Cellman's 350watt front geared hub

N

neoplasticity

10 W
Joined
Aug 27, 2009
Messages
65
Location
Redlands, CA
I ordered the 350 watt front geared up with an upgraded infineon 6FET controller because I wanted to run a 12S battery pack and the LVC was set at 40. I had it shipped SAL and it was very fast. A little over a week. Everything came well packaged in a very sturdy box.

I just put everything together and went for a quick ride this morning.

Couple of things I discovered.

The 700c rim are a bit wide but fit my road bike without much difficulty.

I did have to file and dremel my dropouts a bit for the hub to fit.

with two Turnigy 6S 5000mah batteries in series (so its 50V hot off the charger) I get a no load of speed of 24MPH and I can climb pretty decent hills at about 20mph - I'm very happy with that.

I have yet to see if this battery pack will allow me to do my 8 mile ride with about 1000ft elevation gain. I will know when I try it out on wednesday.

I took the spring out of the twist throttle and then mounted it on the stem so I can just twist it and leave it on and then twist it and turn it off. I need to figure out a better way of doing this. If anyone has any ideas, please let me know. Ideally, I would like something like a thumb throttle on the right brake lever.

I can't comment on the longevity or the heat generated by the kit but I will be able to tell you how well it handles the 8 mile and 1000ft elevation gain ride on wednesday night.

P1030698.jpg


the bike in front of the crate of solar panels i'm getting installed on the roof

P1030699.jpg


closeup of the hub


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closeup of the jury rigged throttle (someone please tell me a better way to do this)

P1030702.jpg


picture of the two batteries, the controller and the series harness I soldered with 4mm bullet connectors from hobbyking ( love the bullet connectors)
 
One way to put the throttle on there is to use a straight bar-end clamped to your drop-bars, and mount the throttle on the bar-end. Put the bar-end whereever is convienient for you to reach. I recommend a thumb throttle rather than full-grip like yours is, but you can add a clamped-on tab of some type to the grip to provide this, placed in a way that lets you reach it with your thumb from your typical hand positions.

If you can't find a straight bar-end, get one that's straight for most of it's length and then just cut the bend on the end of it off. It needs to be the tubular type, rather than the ergo-shaped ones, so the throttle will fit on it.

WIth shorter throttles like thumb types, you can even clamp it right on the curved part of the bar end if it's long enough past the curve.

Some pics of The Velcro Eclipse where I did this with normal handlebars, planning to add more controls up there:
 
If the 1000 feet rise is spread out over at least 2 miles you will have no problems with the motor. I found that gearmotors that small did bog down quite a bit on the steeper slopes, but 5% or so should be no particular problem. It will climb a lot steeper, but not as fast as a motor with more watts would.

With the climb, you'll be pusing 5 ah pretty hard, so you really should get a couple more 5 ah packs. It might just make it, depending on your riding style, but likely it will be a 100% discharge that will lessen cycle lifespan. Pretty hard to keep the amps down on a hill. On flat ground you would make it.
 
Thanks for the review. I have been considering cell man's geared motor for my racer bike, but can't decide between this or friction drive. Something for me to decide.

From the colour difference, did you swap your fork to a stronger material or was it the original fork? Is that steel, aluminum or cro-moly fork?
 
neoplasticity said:
P1030699.jpg


closeup of the hub
Click to expand...

Just a quick note, with the motor mounted like that there is a risk of water dripping down along the cable and into the motor, I would suggest turning it over so the wire exits downwards and then bent up in a "drip loop".

Looks like a sweet bike to ride!
 
That is a cromoly fork. It was changed out so I could put a front motor on it. I read that aluminum forks are no good for hub motors.

And thanks for the tip about the water dripping in. I will change it. Luckily I live in southern california where it rains about 20 times a year at most and I dont ever ride when its even remotely wet so water is never really an issue for me but that's a good thing to know about the water dripping down the cable.
 
Well it made it on my commute with I think plenty of battery power left.

My commute is 8.7 miles to work and 8.7 miles back. On the way to work it is a 1000 ft elevation drop and I essentially coast the whole way to work or its flat so I dont ever use the motor. on the way back home, I only used the motor on the uphill parts of the ride with some pedal assist and then didn't use the motor on the flats because I can keep up 20+mph on the flats on a road bike without motor.

I'm very happy with the performance. I was able to cut my commute back home from about 40 minutes to about 24 minutes. I can climb all the hills at 20mph. When I got home, the motor is barely warm. I'd guess about 95 degrees F. The controller was hot but not hot enough to be painful. I could hold it in my hand forever. I'm guessing that's ok? Anyone know how hot is too hot for a controller to get? Now i did throw my fleece into the pack with the controller so it would probably be much cooler if it wasn't insulated the whole time with my fleece.

My 6S battery pack which I put into series is 25.4V hot off the charger. At the end of the commute, it was 23.7V. So I'm guessing I had plenty of capacity left.

