So I said howdy, now's when I share the good stuff (and the bad stuff too).
In 2016 I built the Jura Big Fifty, using an Electra Cruiser 1 and a Bikeberry 49cc 4-stroke kit. This is what it looked like right out of the barn:
And of course there were problems. First I couldn't get the coaster brake to work. Felt like it was slipping. So in spite of it being brand new, I rebuilt and adjusted it. Got real good at rebuilding and adjusting coaster brakes. Still no go. Then I decided that the coaster just wasn't up to the task of stopping 300 pounds of bike and rider, even with the Sturmey front drum helping out, and ditched it. Got a new rear hub from Bikeberry/BBR that uses a thread-on sprocket and comes with a thread-on band brake.
The sprocket and hub was a wonderful upgrade. The Bandbrake was worthless. Worse than the broken coaster brake. Then the transmission input shaft broke and I had to pedal home. That's when I had the first a-ha moment. I had slip in the pedals while pedaling forward, too! Turns out the problem wasn't in the coaster brake, but in the wide crankset. The sprocket is pressed onto the shaft, and none too tightly. Hit it with the welder (just a couple tacks) and that problem was solved. But now I was stuck with this useless bandbrake, or so I thought.
Finally did something about it when I found a thread-on disc brake adapter. Bought that, a Tektro mechanical brake, made a mounting bracket and welded it to the chainstay. It barely misses the sprocket, and wouldn't miss the chain if I tried to mount it elsewhere. Sorry it's a little hard to see.
I'm sure you noticed the chain's off. More on that in a moment.
The brake cable was way too long, and I almost cut it but then had another a-ha moment. The extra cable goes into a piece of 3/16 brakeline (or a noodle if you want to use bicycle terms) and up under the rear rack, where it attaches to an ATV brake light switch. So now I have a real brake light (a GOOD one, that uses a real 1157 bulb, not LED's). Picked up the switch and lamp on Amazon.
So the wheel's not orange anymore, what's up with that? I changed the front to a 24 to match the rear, and the ride is a hell of a lot better now. And since the new rim was black (Odyssey Hazard Lite, way overkill but a really nice rim) I changed the rear to black as well. Looks better to my eye. Re-used the Sturmey-Archer drum in the new wheel.
Tires are Duro Beach Bum 24x3, with the decals buzzed off. Want to know what really burns me about these tires? The sidewall molding doesn't say Beach Bum, it says EACH BUM. Really, Duro, really? Other than that I really like 'em. A soft ride and nice feel overall.
With more rubber on the road and really good brakes now, I can stop from 25 mph in about 40 feet. Good thing I put a brake light on there.
So guess what happened yesterday?
Yeah, the damn input shaft sheared AGAIN, in the same place, My armchair analysis tells me this is probably machined from the cheapest Oriental bar stock they could find, and there's a nice stress riser right where it sheared off, since the other one broke in exactly the same place. My thoughts yesterday were to get a new one made by a machine shop, out of decent steel this time, and with a radius to eliminate the stress riser. But you'd still be pushing 2 HP through a tiny shaft. Might get away with that if you made it from titanium, but I'm not confident in that. So I'm ditching the 5G gearbox for a Grubee belt drive, which should arrive in a week or so.
One last pic, the bike as it sits today:
In this pic you can see the battery that runs the lights, the brace for the engine to the top tube, and the PMS (Puke Management System). What's the PMS all about? Well, the HuaSheng crapped the bed after about 20 miles of riding. It had so much blow-by that oil filled the chamber above the crankcase and got pushed up to the air filter. It would leave a puddle wherever it went. This engine isn't a HS, it came from a friend who gave up on it. It's another Honda clone. The only identification I can see is a pad that says BRAND. It runs a lot better than the HS ever did. So the PMS isn't needed (yet). It connects to the engine's breather outlet and separates out the oil from the air vented to the atmosphere. So far all it's caught is water vapor.
Stuff you can't see: A handlebar mounted light switch and key switch, wires routed thru the handlebars, memory foam grips, gel seat, lots of good stuff that makes the bike a real joy when it's actually running.
