Electric Bikes - Hub motors suitable for standing start.

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JS Tyro
05-12-09, 12:53 AM
My knees are knackered, so my objective is to put together an e-bike for electric-only usage. Hence, I need to know which front hub motors are suitable for reliable standing starts. Pedaling up to some speed before the motor kicks in is not an option for me.
FWIW, the jurisdiction I live in allows for up to 500W motors, so that allows me more flexibility than some countries.
Some time ago when I first looked into this I found a web site that compared many different models and brands of motors for suitability of standing start vs pedaling start (minimum bike speed>0 before motor takes over). I wish I bookmarked it; now I can't find that site. Anyone know of it?
Alternatively, is there a relatively reliable number for minimum torque required to allow consistent standing starts?
If it matters, the target is a 26" wheel, mixed-use frame (not racing, not mountain bike - I guess "comfort" or commuter bike would be the term).
xtrajack
05-12-09, 01:15 AM
I have no problem doing a standing start with my Ezee front hub motor. I have done this a few times to cross four lanes from a stop. I have only had mine for about 2 months or so. I use it to help with the hills in my area.
I have no idea how it would work as an electric only setup.
The people at Cycle 9 seem to be very knowledgeable,customer service is outstanding.
http://www.cycle9.com/home.html
JS Tyro
05-12-09, 02:13 PM
Yeah - but the Ezee motor is one of the highest torque motors I've seen. Playing with the simulator on the ebikes.ca web site shows it having much higher torque than any other (e.g. Crystalyte).
Ezee is one of the main choices for me as a result, but I'm kind of put off by the price. When I look at cheaper options, they involve non-geared hub motors - sometimes from less-well-known makers.
Rant - I'm really pissed off that so many suppliers in N.A. seem to insist on selling built-up wheels only and not motors. I'd rather make the wheel myself and not pay a premium for someone to throw something together. But that's another story.
snowranger
05-12-09, 02:41 PM
You can get a bafang geared motor for around $300.
Snowsurfer
05-12-09, 09:32 PM
yeah, the eZee is a good kit
i use the Crystalyte and it is great
you can up the voltage and use 48V, or even 60V on it and get lots of torque for a good start
eZee and Crystalyte are great choices, I personally went with the Crystalyte
the controller for the eZee is also waterproof
be sure to get torque arms though for either one
you must have them since there is a great deal of torque generated when you start from a stop
the torque will eventually rip the motor out of the drop outs and you could risk injury
RustyBarnacle
05-13-09, 11:49 AM
I use a Crystalyte 5304 at 36V and 35A. Technically its over 500W but its close enough that I don't think anyone will bother me.
It works fine for propelling my 300lb frame from a stop on its own but I don't do that very often as I am trying to work with it and lose a little weight as my new daily commuter. That is once I find a job again.
Map tester
05-13-09, 02:29 PM
I have the eZee front hub and it has great torque. Link to my thread on my build: http://www.bikeforums.net/showthread.php?t=522723&
JinbaIttai
05-14-09, 01:03 AM
Do you have many hills? I wouldn't want a non-pedaling ebike if I lived around much of an elevation change.
JS Tyro
05-14-09, 10:12 AM
No, it's a pretty flat area.