Trek 830 & cell_man 350w front geared kit

[SamTexas]

Almost 20 years old Trek 830
cell_man 26" 350W front geared kit
recycled laptop 18650 Li-Cobalt, 12s, 427wh

Performance:
With pedaling: 50 miles range, top speed 23mph, avg speed 17mph. 8.54wh/mile.
No pedaling: 32 miles range, top speed 21mph, avg speed 14mph. 13.34wh/mile.
Total weight: 47lbs bike + 135lbs rider.

Like:
Hub motor is very quiet. Never gets hot even in Texas summer. Very efficient.
Controller also never gets hot.
The big red button on the thumb throttle for cruise control.

Dislike:
The controller hisses and whines at low speed and under acceleration. This happens at 10s, 11s and 12s. So it's not voltage related.

Suggestions for improvement:
- The cruise control red button does not pop out when cruise control is cancelled via braking.
- Get rid of the useless 3 LED battery indicator and replace it with a simple volt meter.
- Provide a simple 1 or 2 page documentation indicating the function of the many connectors coming out of the controller.

Overall I'm very pleased with this kit.
Sam

 

[dnmun]

nice rig.

those little centech voltmeters are also used by the guys who run the electrathon buggies.

they have two voltmeters, one set to volts and the other measures the voltage across a big shunt for their current reading.

 

[SamTexas]

... and the other measures the voltage across a big shunt for their current reading.

I had one of those too when I was still learning about the motor efficiency. It's no longer needed now. The volt meter will also be removed soon.

 

[veloman]

I find it really odd that your motor doesn't get warm. I have the same one, but use the 14amp controller (rear wheel), and it definitely got quite warm when it was 105 and I didn't pedal up some low grades. (5 mile ride).

Nice efficiency, and clean build.

 

[SamTexas]

I find it really odd that your motor doesn't get warm.

You meant "doesn't get hot", right? Both the motor and controller got warm after a long ride, but not hot. I would say about 10F higher than body temperature.

Edit to add: I just remember. You bought your motor from Neptronix, correct? If memory serves me right, he bought the earlier 250W version. The 350W version came out about a month later, and that's what I got.

 

[neptronix]

That's funny.
I started out on a trek 930 of the same era with the cell_man geared kit too.

Ditch those tires ( if conditions allow ), get some thinner and non-knobby tires, and you will see an improvement in acceleration and efficiency on such a low level of power.

Decent first build. I give you 3 months tops before you catch the power bug and upgrade to a MAC. I lasted about 1 month myself. :lol:

 

[SamTexas]

I occasionally do off road riding so those fat knobby tires are a necessity.

3 months? I built the 2nd bike after 2 months, and secretly joined the 40mph club last week.

 

[veloman]

I find it really odd that your motor doesn't get warm.

You meant "doesn't get hot", right? Both the motor and controller got warm after a long ride, but not hot. I would say about 10F higher than body temperature.

Edit to add: I just remember. You bought your motor from Neptronix, correct? If memory serves me right, he bought the earlier 250W version. The 350W version came out about a month later, and that's what I got.

I would say my motor got to about 120-130 F. I could leave my hand on it, but any much hotter and it would start to hurt.

Temps over 90 really make a motor a lot hotter. Now that it's 70-85 most of the time, my motor stays much cooler (though I am running a Mac now, which never got as hot as the mxus geared).

 

[SamTexas]

Ok, that's definitely hotter than mine.

Just so no one gets confused: veloman thought his has the same kit as mine. He does not. He has the 250W geared kit from cell_man. I have the 350W front geared kit as stated in the thread tittle.