Will this combination work?

[friendly1uk]

Hello Peeps. Great forum. It has helped me a lot. Nice to be here (it's my first post)

I think I have my plan about straight, So could anybody mark my work for me please

I'm looking at the bmsbattery site.

Q100 24v 328rpm rear kit, with 26" mtb rim and thumb throttle. ( I believe the 24v version is whats on the ebikes simulator)
36v 8Ah lithium ion battery.
Will they go together? This 24v kit and 36v battery.

I want a 15amp limit, and I'm unsure about the controller. It's the ku63 (with pas although I keep reading here the ku65 had that, not the 63). It's 250w rated, but 15A@36v is double that. I have looked at the ku93 with it's 450w rating, and 450w is just what I would like to give the 24v Q100 (although full throttle could burn it out in gradients that drop me below 15mph unassisted). Then I look at it's specs of 36/48 compatibility and 22 amp peak, tap my calculator some more, and don't see how that's 450w. It's over 1000w at 48v and at 36v 22amp is still more like 800w than 450.

I am an electrician with a reasonable electronics foundation, but these controllers are not making a lot of sense to me. I imagine the 22a is pulsed and the 450w is over time. The 22a being something like 13 amps if it were covering 100% duty. So the battery would only need a 13a constant rating and 22a peak. The simulator too would want me to call it a 13a controller, based on average currant rather than this 22a peak. Most of this true?



I'm probably complicating things to much for a simple purchase. So starting again...
What I have done is looked at the sim, choose the Q100 328 and told it my controller is 15 amps(0.06ohm seemed to align it with other controllers), and my battery 36v. This has produced the graph I would like. Top speed of 20+mph and I can add 5mph to that by peddling before the motor drops out completely. Sorted.

How do I now build that?
I think it's the 24v motor with 36v battery, but will the ku63 allow that? I seem to be reading it does, but I'm more drawn to the conclusion the ku93 is needed. (there often bought together according to the site) I just want 15 amps. Even 13 would be enough. That is way over 250w though.

 

[wesnewell]

Controllers will have up to 3 ratings. Voltage designed for. Max amps. And Wattage. Some don't give you anything but voltage. Voltage value is obvious to a point, but it meaningless in other ways. Basically it's telling you that the LVC is set a an sla battery pack of that voltage. A 24V controller will have an LVC of 19-21V. A 36v one will have lvc of 29-31V, and a 48v one of 40-42v. This in no wy is related to the voltage of the battery that it will support. Most 48V controllers have 63v caps thus limiting max battery voltage to 63V. If I had to guess what caps were in a 24V controller, I'd guess at least 50V caps, but I'd open it up and confirm it before putting 50V into it. The mosfets in controller usually will be of a higher rating than the caps but you can check that when you open it too. Max amp rating is obvious. It will pull a max of that amperage regardless of battery voltage. The watt rating is probably the most confusing. It isn't a max watt rating. It's the max watt rating for a continuous duty cycle. As an example I have a 48V 500W controller that has 30A max. With battery at 50V that's a max output wattage of 1500W (VA-W). It's rare to actually pull max amps except on start and steep hill climbing, but it can be done. And you can overheat the motor if you over do it.

 

[friendly1uk]

Thank you Wesnewell. That all sits quite well with me.
The ku63 appears to have no voltage rating. So it does not look after the battery's I guess. Not an issue with the lithium pack though, as the integrated bms takes care of that. It's only voltage issue is as you say, internal component related. Which I'm not even getting close to at 36v (I have seen then take 48)

I'm still puzzled by the wattage. Your controller is 30a but only suitable for 33% duty I'm reading. But will go beyond that duty for short periods.
In my case, 15amp@36v will lead to motor consumption around 450w according to the simulator. The ku63 wouldn't be enough. I would have to use the 450w ku93. However, it's 22amp (if that's correct) will lead to consumption over 450w a lot of the time. Step up to a 500w unit, and it's 30A rating makes it even worse. Besides which, I can't pass 15amp because of battery restrictions.

Should I get the 450w 22A controller and thin the shunts to reduce it to 15 amps? Then my 2kg battery is happy. My 2kg motors is happy. My 450w controller becomes happy.
Or, do I need to look at how thinning the shunts effects other aspects of the controller.

