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  1. #1
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    Good Value Rear Hub Motor/Battery for heavy hills

    First post here in the ebikes forum. I have been lurking and trying to figure out what might work well for me. This is one of those what should I get questions. I do pretty heavy hills in San Francisco, about 15 miles per day, some of it with burley and kids in tow. My commute is 25 minutes from western san francisco to the Embarcadero (16 mph) and 40 minutes back (10 mph). I would like to continue to pedal hard but just cut the commute time down.

    I'd like to outfit my novara randonee touring bike (700c wheels) with a rear hub motor, since I have a really nice hub dynamo setup in the front. I would source a LifePO4. The amped kits look attractive, but are not available in 700c. What recommendations are there for a good value rear hub motor? What capacity battery would work? Also, this bike has drop bars and brifters. What throttle control would be appropriate?

  2. #2
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    what is the width of your rear dropouts? also are your dropouts steel? those two questions will dictate your path more then anything else. I am of course assuming at this point you've got smaller then 130mm dropouts and I am assuming you've got an aluminum frame. Most hub motors are 135mm droputs and anything that can push you up a hill like you've described is going to need torque arms on anything but steel. You might want to look into something like a cyclone where it mounts onto the bottom of your frame and drives the bike through the chain. Or you can do a BMC/Puma, both of those are fairly light weight. Or you could go for the big guns and find a way to get a crystalyte 5305 @ 48v. The crystalyte solution is pretty much the brute force approach while the cyclone might have issues breaking chains. So the BMC/Puma might really be your best option.

  3. #3
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    I forgot to mention that the entire bike is steel. I haven't measured the dropouts yet.

    I also have a full suspension mountain bike, but that one is all aluminum. A hub solution would be preferable to keep the bike as standard spec as possible. The bionx kits are nice with the pedal assist, but the high price tag and proprietary batteries turn me off.
    Last edited by snowranger; 08-26-08 at 12:51 PM.

  4. #4
    Faith-Vigilance-Service Patriot's Avatar
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    I think one of the best for themoney and capability is going to be the 5305 Brute. It's big and heavy, but it'll drag just about anything up a hill at 48v.
    President, OCP
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  5. #5
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    After looking around and thinking about it, I won't be converting my 700 c touring bike. The bike rides beautifully as is, and the drop bars don't go well with a throttle.

    Plan B is to take my old Cannondale SV-2000 mountain bike and outfit it with a rear amped bikes kit slightly overvolted with e 48 V 20 ah ping or goldenmoter battery. I am also considering the evtech as a lighter weight option, but it is quite a bit more expensive.

  6. #6
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    Welcome to this forum.
    If you have steep hills, I recommend you consider a geared motor. It will increase your efficiency at the expense of some noise during power application.
    With a 36V Heinzmann brushed motor, I haven't seen a hill that I couldn't climb.
    You can get geared motors in both brushed (Heinzmann made in Germany) or brushless (BMC China).
    Gearing increases Torque at the expense of top speed, so there is a tradeoff here to be made. With a geared motor you can forget going at above 30MPH. At 36V the Heinzmann does 18MPH (11MPH at 24V).
    Let me know if you need help finding a Heinzmann.

  7. #7
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    Thanks. I didn't realize that geared motors won't exceed 30 mph. Even at 48 volts, is that the case?

    How much are the Heinzmanns running these days?

  8. #8
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    Texas electric bikes sells a geared hub motor that can haul me up steep hills. The whole kit is $699, laced to the wheel size of your choice. Very quiet too.

  9. #9
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    Quote Originally Posted by crock View Post
    Texas electric bikes sells a geared hub motor that can haul me up steep hills. The whole kit is $699, laced to the wheel size of your choice. Very quiet too.
    Thanks. What I'd like to find out is if the included 36 volt controller can take a 48 V battery.

  10. #10
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    I have seen Heinzmann go between $200-300 on ebay.
    I bought a 36V one recently for a spare for $300/ I have an EVG ebike.
    It can be used with a generic brushed speed controller. I have a good source for those too. PM me if you are interested.

