hi all

[OldBob1]

Hi I fitted a 36v 10 A/H battery and controller to a 20 inch wheeled folder with a 200 - 250 W ? rear mounted brushed motor.
I had to increase the chain ring to 54 t so I could keep up with it at 15 MPH, but if I give it its neck it will do 25 MPH, and range at 15 MPH at lease 50 miles.

Great to ride now with Oxford bars and sprung saddle post.

Bob

 

[sil4ps]

Hi I fitted a 36v 10 A/H battery and controller to a 20 inch wheeled folder with a 200 - 250 W ? rear mounted brushed motor.
I had to increase the chain ring to 54 t so I could keep up with it at 15 MPH, but if I give it its neck it will do 25 MPH, and range at 15 MPH at lease 50 miles.

Great to ride now with Oxford bars and sprung saddle post.

Bob

Hi old bob, old mal here.

when you say give it it's neck it will do 25mph, what do you mean exactly, as I was thinking of getting a much heavier more powerful motor to do that sort of speed. say 500w or 1000W.

Also if i get a 250 watt motor and up the battery and controller does that mean the motor will burn out quicker. I need to do 15 miles round trip with a couple of serious hills and a long steady incline some of the way.

thanks for your input.

regards

 

[GT3]

hi, thanks for all the info.

What sort of speed do you get from the 250W Q100 and what range, Also how heavy are you and lastly should i worry about being waterproof, there is one seller on ebay who specifically lists waterproof kits 250W up to 1500Watt alongside non waterproof.

many thanks.

Range is around 35 miles, I don't have much reserve for my journey. I don't bother with the complication of speedometers any more, but would guess I never fall beneath 14 or 15 on the steepest hills and it assists up to around 20 on the flat. I'd like to see a 14 on the scales but sadly see mid 15 stone.

I've never had a water induced failure and I ride in all weathers. The problem of mounting a 20Ah battery with associated frequent carrier and spoke failures outweighs the failures of the ebike components themselves, many times.

I will exceed 500 commutes before the year end and that will be 16K miles, although as I only count the work and back distance, I will have covered a fair few more.

 

[sil4ps]

Range is around 35 miles, I don't have much reserve for my journey. I don't bother with the complication of speedometers any more, but would guess I never fall beneath 14 or 15 on the steepest hills and it assists up to around 20 on the flat. I'd like to see a 14 on the scales but sadly see mid 15 stone.

I've never had a water induced failure and I ride in all weathers. The problem of mounting a 20Ah battery with associated frequent carrier and spoke failures outweighs the failures of the ebike components themselves, many times.

I will exceed 500 commutes before the year end and that will be 16K miles, although as I only count the work and back distance, I will have covered a fair few more.

thanks for that, all very helpful,
So presumably the 250W Q100 is not limited to the uk 15.5.mph, just put a higher spec battery on and it will go faster??? have i got that right?

thanks

 

[KirstinS]

thanks for that, all very helpful,
So presumably the 250W Q100 is not limited to the uk 15.5.mph, just put a higher spec battery on and it will go faster??? have i got that right?

thanks

Yes, within limits though.

You want more amps for more torque (better hill climbing)
You want more volts for faster motor rotation (increased speed)

Volt level is dictated the battery (eg 36v, 44.4v or 48v)
Amps is dictated by controller ( usual range is generally between 14a going up to 30a)

Amp x volts = watts

This is important as I believe the q100 is rated 250/350 watt. There is a limit to the watts you can pump through it before it just burns up

There is a member who has a q100 that he runs at 60v but he also has reduced the amps to 11a so that is 60 x 11 = 700w. He can go very fast but the hill climbing ability is much reduced –it’s a trade off. He also has a configurable controller so he can play with the amps/volts ratio with blowing it up. The controller can also have speed militer contained within it. Just need to get one that you can disable eg BMS battery KU65

I hope this helps – suspect it hasn’t though !!

 

[GT3]

Speed is determined by the motor speed (328 in my case) and the wheel circumference.

Questions of battery spec are too technical for me, but providing the wheel size and motor speed match up, the available batteries are fine. You are possible asking about 'overvolting' but that is a subject for others.

