Advice on conversion-kit

[fruktstav]

1st post here, sup.

I got this bike http://www.helkamavelox.fi/en/models/men/jaakari_3_gear-hmj3nhr_arv_k . It's a finnish bike fashioned from blood, ice and pure solid non-corrosive finnish steel with a maxed out manly-factor. The frame is, as scarecly described earlier, made out of solid steel, making it extremely durable.

Obviously, I would like to to electrify this badboy, pimp it out with an android-dashboard and roam the planet freely and charging my batteries with a foldable solar panel that I carry with me. However, I don't think that I'm properly informed about what sort of kit to buy, and what obvious scams to avoid and I'm hoping that you can give me some clarity on some things.

I got my eyes on a hub mounted motor, because it is more subtle as well as more power efficient than the alternatives. This is a bike that will be used for long treks so climbing really tall hills and running about in terrain is not what I will be doing. Just a constant reinforcement to help me travel further, quicker.

So, first off - front or rear?

I've heard that frontmounted motor is generally better, but I'm not sure how well it fits on my bike.

The thing is that on my front wheel I currently have a dynamo and handbrake combination mounted on the hub (see the link above to get a closer look), where as the rear hub is free.

Am I stuck with a rear-fitted motor then?

Also, what power do you think that I'll need? 24V is that enough? I've been looking at this model http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=261022617365 .

Do you think it will fit my needs?

Also, the spokes on this thing is extra thick, will this be a problem?

Cheers, fruktstav

 

[d8veh]

That bike isn't particularly suitable. It has hub-gears in the back, so you can't fit a motor there, and a hub-brake on the front with no separate fitting points for caliper or disk brake. That leaves only the possibility of a crank-drive. The new Bafang one might be a good choice, but I don't know whether the gear-hub can take the extra torque from the motor.

You'd be better off to find a more suitable donor. The kit that you showed looks OK, but there's better ones. Firstly, there's no PAS sensor. A PAS sensor is useful on a low power bike. Ideally you want one with a panel that gives several different levels. How long are the spokes with that kit? Every rim is different, so the chances are that they won't fit the rim you have/buy.

 

[Drunkskunk]

Welcome to the forum. That bike won't work very well, as d8veh pointed out. A good example of a bike that will work is the Trek 820. It has a 7 geared rear end with 135mm spaced dropouts, A steel frame, good brakes, and plenty of upgradability.

I'm not sure where you learned a front motor is better. Its not. But Rear isn't better either. It just depends on the application and your personal taste. Sometimes front can be easier to install.

The best motor for you depends on your weight and riding conditions. Generaly you're going to want something closer to 500 watts nominal.

 

[Tommy L]

Welcome!

Please update your profile so we may better serve you. Location, location, location.

Tommy L sends.....

 

[dogman dan]

Lets assume northern Europe.

Yeah, solid bike allright, but not particularly best suited for a conversion to hubmotor. Given that you want assist on long hills, perhaps you might look into non hub motor stuff. GNG kit for example.

If you don't have the bike yet, a trek 820, or similar Giant, Specialize, or whatever. Steel frame front suspension mountain bike that would make an easy rear hub conversion. In the lower price range, they come with 7 speed rear derailur and a big roomy triangle for carrying the battery.

Then because you want to climb steeper hills rather than haul ass, get a very low speed hubmotor. 9 continent 6x10 or 5x12, or 12 T Mac. Check out EM3 ev for the deal on a Mac.

 

[fruktstav]

Hi guys, sorry for not answering you all - it all looked so dark for me!

However, I have managed to remove my front dynamo (which is completely unnecessary with a motor on there) and settled for a front-drive hub motor. My location is in Scandinavia, the viking north, in the land of the goths.

I have also decided to only purchase the motor itself, and take care of the control and battery contraptions on my own (the control shouldnt be any more complicated than a couple of graetz-bridges and a potentiometer - right? - got schemtics?).

If you don't see any fatal problems with doing those things by yourself, then what motor should I buy? I'm thinking cheap here, and not especially ultra-powerful motors necessarily, and also that I'm going to order like 10 pieces or something and sell to some locals.

Where should I order then? From E-bay? Got any suggestions as to which brand/model I should go for?

Thanks in advance, fruktstav

 

[corim123]

The controller is probably much easier to but than build. Somewhere there are some schematics on this forum but you can get one for your needs for less than $50. $100 if you want a top of the line one. You'd probably save money in the long run by buying one but that's just me. I enjoy doing DIY as well but the complexity in the controllers makes that prohibitive IMO.

