the beads will be a problem. running tubes in low psi tires is often causes more problems than it fixes. the valve stem usually gets ripped off, tires get out of round exc.. you can use bead sealer or construction adhesive on the bead to help keep it in place. Great progect. Spend alot of time on making the front drive as robust and well built as possible because that will be the part that determines weather the bike will be success
 
W

wardog

Member
#12
#12
jeep2003 said:
I think 4 or 6" wider is too much maybe 3 or 4 to keep it in range but its hard to say without seeing it in person. I dont think the beads will be a problem. running tubes in low psi tires is often causes more problems than it fixes. the valve stem usually gets ripped off, tires get out of round exc.. you can use bead sealer or construction adhesive on the bead to help keep it in place. Great progect. Spend alot of time on making the front drive as robust and well built as possible because that will be the part that determines weather the bike will be success
Click to expand...

Cool. Thanks for the input. I think 4" will be plenty also, but I'm still not sure if I even want to go through the trouble of widening them.
Your tracked bike build inspired me.
 
W

wardog

Member
#13
#13
I gots me some 9"x13" wheels now. I went ahead and widened the wheels 4" and I am very happy with how they turned out.... less than 1/8" runout. Next I have to make the 4 on 4" wheel centers and weld them in.




With the tires and my awesome free cooler.

 
W

wardog

Member
#14
#14
Will this be strong enough?

This is my plan for mounting the sprocket to the hub. Please forgive my sketching skills.



There will be four 1/2" bolts on a 4" circle. The distance from the back face of the hub to the sprocket is about 3".

This will also have to withstand the forces of inboard brakes.
 
T-Town Mini

T-Town Mini

Well-Known Member
#16
#16
wardog said:
Will this be strong enough?

This is my plan for mounting the sprocket to the hub. Please forgive my sketching skills.



There will be four 1/2" bolts on a 4" circle. The distance from the back face of the hub to the sprocket is about 3".

This will also have to withstand the forces of inboard brakes.
Click to expand...
I think an appropriately sized spacer for each bolt fit flush between the hub and sprocket would be better to span that 3" gap. What kind of bolt are you planning on using?
 
W

wardog

Member
#19
#19
jeep2003 said:
I would weld sheetmetal squares to the 4 bolts and itll definatly be strong enough
Click to expand...
That would for sure be strong enough, but because the actual hub is threaded, I would have to cut it up to take it apart. Definately an option if strength is an issue, though.



T-Town Mini said:
I think an appropriately sized spacer for each bolt fit flush between the hub and sprocket would be better to span that 3" gap. What kind of bolt are you planning on using?
Click to expand...
I have some long grade 8 bolts that would have to be fully threaded, or I have some all thread rod, which would be a lot easier to use, but not as strong.



bigrob said:
I have used threaded coupler as spacers , makes it easy to bolt from both ends
Click to expand...
Genius. This is why I joined this forum... for ideas like this. Now I have to find fine thread couplers.



cxbra said:
Single sided rear swingarm?? YEAH!!
Click to expand...
And single sided front fork.
 
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