Add-on e-bike conversion kit - Swytch or eBay kit?

Electrically assisted bikes, trikes, etc.
hemo
Posts: 847
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby hemo » 2 Aug 2020, 12:05am

Budget at least £450 + for a 48v battery to power those heavy 1kw D/D hubs.

Phill Bailey
Posts: 2
Joined: 1 Aug 2020, 9:14am

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby Phill Bailey » 2 Aug 2020, 8:46am

Thanks for your reply still lost ??
I'm an old builder so the tec stuff not me .
I could build you a houes in a field but elec tec Na
It would appear I don't need 1000watts motors from you coments .??
I have a Apollo Gradient 24" frame 26" wheel and the ride for me is just great 7 cassette gears in rear . I only know that because I was told when looking for the conver kit .
You said Amazon kits not good , sorry the 1000watts that I put . Are any of the kits from amazon or eBay worth buying . ??
I need need a kit that will help me have a break when I'm out so hence the throttle help .
And the peddle assistant to get me back home via last small hill . And what makes it all enjoyable again without the pain
So could you say this ?? Plus this is what you need
Thanks again Phill

stodd
Posts: 329
Joined: 6 Jun 2018, 10:24am

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby stodd » 2 Aug 2020, 11:24am

Some kits from Amazon or ebay are fine; for example yosepower that I mentioned before also sell via Amazon.
It is the direct drive ones that are unsuitable (legally and technically).

Some of the kits are 350w not 250w. This makes them technically illegal on the road, even though often the same motor will be sold elsewhere marked 250w; the difference being only the marking. You are fairly unlikely to get legal problems even with a 1000w motor; if you do (for example if you have an accident and the police look into details) the consequences are significant as such a bike is not a pedalec but a motor vehicle, so you can be had for driving without insurance, driving with MOT, driving an unregistered vehicle. Potentially quite heavy fines, lots of points on your licence, and the bike confiscated.

Why don't you insist on going via Amazon or eBay (and so giving them a cut in what you are paying). Go to a reputable supplier who will give good service and support; such as Woosh I mentioned before (https://wooshbikes.co.uk/).

You probably need https://wooshbikes.co.uk/?hubkits#swx02-48v-kit, but do discuss it with Woosh first.
That does come to £569 (*), but you are getting a good quality motor, very decent capacity battery, sensible control circuitry (controller+LCD) and good customer support. It might well be one of the 36v motors is enough, and will save a little cost.

(*) that is similar to what you would pay for a much inferior Swytch by the time you allow for VAT, import duty etc.

hemo
Posts: 847
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby hemo » 2 Aug 2020, 12:49pm

What ever hub you buy ideally needs to be a geared hub, what gives the hub it's power is not the wattage rating but the current the controller can give.
A 250w continuous rated hub is it's legal rating that means it won't overheat running at that rating for 1hr continuous, you can put through it however much current you like but there is a limit at which point it will fail.
Typically a 250w hub will be sold with a 15a controller so temporary power can be about 430w at the wheel, some will go as high as 25a so 720w is the temporary output at the wheel all legal as the motor continuous rating complies with law.
Foe ultimate ease and efficiency 250w/48v is the power combo to go for, to get the efficiency the motor/hub needs to be wound for 48v and not 36v.

hemo
Posts: 847
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby hemo » 2 Aug 2020, 1:07pm

Phil Bailey, what type of bike for conversion only 9mm QR's are suitable, through axle are no good.
Your weight and how steep a hill ?

Fitting a rear hub wheel isn't often just a drop in solution, one has to also think about adding a torque arm to prevent motor hub spinning out of the D/O's, though hubs do come with anti rotation washers they on their own may not be enough for piece of mind.
Filing the D/O's may be necessary to allow the hub axle to sit deeper 1.5 -2 mm is often needed.

Currently on Pedelec forum there is a guy who has bought a cheap Voilamart 250w used motor kit and it climbs better then a Bafang GO6 fat bike hub, it in all actuality shouldn't do so as the former is only 15nm and the latter 50nm. The fat bike is heavier and the tyres will have more rolling resistance but doesn't count for all the lesser performance.

With any decent hub kit with 5 levels of power assist hills should be relatively easy to climb.
The 1KW D/D hubs aren't the be all and end all unless you can have a heavier decent battery to power them.

Bonzo Banana
Posts: 125
Joined: 5 Feb 2017, 11:58am

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby Bonzo Banana » 4 Aug 2020, 11:33pm

hemo wrote:Phil Bailey, what type of bike for conversion only 9mm QR's are suitable, through axle are no good.
Your weight and how steep a hill ?

Fitting a rear hub wheel isn't often just a drop in solution, one has to also think about adding a torque arm to prevent motor hub spinning out of the D/O's, though hubs do come with anti rotation washers they on their own may not be enough for piece of mind.
Filing the D/O's may be necessary to allow the hub axle to sit deeper 1.5 -2 mm is often needed.

Currently on Pedelec forum there is a guy who has bought a cheap Voilamart 250w used motor kit and it climbs better then a Bafang GO6 fat bike hub, it in all actuality shouldn't do so as the former is only 15nm and the latter 50nm. The fat bike is heavier and the tyres will have more rolling resistance but doesn't count for all the lesser performance.

With any decent hub kit with 5 levels of power assist hills should be relatively easy to climb.
The 1KW D/D hubs aren't the be all and end all unless you can have a heavier decent battery to power them.


I was confused by that 15Nm rating for the Violamart 250W hub motors especially as the larger hubs are rated to 45Nm, I wondered if the smaller hubs were direct drive and not geared but it sounds like if they are performing well for torque they must be geared but then what is that 15Nm rating as surely it would be much above that. The larger direct drive hub motors and the smaller geared hub motors produce the same torque typically I think just the larger direct drive hubs can go faster if allowed.

Also the Violamart large direct drive hubs state a 1000W mode but isn't that peak watts and the sustained wattage is more like 400W. In the restricted legal mode the sustained power is only 250W and the peak watts are more like 600-700W. It's effectively only a 50% boost over 250W but if you just read 250W vs 1000W you would think it was 4x the power. The 48V batteries like 48V 12.5Ah provide 10A continous (480W and a short burst at 20A, 960W). While 10A is mentioned as the sustained current output I think in the 250W mode it is more like 5-6A and in 1000W mode only marginally more at 8-9A. As far as I understand the larger direct drive hubs are perfectly legal if run in the 250W mode even if peak watts go to 600-700W which is the same as many commercial mid-drive motors. The issue is of course not using the 250W mode. If you tape up the 250W mode cable so it simply can't be unplugged surely there should be no legal issues. Ultimately it is the controller that govern's the power not the motor, most motors are flexible with how much current they can take. I think the same direct drive hub motors are sold as 500W, 1000W, 1500W and 2000W but only the controller supplied varies.

hemo
Posts: 847
Joined: 16 Nov 2017, 5:40pm
Location: West Sussex

Re: Add-on e-bike conversion kit - Swytch or eBay kit?

Postby hemo » 5 Aug 2020, 10:24am

The answer on pedelecs as to why the geared 250w small FWD Voilamart hub climbed so well hasn't been answered yet, the user has been asked to look to see if the controller shunt has had solder added to it thus giving more current then the 15a supplied.

The 1kw dual watt hubs are illegal believe they are capable of 1kw continuous, at the 250w rating current is reduced and the switching mode allows more current to feed the higher wattage.