Autobike Cruiser Build

[CTripps]

Hey folks

I've been feeling it lately, that "builder's itch" or whatever you want to call it.. the need to start a new bike. After doing my cruiser up I wanted to do another one, so I've kept an eye on CL etc for a frame to start from.

I found this one, the seller wanted $200 but he accepted $150 for it.



It's an Autobike 6-speed. As the wheel spins, the counterweights slide outward on the spokes shifting up, as the rpms of the wheel drop they slide back in, shifting down.

So, it's thinking time.. Here's a bunch of pics as it sits now.

 

[CTripps]

more pics...

1. Parked next to the cruiser you can see the frames are almost the same size.
2. Some rust
3. One of the Autobike labels
4. Back tire has some splits in the tread.
5. Measuring the seatpost.. should be good.

 

[CTripps]

So now it's thinking time.

• I want to use a shift kit on this build. It'll be a first for me, but that shouldn't be a problem, just an opportunity to learn.
• I'm thinking I'll move the front tire to the back, get a new road tire for the front. (The front tire has no signs of splits or damage to the tread). I kind of like the tires it has, smooth in the middle and knobby on the edges.
• Paint. On the one hand I recognise that keeping the Autobike labels intact might make it worth something down the road, but to be honest the metallic grey just doesn't work for me. It already has some little rust spots and a few little blemishes. Right now I'm not seeing the colour in my mind's eye yet.
• Engine.. I have a choice, a black or a 'silver' 66cc China Girl, both are sitting in thier boxes in the garage waiting for thier time.
• Exhaust.. At the least, I'll cut and extend the stock exhaust. Considering adding an expansion chamber as I did on the cruiser.
• Fenders? Doubtful, but if I see the "right" one(s) that could change.

So, while I let ideas whirl around in my head, bouncing off each other and trying to fit to each other I am open to input and thoughts from everyone. It'll be a little while before I'm ready to start on it, at the very least I have to order a shift kit. I'm leaning toward this one, if anyone has another to suggest, please leave a link.


I had considered adding a pull start/centrifugal clutch, however thinking on it for a while, I've decided not to. I suspect the local authorities might have an issue with a completely automatic 6-speed, so I'll have to keep the clutch lever.

Anyway, it's going to take some time to pull this one together. Your thoughts and ideas are always appreciated.

 

[GearNut]

It looks like a great bike to convert.
Without seeing any sort of device for controlling the derailleur, I gotta ask, how does it shift?
I clearly see the 3 weights that slide along the spokes, but no sort of linkage.

 

[CTripps]

It looks like a great bike to convert.
Without seeing any sort of device for controlling the derailleur, I gotta ask, how does it shift?
I clearly see the 3 weights that slide along the spokes, but no sort of linkage.

I tried making a video, but I need another set of hands to hold the camera.. Basically, as the weights slip outward as you gain speed they push a ring out from the spokes that pushes the chain from ring to ring outward on the casette. The deraillieur is spring loaded, so as the wheel slows and the ring retracts, it shifts back to the largest gear on the casette.

 

[Sidewinder Jerry]

You'll definitely want to replace the rear axle with a cromolly axle. The Z chain isn't very good either. I found a Sram 890 to work best.

 

[CTripps]

Here's a quick video of the bike's automatic gear change system at work.

It's a little hard to see as everything (the chain, cassette, mechanism..) is black.


http://youtu.be/XzNDEOqQdLQ

 

[GearNut]

Thank you for the video!
If I saw that correctly...
The big black ring pushes on the chain causing it to jump from sprocket to sprocket.
This causes big black ring to constantly press against the chain at all times.
(I wonder how long the ring will last/ wear issues?)
The big black ring is the only part that controls the chain position, nothing else.
The chain controls the position of the derailleur and nothing else, instead of the typical other way around.
Because the derailleur is constantly under spring tension the derailleur wants to return to the position of the largest sprocket on it's own. As the chain is allowed to change sprockets from smallest to largest the derailleur follows because of this spring tension.
The derailleur's only job is to keep the chain slack in check.

