The rear hub is a shimano 8 gear with coaster brake.
The e-hub ,350W, will be in the front wheel.
I will have a disc brake on the front wheel, my worry is if the coaster brake is strong enough or should I dubble it up with a disc brake?
My first design was no e-hub and only coaster brake, so there was no need for brake handles, but with e-hub I need the disc up front.
I also like the fork to be simple to remove for easier transport. So I want minimal cables between fork and frame and they should be easy to disconnect.
The rear triangle is my first part to assemble.
To finish the tube joining the rear dropout I tried to make the ends into bullet shape.
I cut a small piece of 1/2" tube, cut some notches into one end and hammered the end into a bullet shape.
The 1/2" tube fits inside the 5/8" tube giving me a thicker tube to weld the dropouts to. After some welding and grinding I got some sort of bullet shape.
I also cut out on the inside of the tube so the dropout plate can be welded flush with the inside of the tube.
So this is the finished bottom half.
I found may first mistake, the U bends is 135mm on the inside, the same measurement as the rear hub.
But the rear hubs is about 5mm off centre on the drive side, so I get a 5mm larger gap on the drive side between frame and tire.
I should have made the u bend 130mm and bend the tube outwards on the drive side.
I don't think anybody will notice when the chain is fitted, but I will.
I decided to make the rear dropouts horizontal. The Shimano gear hub has a washer on each side which decide where the gear shift cable will enter the gear hub.
If you look at the rear side of the hub in the picture above, there is a black tube sticking straight up with a circle on top, thats where the gear shift cable goes.
I rather have it follow the frame.
The washer looks like this.
So I'm tempted to make one where the hole and the key are in the correct position so the cable entry will be parallel with the frame.
The rear frame is now fully welded and 75% finished.
So my next step is to complete the frame.
When I made my muck up I realised that the tube on the bottom was about 100mm to long.
Turns out that I miscalculated the angel of the bend with 10 deg, so I hade to re cap the tubes and re-bend them.
So the muck up went from this.
Now it's more like my drawings.
The first bend would make the pedals to far forwards from the frame.
I'm not to pleased with the bends but it will do.
The top tube consist of a short piece of 22 mm tube with a 7 deg bend and then a 25mm tube.
So now I can fit and adjust a standard seat clamp along the 22mm tube.
To make the seats angle bit more comfortable I bought a seat spring, which also gives me more adjustment for the seat.
If the seat don't hit the frame, the seat clamp will be flipped to make the seat lower.
I will fill the sides behind the stearing tube in a chopperish style to strengten the frame and it will also conceal the motor controller.
So next, find the stearing tube and tack it all together.
I decided to hide all the cables in the tubes.
So not to weaken the frame I'm welding insert into the frame for the cables to run through.
This will be under the battery for the power cable to run to the controller.
The coiled wire is so I can pull through the copper cable.
And the other side.
And in the other tube will the cable from the pedals to the controller will go
It's a much bigger connector so it needed a large hole.
I checked and dubble checked before I made the hole and welded in the insert
but of course I cut the hole in the wrong side.
My first thought was to make new tubes, I never liked the bends anyway, but I only have enough tube for one side left.
So out come the grinder and I cut away the bends so I can turn the wire entry point in the right direction.
And I also made some new bends, one good and one ok, but still better than my first ones.
I also realised how much easier it will be to assembly the rest of the frame when I have more pieces to work with.
I have, more than once, tried to weld the front part of the frame to the head tube, but before I got the right angels to all the tubes something always moved.
Now I can do it in steps. First the under frame.
With crossovers for the battery pack
And this how it will look