Autobike - need some help

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Indyjps

Indyjps

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Picked this up for $5 tonight. Looks complete, wanna try to get it going as is, then potentially swap the drivetrain to another frame. Shhh...., could be the start of a MBBO entry, dont tell anyone ;)

Issue: seems like the drive side crank arm is stripped from the sprocket. Arm turns and sprocket stays put.

Does anyone know if the crank is anything special. Looks like i can throw another drive side on there as long as I keep the sprocket count the same. I need to test this out and see if the auto shift actually works.

20180913_212851.jpg


If it doesnt work out, I get a chrome stem, bars, cable hangers, tires, rims, fork, and the coveted embroidered Magna seat outta the deal.
 
If the crank arms turn together, could it have a freewheel bottom bracket?
 
The crankset is supposed to freewheel so that the auto shift can function when you're not pedaling, similar to earlier fixed gear cluster bikes. If it won't shift right it can be converted to manual shift by replacing the derailleur with a standard cheap Shimano and cable, and ditching the doodads on the spokes. The rear cluster is fixed, and will not work with a normal crank set-up.

edit: p.s. If one arm can move by it self, your crankshaft is probably broken or I suppose it's possible the pedal is stripped.
 
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If the whole crank turns forward but the sprocket doesn't move your freewheel is shot. If the crank spins free backward that is normal.
 
Both cranks turn together. Both cranks turn forward and backward free spin, does not engage the sprocket. From deorman's description the crank freewheel is shot.

I wont have time to mess with it this weekend, but will dig into the crank amd see if theres anything apparent going on.

Advice welcome :thumbsup:
 
Indyjps said:
Both cranks turn together. Both cranks turn forward and backward free spin, does not engage the sprocket. From deorman's description the crank freewheel is shot.

I wont have time to mess with it this weekend, but will dig into the crank amd see if theres anything apparent going on.

Advice welcome :thumbsup:
Click to expand...

I've got one. The freewheel assembly is part of the crank spider and it's quite possible that the ratchet pawls are simply gummed up. The bottom bracket on mine appears to be a standard 68mm square-taper crank otherwise. I'd pull the drive side crank assembly and lube the snot out of it. If it does not respond to this treatment, I will be surprised.
 
I agree that old grease might just be keeping the pawls from engaging. Worth a clean out. I remember seeing those bikes new when I was a kid and was intrigued by the idea even though everyone I talked to (including the store selling them) said they weren't very good. But I like the unusual solutions, even if they're not very good (on a car, this is an expensive pain, but on a bike kept for short rides, it's an interesting oddity). If I could find one, I'd definitely try to build something with it. Keep us posted!

Edit: I just looked these up and it appears they make a new version with a Nuvinci hub shifted electronically by a computer powered by a front dyno hub. I imagine they're a lot more money than the old centrifugal versions.
 
If original crank proves unrepairable, mid-drive electric motors also freewheel at the crank.
Consider bare minimum assist like TSDZ2 250W, expecting to auto-derail while under load.
 
Pulled the drive side crank arm. No Go on getting this working, sprocket is wobbling, just a general mess inside here. Doesnt make any sense. No rust, bike is clean, crank frewheel is chewed up.

My fascination with a self shifting bicyle has run its course. All of the rear hardware is in good shape. Let me know if anyone needs parts. Or its going on ebay. For one cycle, then in the bin. Im keeping the rear rim.
 
If you think it could survive shifts at 500W, I still need a rear hub
(Sturmey RXL-RD5 and $200 other parts from Outside Outfitters
no deliver, incommunicado, total scam) Would re-use the Electra's
rims anyhow. Still requires rim brake, which I don't know is going
to tear up my red powdercoat?

Already have motor with crank freewheel. Guess I would also need
the strange push-out derailleur that goes with. Maybe spokes too,
if compatible with 26"? Even if mine by luck were same length, they
are all coated black and weights might not slide properly. So would
need at least six salvageable spokes, if not the whole set. Nothing
some sandpaper wouldn't fix.

