Upgrading hub motor on a 20 inch wheel

[PDodd]

Several years ago in Taiwan I found a unique (to me) electric bike, a "Navajo"


It is most likely a Taiwan knock off of the Giant Revive. My Navajo has a 5 speed derailer and boxy handlebar stem like this Revive:


What I liked was the more relaxed seating style, the cast wheels and the old 24V*9AH NiMH batteries were stored in the main frame tube accessed by moving the rear rack out of the way. It was hard to tell it was electric powered.

The little 180 watt rear hub motor seemed fine around the parking lot, but quickly became pathetic on the road. I thought it might be the old batteries, so I rigged up some new ones which gave me longer life, but no better power or speed. So it sat while I tried to find alternatives.

After a year or so I found the Golden Motor Magic Pie system which had a cast rim which would keep the look I liked and lots more power! They were all over eBay.


However, I could not find a Golden Motor supplier in Taiwan and if I tried to import one, the shipping was massive and there was no telling how much import duty/tax/customs I would end up having to pay. So I waited until I was back in the States for a longer stretch and that took a few more years! I guess it wasn't a high priority.

Now that I am back for a bit, it seems Golden Motor Magic Pies aren't as easy to find as they used to be. EBay only lists one odd one right now.

But looking around here, some of you suggested Leaf Bike motors and systems. So i checked them out and they have a 20 inch cast rim and 1000 watts!


And they have 1500 watts...but not in the cast rim, at least as far as i can tell.


My questions are:

• 1) What are the drawbacks to using a cast wheel and the advantages of spokes? Maybe i haven't looked hard enough on line.
  2) Are there other manufacturers who make a 20 inch cast hub motor I should consider?
  3) The reviews/comparisons that I have been able to find for Golden Motors seem to be rather out of date. so between them and Leaf Bike's motors, which would be more durable, and which would be easier to install?

My ebike situation when I return to Taiwan is no real hills, out in the "country side" so 3-5 mile round trip to town to get things, and 220 pounds plus what ever stuff I have to pick up in town. It will be more of a scooter than peddle power. It won't help me lose weight but it needs to get me there without me turning into a pile of sweaty goo from the high humidity.

Any suggestions and insights would be appreciated!

Thanks!

 

[tigcross]

Hi there, I would look into Golden Motor Canada. Gary the owner is very responsive and a pretty ethical business man. He deals directly with the Golden Motors. I would use a cat rim instead of a spoked unit as the spoke angle on a 20 inch rim is awkward and could result in a lot of broken spokes.

 

[docw009]

Seems to me that 24V9AH and existing controller will not be enough to spin a 1000W hubmotor very fast. Maybe you can add a booster battery in series with the existing one. That by itself will get you to the store faster with the old motor.

With a series arrangement, you do add some risk of electrical issues. Controller could blow up. Battery faults. Not necessarily a free lunch.

 

[PDodd]

Thanks Tigcross ! for the suggestion of using the cast wheel over spokes which would tend to break. I would not have thought of that problem. I am glad it is not just my vanity wanting the look of the cast wheels!

I am assuming I will have to replace the old wiring, controller and other stuff. The old battery is definitely shot now, but I found folk in Taiwan now who can build a new battery which will fit the tube and is 48v and LiPo...unless there is a better, less expensive option. The battery part I can negotiate without shipping and custom duty tax stuff. When i try to find a motor in Taiwan they just want to sell me a whole bike. I'm sure there are folk there doing their own mods, but finding them is the issue!

Thanks!

 

[markz]

Cyclone is mid drive, they are in Taiwan
search CycloneTW

For Leaf motor, great choice but go with 1500W and buy their kit.
If you are back and forth a lot, to the USA a lot, just rent a mailbox or get it shipped to friends/family house. If mailbox rentals dont hold parcels, then a freightforwarder would hold them, something like USADDRESS dot com or something. However you are so close to China, why not go there. Thats where everything comes from, even Leaf motors. BMS Battery has a store there.
Guangzhou, Guangdong China

I bought my MXUS motor from the manufacturer.
http://mxusebikekit.com/contact.aspx

Rent a mailbox on mainland china, close to Taiwan so its just a quick trip over and back.


Leafmotor
Address:
NO.35,Zhousan Lane,Jiannong Village,
Yaoguan Town,Wujin District,Changzhou,
Jiangsu Province,China 213102
* Email: sales@leafmotor.com
* Cell phone: +86 137 7505 4726
* Tel: +86 519 8870 4321
* Tax: +86 519 8870 4321

 

[PDodd]

Markz, thanks for the info for Cyclone motors and parts in Taiwan! When I get back to Taichung in July i will try and look them up. On their page they do have a hub motor...a 20kw hub motor, maybe a little overkill for a 20 inch wheel. I'm not sure how a mid drive would work with the Navajo's odd frame and swing arm. I suppose I could avoid the hassle of the peddles and just turn it into a "scooter". That would simplify things.

When I go back we will be sending a small shipment (by boat) of furniture and such, so a small but heavy item would go well. that was my plan. But if everything is actually being shipped to the US from China, then i am wasting money on shipping. I tried a few years ago to get Golden Motor to ship me a kit in Taiwan. They seemed reluctant to waste their time on a single motor. They wouldn't tell me what the final cost would be. Probably the strange political situation between Taiwan and the Mainland.

Maybe my best bet and least expensive solution, is to have a friend in China order something and have it shipped to them and then they can bring it to me in Taiwan when they need to do a visa run. They would need to be good friends to do all that and then schlep it over to me!

So, would the Golden Motor Magic Pie 5 (with bluetooth) in a 20 inch cast wheel be the best option or is there a better option? Does the Leaf Bike 1500w hub come in a cast wheel? Ah! Markz gave me an email address for Leaf Bikes! i can write them!

Thanks! we will see what is possible!

 

[amberwolf]

Regarding broken spokes--if they are the rigth size (gauge--probably 14-15butted for your wheel) spokes and at the right angle (radial for such a small wheel and large motor), then I doubt the spokes would break.


I use 20 inch wheels with MXUS 3K motors (and previously an X5304 and an HSR3548, both of which are the same diameter as the MXUS) on my very heavy SB Cruiser trike (and the HSR before that on CrazyBike2, also heavy) and both are hardtails, no suspension to soften the potholes and bad roads.

Since lacing with the right spokes in a radial lace, I have not broken any spokes, despite the weight of trike/bike and cargo, the potholes (which *have* broken rims and axles), side-loading, etc.

The only time I have broken spokes (besides really extreme loads on wheels from chaindrive failures) is from poorly built wheels, with loose spokes either from a bad build or from too large spokes for the rim, so that the spokes cannot be tensioned sufficiently to stay tensioned without damaging the rim (which then loosens the spokes, so they can then break).