Alternator to Bicycle Connection

[Erdling369]

Hi,
I am currently planning out my project for school. Basically, I am wondering what might be the simplest solution to connect the car alternator to the bike's rear wheel, and mount it to the bike itself. What kinds of solutions would you recommend? I haven't been able to find anything concrete as of yet, aside from one online which requires a hefty mod of the frame and gears. Any help much appreciated.

 

[amberwolf]

I moved your thread to the ebike non-hubmotor subforum that already has a number of DIY builds you can poke around for ideas from.

There are also various bikes and vehicles using modified alternators to drive them in various ways, many of them in this subforum, and probably others scattered around in others. Alternator and Altermotor are possible search terms for them.


Regarding mounting/drivetrain methods, those would be specific to your particular bike, and how you intend to gear it to match your specific usage, terrain, riding conditions, etc. Also depends on how much battery you will need for those to get the range and performance you want, to supply the controller's demands under those conditions, and where and how you will have to put that battery on the bike.

 

[Erdling369]

Hi, thanks. I'll continue to investigate more. I haven't come across what I need as if yet. The bicycle in question is the Carrera TDF LTD. I've attached an image of the rear wheel. The rear derailleur is basically off. My goal is plain and simple: to get this to work. Performance and train, etc are things I want to explore in greater depth at a later date in my own time (part of the reason why I threw myself into this project was because I needed a kick to finally do it and it has been a longstanding curiosity). Whatever means of mounting is the simplest and quickest will be very much appreciated. I have a rear rack from another bike that I want to use here to hold the battery, and any other components. That's the very general idea. I'm currently in the process of modifying the alternator itself. Any help very much appreciated. In the mean time, I'll continue to investigate to see what I can find.

Kind regards

 

[amberwolf]

My goal is plain and simple: to get this to work.

What's your definition of "work"? If you mean getting the motor to spin the wheel, that's relatively easy, once you get the motor spinning on it's own.

I have a rear rack from another bike that I want to use here to hold the battery, and any other components. That's the very general idea

Unless the rack you have is considerably sturdier than most, you're probably going to have to build one specifically for this project, preferably one that is of welded construction as one unit, with sufficient triangulation to prevent lateral wiggle or movement of any kind relative to the frame.

If there is any movement of the rack, the chain (or belt) from motor to wheel is likely to derail, and that can cause all sorts of damage if it comes off the wrong way into the wrong stuff, including you since it will effectively be under your butt.

I recommend you check out these posts for a rack that if securely bolted to the frame would not move; you've got good mounting points already built into the frame there.

Flimsy, broken battery rack.

 

[Erdling369]

Welding won't be a problem; the rack is very similar to what you have in those photos. I can take care of this component.

It's the attaching of the alternator to the rear wheel that's puzzling me. You say that it's quite easy, could you please elaborate a bit further for me?

 

[amberwolf]

I only said that spinning the wheel with the motor is easy--the mounting depends on the parts you have or can fabricate, what your alternator design is like, what kind of output it has (shaft with removable belt pulley, integrated, etc), how you intend to drive the wheel (chain, belt, etc), how exactly the rack is designed, where everything is relative to the wheel both vertically and laterally, etc.

One of the easiest ways to mount things is to use the actual moutnings they used in their original purpose. Or look at how those are designed, and adapt the design to your usage and available parts.

You haven't shown us what you have to work with, so can't suggest any specifics. When you decide how you want to do things, and show us what you are doing it with, we can start suggesting specific ways to do things, or other parts you can use for them. Since we don't know your DIY skills, you'd need to adapt suggestions to your own skillset.

Regarding welding stuff onto your rack--that's not what I was referring to. I doubt your rack is steel; few are, adn most of those are made of flexible garbage steel and/or have adjsutable mounts that will probably not work for your needs. The rest are usually made of aluminum (often hollow or thin or both), and those without adjustable mounts usually crimp the ends to make flat spots for moutning bolts, weakening the structure at the transition. (true of both steel and aluminum racks).

I built that rack from square tubing specifically for the bike it is shown mounted to, for that rider's specific needs; that's what I'm suggesting: Design your drive system, and build the rack from scratch to do that.