This is just a new thread so it will help other people as the previous one was off topic 
Here is the older thread:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=103065&p=1508961#p1508961
So it turns out they told me I had the wrong controller!
I do not have a 14 amp controller but a 30 amp one
Why didn't I check? I had water proofed everything and sealed it. So I took it all off just now. Everything you have said did not tally up with the performance I was getting. However my performance was too good. It can go about 30mph and pull a lot.
I agree, a lighter geared motor would be better.
How can I figure that out? I have a turnigy watt meter. I know its a 15a/h dolphin 48V
Edit I have found out is 12ah not 15. Its was 36V @15, 48V @12
I have had no problems at all pulling so far but the motor is just so heavy and the cogging is terrible. Do you think I can just change the motor and keep the controller etc?
Here is the older thread:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=103065&p=1508961#p1508961
So it turns out they told me I had the wrong controller!
I do not have a 14 amp controller but a 30 amp one
motomech said:With your BIG wheels, you need to go w/ a low-speed range (201) motor and I would recommend a geared motor to get the best performance w/ your batt. pack.
I agree, a lighter geared motor would be better.
motomech said:Next, you need to see what the discharge rating of your pack is, which you cannot exceed.
How can I figure that out? I have a turnigy watt meter. I know its a 15a/h dolphin 48V
Edit I have found out is 12ah not 15. Its was 36V @15, 48V @12
motomech said:The Q128C will like a controller in the 25 to 30 Amp range and is said to produce good "torque" (really a misnomer), probably partly due to high compound gear ratio (like the Q100).
Next step up would be the "large" geared motors like the BPM, Mac, Ezee, etc. Controller rating that match well w/ these can range quite a bit, but figure 30 to 40 Amps."
I have had no problems at all pulling so far but the motor is just so heavy and the cogging is terrible. Do you think I can just change the motor and keep the controller etc?
ScooterMan101 said:I had a 12 fet controller on my Mac 6T conversion . up to 48 volts and 40 amps.
I would get a 12 fet or bigger controller when using a Mac or a DD rear hub from now on.
Right now I have a infineon Clone 36-72 volt 30 amp 9fet on my DD rear hub bike and I could really use a 12 fet 40 amp or more.
Same
On my latest conversion the GNG cyclone 3k It has a lyen 9 fet that I can use up to 72 volts on but only 30 amps , It has stalled twice now trying to go up very steep and long mountains around where I live.
For
the Mounatains around me I really need a 40-60 amp controller , but I must sell off some other parts first to pay for a new/different controller, so I can not report the performance gains until that happens off in the future .
Ltc433 said:I really don't like the cogging on the direct drive and the weight so I was thinking of a mac 8t with upgraded gears. The hauling is only occasional. Do I need an infineon 12 Fet controller? What do you use?
Ltc433 said:ScooterMan101 said:the Mounatains around me I really need a 40-60 amp controller ,
So is the amount of amps the amount of power you deliver to the motor and your controller isn't powerful enough right now? I am new to this and its helping me understand why there are so many variants. I also think I have worked out why I was having problems hauling. My controller is a 36V running at 48V 14amp on a 1000w motor. It is fine on smaller hills, pulling power but its heavy. My Q100C controller goes up to 17amps. My controller is KT36ZWS-XFCF01R.
motomech said:First thing, you can't think about electric motors like they are gas engines, so forget everything you know about ICE's.
In very simple terms, the motor, controller and batt. are a system and should be thought of as such.
The controller responses to the demand it "sees" from the motor, think electrical feedback.
The rating on the motor is a guideline to how much power in Watts (A X V = W) it can sustain. A crude "rule of thumb" is hub motors can do 1 1/2 to 2 times their rating in reasonable outside temps.
The controller rating equates to Max. Amps, a spike that occurs at or right after start and tapers off.
The single most important Rule of Elect. Motors is;
Never allow the climbing speed to fall below 1/2 the top speed. To use one ICE analogy, don't "lug" the motor, because around this point, the motor starts to produce more heat than locomotion.
