Building Electrical Exercise Bike

Errr, why do you need a motor on an exercise bike???? Now't wrong with good old simple friction?
Del

To what source of power is the motor attached, and why?

350W will easily overcome the muscles of all bar the fittest of human specimens. Or is this machine intended for exercising a different species?

As you said, it can be done without any electrical component but it is a project. It should be done with brushless motor

Edit: 350W is just an assumption, that can change

No useful additional information has been forthcoming in that response.

Sorry. I couldn't express the idea. This is a spa bike project. Our purpose is that any person can adjust the difficulty of cycling. To do this, we considered 300-350W brushless motor would be fine. I need your suggestions about choosing appropriate motor and other components

In other words you want someone to do your homework.

Well, you sound pretty attached to your motor, so all you need now are some pedals, some tubing, maybe handlebars and handgrips and if it were me, I also throw in a seat of some kind. Viola!

If you really want to make it difficult, leave out the seat.

If you're determined to go electric, you need a generator, not a motor. Set it up to feed power into the mains and get paid for it.

D'oh!

Why not just buy one already made?

http://www.amazon.com/Exerpeutic-7101-Active-Cycle-Exercise/dp/B00EBXK14C

If you bought this one, all you'd need is an adjustable-position chair for the users to sit on. Which you could buy or build.

Why in the world are you fixated on a brushless DC motor? A brushed motor working as a generator will easily do what you need.

The whole project is bonkers! You can't adjust the turning resistance of a brushless electric motor without applying a load, as redfred has said. Since there is no generator in this lash-up, there is nothing to supply any power.

You are displaying a complete lack of reasoning in this school project. You have done no independent research, yet or you would know this.

Return to your instructor and challenge them, or do the research you should have already done.

If using the following as a guide, please be certain that both CR4 and Instructables are listed as sources for your project:

Turn an exercise bike into an energy bike - Instructables

Why would you want to make an exercise bike that is powered by a 350 watt motor? That is almost 1/2hp so you will never have to pedal, including up hills. 1/2 of horses are hard to find. They usually come in whole units. Is a 1/2hp a mule? They are bred from a male donkey and a female horse.

Good Luck, Old Salt

Yes you can increase the load by turning on additional lights, or gearing up the sprocket....

http://www.alibaba.com/product-detail/Hot-sale-generator-brushless-hub-motor_60120602884.html?spm=a2700.7724857.29.30.C2SPKQ&s=p

Guys, thanks for sharing your opinions.

This is not a school project or homework. My company wants to produce it. To be honest this field is where I'm not qualified on. That's why I told I need your suggestions. I just need to decide where to start. Motor type and power values can change.

So, your company wants to market a product designed by an anonymous internet forum team led by someone who, by their own admission, knows nothing about mechanics or electronics?

I hope that you can see that this is doomed to fail.

<unsubscribes>

Yes, something like that. This field is not my profession but this is my responsibility. I have to learn everything about this from all possible resources including anonymous internet forum.

I recommend you update your resume.

It sounds like you are being put in a position you are not comfortable with. If you have no electrical knowledge or qualifications you are putting yourself and the general public in a rather dangerous position and setting your company up for bad things in the future.

Normally when we (in the industry) see dangerous and poorly thought out products put on to (and often quickly pulled off) the market we don't get to see the reasoning behind why someone would think it was a good idea in the first place. Kudos for helping to show us the other side of poor product design and planning we so rarely get to hear from.

I would be interested to know why your company thinks they needs to design a product that is outside their core market and skill set (missing piece of an existing product range offering perhaps?).

If I were in your position I would consider proposing the company source, purchase and rebrand another companies existing product, I am sure there are plenty of companies that mass produce these products that would be willing to sell to you, and likely at a considerable saving to your company than having to build your own inferior and potentially dangerous product from scratch.

Something to seriously think about, and a positive win-win for all concerned.

Well said.

Thanks. Often it's not about the 'what' or 'how' of the question but the 'why' that we can most learn from.

http://www.thegreenmicrogym.com/the-story-of-the-upcycle-eco-charger/

No need for any complexities. Just use a rotating aluminium disc and 2 flat magnets that just clear the surface, and you arrange a mechanism to cover more or less of the surface to adjust the drag. These are called Eddy Current brakes

The Aluminium disc is a conductor moving in a magnetic field = an eddy current is induced that is shorted by the mass of aluminium = force to counter the motion. As the wheel moves between the gap it 'sees' more of the field = more drag. Automatically more drag if you pedal faster. Very simple mechanically.

lots more here

As someone who rides around 3000 miles/year on a bike, I assume you are no cyclist, or:

1. You would want a bike stand, not a pedaling contraption, so you can allow the user to use his own properly fit bike and be comfortable while exercising. Bike fit is ESSENTIAL to comfort which correlates to time on the device. As poorly as a bad fit feels, this may not be a 1 to 1, but a square law. A poor fit leads to knee problems quite rapidly. A good cyclist knows within a few minutes if any setting on the bike is out of size by less than an inch. The common exerciser wouldn't and could cause real damage to his knees with a bad fit, not to mention back strain.

2. You would know that there are bike stands built with many forms of adjustable resistance, the closest to your idea, is the generator stand. Yes - you can run a small TV while pedaling to distract you from the monotony of exercise. There are also fan loads and several forms of resistance loads through friction.

We got to ride on one of our friend's computer controlled exercise bicycle. It had a video screen on it. It's like a video game you can pedal. And you had your pick of numerous programs.

(107) fit.pl