Just bought a used Woosh Fat Boy

[MikeFB]

Hi all, not long joined and was initially after a fat bike to convert into a fat ebike. Having been let down a few times in trying to buy a fat bike and knowing conversion kits are thin on the ground in the UK, I just bought a used Woosh Fat Boy and will be picking it up tomorrow.

Still tempted to get a 'full' fat bike at some stage?

Any advice/comments with regards my first ebike purchase much appreciated.

 

[MikeFB]

As I've had a flood of advice/comments, I'll ask some direct questions instead . The Fat Boy I have has a Bafang G06 36v motor rated at 250w and a 36v 15ah battery with an integrated Lishui 17A controller in the battery cradle.

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. Don't get me wrong I still want to cycle for fitness, not just for getting from A to B. However:

My question is, would upgrading to a 48v battery improve torque? If so what advice can someone give with regards a suitable replacement battery and controller. I'm also considering getting a better LCD display, any advice is much appreciated.

 

[vfr400]

48v will give more torque and speed. You have to ask Woosh whether the controller is dual voltage 36v/48v, otherwise you need a new controller and LCD.

 

[Woosh]

the controller is 36V 17A, the LCD is 36V.
You can't use a 48V battery on it.
If you still want to convert to 48V, you'll need a 48V HL controller, 48V LCD, a new cable loom and of course new 48V HL battery.
the budget is about £400 and you may shorten the life of the motor.
I wish that members stop suggesting overvolting.
Who is going to pick up the tab when smoke comes out of the bike?

 

[MikeFB]

the controller is 36V 17A, the LCD is 36V.
You can't use a 48V battery on it.
If you still want to convert to 48V, you'll need a 48V HL controller, 48V LCD, a new cable loom and of course new 48V HL battery.
the budget is about £400 and you may shorten the life of the motor.
I wish that members stop suggesting overvolting.
Who is going to pick up the tab when smoke comes out of the bike?

Hi Woosh, I'm going for my second ride today, so it may be I just need to get use to riding an ebike. I'll take your advice on not overvolting the FB.

However I'm also seriously considering your 48v G06 fat bike conversion kit for next year for another fat bike. Is there a significant difference in torque and hill climb ability with the 48v kit over the 36v G06 fitted to the FB? Thanks.

 

[Woosh]

yes, 30% more power.
If you want to build an even more powerful fat bike for off-roading, I can sell you just the motor.
The beast in the G06 kit is made specially for 4" wheels. You can use a 48V 25A controller with it.

 

[MikeFB]

yes, 30% more power.
If you want to build an even more powerful fat bike for off-roading, I can sell you just the motor.
The beast in the G06 kit is made specially for 4" wheels. You can use a 48V 25A controller with it.

OK thanks for that. This is something I had in mind originally, so will be looking into this sometime next year, once (if) we ever get back to some normality, Cheers.

 

[vfr400]

We've been over-volting motors on this forum for ten years, can you name anybody that smoked a motor, Mr Woosh? I call hysterical horse shite.

Despite what's written on motors, they don't have a voltage rating. They don't care about voltage. It's current that burns them.

 

[Nealh]

My 36v AKM 128c is set up for 23a and is used at both 36v & 48v out on a ride.
Down tube battery is 36v PF cells and utilises a on/off switch on the V+ line, the 48v PF celled 7p softcase is carried in top bag on the rear.

Users wanting to over volt need to realise that they do so at there own risk there is no real danger involved, though one could strip the nylon gears or over heat the controller at vey slow speeds with too much current.
Advantage of over volting is more wh for battery using the same cells in parallel, torque/speed is increased. For me it is more lower end current in PAS 1 or 2 which is gentler then using PAS3 @36v.

 

[Woosh]

We've been over-volting motors on this forum for ten years, can you name anybody that smoked a motor, Mr Woosh? I call hysterical horse shite.

Despite what's written on motors, they don't have a voltage rating. They don't care about voltage. It's current that burns them.

it's not the motor I am worried about.
It's the collateral damage when things don't go according to plan.
As I keep repeating, if you don't derestrict the bike, you don't have much to worry about.
When someone wants to put a 48V battery onto a 36V bike, derestricting is a probable action. A derestricted overvolted kit is not going to be as safe or good as a 48V kit. It's just common sense.
I put Samsung and Panasonic cells in my bikes or kits' batteries for safety. They'll get replaced by Chinese cells. Would you like it if you supplied the bike with your name on it?

 

[vfr400]

it's not the motor I am worried about.
It's the collateral damage when things don't go according to plan.
As I keep repeating, if you don't derestrict the bike, you don't have much to worry about.
When someone wants to put a 48V battery onto a 36V bike, derestricting is a probable action. A derestricted overvolted kit is not going to be as safe or good as a 48V kit. It's just common sense.
I put Samsung and Panasonic cells in my bikes or kits' batteries for safety. They'll get replaced by Chinese cells. Would you like it if you supplied the bike with your name on it?

There's nothing wrong in saying that you don't want somebody to fiddle with one of your bikes for whatever reasons you want, but what you're doing is unsubstantiated scaremongering.

