Just bought a used Woosh Fat Boy

[WheezyRider]

wheezy, you misunderstand my position.
When you optimise, you consider compromises.
That's why I asked you to select your motor winding for your 52V or 59V battery.
Vfr400 posted the motor winding table for us to use. I use of course the same table because I buy the motors from Bafang themselves.
Choose your motor winding then explain why you choose that one instead of a higher or lower code.
Alternatively, imagine you shop for a 36V kit. The OP's Fat Boy has Bafang G06 code 13.
Which motor winding would you like? Would you like me to supply you with another code?
The argument is the same, if you optimise for one voltage say 36V, it's not going to be as good using a battery higher or lower voltage, 24V or 48V.

The point of the exercise of over volting is to get more real world utility out of existing kit.

"Optimisation" all depends on the manufacturer, which from my experience, the parameters that are optimised are often not ideal for many real world situations.

Please have another look at the simulation. I have taken the same motor and done a side by side comparison, with 36V 20A and 59V 15A setups. The 36V system can't maintain 25kph on a slope, whereas the 59V system can.

Ok, let's go to a 25A 36V system as you suggest:

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

www.ebikes.ca

It doesn't help, still stuck at less than 20kph on an incline.

If I've overlooked something on the simulation please let me know, I'd really like to see if this is wrong.

In terms of financial cost, if someone can keep all their original kit and just change their battery, that is a major win. With your controllers, it may not be possible to over volt, I've never had one to play with, but with all the other 36V controllers I've had, they have operated at 60V without modification or even up to 72V (with cap upgrade) without issues.

For me, with my limited budget, I would find it hard to justify spending getting on for £600 on a kit. That's more than my bike is worth. My Bafang kit cost £170 and then I spent another £165 on the original 36V battery. Since then I have been making my own packs at a much lower cost to suit the voltage I want.

My second bike cost £117 for the Voilamart 250W kit and I bought another 36V pack initially, but I also use my own packs with that now. This kit only has 15Nm torque, so it really benefits from over volting.

So I have two e-bikes for not much more than the cost of one Woosh kit and if I want to try over volting and having a better riding experience I can do that and know it's not the end of the world if something goes wrong.

 

[Gavin]

So I have two e-bikes for not much more than the cost of one Woosh kit and if I want to try over volting and having a better riding experience I can do that and know it's not the end of the world if something goes wrong.

I've been watching this discussion with interest and I've already learned loads (thanks everyone).

On this point though @WheezyRider you're not comparing apples with apples. You're (I assume) a guy working in his shed who clearly has a huge amount of knowledge and confidence in that knowledge. You're fully aware of the risks and consequences of your modifications and willing to "give it a go". I salute you for that.

I suspect you're very different however to most ebikers, and most of @Woosh's customers who want to buy a finished product and just ride it.

Also consider that @Woosh has to put a warranty on products, after sales care and support, pay tax, rent, NIC's and pension contributions to employees and all the other overheads of running a UK business. This is partly where the price difference lies....

 

[Woosh]

It doesn't help, still stuck at less than 20kph on an incline.

the motor on the OP's Rio fat boy is a Bafang G06. It's twice as big a the MXUS07.
Here is the simulation:
https://www.ebikes.ca/tools/simulator.html?motor=MG60_500&cont=C25&grade=4.5

this is with the supplied 17A Lishui controller and 17AH battery:
https://www.ebikes.ca/tools/simulator.html?motor=MG60_500&cont=cust_17_70_0.03_V&grade=4.5&batt=B3617_35E
All my bikes climb hills very well. Would you want to overvolt it?

 

[RossG]

Interesting debate....out of curiosity and talking of motor codes, does anyone know what this code relates to winding wise ? It's on the 36v Bafang Motor that's fitted to my 20in folder.

 

[WheezyRider]

I've been watching this discussion with interest and I've already learned loads (thanks everyone).

On this point though @WheezyRider you're not comparing apples with apples. You're (I assume) a guy working in his shed who clearly has a huge amount of knowledge and confidence in that knowledge. You're fully aware of the risks and consequences of your modifications and willing to "give it a go". I salute you for that.

I suspect you're very different however to most ebikers, and most of @Woosh's customers who want to buy a finished product and just ride it.

Also consider that @Woosh has to put a warranty on products, after sales care and support, pay tax, rent, NIC's and pension contributions to employees and all the other overheads of running a UK business. This is partly where the price difference lies....

Yes, I get that Gavin, and I think I've made those points several times already. Some people will want to buy off the shelf, others will want to tinker and DIY (out of personal interest or just necessity).

