Singletracked's crash course in moto bicycles.

[Singletracked]

I shortened the head tube about 9/16"
The steer tube is just long enough but enough. It will have a flush top cap.
I started on the fuel tank. I used card stock aided design to get my shapes right. Transferred those to 16guage sheet. Then started tacking it together.
So far I like it. Not bad for my first tank, far from done though.

 

[Singletracked]

Productive day today.
Weld a ton, grind a ton. Weld more. Grind more. The tank is pretty much welded. Still have to add a filler cap and a petcock.

Then I cooked up some mounting tabs. The front is drilled and tapped into the down tube. Two 5/16 bolt hold the tank well enough.

Then the rear:

 

[Singletracked]

I ordered my jackshaft set up. Kinda experimental gearing cause I couldn't get a answer for a good starting point. I used a gear calculator to get 9.6:1 ratio.
Clutch is 10, 22 jshaft input, 10 output to a 44t rear sprocket. All with #41 chain. Tell me what you think

 

[Fv2]

Those numbers remind me of those little electric scooters. They worked fine, so I don't see why this won't.

 

[Singletracked]

I guess we'll see. The jshaft kit I ordered comes with a 14 and a 10. So if it's too low I can go higher with out ordering a sprocket

 

[Singletracked]

Look familiar? I cut the filler neck out of the old Briggs fuel tank and burned it it in mine.

I ran to the hardware store and picked up some plumbing. I cut the locking part off a quick disconnect fitting and welded it in the bottom.
I poured some solvent in the tank to see were it would leak from. There is a couple spots but it's minimal. Fuel tank sealer will take care of that. The tank is about ready to use

 

[Singletracked]

Threw some bars I had laying around on, upside down.

I lowered the fork 2" by removing the air piston, cutting the piston shaft 2". Then re-drilled and tapped threads into it again.

 

[Singletracked]

Started on the jackshaft bracket

 

[Singletracked]

It will be gusseted and boxed.

 

[curtisfox]

Awesome job, liking your build...................Curt

 

[Singletracked]

Thank you Curt! Bit by bit

 

[Singletracked]

Jackshaft bracket complete

 

[Singletracked]

The new seat post. I made it bolt on so it would be easier to change if I wanted to.

I cut the tail off a old skate deck. Works pretty well.

It will need some shaping still but I like it so far

 

[Fv2]

Missed updates on this, looking good so far. Great way to recycle skate board decks.

 

[Singletracked]

Updates!
Front brake is done thanks to my buddy at Hope tech USA. It's a V4 4 piston caliper. Stainless braded hose

I also got the chain set up.

I think I lucked out and am able to run it with out tensioners.
It's getting close! Lots of small stuff left

 

[RustyGold]

Looking good!

Jason

 

[Singletracked]

Update!
Carburetor and exhaust.
Whittled up a few flanges.
They are not quite the same but I'll take care of that.

2 sets of Handle bars were donated to the build by a co worker. Perfect size tube for the ports. .75" ID or so..
Intake mock up

The bolt holes on the engine side are around 1 3/8" apart. So I had to oval the tube to get it to fit between the bolts well enough for clearance.

Welded up. I will smooth out the interior.
The bends in the cruiser bike bars where nearly spot on. It comes straight back, curves to the left then right and up to fit right under the seat. The way it is now it exits toward the right of the bike (riders right). I'll probably add a 45* to point it directly inline of the rear tire.

Rider view

I did add a smaller pipe at the flange. It fit inside the flange ok so I can weld it inside and out; also add some back pressure, I guess..... Haha!
I don't have plans for a muffler.

 

[pholTmonx]

Awsome stuff, curious to see what needs to be done regaurding the vacume fule pump and swapping carb styles.
I have a 2hp early alum briggs on my bench...
Only thing that caught my attantion was the lead sproket on the jackshaft.. the shaft collor is sitting on the heads of the nuts attaching the sprocket. Is there a way to maybe key the collar so the nuts lock in on it or build a spacer...

 

[Singletracked]

Awsome stuff, curious to see what needs to be done regaurding the vacume fule pump and swapping carb styles.
I have a 2hp early alum briggs on my bench...
Only thing that caught my attantion was the lead sproket on the jackshaft.. the shaft collor is sitting on the heads of the nuts attaching the sprocket. Is there a way to maybe key the collar so the nuts lock in on it or build a spacer...

No fuel pump. Gravity fed. The carb is off a horizontal 5hp lawnmower. It has a float.
I believe you where seeing the gear in mock up hardware.
I have since drilled and tapped the hub so no more nuts. Like so

Yes the key is sticking out. It will be trimmed at final assembly

 

[pholTmonx]

Yup thats what i was seeing.
About the carb, do you have to put a block off plate on the old vacume thats below the carb and exhaust? Id cut one from 6160 and was unsure if it needed to ramain vented for some reason.
And this thing is awsome by the way... sorry got excited to ask questions first