Remember, if it wasn't for guys like us, you'd still be fitting 14 amp controllers to your bikes and nobody would buy them because they suck!

 

[Woosh]

14A controller is perfectly good for an e-bike if you don't weigh more than 14 stone. 17A controller for 18 stone, 20A controller for 25 stone.
If it's safe for my customers to slot a 48V battery in a 36V bike, why did I say 'don't do it?' or are you saying you know Lishui controllers and King Meter LCDs better than me?
If those who listen to you happens to have their 2.2mF capacitor blow up in their face, what will you say?

 

[mike killay]

14A controller is perfectly good for an e-bike if you don't weigh more than 14 stone. 17A controller for 18 stone, 20A controller for 25 stone.

Woosh,
Do you offer these controller options to purchasers of new bikes?

 

[WheezyRider]

14A controller is perfectly good for an e-bike if you don't weigh more than 14 stone. 17A controller for 18 stone, 20A controller for 25 stone.
If it's safe for my customers to slot a 48V battery in a 36V bike, why did I say 'don't do it?' or are you saying you know Lishui controllers and King Meter LCDs better than me?
If those who listen to you happens to have their 2.2mF capacitor blow up in their face, what will you say?

Woosh, have you ever connected up a "36V" controller to a 48V battery to see what would happen?

In my experience, most 36V controllers are fine at 48V, so long as they are fitted with 63V or higher capacitors and the MOSFETs are rated for more than 54V (which is generally the case). Yes, the LVC will be wrong, but there are solutions to that.

 

[Woosh]

Woosh,
Do you offer these controller options to purchasers of new bikes?

yes, I did that about 6-7 years ago. I connected a GSM CD motor to it.
I run the kit for a while on the test bike.
I did the same with a TSDZ2. 48V battery does not work with 36V TSDZ2.
Safety margin is built into a system for obvious reason.
I did the same with a number of hub motors.
The safety margin built into the 36V controller can be easily blown by connecting a fully charged 48V battery to it.

 

[Woosh]

In my experience, most 36V controllers are fine at 48V, so long as they are fitted with 63V or higher capacitors and the MOSFETs are rated for more than 54V (which is generally the case). Yes, the LVC will be wrong, but there are solutions to that.

ask around - any suppliers will give you the same answer. Safety is the reason that they do not want you to 'mod' the electrics of their bikes.
When you build a kit, you are the manufacturer, you know the risks. When you buy a ready made bikes, please leave the electrics well alone.
I sell 48V kits and 36V kits. It's not as if I have anything against those who want to buy 48V kits.

 

[WheezyRider]

ask around - any suppliers will give you the same answer. Safety is the reason that they do not want you to 'mod' the electrics of their bikes.
When you build a kit, you are the manufacturer, you know the risks. When you buy a ready made bikes, please leave the electrics well alone.
I sell 48V kits and 36V kits. It's not as if I have anything against those who want to buy 48V kits.

Perfectly understandable as a retailer that you don't want people to mess with kit and then expect you to pick up the pieces if it goes wrong.

However, I do worry about the ever growing pile of WEEE waste in the world, often caused by someone having to buy more and more kit because what they have doesn't do what they want. So if we can get more out of what we already have, so much the better.

I have two "36V" controllers I am regularly using at 59V and I have bench tested one at up to 72V after upgrading the caps to 100V.

If someone decides they need to upgrade to 48V, can you offer them something for their used kit?

 

[Woosh]

Give me a valid reason to explain why you want to overvolt your kit.

in my experience, the only reason for overvolting is because of this formula: RPM = Kv * Voltage.
You want to shift your hub motor's RPM up by 30% when you put a 48V battery in a 36V kit.
Take any of my hub kits: if you derestrict them, you can easily ride at 22mph. If you overvolt one of my kit, you will likely to ride them at 22mph * 1.3 = 28mph.
I do not wish to make 28mph kits. Besides legal aspects, direct drive kits work much better than geared hub at 28mph.
Those who have engineering skills should know how to be kind to the equipment in their charge.

 

[WheezyRider]

Well, I could bounce that back at you and ask you why you want to undervolt your bike?

The ride experience is so much better at 59V. I get a good pull away from standstill and better acceleration and hill climbing, while only using 15 A.

36V might be ok for an old granny on the flat, but the OP wanted to have a reasonable speed getting up a hill. You want to do this without using too many amps in a low speed condition, so "over volting" is a great way of doing this without using loads of amps and cooking the motor.

If you set up the wheel size properly, the controller will still cut out at 25 kph.

I don't see the difference between selling bikes that can do 20 mph if the wheel size is set up incorrectly by the user, or selling a bike that can theoretically do 28 mph if the wheel size is set incorrectly by the user. At what point over the speed limit do you have to go before it becomes a moral issue, preventing you from selling?

 

[Woosh]

as I said before, if you build a bike for 28mph, you are better off with a direct drive. You won't blow up the motor in 1000 miles.
Let's recap, overvolting means you stick a 48V battery on a 36V bikes.
Let those who did so to their bikes come say how many miles they've done with their overvolted bike here.
to play with their kit for 5 minutes is just that, playing, never a practical proposition.