I feel I'm getting somewhere now
Thank You

 

[Wurly]

I think you want to forget power ratings and go by the max current for these controllers. That is battery current. All these controllers will current limit set by a resistor network including the shunt resistor. A ku63 will be fine and it does work with a pedelec sensor, faster you pedal the more power the motor will get. The only problem i see is that the rpm hub you are choosing might too much for your battery. 8ah isn't much and your controller will be supplying max current eg 15A for longer periods if you aren't pedalling hard or you get to an incline. To maintain 20mph will require alot of pedalling with a low power set up.
A ku93 will definately be too much power for your battery, but you can reduce the shunt resister value i have done that and have mine set at 17A for 48V 15ah ping battery 500WBPM. The maximum power is around 850W, which for me, is plenty.

 

[d8veh]

Unfortunately, there's flaws in you plan.
You can't use the 328rpm 24v Q100 at 36v in a 26" wheel. It'll try and spin too fast and be hopelessly inefficient if it doesn't burn out first. The Q100 has enough power to sustain 20 to 22mph depending on your weight, so about 25mph would be a good no load speed target.
The 24v 201 rpm one is the one you want because it has a no-load speed of about 24mph at 36v.

You need about 18 amps to get the best out of it. They can't take the 22 amps that the KU93 gives, so best is to use a 15 amp controller and solder the shunt to increase it to 18 amps. The one you want is the KU65 because it has three levels of pedal assist. Th KU63 has one, which is maximum. Make sure that it gets plenty of air flow because it'll get warm/hot

I guess you're looking at the 8aH bottle battery. Unfortunately it struggles at 15amps, so you need something more powerful for 18 amps. The 10.4 aH one would be better if it fits. Don''t forget that you need room to lift the top end of the battery out of its holder and space is very tight in the top corner of the triangle. A 12 or 15aH battery would be better for 18 amps

You won't be able to add anything to the top speed by pedalling. The motor power drops right of as you get past its top speed, and unless you're an Olympic cyclist, you won't be able to pedal a bike past 22mph on your own.

To summarise:
24v 201 rpm Q100 kit with LED display.
Ideally 12aH or more 36v battery.
Additional KU65 36v controller (maybe they'll swap the 24v one if you ask)
2 hidden wire brake sensors if you have cable brakes
Pair of torque arms (only need to fit one)

 

[mlt34]

d8veh has the right plan outlined for you there, follow his advice. Your plan of over-volting the 328 rpm 24V motor to 36V in a 26" wheel would mean the motor would be attempting to spin approx 38 mph. Obviously, this would be impossible due to the power restrictions and would result in a seriously inefficient setup.

Additionally, that 36V 8.8ah battery is going to have some serious voltage sag. I have a couple, I've seen it. The 10AH version will be slightly better, but the bottle batteries simply aren't great batteries. Stick with at least a 10AH lithium-ion or lifepo4, though 12AH is better.

The KU63s and KU65s are great little controllers. They max out at about 18A, which should be plenty for the 201 RPM Q100 motor.

I have some that I'm going to be adding a Cycle Analyst connector to shortly, if you're interested in that.

Are you using a steel or aluminum frame? If it's steel, you won't need the torque arms, there simply won't be enough power in your system to matter for a steel frame. If you're working with aluminum then it's questionable at most on whether you'd need the torque arms, but at that point they can't hurt.

The kit comes with e-brake levers so you don't need the hidden wire brake sensor unless you're just in love with your stock brake levers (or you hydraulic brakes which I'm doubting).

So yea, in summary: Get the 24V 201 RPM motor with display, over-volt it to 36V, I wouldn't recommend soldering the shunt because you can be asking for trouble, and the stock 15-ish amps should be plenty for you, and pair it with a decent battery. Their 36V lifepo4 headway cells packs would be a good option.

 

[mlt34]

Oh yea, and while you're on their site, pick up an extra throttle, PAS sensor, etc. They're only a couple bucks, but if you ever had to replace it, you'd be paying the $2.00 plus another $50 for shipping.

 

[friendly1uk]

Fast moving forum!