  11. #11
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    Here is what I ended up with:

    After buying a Heinzmann hub and later learning that it wouldn't stand up to the Ping 48 v 20ah battery I bought, I decided to look elsewhere. I found and ordered a geared rear BMC hub motor and ECrazyman 600 30 amp watt controller.

    The most time consuming part was building a battery box that could squeeze between my saddle and xtracycle snap deck. I built a wooden box out of 1/4 inch oak plywood using butt joints and glue. It has a lid with a hasp for a padlock and a power switch. The switch either turns on the controller or completes the charging circuit. The box is mounted to the brake bosses where the old wheel was located. Two inches were removed from the snapdeck to squeeze the box in.

    The BMC hub is mounted with a beefy torque arm (probably overkill). I upgraded the phase wires up to the entrance to the hub. The proper wire combination required switching green and yellow for both the halls and 3-phase wires.

    Top speed seems to be 26 mph based on GPS. What's really impressive is the hill climbing torque of this little motor. The battery doesn't seem to have any voltage sag at all. Here are some pics. Thanks out there for the advice and assistance.








  12. #12
    Hooligan Abneycat's Avatar
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    +1 BMC. Excellent torque output, reasonable cost, lightweight.
    Power in Motion here in Calgary also has found a way to use BMC motors with Crystalyte controllers, which has been convincing me to switch over soon. Supposedly, you could then use a cycle analyst with a BMC as well as pedelec sensors or other plug ins.

  13. #13
    put our Heads Together cerewa's Avatar
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    Where'd ya get the BMC mtoors, guys? They seem like a great choice.
    Some awesome folks who are working to give Haitians the ability to manage their safety and their lives:
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  14. #14
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    Cycle9. I got one of their beta test motor wheels without controller, freewheel, or throttle. Check out ecoforumz also. The admin seemed to be selling them as well. There is also comcycle and hi-power but their prices seem on the high side.

  15. #15
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    Very smart looking build and nicely executed. You must be happy with that power when the bike gets the load on it that it will handle especially at intersections and the uphills eh? Plus I bet it still handles/pedals well with the power off too.

  16. #16
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    Yes, the resistance free freewheeling is really nice when you just want to just ride without power.

    Blipping the throttle from a standstill helps to balance the load and make it safely through intersections.

  17. #17
    Senior Member coldfeet's Avatar
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    Snowranger, what range are you getting with heavy use of the throttle?

  18. #18
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    Don't know yet. I've done up to 30 miles so far of hilly terrain with moderate pedaling. The battery was still at 52 volts. I need to get a watts up meter to really find out.

  19. #19
    Senior Member coldfeet's Avatar
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    Quote Originally Posted by snowranger View Post
    Don't know yet. I've done up to 30 miles so far of hilly terrain with moderate pedaling. The battery was still at 52 volts. I need to get a watts up meter to really find out.
    Thanks, will be interesting to see what the end result is. I note the BMC motor will take an 8 speed freewheel, but does anyone still stock them?

  20. #20
    put our Heads Together cerewa's Avatar
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    I note the BMC motor will take an 8 speed freewheel, but does anyone still stock them?
    Found by going to google, searching for "8 speed freewheel" and then clicking "shopping" at the top--

    http://www.bikeman.com/FW2125.html
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  21. #21
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    A 7 speed freewheel with 8 speed shifter also works very well.

  22. #22
    Senior Member coldfeet's Avatar
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    Thanks guys.

  23. #23
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    Update:

    I have added a BB7 203 mm brake to the hub motor. This confirms that there is enough clearance for disc brakes with the BMC.



    I have also added a watts up meter to monitor consumption. I am averaging 12 ah for each 30 miles on hilly San Francisco terrain with moderate pedaling and throttle. Average speed 18 mph. This means that the Ping Battery is probably good for 50 miles at this level. I'll check capacity by running the battery down to 44 volts.
    The power consumption averages around 400-600 watts on the flats with bursts up to 1000-1200 watts when accelerating from a stop or climbing steep hills. I am rolling on the throttle gently and pedaling at starts.

  24. #24
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    On the last cycle, I got 49.7 miles before cutout with moderate pedaling. Measured discharge 18.2 ah. Measured charging 19.2 ah so far. Seems to be balancing now.

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