 

[CTripps]

That's pretty much it. The three counterweights each push the ring out through a linkage of thier own to separate risers, the derailleur resists about as much moving it by hand as a shifter controlled one does if you pull it toward the high gear.

I wonder how well the ring will wear too. Once it's in a gear and travelling at a consistant speed the ring isn't in constant contact with the chain.

When I drop the rear wheel I'm going to take the reflector out of it, it badly off-balances the wheel.

 

[GearNut]

So it seems that the flyweights and linkage are indexed somehow to only move the big black ring a specific amount during each "shift" to prevent constant contact between the chain and big black ring?
Hmmmm...
I want to get one of these wheels even if only to see the details of this mechanism.
I wonder how well one would work with a shift kit?

Edit:
I didi a search for Autobike and it seems that they are no longer made.
The closest I could find is a different company by the same name that utilizes a NuVinci 360 rear hub with some sort of automatic controller.
Too bad the NuVinci is not up to the task of engine power.

 

[CTripps]

Here's a couple of pics of the mechanism...

At 'rest'.. the weight is attached to a spoke-guage rod, then to a lever that pushes out the riser.



Pulling the weight outward... The lever is sort of "J" shaped.



...which pushes out the rod that pushes the ring.



There are three independant weight mechanisms.



I'll play around more with the wheel and weights before it's all assembled, but the plan is to run a shift kit on it. On that topic I'm pretty sure of what I need to order now, I took the cranks apart and this is the spindle (the other bearing is still inside the bottom bracket during this pic).



So I'm pretty sure I only need the kit, and won't need to add tools or an adapter to the order.

 

[CranbrookKid]

Interesting bike, I'll be watching this build.

 

[Intrepid Wheelwoman]

That shift mechanism is really interesting. I'll keep following this thread to see how it works out.

 

[GearNut]

Thank you for sharing more photos and information on that auto wheel.
That shift mechanism is so simple in function! I assume that the three rods that the J shaped levers push against are spring loaded to retract back, away from the gear cluster.
I really hope that it works well with a shift kit. It certainly seems durable enough!

 

[CTripps]

No problem, GearNut. And yes, I neglected to mention that each of the shifters feels like it has a spring inside the riser assembly to push it back to low gear.

CranbrookKid, Intrepid Wheelwoman.. Thanks. I'll try not to disappoint with the thread. Fair warning however, it may take a while before anything really gets going.

 

[Intrepid Wheelwoman]

No rush, no pressure

 

[Sidewinder Jerry]

Look familiar.

 

[CTripps]

Look familiar.

No doubt.

No progress yet, besides hanging it in the work sling and taking the wheels, cranks and seat off.

 

[Sidewinder Jerry]

Here is what I currently run. Robin Subaru EHO 35 engine, 1.6 hp, 1.2 ft/lbs torque. 18.75:1 gearbox. GB to shiftkit 18/44. SK to rear 5 speed freewheel 34/(34,28,24,20,16).

This will be a near future upgrade. Honda GXH 50 engine 2.1 hp, 2 ft/lbs torque. 16.07:1 gearbox. GB to shiftkit 22/44. SK to rear 5 speed freewheel 34/(34,28,24,20,17).

I'm able to adjust my derailleur for what speed I want it to change gears at. The gear transition is quite smooth. Good luck with your build.

 

[BigBlue]

Here is what I currently run. Robin Subaru EHO 35 engine, 1.6 hp, 1.2 ft/lbs torque. 18.75:1 gearbox. GB to shiftkit 18/44. SK to rear 5 speed freewheel 34/(34,28,24,20,16).

This will be a near future upgrade. Honda GXH 50 engine 2.1 hp, 2 ft/lbs torque. 16.07:1 gearbox. GB to shiftkit 22/44. SK to rear 5 speed freewheel 34/(34,28,24,20,17).

I'm able to adjust my derailleur for what speed I want it to change gears at. The gear transition is quite smooth. Good luck with your build.

Does the derailleur always index correctly or does it sometimes shift in between freewheel sprockets sometimes?

I've read posts on the Net that sometimes you have to pedal slower or faster to get the derailleur to index.

Chris
AKA: BigBlue