I don't think I can ignore the wattage ratings. The ku93 does not actually give a current value(over there). The ku63 does though, it is 12amps, which I can increase. Trying to pull twice it's rated power does not seem wise though. I'm fairly set on the ku93 derated. If them fets fail closed, I could need another motor too. They won't charge me any more, if I choose a different controller in the kit they said. The only gain from the ku63 that I can see, is that nice little frame mounted box it goes in. The ku63 can pass 12amps(they say) but not at the duty cycle I'm demanding I don't think, the maths don't seem to support it. Examples do exist though don't they. I guess if it can do it for a moment, It can do it all day. It just needs to keep cool.
It's interesting that to achieve 20mph you think I would have to pedal. It's meant to do 22mph with no assistance from me. That's at 15amp, from the 15 amp continuous battery. I do intend to pedal though, not scoot around. Below 15mph I will (would?) have to back off, if the prediction is right.


I couldn't see a bottle battery that was suitable. There 10 amp continuous. I'm looking at the 2kg lithium ion pack. 15amp continuous and fits the frame with bags of space. I would like to show it to you all, but there site won't let me link to it and they don't use product numbers. It's as if they don't like people advertising there stuff.

What Q100 328 is on the simulator? It appears correct at 24v and with 36v it over performs. I'm quite sure it's the 24v version. I have used the simulator and see a no load speed of 29mph@36v. I'm very surprised the 201 would achieve 24mph. Is it not the same unit with a different gear ratio?

I can't come to 18 amps. My battery choice won't have it. One that will weighs double and costs double. It's not worth it for 3 more amps.

Phew, quite a bit to address there. I will pop back. I'm not feeling great right now(2am..bad day)
Edit: Popped back and tidied up.


Is the 201 on the sim under another name?

 

[Wurly]

I think your assumptions over wattage is correct, whether you use a soldered up Ku63(65) or a modded Ku93, you will probably be pulling around 12-15 amp continuously, the ku93 will be able to cope better. Mine gets only slightly warm on some hills but i would expect a Ku63 to be ok but run hotter and probably go pop before the ku93, but who knows? mount them so they get airflow and i doubt you'll get any problems. I stated my max power was around 850W but avaerage is 400w maintaining 20mph with a bit of pedalling.
Do you intend to use a pedelec sensor?
I still think you need more battery capacity, it could be false economy to get the 8ah. How long would it last i wonder?
I don't know the hub you intend using but i would take note of d8veh comments, good advice as usual.

 

[d8veh]

I don't want to seem big-headed, but I've built several bikes with every version of the Q100 motor. A also have several other bikes that I've built with every version of the KU series of controllers, so I know them fairly well.

The KU63/65 take 15 amps from the battery and can be pushed to 22 amps if you solder the whole shunt
The Ku93 takes 22 amps
The KU123 takes 30 - 32 amps

When you use a wattmeter or ameter, it measures the current from the battery, so that's the parameter that I'm using.

If you want to sustain 20mph without pedalling, you need the 201 rpm 36v 500w Bafang BPM motor and 48v 15aH battery or 500w Bafang CST motors with 36v 20aH. The Q100 is tiny and although it'll get you up to 22 mph on the flat, it'll soon slow down and need some help on any sort of incline. You have a better chance if you weigh 50kg or less.

As far as I can see, the simulator's incorrect. I believe that those plots are for the 201 rpm motor. The no load speed shown at 24 v is 19mph, when it should be about 27mph. Edit: Figured it. It's the 36v 328rpm one.

It's always better if you state your weight, the type of terrain you'll be travelling on (hills), how far you want to go, how hard you want to pedal and your budget, then people can advise you on what options you have.

 

[mlt34]

Also, it sounds like you are limiting your battery options pretty hard based on the vendor's specs. You should know that you have some wiggle room there. Just because the vendor says the battery is rated for 20A max doesn't mean that if you connect a KU93 and it pulls 22A that the battery will go pop (or fizzle or let out its magic smoke or whatever). You have a little room to play there. Of course, a battery stated at max 20A shouldn't be left to pull 22A all day, but it's not like you're going to destroy by going over the vendor stated limit for short periods during acceleration or short hill climbs. Though that's why it is always good to use a CA or watt meter so you can see your battery usage in real time and adjust your driving when you see that you might be stressing your battery more than you intend to.

 

[friendly1uk]

As far as I can see, the simulator's incorrect. I believe that those plots are for the 201 rpm motor. The no load speed shown at 24 v is 19mph, when it should be about 27mph

It's not looking right to me either. I'm picking the 328, putting in 36v, and getting 328 from it(unloaded). That's a 36v 328 motor, not a 24v 328 motor. Would that explain 24v achieving 19 not 27? Making it a 36v 328 there plotting with. They do say 328 but leave me guessing the voltage.