So you are looking up a long steep hill and wondering; Is it better for me to have a high Amp controller, or one w/ a lower value?
Although it might seem counter intuitive, it's better to start out w/ the highest power your system will handle. Why? To maintain as much speed up the hill before reaching that dreaded "half speed". The "safety valve" is between your ears, knowing when to jump off and push.
Of course there are limits and a geared mini-motor, being the weakest sister, makes a good example. Mini-motors, when fed by controllers at and above 20 Amps start to experience "motor shocks" that can damage the gears. Sine wave controllers, w/ their sine wave form are "softer" in this regard than a square wave controller and in general more power can be fed w/ a sine wave. High performance square wave controllers like older Infineons and the "hot rod" Lynn's can really hammer a sm. geared motor.
The key to an efficient and non heat prone system is matching the components and expectations. In particular, whl. size, pack Voltage, MOTOR SPEED RANGE, and controller rating to achieve the desired reasonable top speed.
Ltc433 said:Thank you for a reasoned and logical explanation.
Now I understand why the 17A on my Q100C is fine. However on my DD 1000w a 14 amp controller may be too low perhaps? Its ok as I was thinking of replacing the whole system anyway as I only need occasional trailer pulling. Id much rather trade the 6kg weight of the DD for a 4kg mac or bafang hub motor. I'm just undecided on mac vs bafang etc. I think the Q100/Q128 wont be able to handle pulling a trailer at all. The mtb is a 29inch, using the same voltage 48V, i was hoping just to swap the motor out but at 14 amps the controller may not be powerful enough.
AngryBob said:Your DD motor is severely amp-starved. That is a 1000W motor, which will likely handle easily double that for fairly short periods, and you are only giving it a bit over 700W.
It is important to have some sort of INTERNAL temperature monitoring to avoid melting the motor, but you can safely feed that thing double the current amp load, again, for fairly short time periods. A few minutes, maybe even 10-20, but that leads back to the necessary temperature monitoring, and again, INTERNAL temp sensor.
That leads to oil or ATF fill, or Statorade, and/or external heat sinks.
motomech said:Ltc433 said:Thank you for a reasoned and logical explanation.
Now I understand why the 17A on my Q100C is fine. However on my DD 1000w a 14 amp controller may be too low perhaps? Its ok as I was thinking of replacing the whole system anyway as I only need occasional trailer pulling. Id much rather trade the 6kg weight of the DD for a 4kg mac or bafang hub motor. I'm just undecided on mac vs bafang etc. I think the Q100/Q128 wont be able to handle pulling a trailer at all. The mtb is a 29inch, using the same voltage 48V, i was hoping just to swap the motor out but at 14 amps the controller may not be powerful enough.
Yes, DD motors really start to sing when fed lot's of power.
Trailer pulling, like most things w/ hub motors, is all about the hills.
Your Q100C w/ it's "soft" controller, would have little problem pulling a trailer,....in the flat. Start adding hills to the mix and something will have to give.
With your BIG wheels, you need to go w/ a low-speed range (201) motor and I would recommend a geared motor to get the best performance w/ your batt. pack.
Next, you need to see what the discharge rating of your pack is, which you cannot exceed.
The Q128C will like a controller in the 25 to 30 Amp range and is said to produce good "torque" (really a misnomer), probably partly due to high compound gear ratio (like the Q100).
Next step up would be the "large" geared motors like the BPM, Mac, Ezee, etc. Controller rating that match well w/ these can range quite a bit, but figure 30 to 40 Amps.
Top speed for all these combos will be around 20 MPH, due to the low-speed range motor. If you were to use 26" wheels, you could go to a mid-speed range motor, add a couple MPH and climb almost as well.
If the Large geared motor on 40 Amps doesn't pull the trailer as well as you like, you will need the pick a less hilly route, because the next step up in power will require more Volts and an expodental increase in component costs.