In 2016 I built the Jura Big Fifty, using an Electra Cruiser 1 and a Bikeberry 49cc 4-stroke kit. This is what it looked like right out of the barn:
And of course there were problems. First I couldn't get the coaster brake to work. Felt like it was slipping. So in spite of it being brand new, I rebuilt and adjusted it. Got real good at rebuilding and adjusting coaster brakes. Still no go. Then I decided that the coaster just wasn't up to the task of stopping 300 pounds of bike and rider, even with the Sturmey front drum helping out, and ditched it. Got a new rear hub from Bikeberry/BBR that uses a thread-on sprocket and comes with a thread-on band brake.
The sprocket and hub was a wonderful upgrade. The Bandbrake was worthless. Worse than the broken coaster brake. Then the transmission input shaft broke and I had to pedal home. That's when I had the first a-ha moment. I had slip in the pedals while pedaling forward, too! Turns out the problem wasn't in the coaster brake, but in the wide crankset. The sprocket is pressed onto the shaft, and none too tightly. Hit it with the welder (just a couple tacks) and that problem was solved. But now I was stuck with this useless bandbrake, or so I thought.
Finally did something about it when I found a thread-on disc brake adapter. Bought that, a Tektro mechanical brake, made a mounting bracket and welded it to the chainstay. It barely misses the sprocket, and wouldn't miss the chain if I tried to mount it elsewhere. Sorry it's a little hard to see.
I'm sure you noticed the chain's off. More on that in a moment.
The brake cable was way too long, and I almost cut it but then had another a-ha moment. The extra cable goes into a piece of 3/16 brakeline (or a noodle if you want to use bicycle terms) and up under the rear rack, where it attaches to an ATV brake light switch. So now I have a real brake light (a GOOD one, that uses a real 1157 bulb, not LED's). Picked up the switch and lamp on Amazon.
So the wheel's not orange anymore, what's up with that? I changed the front to a 24 to match the rear, and the ride is a hell of a lot better now. And since the new rim was black (Odyssey Hazard Lite, way overkill but a really nice rim) I changed the rear to black as well. Looks better to my eye. Re-used the Sturmey-Archer drum in the new wheel.
Tires are Duro Beach Bum 24x3, with the decals buzzed off. Want to know what really burns me about these tires? The sidewall molding doesn't say Beach Bum, it says EACH BUM. Really, Duro, really? Other than that I really like 'em. A soft ride and nice feel overall.
With more rubber on the road and really good brakes now, I can stop from 25 mph in about 40 feet. Good thing I put a brake light on there.
So guess what happened yesterday?
Yeah, the damn input shaft sheared AGAIN, in the same place, My armchair analysis tells me this is probably machined from the cheapest Oriental bar stock they could find, and there's a nice stress riser right where it sheared off, since the other one broke in exactly the same place. My thoughts yesterday were to get a new one made by a machine shop, out of decent steel this time, and with a radius to eliminate the stress riser. But you'd still be pushing 2 HP through a tiny shaft. Might get away with that if you made it from titanium, but I'm not confident in that. So I'm ditching the 5G gearbox for a Grubee belt drive, which should arrive in a week or so.
One last pic, the bike as it sits today:
In this pic you can see the battery that runs the lights, the brace for the engine to the top tube, and the PMS (Puke Management System). What's the PMS all about? Well, the HuaSheng crapped the bed after about 20 miles of riding. It had so much blow-by that oil filled the chamber above the crankcase and got pushed up to the air filter. It would leave a puddle wherever it went. This engine isn't a HS, it came from a friend who gave up on it. It's another Honda clone. The only identification I can see is a pad that says BRAND. It runs a lot better than the HS ever did. So the PMS isn't needed (yet). It connects to the engine's breather outlet and separates out the oil from the air vented to the atmosphere. So far all it's caught is water vapor.
Stuff you can't see: A handlebar mounted light switch and key switch, wires routed thru the handlebars, memory foam grips, gel seat, lots of good stuff that makes the bike a real joy when it's actually running.