This is a very poor start for me.



Busy day. I will be back

Thank You

 

[motomech]

If you want to sustain 20mph without pedalling, you need the 201 rpm 36v 500w Bafang BPM motor and 48v 15aH battery or 500w Bafang CST motors with 36v 20aH. The Q100 is tiny and although it'll get you up to 22 mph on the flat, it'll soon slow down and need some help on any sort of incline. You have a better chance if you weigh 50kg or less.

As you know, I run my Cutes on 12S, not 36V. so I'm thinking that the 36V "201" Q100 on 12S(or 48V) and shunt modd'ed to 17A could do 22 mph and still climb fairly well. Like you said the lighter the rider the better. But that is the on ly Cute I would use in a 26" or larger wheel.

As far as I can see, the simulator's incorrect. I believe that those plots are for the 201 rpm motor. The no load speed shown at 24 v is 19mph, when it should be about 27mph.

I too realized something was wrong with the Q100 sim. and added this to the GHeared Motor's sticky back on Mar. 10th.
"The "328" Cute has recently been added and I have been comparing the sim. results with those I obtain in the rear world and I think some "rectifying" is in order. As it stands now, the sim. results seem to me to be more in the order of what would expect with the larger 4 to 5 Kg. geared motors.
What I have found is, to get accurate "real world" results, one needs to reduce the "Amps" setting when setting up the custom controller.
For example, the stock KU63 controller will realize around 14 amp nominal readings. For the sim., try 11 to12 amps instead.
For a shunt-modified KU63 which, if done right, will be around 17A. Instead, insert 13-14A.
I understand that the controller ratings generally don't effect top speed, but these little motors are "power limited" on top speed, rather than "RPM limited", as the majority of hub motors are."

The sim. acts like the 328 Cute has the power to pull rpm limits with the stock controller values, which, of course, we know that it won't.

 

[d8veh]

I think we have enough real-world experience not to need the simulator.
The 328 rpm Q100s seem to be a bit more temperamental than the 201 rpm ones. Myself and others have experienced start-up problems, so it's probably best to use a 201 rpm one.

Like Motomech says, the best performance comes with 17 amps and 12S lipos. You get 20-22mph and good (for a small motor) climbing ability. You need to do your homework if you want to use lipos. It's a shame you can't get plug-and-play batteries at that voltage

The next best choice, to me, would be the 24v 201 rpm version at 36v, which is what I have in my 20" folder, except I have two batteries, one of which is 12S lipos.

 

[friendly1uk]

d8veh your separating the 24v 201 from the 36v 328 as different motors, Is that right? Only some time ago, just before you intended to open a 36/328, you were saying there the same. Based on freewheel speed tests that someone else reported. Not your own work.

If you now feel the simulator is using the 36v 328, do you also feel there projections are correct? Like motomech I also had to fudge the spec's, but increased resistance from 0.03 to 0.06 rather than dropping currant. I'm not sure what the controller resistance is though tbh. I have decided to try the 250w controller though, as I now know the controller wattage is more of a guide to motor choice, Not actual ohms law calculations. I might be running a higher voltage, but that just means it will be switched off sooner. Over time the wattage remains the same. It's having a fan if I use that nice little frame mounted pod though. Any power increase will come from altering the circuit properly, not soldering, but I probably won't bother.


I tried a cyclomatic 26". 24v and looking like an 8fun. The 250w 8fun graph does not go past 25nm along the bottom axis. This provided plenty of acceleration. It was 7 speed, and I pulled off in the fastest. As soon as the motor clicked in it was away far to quick. It left me nothing to do. I didn't pass 10mph round the bike shop carpark but it had pleanty of poke at these speeds. This is why I was happy with the original simulation graph. It appeared I can have the same sort of acceleration by turning the power down at low speeds to stop burning and let me pedal. Then over 15mph go for full power. Perhaps a programmable controller could do even better, but I'm not spending much on my effort. It is really just a benchmark. That is why the £100 36v8ah battery is so appealing, with it's 15amp constant rating. This simulator driven combination would be sat at 15 amp a lot. I liked the fact the power and efficiency don't drop off rapidly, as it gives me chance to assist. I can do that speed for short durations. Averaging perhaps 18mph on a normal road bike. I tried to enter my weight on the sim, but it starts at 100kg and me+bike won't be that much.