But, say you'd bought an off the shelf kit second hand. Had it for a while and learned some things and find it doesn't quite do what you want, and to get it to do what you want, you're expected to shell out for a lot of new kit. At that point, it's got no warranty any more, so you might be prepared to experiment and see what you can do to make it more suitable.

Either approach is fine, splash the cash and buy all new stuff off the shelf, or experiment and try and get a better experience from what you have. But someone can't just say to someone else "Don't do that! It's foolish to do anything other than what I say" when their are many people on the web who have successfully adapted their kit to their requirements.

 

[WheezyRider]

the motor on the OP's Rio fat boy is a Bafang G06. It's twice as big a the MXUS07.
Here is the simulation:
https://www.ebikes.ca/tools/simulator.html?motor=MG60_500&cont=C25&grade=4.5

this is with the supplied 17A Lishui controller and 17AH battery:
https://www.ebikes.ca/tools/simulator.html?motor=MG60_500&cont=cust_17_70_0.03_V&grade=4.5&batt=B3617_35E
All my bikes climb hills very well. Would you want to overvolt it?

Ok, but 500W that's illegal for use in the UK isn't it? So why have you been so concerned about going over 15.5 mph in your other posts in this thread? The simulation shows that this will do 34kph on the flat.

 

[Woosh]

Ok, but 500W that's illegal for use in the UK isn't it?

You misunderstand the nominal power.
500W on the simulator is the capacity of the copper and magnets, not the nominal power which is 250W and is used on flat roads. If you respect the speed limit, the bike uses only about 200W to maintain 15mph on a flatish road. There is absolutely no need to mess with the electrics.

As I said many times, if you don't derestrict your bike, there is no need to mess with the electrics. I made all my hub bikes so that even if the bike is derestricted to 22mph, the electrics is still within its operating margins. The only reason to overvolt the Fat Boy is to ride it at 28mph.

 

[Nealh]

Interesting debate....out of curiosity and talking of motor codes, does anyone know what this code relates to winding wise ? It's on the 36v Bafang Motor that's fitted to my 20in folder.

A production code, probably year date (2018 March) , H is probably the factory. 10002 s/n & 1 line number.

 

[WheezyRider]

So if the 17A Lishui controller could be over volted to 59V with the same motor set up, this is what you get when climbing an 8.5% incline:

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

www.ebikes.ca

The 36V system can't maintain 25kph, while the 59V system can, with an efficiency >3% higher.

Ok, so go to a 25A controller:

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

www.ebikes.ca

Efficiency is improved, but it still can't get up the hill at 25kph.

Am I missing something?

 

[WheezyRider]

You misunderstand the nominal power.
500W on the simulator is the capacity of the copper and magnets, not the nominal power which is 250W and is used on flat roads. If you respect the speed limit, the bike uses only about 200W to maintain 15mph on a flatish road. There is absolutely no need to mess with the electrics.

As I said many times, if you don't derestrict your bike, there is no need to mess with the electrics. I made all my hub bikes so that even if the bike is derestricted to 22mph, the electrics is still within its operating margins. The only reason to overvolt the Fat Boy is to ride it at 28mph.

Yes, I get "nominal power", but if it has a 500W sticker on it, it's going to raise questions, compared to one with a "250W" sticker on it.

 

[Woosh]

es, I get "nominal power", but if it has a 500W sticker on it, it's going to raise questions, compared to one with a "250W" sticker on it.

of course I asked Bafang to make me 250W G06.

Am I missing something?

yes, power consumption.
Use my original configuration, Lishui 17A G06 and change the gradient to 8.5% - 29WH/km
Your system A G06 same gradient: 35.7WH/km
Your system B G06 same gradient: 37.8WH/km
Your system A XF07 same gradient: 49.5WH/km
Your system B XF07 same gradient: 51.4WH/km

there is no free lunch.

 

[RossG]

A production code, probably year date (2018 March) , H is probably the factory. 10002 s/n & 1 line number.

