Build spec by committee, might that include you?

[soundwave]

'Ferocious' boars who roam the Forest of Dean transformed into lovable piggies who will eat out of tourists' hands

Hundreds now live in the Forest of Dean, Gloucestershire, where several are happy to take food from visitors' hands and even accept a stroke on the snout.

www.dailymail.co.uk

 

[I893469365902345609348566]

View attachment 53140

'Ferocious' boars who roam the Forest of Dean transformed into lovable piggies who will eat out of tourists' hands

Hundreds now live in the Forest of Dean, Gloucestershire, where several are happy to take food from visitors' hands and even accept a stroke on the snout.

www.dailymail.co.uk

To cook one badger you’ll need:

1 badger
1 glass of pig’s blood
1 small glass of armagnac
1 ginger root
1 bottle of dry, sparkling white wine
2 eggs
1 pot of crème fraîche
salt and pepper
500g forest mushrooms OR chestnuts to accompany
100g butter
oil

Badger stew – Gastronomy Domine

 

[FastFreddy2]

This is tricky, you're still not getting it.
A motor marked as 250w does not consume or output 250w. It consumes what the controller gives it.

Yep, know that.

As Saneagle explained, the 250w rating is merely a statement by the manufacturer that the motor will not overheat if fed that power continuously.

Yep, know that.

So a motor run at 36v and fed 10A will be 'using' 360w. If fed 15A it will 'use' 540w. Now run that motor at 48v with the same current applied and the figures would be 480w and 720w.
The motor will happily run at these wattages for some time as there is always 'headroom' built into the figures.

Yep, know that. Plus I'm not so old/decrepit I can't do the same multiplication sums children are expected to.

To re-state. Any motor labelled by the manufacture as 250w will be legal.

Yep, know that. And I'm pretty sure it was you I quoted saying so earlier.

What you feed into it is up to you and your requirements.

Hence this thread.

Speed limitation is achieved by the controller, normally via a wheel size setting. It gets rpm feedback from the motor so knows what to allow at the stated wheel size. So long as this is limited to 15.5mph, the bike will be legal.

Yep, got that too. (And used that and at least one other variable.)

Kt controllers are dual voltage (36,48), it is possible to run a system on either voltage with one of these. Motors are not voltage sensitive (within reason) and a motor specced as 36v but run at 48v will give approx 30% more power and torque. Speed will still be limited to 15'5mph as this is rpm derived. So the bike will still be legal.

Now this is interesting, because it suggests (within working parameters) volts and amperage aren't significant in themselves, it's the wattage consumed that is important. Again within limits, the combination ratio isn't critically important.

I've eluded to the following earlier, that my understanding was that under-volting a motor, could cause it to overheat. So I was quite surprised to find (in my own research) that the voltage varies with the level of assistance , from zero up to the maximum fully charged batteries can output.

So this controller:

T09S 36V/48V500W 22A KT Sine Wave Controller with Julet Waterproof connector [T09S controller waterproof plug] - $31.85 : Zen Cart!, The Art of E-commerce

Zen Cart! T09S 36V/48V500W 22A KT Sine Wave Controller with Julet Waterproof connector [T09S controller waterproof plug] - ★★★★★ T09S 36V/48V500W Torque Simulation Sine Wave Controller With Julet Waterproof connector 1--Rate Voltage: 36V/48V Compatible 2--Maximum Current:22±1A 3--Low Voltage...

www.topbikekit.com

is a dual voltage 22A sine wave controller. 22A is the maximum current only achieved in the top assist setting. At 36v this will give 792w, at 48v 1056w. It would need to be backed by a battery with a maximum output amperage of around 30A in order to avoid voltage sag and potential battery damage/life shortening.

You are suggesting for the battery to utilise a 22a controller, it needs an upper battery output in the 30a range to be able to have the headroom to supply the controller and the motor reliably at high levels of demand.

Sine wave controllers make the motor quieter as opposed to square wave where the motors tend to growl more at low revs.

Thank you for confirmation.

 

[soundwave]

tbh the place is over run these days unless you know where to look you wont see them on the trails i keep what i kill if i can download it

 

[FastFreddy2]

Aluminium dropouts stopped me considering installing a powerful (22A) but legal 48V 250W rated rear hub motor to my Dahon Espresso.

If I wreck the bike, I'll be £40/£50 out of pocket. I only own aluminium bikes, so there is no alternative.

 

[guerney]

If I wreck the bike, I'll be £40/£50 out of pocket. I only own aluminium bikes, so there is no alternative.