Are there any spec sheets for these Q100 motors? I settled on the sim being a 36v328 as it appears it's doing 328rpm. Everything I read has a contradiction though, and I'm reading elsewhere the 201 36v is actually 230rpm while the 328 36v is 270rpm. That would make them very close, making me happy, but without spec sheets it is hard to tell what the truth is. Just knowing the reduction gear ratio's would help clarify that. Really I would like to see the actual specs and make an informed decision. This following blindly approach is not really me. Not without an actual example at least.


Thank you all for your continued help

 

[motomech]

d8veh your separating the 24v 201 from the 36v 328 as different motors, Is that right? Only some time ago, just before you intended to open a 36/328, you were saying there the same. Based on freewheel speed tests that someone else reported. Not your own work.

They are different and D8veh did take the 36V version apart.

Are there any spec sheets for these Q100 motors? I settled on the sim being a 36v328 as it appears it's doing 328rpm. Everything I read has a contradiction though, and I'm reading elsewhere the 201 36v is actually 230rpm while the 328 36v is 270rpm. That would make them very close, making me happy, but without spec sheets it is hard to tell what the truth is. Just knowing the reduction gear ratio's would help clarify that. Really I would like to see the actual specs and make an informed decision. This following blindly approach is not really me. Not without an actual example at least.

The data and graphs that come from the Chinese don't make any sense.
I came up with those no-load speeds(@36V) after weeks of reading, both here and at Pedalecs UK.
Then I purchased one of each wind and tested them myself.
If you don't believe that I got the number correct, then I suggest you start reading.
Go back a couple years and focus on usernames like mkeefer, cell-man, lynchy, russell and others that I can't remember at the moment.
Or get out your wallet and buy one of each and test them yourself.

...but without spec sheets it is hard to tell what the truth is.

Even if the number are not perfectly accurate, they are true. True because to the best of my ability, at the time I posted them, I believed them to be accurate..

 

[lbz5mc12]

Are you going to be using their 36V 8A water bottle battery? I just installed their 36V 10.4A water bottle battery on my roommate's bike with a 24V 450W Currie kit with a 36V 30Ah Currie controller which limits the current draw so as not to burn up the motor and his bike now has a top speed of 30+ but we're not sure of the range. In my experience, so far, most of the motors seem to be able to handle one more step up in voltage as long as you use the correct voltage controller which also has lower Amps. So a 24V motor would be fine at 36V as long as you use a 36V controller that has below 15Amps. Right now I'm using an e-bikekit rear DD hub motor at both 36 and 48V. I just switch back and forth between my packs based on the terrain. Both my batteries are bms batteries. I believe that the e-bikekit controller doesn't have an LVC so I rely on the BMS's in the packs to protect them from overdraw.

 

[friendly1uk]

Thanks motomech.

You make some good posts. One of yours was the best roundup by far.

No-load motor speed A@ 36V with a 26" rim

Q100 36V "201" = 230 rpm
Q100 36V "328" = 273 rpm
Q100 25V "201" = 290 rpm

Anything wrong with this list?

looks like the 24V slow wind Q100 @ 48V in a 26" wheel would be a nice fast wind mini-motor for those without severe hills to climb.

Every crucial detail. I just wish your twin motor project rolled on 26's, then it would be everything I wanted to know, All in one place

work... I will be back

 

[friendly1uk]

These Zippy 8ah battery's from hobbyking are interestingly priced.
2s1p 30c £19.53 (£23.52 delivered) = £9.77(£11.76) per cell
4s1p 30c £37.14(£41.13) = £9.29 (£10.28) per cell
5s1p 30c £49.82(£53.81) = £9.96 (£10.76) per cell
6s1p 30c £71.72 (£75.71) = £11.95 (£12.62) per cell

So a 12s 30c is £123.39 in sets of 4, or £151.42 in sets of 6.

These are actually in the UK where I need them.

I guess each pack would need it's own bms and charger. So a rewire would be in order to make a single pack perhaps.

This is quite interesting, but I'm not sure it compares with the bmsbattery offering.

36V8Ah Li-Ion NiCoMn shrink tube electric bicycle battery pack. Included 10S4P 18650 2.0Ah polymer cells, 1pcs 15A continuous discharge current smart BMS, 1pcs 36V2.5Amps EMC-120 Lithium Ion battery Alloy shell charger.

£93 including bms&charger but unknown postage costs. Similar weight per unit of capacity.