Ah, that partly explains it. It's not all that fast but has quite a bit of torque, there's small wheels for you great fun

 

[WheezyRider]

Well, you would expect to use more energy if you are going faster

This is interesting, if you throttle back to match the speed of the 25A 36V system, the time to overheat is longer and max temp is lower and energy consumption is lower:

Motor Simulator - Tools

Our ebike motor simulator allows you to easily simulate the different performance characteristics of different ebike setups - with a wide selection of hub motors modeled, and the ability to add custom batteries and controllers and set a wide variety of vehicle parameters you'll be able to see...

www.ebikes.ca

 

[Woosh]

This is interesting, if you throttle back to match the speed of the 25A 36V system, the time to overheat is longer and max temp is lower and energy consumption is lower:

the battery consumption is pretty much the same, 36.8WH/km against 36.9 WH/km
don't see much in it.
there may me a tiny difference in motor yield at that point but it's difficult to solve the yield equation without knowing the frequency and pulse width/duty cycle. BTW, the equations and formulas for back EMF are in the doc that Sturmey posted.

https://www.pedelecs.co.uk/forum/attachments/toshiba-pdf.36673/

 

[vfr400]

I've been watching this discussion with interest and I've already learned loads (thanks everyone).

On this point though @WheezyRider you're not comparing apples with apples. You're (I assume) a guy working in his shed who clearly has a huge amount of knowledge and confidence in that knowledge. You're fully aware of the risks and consequences of your modifications and willing to "give it a go". I salute you for that.

I suspect you're very different however to most ebikers, and most of @Woosh's customers who want to buy a finished product and just ride it.

Also consider that @Woosh has to put a warranty on products, after sales care and support, pay tax, rent, NIC's and pension contributions to employees and all the other overheads of running a UK business. This is partly where the price difference lies....

I can't argue with that; however, your missing a point: We advise people what to do and how to do it. I wouldn't advise anybody to do anything that I don't have confidence that it would work without problems.

What this thread is about, like many before it, is that somebody gives a practical solution to their problem that is know to work, then the hysterical people come along, spouting off because either they haven't got a clue of how things work or the solution doesn't suit their agenda.

 

[WheezyRider]

the battery consumption is pretty much the same, 36.8WH/km against 36.9 WH/km
don't see much in it.

Exactly, so if you can get away without having to splash out on a new controller etc and have less heating, better hill climbing capability, I know what I would chose.

Of course, it may not be possible to run this particular Lishui controller at a higher voltage, someone needs to do that experiment and if it won't work, take it apart to find out why.

However, there are a lot of other controllers and kits out there of similar spec, which can be over volted and thanks to these simulations, we can see the benefits that can bring.

 

[Woosh]

you still don't get it.
The OP has a G06, his situation does not call for overvolting. If he wants speed, he does not have to spend anything. If he wants to climb 10% hill, he does not have to spend anything. Why should he (or someone with a similar kit) spend £400 to run his bike at 48V?
Now, let's examine the argument that he'll climb faster at 48V than at 36V.
Let's say he has 300ft vertical to get home and the gradient is 8% so the length is:
tangent of 8% = 0.0801, let's call it 8%. Length = 300ft/0.08 = 3750ft = 1.143km

His bike at present will go up at 22kph and take 187 seconds to complete the climb before he gets hit by legal speed limit.
If he spends £400 on the overvolting,
https://www.ebikes.ca/tools/simulator.html?motor=MG60_500&cont=cust_17_70_0.03_V&grade=8&batt=B4816_GA
he'll be going up at 26.1kph and take 3600sec * 1.143/26= 157.6 seconds.
in fact, he would be hit by the speed limiter (remember, he is a law abiding citizen): 3600 s * 1.143/25= 164.6s
Would anyone want to spend £400 to save 187 secs - 164.6 secs = 22-25 seconds a day?

 

[WheezyRider]

The OP said:

"I took it out for my first ride this afternoon and at level 6 PAS I still needed to pedal quite hard up (admittedly a steep) hill trying to keep a good cadence."

Then he went on to ask whether it would be better with a 48V system (blissfully unaware at that time, of the can of worms he was about to open ).

From that it doesn't sound like it is hill climbing very well, or at least to the user's satisfaction.

As I've shown from the simulations, over volting is a possible solution for many people to improve their set up without spending a lot of money, but it is not for everyone.

I think I've covered this topic quite comprehensively now, so unless something new and meaningful is put forward, I'm going to leave it at that.

 

[Woosh]

"I took it out for my first ride this afternoon and at level 6 PAS I still needed to pedal quite hard up (admittedly a steep) hill trying to keep a good cadence."

he should give us the location of the hill so we can see.

 

[Gavin]

What this thread is about

Ultimately, what this thread is about is differing opinions and viewpoints, all of them equally valid (in my opinion). What makes it interesting (for me at least) is the level of technical debate and the educational potential contained therein.

The point I was making (and will make again) is that the use of financial cost as a measure of who's opinion is correct, is flawed for the reasons I outlined previously.

Anyway, crack on with the debate chaps 'coz I'm learning loads from this....