Tandem Motorized Bicycle Project

[Tom]

Ever since the Theft of my Green Machine, I have had the itch to build something new.

I have always wanted to try a rack-mount engine, and had that tandem bike sitting around collecting dust.

The only problem is that it was so rickety to even ride without a motor, I couldn't imagine motorizing that tandem. I went ahead and stripped the frame down. I am going to put on a bunch of new components including:

- New wheels/tires/hubs
- New brakes
- New gearing with a derailer in the rear

I would also like to:

- Sand the frame/fork/bars down and paint them (any color suggestions? Maybe green in memory of the green machine?)
- Add some accessories like a kick-stand (my last bike never had one), mirrors, lighting, new grips/seats, etc.

Once I get the bike up and operating again, it will be time to add a motor. It must be a 4-stroker (cleaner and quieter), and it should have ample power to scoot two people along at 15mph. I guess that as long as I have high enough gearing, I should be able to do this. I am going to start by looking at GEBEs.

Finally, I want to do some sort of advanced security system. Anyone know if a sort of bike alarm exists? My last kryptonite lock failed to detour the previous theif(s).

 

[DetonatorTuning]

Tom,

good to see you moving on a new ride.

you might consider using left side drive cranks from front to rear BB's then a thescooterguy mount just ahead and above the right side of the rear BB with a freewheel crank on that side, going on back to the rear cassette.

if you freewheel the left side of the rear BB too you would have both independant no drag pedaling and motor drive.

then if you wanted to, you could add a horizontal frame member between the 2 seat posts to add panneirs (sp) and have room for a real cargo outfit out back.

PM thescooterguy about the SUPER idea he has for a bike security system.

steve

oops, sorry i didn't read your whole post to see that you wanted to use it as a tandem, my idea won't work well in that layout. sorry..................

 

[Zev0]

Tom, WavyGravy has a schwinn tandem with a Robin/Subaru GEBE set up on it. He's been known to hit 30mph with the little 35 cc engine.

 

[augidog]

yay!

contact me for gebe "help" if that's the direction you take. yup, wavy's tandem/RS35 has more than proven itself...

there is a functional motion-detector (loud!) available for bicycles, but the name & source evades me at the moment.

you want a "greenfield stabilizer" kickstand. looks like you have plenty of room to carry/run real lighting, too...i sure hope you consider a 12V-SLA setup...simple, reliable, EFFECTIVE.

 

[Tom]

Zev0- I took a look at Wavy's tandem while I was up in Ocean Park last August. Unfortunately, at the time, it wasn't running. It was a much nicer tandem bike to begin with than mine. That sure is one sweet ride.

Augie- I am leaning towards the 35cc 4-stroke from GEBE, however, the motor is going to be the last piece to the puzzle. I'll have plenty of time to research the different options as I put the actual bicycle together.

I would definitely want to do the mega-lighting system with a 12v battery. I will be looking at your thread and some of the other stuff on the forum while setting that up.

The security system will be one of the last things I do, but I just want to make sure I don't lose the bike. Maybe some sort of lojack system? I would love to be able to locate it and beat the **** out of anyone who tries to mess with it.

Some additional things that I want which I just thought of: A speedometer (easy), but also a tachometer. I would really like to be able to see how many RPMs i am actually running.

Right now I am just getting new components, trying to get it to be a stable human-powered bicycle, and then I will start tinkering with concept of motorization.

 

[srdavo]

Finally, I want to do some sort of advanced security system. Anyone know if a sort of bike alarm exists? My last kryptonite lock failed to detour the previous theif(s).

Tom, have you seen this? http://www.motoredbikes.com/showthread.php?t=19117
we better hurry....I bet they SELL FAST!

also....here's the tiny tach -- http://www.tinytach.com/tinytach/index.php

 

[Tom]

Wow! That thing is sweet! I just ordered one and a bunch of other cool stuff from that site. Way cheap!

Tinytach seems like a viable solution for my tachometer needs.

 

[augidog]

http://www.motoredbikes.com/showthread.php?t=12218

 

[SimpleSimon]

Onthe lojack idea, it seems to me that it is viable and utterly concealable. I've thought about getting a prepaid basic cell phone, pulling the works out of the case, and slipping it all into a package that sldes inside a frame tube and uses the frame itself as the antenna. Get that "track your teenager" software on your comp, feed it the cell number, and use the built-in GPS of the phone to have it tell you where it is in the event of a theft. Honestly, I'm not sure this is workable, but I can't see why it wouldn't be.

I've also been looking at a sliding pin lock system that is key activated, and uses a solenoid to push/pull the pin - much like an electric door lock on a car. Heck, set it up so that default is locked, and it unlocks only when the key is inserted and turned to activate the electrical system on the bike. Be straightforward enough to set that up so as to also close a kill circuit for the engine.

The pin lock can be inside the top tube just aft the forks, set up so that the forks lock at a set position (say, max turn). Ain't nobody getting away on such a bike except by carrying it.

 

[Tom]

brilliant ideas! You just made me think of another: You could rig something up wired to the speedo sensor. If the front wheel makes a full revolution when the bike is locked up and the alarm is activated, there will obviously be some foul play going on.

Augie- Thanks for the tacho link. I'm excited about having something like that.