I have gone and lost an important post. Who was it that seemed to of split from bmsbattery? The post said there kit was about £130 delivered, but bms bump there £100 kit to about £160 with ridiculous postage costs.
Edit: Green Bike Kit perhaps

Does anyone have the specs for the Q100 ? I need gear ratio's at least. I know I have been told they don't makes sense, but who would listen to that? If someone is looking at something saying they don't understand it, all you want to do is take it off them and see for yourself isn't it. Whatever it is.
I have chinese factory and design contacts based around the gear industry. They could well have a hand in the design of these motors, and certainly speak chinese and would understand anything that we might find oddly represented if it's just different ways of doing things.

Perhaps I should get some of the better pics here, then count the teeth.


To me, designing is a science. Predictions can be wrong, and I can live with that. Just copying blindly offers me no joy.


I have been trying to rationalise the difference between a 36v 273 and a 36v 230. It is a 19% shift. The 238 is 19% faster, with 19% less torque.
Then I look at the difference between 24 and 26" wheels. 7.5% difference.
A 273 in a 24 is about 12% faster than a 230 in a 28.

Let me see if I can prove that
24x273=6552
26x230=5980
5980x1.12=6698 Which is damn close when you concidder I kept rounding figure's.

Motomech found the 328 in a 24 a little lacking in torque when it came to the 11%(1 in 10ish) test hill. A 230 in a 26 would have 12% more. This was done with 12s (44v) around 15amp.

So, just copying I have some benchmarks forming. It is not really how I want to go on though. I like actual science.

 

[dnmun]

you should just use a 36V controller and not try to spoof the 24V controller. you cannot assume that the 24V controller will handle 45V from your 36v lifepo4.

it may handle the 41.2V of the limn2o4 10S packs they sell as 36V though but until you open the controller and look you cannot assume anything about it.

i would not use the bottle batteries. just buy a regular 36V lifepo4 pack. 15Ah at least.

 

[wesnewell]

If you want the best bang for buck in HK lipo, the 5000mah 4s hardcase packs for ~23 each is the best you can do. ~$275 for my 24s 2p 888wh pack.

 

[d8veh]

Something''s going on at Greenbike kit. They've got a new website with hardly anything on it. I'd stay clear for a bit until it settles down. BMSBattery have exactly the same stuff, but more batteries. Always check the shipping costs: They're often relatively high.

We don't usually use a BMS with lipos. Instead the charger manages the charging and we use voltmeters, Cycle Analysts, watt-meters, lipo alarms etc. to limit discharge. You also need to factor in the cost of the charger, it's power supply, leads and connectors, and discharge monitoring stuff to get the total price.

The Cyclamatic goes a lot faster and climbs better with a 36v battery, which can slot straight in with no modification, although a better solution would be to add a 36v rack battery; empty the original battery case; insert a better controller with several levels of PAS (like the Conhismotor ones); change the gearing, which is too low for higher speed (11T DNP free-wheel or 53T chainwheel).

I did indeed dismantle the 36v 328 rpm motor, and it looked the same as the 201 rpm one. The 24v one was different in that it didn't have the two stage gears inside.

The Simulator for the 36v 328 rpm Q100 looks close enough to me, but if you need more accuracy, you can trust Motomech's results.

Be careful about speeds that people quote. Some mean no-load speed, which will be a lot different to a 100kg rider going up a slight incline. On a normal road without significant inclines, a 250w motor with 15A controller will go between 12mph and 20mph without pedalling depending on the incline - assuming that it has a no-load speed higher than 24 mph. On steep hills, you'll be down to 8mph or less and pedalling hard. A 36v 500w one at 30 amps will do 18 to 24mph in similar circumstances.

If you want to get extra speed by pedalling over 20mph, then a crank-drive will be a better solution because speed isn't limited by the motor, i.e. you can pedal at 20 mph and still get full power from the motor to add to your pedalling. If you look on Pedelecs UK forum later this week, I'll be posting a review of the Woosh Sirocco chain-drive bike with the new TCM motor that we think could make a good candidate for converting a bike if we can get the motor on its own,which should be possible.

 

[friendly1uk]

Thank you chaps. Helpful as ever
You know what I'm going to do now don't you. 12c 5Ah for £60 lol. Nice one! I will have a second pack at some point, but as I'm only teething, One will do for some local runs. It's a pedal bike, I don't need battery all the time. Just how often remains to be seen. I really would like a bms of some sort though, It fits my needs for simplicity, as this bike will get loaned to friends occasionally. I will have a look about at some of the battery construction threads, I know there out there.