It's physical damage to the person I'd worry about (particularly if that person is me), not financial. Despite knowing absolutely nothing whatsoever about ebikes, I feel supremely confident and fully qualified to advise that you fit a front hub motor to your steel forks, if you have those. Guesstimating recklessly based on your stated weight, and hill climbing experience you've written about in the post below, I think it likely you'll cope fine, even without a recumbent... but I could be horribly and disastrously wrong:

https://www.pedelecs.co.uk/forum/threads/my-name-is-and-im-new-here.45132/post-688149

Wait for better informed opinions before buying anything lol!

@saneagle suggested the Xiongda two speed recently:

https://www.pedelecs.co.uk/forum/threads/looking-for-an-alternative-to-swytch-and-would-appreciate-some-advice-in-conversion-kits-general-discussion.45712/page-3#post-686768

Xiongda 2-speed hub motor Review – First impressions

Foreword I wrote the page below a few years ago, when I first installed a Xiongda 2-speed motor in my folding bike. Since then...

bruceteakle.blogspot.com

 

[I893469365902345609348566]

tbh the place is over run these days unless you know where to look you wont see them on the trails i keep what i kill if i can download it

You'd get bored eating a whole boar.

 

[Benjahmin]

You are suggesting for the battery to utilise a 22a controller, it needs an upper battery output in the 30a range to be able to have the headroom to supply the controller and the motor reliably at high levels of demand.

If you were to choose that controller, then yes.
The priniciple is that the maximum amperage of the battery is equal to, or preferably exceeds, the maximum rating of the controller. This way you avoid battery strain and degradation.
Of course you may never use the maximum assist setting so never draw the maximum current. Or you buy a lower rated controller.
Sorry for the repetition, just trying to achieve clarity amongst the thread hijacking.
We haven't even considered the motor yet !
As you mentioned hill climbing in your OP, perhaps a 36v hub run at 48v may be best for you. This way you get 50% more torque which is the hill climbing friend.

 

[saneagle]

Aluminium dropouts stopped me considering installing a powerful (22A) but legal 48V 250W rated rear hub motor to my Dahon Espresso.

There's no problem with a rear motor. I would advise a single torque arm on the left side. If you have 20" wheels, 15A at 48v should be more than enough to deal with steep hills.

 

[FastFreddy2]

It's physical damage to the person I'd worry about (particularly if that person is me), not financial. Despite knowing absolutely nothing whatsoever about ebikes, I feel supremely confident and fully qualified to advise that you fit a front hub motor to your steel forks, if you have those. Guesstimating recklessly based on your stated weight, and hill climbing experience you've written about in the post below, I think it likely you'll cope fine, even without a recumbent... but I could be horribly and disastrously wrong:

While I don't hop over vehicle sized obstacles, I do pull the front of my bike over the occessional fallen tree, large enough (twice) to clonk my chainset before the back wheel climbs the same tree trunk. (Another reason a mid-drive is not wholly suitable.) I think I reported recently, the last time I went over the handlebars was as recently as two weeks ago, and before that, a moderately serious spill in November. (Damaged was caused to my bike, as well as my head, despite a helmet.) A front mounted motor isn't going to work for me, although it would be very convenient.

The Xiongda two speed rear with disc brake capability seems like an ideal solution. My days of riding bikes without discs front and rear are (very) long gone. I've watched the video, and looked at the blog related to the drive, and I am very impressed. If that hub comes in black, and isn't 4 times the price of the competition, that could well be the way for me to go. Thanks for the tip.

 

[FastFreddy2]

If you were to choose that controller, then yes.
The principle is that the maximum amperage of the battery is equal to, or preferably exceeds, the maximum rating of the controller. This way you avoid battery strain and degradation.
Of course you may never use the maximum assist setting so never draw the maximum current. Or you buy a lower rated controller.
Sorry for the repetition, just trying to achieve clarity amongst the thread hijacking.

The hijacking isn't a problem, I'm pretty centred on this project and useful advice provided. What is slightly counter intuitive, is to have an over-powered system. Meaning greater energy available than can be handled by the motor if used at a constant rate. On the face of it, one would expect it to be a recipe for an expensive burnt out hub. The controller, is supposed to stop that, by acting as a restriction. Either through programming, or its own capacity.

We haven't even considered the motor yet !
As you mentioned hill climbing in your OP, perhaps a 36v hub run at 48v may be best for you. This way you get 50% more torque which is the hill climbing friend.

