What power are you running?

[Marsbar]

I had to adjust the power today from 15A 750W to 10A 500W. The bicycle seemed to work better now, as I can pedal along better. Had a problem that my battery got discharged too fast, and the roads here are no good anyway going 40km/h... I also have to mention that I have changed rear gear cassette to a 7 gear one giving me fewer teeth in the smallest gear.

Also read that a top professional (doped?!) cyclist cannot output more than approx. 400W, and if I can output 150W I will have 650W.

Never thought I would trim a motor down... but it was needed. 500W seems perfect for me now, even going up steep hills.
I also hope the battery will last longer than before, as I now can paddle along... Should last 1 hour now using 10A 48V.

Now for my 2nd motor, or 2nd build if you like, I am wondering if the SmartPie in a 28" would do the trick for me, as I really don't need more power due to the fact I would like to avoid the police attention too much and also be more careful in traffic. Anybody has compared the two in daily use?

[Andrew]

Have you considered a geared motor rather than a direct drive. This will be much better for pedalling and freewheeling and if you get a motor with a slow turn i.e 201 or 260 rpm you will get much better initial acceleration and a more efficient motor and only a top speed of about 18 -20mph.

I am not suggesting you get the GM 250w motor as the rear motor freewheel thread have a reputation of sheering off under heavy pedalling, I have one here as proof.   But there are other manufacturers out there that will do 500w at 48v and will take a lot more wattage for short bursts.   I have a front GM mini gear motor which is ok, though I think the rpm is about 350, and if anything goes wrong with it such as stripped nylon cogs I don't think they will be easy to find replacements for.

I have no experience with the mini pie, but putting it into a 28" rim (my opinion) will not give you much 'omph' when launching or going up hills.

Obviously this is a Golden motor forum so I don't really want to go against the grain of the manufacturer,  but as stated above a slower/higher wound motor is what you need.

Andrew

[Marsbar]

Maybe I should stick to what I have for my 2nd bike and order the same motor.

Was DEFINITELY not going for a 250W motor as this is way to low for any fun 

The EU rules are not fair, because 250W in Denmark is not 250W in Norway due to heavy wind and steep hills!

I'm using Magic Pie now with built in controller. Torque and acceleration is superb compared to my old motor that was intended for 26" wheel.

[Andrew]

I have a mk2 pie running 2000w, a GM 250W running at 430w peak, and a bafang BPM 500w geared/freewheeling 216rpm motor running at 500w up to 1000w peak.   The bafang BPM is a cheapish motor that is 216rpm and only does 18mph but has lots of torque/acceleration, I even take it off roading for the low speed high torque capability. The BPM motor is small and disctrete motor and well worth considering as it is much smaller and mujch lighter than a pie.
http://www.greenbikekit.com/index.php/electric-motor/rear-bldc-1/bafang-bpm-48v-500w.html

of courrse you would need an external cxontroller for this..

worth considering.