I nearly handed over the money when I viewed the cyclomatic. He assured me I couldn't fit a 11t in the back as there was no room. Puzzled I questioned swapping the entire set or a single gear, and he assured me there was no room for changes. Looking at the crank he said it was a 44 and I couldn't fit bigger. I then felt unsure he understood, lent it on the wall, and left. He actually lost interest in me when I said I wouldn't impulse buy, but would come back. I knew something was wrong. Turned out this used bike for £600 was a total skank, they are £500 new and delivered. He knew nothing about 'over volting' as I called it. The long eaton electric bike shop (nottm derby boarder) is a no go area imo, but you see a lot of his kit locally.


With this new battery possibility, I can think about another motor i guess. Making all my work to date pointless.

If you want to sustain 20mph without pedalling, you need the 201 rpm 36v 500w Bafang BPM motor and 48v 15aH battery or 500w Bafang CST motors with 36v 20aH.

I have a 7 speed cassette on the back, with the 13t being removable. I thought I had read elsewhere that these motors were the same though. I'm not sure if there padal as well too. Be back in another week lol

Edit: I'm looking forward to the crank drive thread

 

[friendly1uk]

Looking again at the battery, I might go with the 8Ah 10 cell one with the built in bms still. The price is about the same, I just wont get it in a frog box in it's currant shape. However it is no bigger than a race number flag that one might put within the frame. A better location for the weight anyway. So that bms is keeping me at 15amps which is the real drawback. But it's 2kg weight, and tidy controller box solution is appealing. So I'm still looking at the Q100, But which.

I still think the 270rpm one looks like a fair candidate, as does the 230rpm one, both in 36v form.
The 270rpm one will get hot due to high gearing. Some have said it's free wheel speed is to high at 38mph, but I think its 23.5mph and the sim has it under 30mph. 23.5mph was reached by the 26" wheel x 3.14 for circumference, making on revolution cover 81.64" which is 2.0737 meters. If that laps 273 times a min, or 16380 times an hour, that's 33.967kmh or 21.2mph. Which gets lower every time I work it out, I must be wearing out my calculator lol. What am I missing?
I have also heard

Get the 24V 201 RPM motor with display, over-volt it to 36V,

But I'm guessing the 24v 201 has higher gearing than a 36v 328, It has a higher rpm at 36v, So I'm puzzled by the recommendation. Is my choice not:
230rpm from the 36v 201 = 17.85mph
273rpm from the 36v 328 = 21.2mph
290rpm from the 24v 201 = 22.5mph
340rpm from the 24v 238 = 26.4mph <<<<<<<<<< This is just scaled. Based on the speed increase the 24v 201 got from the extra voltage.

Why are my speed estimates off?

Edit: I just rolled a 26" wheel and tyre combination along the floor. It fell short by 3cm. My speed calculations are a little bit high for my worn tyre.

 

[friendly1uk]

I have lost my way lol
With my increased knowledge (thanks lads) I need a recap.
I started at the 328 24v. The least torque available. Using excess voltage to achieve higher speed. This is perhaps the weakest option I could find, but it's long gearing makes pedaling worthwhile.
d8veh recommends the 24v 201. Both 24v versions must work. This is the one with more torque, less speed.
motomech has used the slightly more torquey again (is that a holiday destination) 36v 328 and found it lacking on a 1 in 9 hill, and he has a slight advantage from his 24" wheels. I'm not actually sure I need to get up a hill that steep very often.
The 201 36v motor offers the best climbing. I'm not sure I need that much. It's trimming down the top speed to almost legal standards.

All this is somewhat pie in the sky though. I'm presuming these motors are the same, using different gear ratio's. They could have different pole spacing to account for the slower currant rise you see on lower voltages. We have seen them come in different widths under the same Q100 heading, so why not... But with no drawings available I can't pin it down. I will just have to do as I'm told and find some middle ground. That is as scientific as I can get.

I thank you all for your help. If you see any Q100 at all in a 26" wheel I'm still looking. I have not found one yet, and it would be a great benchmark.
The simulator gives readings nothing like the rpm data above. Non of them. It is free wheeling at 29mph. I wish I could see some actual results, as I just have motomech's in a 24 with no comparisons.

Thanks again
Richard