I'm very much warming to the 250w motor x 48v battery solution. The Xiongda two speed is looking promising, if it's affordable.

 

[FastFreddy2]

There's no problem with a rear motor. I would advise a single torque arm on the left side. If you have 20" wheels, 15A at 48v should be more than enough to deal with steep hills.

I'm pretty sure I've made it plain this is going on a bike with 700c wheels..... 622 sized rims. I think you are getting confused with the trike project, now concluded. (Until winter at least.)

 

[saneagle]

While I don't hop over vehicle sized obstacles, I do pull the front of my bike over the occessional fallen tree, large enough (twice) to clonk my chainset before the back wheel climbs the same tree trunk. (Another reason a mid-drive is not wholly suitable.) I think I reported recently, the last time I went over the handlebars was as recently as two weeks ago, and before that, a moderately serious spill in November. (Damaged was caused to my bike, as well as my head, despite a helmet.) A front mounted motor isn't going to work for me, although it would be very convenient.

The Xiongda two speed rear with disc brake capability seems like an ideal solution. My days of riding bikes without discs front and rear are (very) long gone. I've watched the video, and looked at the blog related to the drive, and I am very impressed. If that hub comes in black, and isn't 4 times the price of the competition, that could well be the way for me to go. Thanks for the tip.

Everything has advantages and disadvantages. The main disadvantage of the XD motor is its width. You already have to stretch the frame to get it in, but then the rim won't be central. There are two ways to deal with that. First, you can build an extreme dish into the wheel, but then the spokes on the brake side have no tension. Secondly, you can add spacers to the brake side axle, which means stretching the frame further and figuring out how to get the disc to line up with the caliper. I wrote loads about all that on this forum several years ago, if you want to search for it.

Also, the two-speed shifting is novel an interesting at first, but then starts to become annoying because it doesn't always shift when and where you want it to.

Considering everything, I abandoned the XD motor after about 2000 miles and switched to an ordinary middle-sized motor run at 48v, which gives all the climbing power you need without the complication. For towing, very heavy riders and extreme climbs, I think the XD has its place.

When you choose a motor, you need one that will spin at a maximum speed of 1.3 times your planned modal speed. You choose the motor and voltage together to get that speed, then you choose the current to get the power you need. The motor needs to be able to handle the power. Middle-sized motors with 5:1 internal ratio are OK up to about 850W from the controller. Small ones can manage about 600W and large ones can do 1200W. Motors with higher reduction ratios can do 10% more.

 

[saneagle]

I'm pretty sure I've made it plain this is going on a bike with 700c wheels..... 622 sized rims. I think you are getting confused with the trike project, now concluded. (Until winter at least.)

That was in reply to Guerney, not you.

 

[FastFreddy2]

The only rule is that power must stop when the pedals stop rotating. Many controllers will work the throttle like that.

the throttle + pedalling = legal + precise control of the amount of assistance, from snail's pace (negotiating gates for example) to 15.5mph while pedalling as little or as much as you like.
A combination often overlooked because difficult to explain to the police and most people don't need the throttle.

When I asked why anyone would want a throttle that was deactivated when pedalling stopped, I didn't understand this meant the throttle wasn't turning the motor assisted bike into a moped. If I (now) have this right, the throttle effectively replaces the display setting with infinitely variable levels? That being the case I can (i) see how this would be legal, and (ii) how useful it might be.

The cruncher is..... Does the throttle also provide a "push" function to get the hub rotating from a dead stop, (say at the bottom of a hill) to allow pedalling to commence? Or does that still have to be done from the display? (Lower left button on KM 529.)

 

[FastFreddy2]

Everything has advantages and disadvantages. The main disadvantage of the XD motor is its width. You already have to stretch the frame to get it in, but then the rim won't be central. There are two ways to deal with that. First, you can build an extreme dish into the wheel, but then the spokes on the brake side have no tension. Secondly, you can add spacers to the brake side axle, which means stretching the frame further and figuring out how to get the disc to line up with the caliper. I wrote loads about all that on this forum several years ago, if you want to search for it.

Also, the two-speed shifting is novel an interesting at first, but then starts to become annoying because it doesn't always shift when and where you want it to.

Considering everything, I abandoned the XD motor after about 2000 miles and switched to an ordinary middle-sized motor run at 48v, which gives all the climbing power you need without the complication. For towing, very heavy riders and extreme climbs, I think the XD has its place.

