Help! Too much info., I'm choking!

[ArDub]

First off let me say hi, this is my first EVER post anywhere. Normally I can figure things out pretty well on my own but I've hit a wall. What I'm looking to do is add a BLDC motor to my 4-wheeled "Surrey" bike. I've attached a photo of a bike similar to mine (and in no way advertising or promoting this product, it's JUST similar). I'd have to say the front wheel hub motor would be a no go for the simple reason I'd need 2 of them (esthetics and cost). So what I'm thinking of, is putting a mid drive system in and this is where my head has a hole in it from all the scratching. My bike has independent 7 speed internal hub gearing on both rear wheels with separate shifters. I need to find "something" that will propel upwards of 750 pounds ... NO, it won't just be me on it. It will hold 3 small children on the upper front bench and 2 adults + 1 child on the main bench. Now add the weight of the batteries, motor and any other extras I want to pack on. Needless to say it's going to be heavy, with all the hills around town, pedaling alone makes any enjoyment with this bike disappear. Do I need something that's geared already? Speed definitely isn't as important as torque but what size motor is going to provide what I need. The hills aren't in-your-face steep but in the town I live in, it's all uphill from one end of town to the other (suffice to say it's all downhill going home :0)

If anyone can supply me with a path to go down, that would be fantastic! Maybe my hair can grow back in "that" spot

[Bikemad]

A pair of front hubmotors is the most obvious choice, but as you don't wish to go this route, perhaps you could mount a fifth wheel centrally on the rear using a pivoting swinging arm arrangement.

A 1000W 16" wheel should be small enough to provide a reasonable amount of torque to assist on the inclines:


 
The wheel could even be incorporated into a single wheel trailer, similar to this non-powered setup:



This should at least give you something else to think about.

Alan
 

[ArDub]

Thanks Bikemad. Now that you mention the trailer idea, I seem to recall one of the thoughts I had a while back was to, for the lack of a better word, make it into a pickup. The thought was to create a carrier with matching canvas siding on the box. Under the deck of the bed would be the batteries. With the weight of batteries and keeping the box frame rigid to the bike frame, there would be enough force down to keep the wheel friction to the pavement and not spin trying to push the weight of everything. Sweet! I really appreciate your input ... Input is good.

[GM Canada]

There was a video I saw on youtube sent to me by a customer. He put a cast Magic Pie wheel on the back on one side and it realy seemed to work well. I always thought he should have used two Magic Pies as it would push more evenly and looks awesome. Now I just wish I could find the video. I treid for sometime on youtube. I am going to look some more.

I found a picture with a 500w 48v motor on alibaba, don't buy from alibaba though, too risky.

http://www.alibaba.com/product-gs/209925555/Electric_Four_Wheels_Surrey_Bicycle/showimage.html

This ones a little off topic but check out the electric low speed cars!

http://surreycompany.com/whats_new.htm

I am amazed at the videos I am finding tonight. Check out the wheelchair addon! Can a wheel chair actually handle this kind of abuse for a long period of time?

http://www.youtube.com/watch?v=JikRgENekuw

Gary

[GM Canada]

Found it!

Its a three part video...

http://www.youtube.com/watch?v=HyUMzR3eiCY&feature=related

http://www.youtube.com/watch?v=i1fd0C2eLEc&feature=related

http://www.youtube.com/watch?v=bS2p3yqYb-I&NR=1

Gary

[ArDub]

Thanks Super G for the links. Well, now there's more to consider/reconsider. Okay, now I'll show my true ignorance to all ... and I can live with that if it helps. IF I were to use 2 front hub motors (there are 16" wheel on the bike now), can one upgraded controller be used to split the power equally and would I also need to double the batteries? When it comes down to dollars and "sense", what would be the best route? Anyone's opinion is more than welcome. Also, the bike is just to be used for recreational use, it won't be a daily driver.

[DirtyGinge]

personally, I would go for 2 external controller pies, and 2 infineon controllers ...6 fet versions can be purchased really cheap ....

[Bikemad]

IF I were to use 2 front hub motors (there are 16" wheel on the bike now), can one upgraded controller be used to split the power equally and would I also need to double the batteries?

With brushless motors, each motor must have its own controller, but they can both share a single throttle.

A single battery can be used, provided its continuous power output is high enough to cope with both motors under full load.

Alan
 

[GM Canada]

Why front motors? I think they would look better on the rear. Actually how about a four wheel drive

Gary

[MonkeyMagic]

My bike has independent 7 speed internal hub gearing on both rear wheels with separate shifters.

I would say that's why Super G however, I prefer your style of thinking !!!!!!!!!

Of course if pies are added, not much pedalling will happen anyway I presume

[ArDub]

Hi again. Just got back from a short trip to the Rockies, Jasper area. It's just down the highway a bit so why not. Had time to reflect some more on other questions (I oughta get a hat made with the big question marks popping out the top). 4 wheel drive! I love it ... turn it in to a rockhopper ... more trips to the mountains. But alas, if I can't get 1 wheel going. I've supplied a few more pics here today. With the bike having rack & pinion steering I honestly can't see how things would work without  going down the path of fab. work for a front axle. Again with the back wheels and the internal 7 speed hub (shifter on one side and disc. brakes on the other ... pics) would I need to nuke both of them. On one wheel, the sprocket is to the outside while the other wheel it's to the inside. Basically they're motorcycle rims using spokes about 3mm thick (10-11 gauge), so would swapping the wheels out be a huge mistake as far as load capacity/terrain/etc? Mid drive motor setup? Do I need to find an old farmer who can MacGyver anything to create a front dual freewheel front sprocket? I've seen one on YouTube and other forum posts but it's not an over-the-counter purchase. So, back to your idea Alan, with the trailer. I've thought about this idea probably more than anything else and hey, where's my question mark ball cap. Like building any other trailer, keeping it square to itself is huge because of the width of the bike, if not this thing is going to track to one side or the other. With a single drive wheel, and 2 wide attachment points to the bike frame I can't see any issues other than the "spunk" needed to push this load.

DIRTYGINGE wrote "personally, I would go for 2 external controller pies, and 2 infineon controllers ...6 fet versions can be purchased really cheap ....

Would this idea fly for a trailer as well? I really want to get something going before the season is over ..... hmmmmmm .... has anyone ever made a 4 wheeled bike in to a 4 point snow machine??? Skis on the front, snow tracks on the drive. No No No, 1st things first!!

[DirtyGinge]

oh yea, skis on the front, then on the rear tyres, stick 200 screws from the inside out on each road...snow motocross

[Bikemad]

After looking at those pictures, it is obvious that a front wheel conversion is not really suitable due to the single sided fixing point and the weight it has to support.

Does the rear box section on the chassis go straight across as I've shown in the attachment below? If so, a standard tow hitch could be used for a two wheel trailer along with a small DIN socket for the throttle and brake connections (all the heavy duty power connections would remain on the trailer along with the batteries).

If you are going for a single wheel in the centre, don't forget it must pivot sideways as well as up and down to prevent the tyre from scrubbing while turning corners. Reversing will be very difficult if the trailer is too short.

Now you have a few more ideas to consider.

Alan