500W is roughly 2/3 HP. Plus human power. Just saying no tears
if/when it folds, cause the setup I propose will not go easy on it...
 
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That's discouraging. The rest of the bike does not appear to have been abused...and the red ones are fairly uncommon, I would think. This is first I've seen other than blue-black. If you lived nearby, I'd give you your five bucks back!
 
Are you sure those bars are upside down, or just pulling my shift cable?
Must realize the derailleur is pushed by a ring and centrifugal bell-cranks.
The black ring that surrounds the sprockets moves outward with speed.
 
Were the cranks loose from the beginning? I'm thinking that bike had very little use, so everything is probably still there and in good shape. I agree that there must be at least 2 pawls that engage when you pedal forward so the cranks engage the chain wheel. Somehow that isn't happening, either it was put together wrong or loosened up so the pawls wouldn't grab. I'd like to see the whole thing, guts and all, laid out to get an idea of how it worked. I'll bet it's an easy fix. Maybe pawl springs out of place or broken.

That drivetrain would be cool on something.
 
Yup--I haven't disassembled mine, but I can't imagine its innards are any more sophisticated than the simplest freewheel. Just like a freewheel, it likely has an adjustable threaded collar to take out the slop.

I'd have pushed harder, but it sounded like Indy had already burned through his enthusiasm.

5sn57.jpg
 
How far do bellcranks protrude from the three lobed plate?
Bellcrank pic from random sales on ebay. Yours may differ.

bellcranks.pngs-l1600.jpg

Asking clearance of band or drum brake possibly bolted with spacers.
Link to 100mm drum with all dimensions given:

https://www.aliexpress.com/item/Bic...ar-Brake-Pads-Universal-Rear/32830915477.html

Attached pic of 80mm band. Unsure of external dimensions.

Electric-Bike-80MM-Rear-Drum-Brake-Assembly-Metric-Thread-Bicycle-E-Bike-NONE-Asbestos.jpg

90mm Sturmey drums were already paid for, front and back.
But three months later, have to admit my money was stolen.
Going cheap this time around. I might still use a Sturmey for
the front. My fork was made with a loop for that purpose.

Disk brake of ginormous diameter or offset might also work.
after finding better pics of the bellcranks, I don't think they
deploy (on brake side) any worse than rest. Would 200mm
disk be safely outside those lumps?
 
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I now own this problem. The friction freewheel is Sunrace. Looks like it wants a Park FR-1.3 to get it off. And I will need to do so for two reasons.

1) The auto shifter is trapped behind the freewheel like a spoke guard. And both have to come off to replace the spokes.

2) Brake can't be brazed to the 3 lobed plate. Well, it could, but the plate isn't attached to anything but snapped onto the autoshifter. Regardless how solid it looks in photos, the autoshifter is a lightweight hunk of plastic. Not made to take torque. So I need to attach a brake rotor some other way.

Looks like the other end of the hub was made to be threaded, but no threads were ever cut. A machine shop ought to be able to fix that, and then I can screw on one of those six bolt brake rotor adaptors. That should also secure the 3 lobe plate in a less cheesy way than it is now.

----------

So, I havn't fully disassembled yet to be sure, but the friction freewheel may be same or similar to Sunrace MFM05 6DS, which is still available. Looks to me like a normal freewheel with a purposely overtightened cone. It will give if pantleg needs to be extracted from the chain, or to frustrate any attempt to unscrew it, but otherwise doesn't freewheel. Not easy, but I can apply enough torque by hand to overcome that friction and make it wheel. When it does, pawls are heard. There are two dimples on the face of what appears to be the cone nut, and probably where the difference between free and friction was dialed-in. I see no reason to mess with that adjustment. Doesn't normally turn, so unlikely to ever wear out or need re-grease.

The freewheel seems a little strange (or maybe normal and I just don't know anything). Cause the outside is shaped like a big cassette with two different sized tiers. The castles are oddly shaped and spaced to assure the gears can't be put on backward or with specially shaped teeth or side indentations out of alignment with neighbors.

I got pictures to attach later.
 
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