Okay, no point in ignoring advice I've asked for, and even less sense ignoring someone with practical experience. I hope I'm not heavy/heavy at 13st (though I'd like to weigh less), and I won't be towing or doing extreme climbs.

When you choose a motor, you need one that will spin at a maximum speed of 1.3 times your planned modal speed. You choose the motor and voltage together to get that speed, then you choose the current to get the power you need. The motor needs to be able to handle the power. Middle-sized motors with 5:1 internal ratio are OK up to about 850W from the controller. Small ones can manage about 600W and large ones can do 1200W. Motors with higher reduction ratios can do 10% more.

Wheel rolling circumference will effect the required rpm of the motor to achieve the planned model speed of 8-9mph with a 700c wheel...

"Smaller" motors, I assume mean 250w ones? When you say manage 600w, is that continuous or peak? I thought I'd read peak was somewhere in the 700w range?

I haven't spent many hours looking, but I've seen very few motor specs that mention optimum or maximum spin speeds, though I have started to notice when sellers mention "geared". Not noticed any obvious mention of gearing ratios though. Possibly I should be trying a bit harder.

 

[Cadence]

There is a range of motors here with a choice of gear ratios and RPM:-
Motor with Wheel rim : Zen Cart!, The Art of E-commerce (topbikekit.com)
However, the only 250w. one listed is this:-
Ebike AKM-100SX 36V 250W Front/Rear/Cassette Gear Hub Motor+16/20/ 26inch/27.5inch/28inch Wheel Rim [AKM-36V250W Motor 16/20/26/28] - $99.75 : Zen Cart!, The Art of E-commerce (topbikekit.com)
RPM 328 or 201, both with reduction ratio of 12.6.

 

[Woosh]

The cruncher is..... Does the throttle also provide a "push" function to get the hub rotating from a dead stop

On bikes, I have to comply with the 1/1/2016 law, twist and go throttle is not allowed. You have to pedal or long press the - button to start and then pedal for a few seconds to activate the throttle.

On kits, that law does not apply, you have twist and go throttle. That means the throttle is active all the time, you don't need to pedal first, unless you switch the throttle off with the square button below the thumb lever. You only have to push on the thumb lever and the motor will start.

Pedalling is thus optional on kits but not on ready made bikes.

 

[Benjahmin]

The cruncher is..... Does the throttle also provide a "push" function to get the hub rotating from a dead stop, (say at the bottom of a hill) to allow pedalling to commence? Or does that still have to be done from the display? (Lower left button on KM 529.)

If the settings are for walk assist then the throttle will give 'push' start but only up to 6kh IIRC. if set to full throttle then you would have to pedal first.
As Tony says, because kits are not specifically mentioned in the legislation, there is a loop hole that means builders kit bikes can fit a full acting throttle. In effect kit bikes do not exist in law because they aren't mentioned. This is why some bike suppliers, when you buy from them, will supply a throttle for you to fit yourself. This way it becomes a kit bike.
It's iffy and esoteric in nature. I'm not sure that you could explain this and prevent your bike being confiscated in a roadside stop and the solicters bills to get it back could be costly.

 

[guerney]

On kits, that law does not apply, you have twist and go throttle. That means the throttle is active all the time, you don't need to pedal first, unless you switch the throttle off with the square button below the thumb lever. You only have to push on the thumb lever and the motor will start.

Pedalling is thus optional on kits but not on ready made bikes.

If the settings are for walk assist then the throttle will give 'push' start but only up to 6kh IIRC. if set to full throttle then you would have to pedal first.
As Tony says, because kits are not specifically mentioned in the legislation, there is a loop hole that means builders kit bikes can fit a full acting throttle. In effect kit bikes do not exist in law because they aren't mentioned. This is why some bike suppliers, when you buy from them, will supply a throttle for you to fit yourself. This way it becomes a kit bike.
It's iffy and esoteric in nature. I'm not sure that you could explain this and prevent your bike being confiscated in a roadside stop and the solicters bills to get it back could be costly.

Do these cops know that? I've disconnected my kit's throttle, just in case...


"Any electric bike that exceeds 15.5mph or has a throttle on the bike is classed as a motorcycle and not a bicycle. "


Lorry full of e-bikes confiscated on the streets of Cardiff as part of new crackdown

• 19:25, 31 JUL 2023

Lorry full of e-bikes confiscated on the streets of Cardiff as part of crackdown

The bikes which were seized had the capability to travel at speeds of between 30mph and 42mph

www.walesonline.co.uk