What I can say is that the concept of 'going faster' depends entirely upon the effort you put in. If you don't wish to contribute, then you do need bigger motors, but that's never been my desire and if you are a fit cyclist already, I doubt you will either.

 

[sil4ps]

Speed is determined by the motor speed (328 in my case) and the wheel circumference.

Questions of battery spec are too technical for me, but providing the wheel size and motor speed match up, the available batteries are fine. You are possible asking about 'overvolting' but that is a subject for others.

What I can say is that the concept of 'going faster' depends entirely upon the effort you put in. If you don't wish to contribute, then you do need bigger motors, but that's never been my desire and if you are a fit cyclist already, I doubt you will either.

At first i was amazed at the claims of 45 +km / hour twin 1000W motors 3000W motors, I have a motorcycle but find taxing/mot / service/ petrol/ insurance for the little i use it becoming more of a hassle.

I love cycling and used to do the journey regularly but age, kids, weather and HILLS have worn me down. I now don't do it and it bothers me.

So after all the research and help from everyone I think a smaller motor with a battery that can sustain 20mph for 15 miles each way but can charge at work no probs and pedaling with my help to get me up some big hills will be great.

So do i go for a 250-350W with 36v15ah battery or a 500W with a 48W 20ah battery

Also i'm tempted with front wheel motor as i like the ease of installing and removing but happy to go for rear if the general concensus is that it's better.

I don't want something that will become tedious after the initial excitement but i don't want something impractical unreliable and ultimately dangerous on the road.

Again thanks for all the input and help.

 

[OldBob1]

On the flat with motor only it will get to 25 MPH, I find now that I seem to do more pedling and feed the power in when needed.

Bob.

Hi old bob, old mal here.

when you say give it it's neck it will do 25mph, what do you mean exactly, as I was thinking of getting a much heavier more powerful motor to do that sort of speed. say 500w or 1000W.

Also if i get a 250 watt motor and up the battery and controller does that mean the motor will burn out quicker. I need to do 15 miles round trip with a couple of serious hills and a long steady incline some of the way.

thanks for your input.

regards

 

[sil4ps]

The C rating is the amount of current that it can give compared to its capacity. A 10aH 1C can give 10 amps, a 2C 20 amps, a 15aH 3C 44 amps, etc.

There's a lot of things you have to balance when making decisions about kits. Weight and hills determine the torque you need. Your max speed is determined by the motor RPM and battery voltage. The controller has to give the current you need for the torque. The motor has to be able to handle the current. The battery has to be able to provide the current. It's capacity affects how far you can go. The bigger your motor and battery, the more power and speed you get, but the heavier it is, the harder to install, and the more cumbersome becomes your bike. High C-rated batteries can be smaller and lighter, but you don't go so far.

For me, the best balance of all these things comes from a 500w 270rpm 36v geared rear hub-motor with 20aH 36v battery and a 25 -30 amp (depending on weight) controller. You will be able to pedal comfortably on the flat at about 22mph, manage serious hills without much effort, and reach a distance of 50 to 70 miles. That's my personal preference. I've tried lots of motors with different speeds and powers. I have double and triple motored bikes. I like them all, but you can't beat the simplicity and robustness of a simple rear hub-motor.

When you go faster than that, the experience is not so much like cycling, and it would be more dangerous on cycle paths etc. Your bike would be heavier and less manageable. At first, it seems like fun, but soon becomes tedious. A motorcycle then becomes more attractive, especially when you also consider the cost.

Hi D8veh,

on your advice i'm going for the cst500W rear 270 rpm keeping my 9 speed cassette

with the following

S12S 500Watts Torque Simulation Sine Wave Controller for 36Volts
36V15Ah Li-Ion NiCoMn aluminium alloy sheel electric bicycle battery pack + rack (15 miles each way)
Brake Grip for electric bicycle
Half Twist Throttle with LED Voltage Level Display

is this all i need or have i missed anything. I've emailed bms for info but i get one line answers that don't make sense or no reply at all.

many thanks.