Cruiser eBike

[stoneaxe]

Looking great.

[fishetc]

http://custommotoredbicycles.com/fat_bike_wheel_parts_170mm_hubs_26_x_25_wide_rims

[PonoBill]

Looks good. I ordered one. I'll let you know how it goes. Welding on lugs for the caliper should be pretty easy.

[PonoBill]

Fish, the front brake installed pretty easily. The holes drilled in the hub are obviously for some kind of disk brake adapter and the lugs on the fork leg were bolt-on for the calipers I bought. I found a front and rear disk brake kit intended for a bike with an 80cc gas motor--that's how it's listed anyway. When I bolted on the caliper it didn't fully engage the disk. I can't see the differences on simple inspection, but swapping to the other caliper solved the problem. I drilled out the holes in the supplied adapter, which is intended for hubs that are threaded (mine aren't) and used it along with some aluminum spacers from the hardware store to mount the disk. I had to open up the big threaded center hole a bit. Too lazy to set it up in the lathe, I just ground out half the threads with a die grinder, being careful to just barely cut to the thread root all the way around. Worked fine. I'll shoot some pictures.

Next up is getting the new hub laced up and mounting a back brake, but for now, the front brake is fine.

[fishetc]

since you used the 100mm motor and a 170mm rear hub did you have to shim out the crank chain ring to line up the chain?

[PonoBill]

No, it lines up fine. When I cut the chain side of the BB I made sure the chain ring was in the ballpark of straight to the rear sprocket. With such a long chain it doesn't have to be super straight. It does need a tensioner though, with all the torque of the motor that loose side of the chain sags too much under tension.

[fishetc]

ok got it ,looks pretty cool, let me know how the rear brakes go?

[stoneaxe]

Needs better handlebars......

[PonoBill]

Like what??  The need a lot of pullback for the riding position. Could do some kind of apehanger, but these work well. I have them positioned a little low. Might do dog bones and something flatter, but then you get that tiller thing going.

[stoneaxe]

Ian looks hunched over a bit...longer ape hangers seem like they would give a better riding position and look cool to boot.

[PonoBill]

I'll look at some, but they seem a bit trite. The other bits I'm working on all have a vintage look

[stoneaxe]

Maybe just longer and higher....I agree the hangers seem trite. LOL....this thing reminds me of that old Matchless 500 you used to have (or more probably still have somewhere)

[PonoBill]

Maybe just longer and higher....I agree the hangers seem trite. LOL....this thing reminds me of that old Matchless 500 you used to have (or more probably still have somewhere)

Nope, gave that to a friend--his father-in-law does beautiful restorations and he returned it to a glorious original state. A G80CS Desert Sled.

Elvis is pushing me to help her restore the BMW cafe racer I built long ago. Makes me nervous thinking of her riding a bike, but then again it makes me nervous thinking of her fighting forest fires, cutting people out of wrecked cars, and running into burning buildings. I don't think I have much choice, she's a pushy kid.



She pulled it out of the shop and cleaned it up. I gave it to her years ago but I've dragged my feet on getting it back on the road.  Hard to believe I've owned that thing since 1972.  Probably should have kept it stock, but what did I know back in the 80's. Wanted something racy, all I had was an R50/5 beemer, so I did that. Bored to 600cc, R60/5 heads, R90S clutch, lightened flywheel, CV carbs from a Yamaha XS1, blah, blah. I probably have less than a thousand bucks in 1970 dollars in this thing--bought it as a insurance wreck for $350 and all those parts were either refurbished from junk or a special deal from the BMW importer who had an order for 200 BMW R60/5 police bikes canceled. I had over 100,000 miles on it before I did the cafe stuff. Probably close to 200K now, but no odometer. My only real transportation back when I lived in my van and worked as a motorcycle mechanic. That bike got parked at the wedge and ridden with salty boardshorts and sandals hundreds of times.

[PonoBill]

Got the new rear wheel hub installed. So now I have a brake rotor on one side and a sprocket on the other. I'm building a chain tensioner and reworking the chainguard, next step is to finish those and mount the rear caliper. I might have to make my own floating plate. I've looked at how a lot of rear brake calipers get installed. They all assume the rear wheel is going to always be in the same position (or close). On this bike the rear drop-ins are long slots, intended to adjust the chain. I have two choices. Eliminate chain adjustment and make the wheel position fixed, and mount the caliper in an optimal position (and use the chain tensioner to take care of adjustment) or mount the caliper on a bracket that fits on the axle, so moving the wheel in the frame doesn't screw up caliper to rotor engagement.

I think I'm gonna do both. Position the wheel all the way forward and weld in an adjuster on the brake side to get the sprocket aligned while the chain side is fixed all the way forward, and put a bodacious spring on the chain tensioner I just made to wrap the chain on the sprocket a bit. The chain wants to jump right now, I got a little carried away hacking the motor. Full power is 1800 watts, but it's only for a very short time. It's a single speed, and it gets to max RPM in a heartbeat. Probably 20 MPH--but it will probably pull about anything up a hill.

I dug out some chromed 1/2" steel tubing from the rafters of the garage. The previous owner's idea of cool curtain rods. My idea of a cool board rack. I'm gonna try double bars, front and back. Should be pretty as long as I don't toast the chrome too much welding it.

[johnysmoke]

That's a pretty sick cafe racer. BMW has always done pretty amazing stuff with their bikes. If I were to ever get back on a bike might be a Beemer, if not a Triumph.
Lots of cool little commuter options nowadays, from the new onewheel deal which looks like a blast, to the motorized skateboards, and now this thing just came up on my Facebook feed. https://www.startengine.com/startup/monday-motorbikes?utm_source=facebook&utm_campaign=m6_prospecting&utm_medium=ad