Is the voltage drop linear as the battery drains? Like if my LVC is 40V on the controller (so 20V each pack), does that mean i've used less than half the useable capacity of my pack? If so, i'm going to use it some on the flats too!
 
you had plenty of power left. there's a graph floating around in here that shows the voltage drop. you had around 3.95v/cell which is well ahead of the 3.7v or so when it starts to really drop.

you should air cool that controller. definitely don't store it in with your jacket, etc.

light road bike with a front hub...sounds like that might just be my next project. :)
 
24_dischargingmechanics.gif


At 12s, 40v is about 3.33v/cell, which is a bit low, but when you account for voltage sag on a 5ah pack, it is allright..... if your cells are in balance.

42v would be better. I say get a watt meter or cellog 8s and program it to beep at you.
 
So an update. I'm very happy with the system so far. I've used it daily for 16miles round trip. Again, I only use it on the way back which is 8 miles but with a 1000 ft vertical climb over 8 miles. I actually get a more aerobic workout with the motor than without because I'm pushing the whole way to keep me at a constant 21mph. Before I could not sustain that level of output for the 50 minutes it took me to get home but I can keep it up for 25 minutes. And its just alot more fun to go 21 mph than 10mph.

I still worry that maybe I should get a torquearm but so far everything seems to be good.

Yesterday, I used the motor the whole way back. Even on the flats. I did assist all the motor the whole time, more so on the hills and less so on the flats. When I got home the voltage on my two 6S batteries was 23.4 down from 25.2. So it seems like I have alot of power left. Anyone know what the Wh/mile would be for me? seems pretty efficient. I think I could go at least 15 miles before my batteries reached the LVC of 41V.
 
You shouldn't enclose the controller in the battery bag. That's just asking for heat failure.
 
wesnewell said:
You shouldn't enclose the controller in the battery bag. That's just asking for heat failure.
Click to expand...

I've been running my 9FET in an enclosed bag for 6 months. Depends on how hard you are pushing it and if you live in Heatsville, USA or not.

If you run the bag a bit open, have good airflow, and aren't pushing the controller to or near it's limits, i don't see why it would be a problem.
 
Theres a variety of reasons you may want to have the controller out of site inside a bag. Heat has been a constant concern with all E-bike components, even if you are simply using the stock power levels.

If you desire to keep the controller inside and out of sight, I would highly recommend enshrouding it and adding two very cheap 48V CPU fans, possibly temp actuated, so no battery drain except when the controller is actually warm. One pushing and one pulling (a single fan failure does not damage the system that way). There is a temp-monitoring thread around here somewhere, and one of the choices has two probes, with the motor stator coils and the controller being the two items of heat concern.

Is the voltage drop linear as the battery drains?
Click to expand...

With old-skool SLA, the voltage drop is linear with capacity, and a voltage meter can be used as a fuel gauge. With LiPo, as the posted graph shows, 90% of your capacity reads a fairly flat voltage. For pack health, because of Chinese-quality LVC and charger performance and readout variations, I recomend staying between 4.1V per cell at the top, and 3.65V at the bottom. If something is a hair off, the pack will not be harmed due to your small safety margin.

Using your system only for the hills is the best possible use of an E-bike. Best of luck!...
 
Did you figure out a better solution for your throttle? If your controller has the connections then you may be able to fit a PAS sensor and then use a potentiometer as the throttle. Mount the potentiometer on a small box and clamp it to the bars where you have the throttle now.
They use a similar set up as an option on some of the ezee ebikes http://www.nycewheels.com/ezee-electric-bike-part-eaf-dial.html.
 
I've been putting the controller in the mesh compartment of my bag. Barely even gets warm.

I actually have gotten used to the throttle setup. It looks ugly but works great.
 
hillzofvalp said:
How much do u weigh to be reaching 24mph? How much wattage are u running usually? Man, this tempts me to comvert my cannondale road bike... But it's aluminum and the front fork is cf.
Click to expand...

I weigh 160lbs.

the unloaded speed of the motor is 24mph. I can easily attain that on the flats without assist. it pulls me on flats at about 21mph unassisted. On hills, I can sustain about 20 to 21mph with moderate assist from me.
 
neoplasticity said:
I still worry that maybe I should get a torquearm but so far everything seems to be good.
Click to expand...

If you do not have a torque arm, make sure to check your axle bolts often and tighten them when necessary. If they get loose, you will thrash your phase wires.
 
How do you find the noise of the motor when under heavy load (going up a steep hill)? I have a Cute 100 front motor, and find it too noisy. Thinking of replacing it (and using the original rim that came with the bike, because the kit I got has a rim problems. I bought the more powerful motor from Cell Man, but would like to hear about your front 350 before I place an order from him.
 
I don't notice the noise from the motor unless I'm listening for it. So it's audible but not loud by any means. I don't think any of the spandex guys I blow by up hills even know that I have a motor. They just think I'm a cycling phenom.
 
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