 

[wesnewell]

****Do this before your first post or now (it's retroactive)*****
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. Without knowing what country you are in it's hard to make any recommendations and you will waste your time and others. Thank you.

I already forgot what country you're in. This way, one just has to look at the profile.

 

[lollandster]

I don't know much about hub breaks, but I did notice a rollerbreak compatible front hub motor when I was browsing the other day http://www.elifebike.com/peng/iview.asp?KeyID=dtpic-2011-92-KQ9P.8RWUG
I don't like elifebike much since they always throw me a curveball when it comes to shipping.
250w is alittle low, but I belive it's the legal maximum in finland. The controller is only usd$17 so I wouldn't worry about building one to save money.

 

[migueralliart]

I would advice you not to buy from CHINA. Go for ebikes.ca they have a sale of 9C motors. Get one of those and a throttle and order a controller from Lyen. That's as reliable as you're gonna get.

It sucks when you order from China wait 3 weeks for your stuff to arrive and if there is a problem then dealing with it is not convenient at all.

 

[wesnewell]

He's somewhere in Scandinavia but instead of ordering from China he should order from a place in Canada that orders their parts from China. Yeah that makes perfect sense.

 

[Drunkskunk]

I have also decided to only purchase the motor itself, and take care of the control and battery contraptions on my own (the control shouldnt be any more complicated than a couple of graetz-bridges and a potentiometer - right? - got schemtics?).

If you don't see any fatal problems with doing those things by yourself, then what motor should I buy? I'm thinking cheap here, and not especially ultra-powerful motors necessarily, and also that I'm going to order like 10 pieces or something and sell to some locals.

Where should I order then? From E-bay? Got any suggestions as to which brand/model I should go for?

Thanks in advance, fruktstav

I think you may have the wrong idea about how a brushless motor works. There wouldn't be any use for a Graetz-bridge in the BLDC controller. BLDC works more like a DC brushed motor than an AC motor. For a short explanation, Lets Ignore the 3rd phase for a moment. Brushes control the timing and distribution of power in a brushed motor. As a motor's coil rotates into the right position relative to the magnet, it's contact pad rotates under the brush. The coil then gets power and pushes against the magnate, rotating the motor further, until another coil is aligned with it's pad and takes over. If you want the coil to power sooner, you move the brushes so they contact the pad sooner in it's rotation. If you want the coil to have power longer, you use either a wider brush, or a wider pad. All the motor's timing and power distribution is done mechanically.

Now Imagine replacing the brushes of a DC motor with a computer, some sensors, and some switches. Now the computer can decide which coil needs power, and when, and for how long. The computer will decide which coil it wants to send power to, and for how long. It can even decide how much power it wants to send. That means we can have a motor with only 1 moving part, and lose all of the efficiency robbing drag of the brushes. But it also mean we can use the computer to better utilize the motor's power.

Now without the brushes, we can add in extra phases much easier. Most Ebikes use 3 phase, but there are bikes that use even more. (5 in a Bionix, 6 in John's hubmonster) That all leads to more efficiancy and much smoother torque delivery, along with more flexibility in how the power is delivered.

Its possible to build your own controller, others have done it. But a basic Ebike BLDC controller can be had for $25. it will cost you more than that in parts to build your own.


As for the motor, its hard to recommend one unless we know how you'll be using it. But a very good generic motor that meets most anyone's needs would be a Nine Continents 2807, or any of the clones of that motor. Its a true 500 watt motor, although many ebay clones claim to be 1000 watt motors.

 

[d8veh]

I had another think about it. The Bafang mid-drive would be good for your bike. Finland is in the EU, so EN15194 applies, which means that you can't have an independent throttle, and the motor must only operate when you're pedalling. This kit complies with EN15194 as long as you don't fit the throttle. The kit comes with everything you need. The controller's integrated into the motor, so very easy installation. You wouldn't need to change any of the rest of the bike. Just check that you've got a standard bottom bracket. You need to add a suitable battery to get the distance you need. A 10aH 36v one will take you 50 to 70km. I found this German supplier, otherwise look on Aliexpress, where they're cheaper, or Google "Bafang BBS01" and "8fun BBS01"

http://www.bike-emotion.org/Bafang%20BBS01.htm

I've bought stuff of this guy:
http://www.aliexpress.com/item/8fun-Bafang-electric-bike-mid-drive-motor-kit-BBS-01/1117488279.html

 

[999zip999]

I would like to hear of a reveiw on this mid-drive.