Converting an old bike to an ebike

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Govnor
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Joined: 6 Jun 2021, 8:33pm

Re: Converting an old bike to an ebike

Post by Govnor »

squeaker wrote: 8 Jun 2021, 9:43am
Govnor wrote: 7 Jun 2021, 6:52pm...surely trading standards should be chasing up this?
Business seller information
Guangzhou Huangpu Technology Co Ltd
Kuilin Wang
Room 502 Uinit 8 jingxi street yihe xiang
510000 Guangdong, 广东省
China
ROTFL :roll:
Most of the items for most things come from China, Now the obvious thing to do would be to limit or ban such items as they already do as Wish don't sell stun guns etc for UK dispatch any more due to pressure to stop distribution in case they got into wrong hands.
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Paradiddle
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Re: Converting an old bike to an ebike

Post by Paradiddle »

I wouldn't trust a random listing on eBay though unless there have been some decent reviews and the seller is reputable.

Check out Swytch conversion kits. Reputable UK brand.
Jdsk
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Re: Converting an old bike to an ebike

Post by Jdsk »

Guardian article on Swytch:
https://www.theguardian.com/environment ... -the-gizmo

Jonathan
Govnor
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Re: Converting an old bike to an ebike

Post by Govnor »

Jdsk wrote: 11 Jun 2021, 10:53am Guardian article on Swytch:
https://www.theguardian.com/environment ... -the-gizmo

Jonathan
There is these Baofang drive units, are they legal and any good? Seems you could move from bike to bike if a proper job and reliable.
Nigel
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Re: Converting an old bike to an ebike

Post by Nigel »

There are Bafung motors and Bafung motors, both wheel hub and bottom-bracket based, and there are other motor makers as well.
If they're displaying a 250W power rating on the casing, then they're legal when installed on a bike in the UK, subject to the rest of the e-bike rules also being followed in building up the bike: including a speed cut-out to limit the max speed at which assistance is given, and being pedal-assisted (ie. not a throttle driven bike).

The kits mentioned from the likes of Woosh or Swytch are going to be legal if installed correctly in the UK (*). There are ways of doing it cheaper, arguably better, and remaining legal. But that requires more work identifying and sourcing parts.

(* Though Swytch suggest there is a power limit by-pass option for the UK for "off road", that's only legal if you are on private land, with the land-owner's permission. Its not legal with the power-limit removed on a bridleway, cycle path, or any public route. The laws being broken are those covering riding an uninsured, unregistered and illegal motorcycle, because an over-powered e-bike is a motorcycle in UK law. )
GayUnicorn
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Re: Converting an old bike to an ebike

Post by GayUnicorn »

Just looked at Baofeng and a radio came up, so I presume a common name as found Bafung.
Does the area pedals connect to have to be modified or do they come with a range of adapters?

Can you buy these and there was a repair cafe locally that fixed things for a donation-puncture was a couple of pounds.

Would they do this as it seems at least one a retired college tech or machinist or lecturer.

What would it be fair to pay for fitting £40-£50
thirdcrank
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Re: Converting an old bike to an ebike

Post by thirdcrank »

This is the sort of thing I imagine Graeme Obree would do well. I'm not suggesting he might need motor assistance - far from it - but I could easily imagine him recycling some junk into a working prototype (immediately to be banned by whatever body regulates ebikes.)
Oldjohnw
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Swytch

Post by Oldjohnw »

An interesting comment on motorising an old bike.


https://www.theguardian.com/environment ... SApp_Other

My personal approach is it’s almost almost preferable to upgrade a bike you already like. If I were replacing my bike I would probably choose a bike I liked and add a motor.

The bike in the article, a Specialized, was presumably a decent bike. Was the saddle destroyed for illustrative purposes to make a point?

[edited for typo]
Last edited by Oldjohnw on 12 Jun 2021, 8:46am, edited 1 time in total.
John
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squeaker
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Re: Swytch

Post by squeaker »

Oldjohnw wrote: 12 Jun 2021, 7:31am He bike in the article, a Specialized, was presumably a decent bike. Was the saddle destroyed for illustrative purposes to make a point?
Suspect some journalistic jiggery pokery going on :?
I decided to electrify a very old, very tatty hybrid bike,....But also I realised the bike I was going to use had carbon forks, and I was wary of putting too much strain on them.
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Paulatic
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Re: Swytch

Post by Paulatic »

Oldjohnw wrote: 12 Jun 2021, 7:31am Was the saddle destroyed for illustrative purposes to make a point?
More than likely as I find it hard to imagine anyone riding it in that position.
The Swytch advert targets me most days on YouTube and I think it is also one I’ve watched right through the first time. All looks great initially but soon resemble a lot of marketing hype.
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Richard D
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Re: Converting an old bike to an ebike

Post by Richard D »

I’ve just fitted a 250w torque-sensing Tongsheng motor and 48v battery to my wife’s Dawes Karakum. It was pretty straightforward; if you know how to service a bottom bracket or install Dynamo lights this is no harder.

Not really tried the bike yet, as it’s developed a problem pushing its front tyre off the rim. So only taken the bike round the block for a test. But I like it a lot so far (apart from the fact that the bike is way too small for me - and that’s with me riding a 52!)

The battery was from eBay, the motor from AliExpress. And its much better than the Swytch kit for about the same money - bigger battery, more torque on the motor, crank drive not front hub, and a torque sensor instead of a cadence sensor for much more natural feel. So you can buy the right stuff from China (it’s where most things are made after all). But it’s worth getting the right advice - I did a lot of reading on forums such as Pedelecs first.
Jdsk
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Re: Converting an old bike to an ebike

Post by Jdsk »

Richard D wrote: 12 Jun 2021, 9:24am I’ve just fitted a 250w torque-sensing Tongsheng motor and 48v battery to my wife’s Dawes Karakum. It was pretty straightforward; if you know how to service a bottom bracket or install Dynamo lights this is no harder.
That's a useful way of describing it.

Thanks

Jonathan
Bonzo Banana
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Re: Converting an old bike to an ebike

Post by Bonzo Banana »

Govnor wrote: 7 Jun 2021, 6:52pm
iandusud wrote: 7 Jun 2021, 1:31pm
tatanab wrote: 7 Jun 2021, 10:48am
https://www.gov.uk/electric-bike-rules
Basically, age limited to over 14, power limited to 250W and assisted speed limited to 15.5mph
This. Also be aware that using a non-legal ebike on off-road trails is also illegal unless it is private land and you have the land owner's permission.
Ta
That had me wondering why there is no warnings as I would have bought 1000w ones and not even considered it-surely trading standards should be chasing up this?
It's a really grey area with a huge number of ebikes on the road above the 250W legal limit. In fact commercial ebikes Bosch based etc have been shown to have peak watts up to about 800W without any modification etc. They may claim a sustained, nominal or rated 250W but most ebikes exceed that. What mustn't be exceeded is the 25Kph assisted speed. No commercial legal ebikes do that unmodified although I'm sure some may slightly exceed it as there is bound to be a tolerance. There are videos on youtube of people riding ebikes at 30mph assisted on country paths and the evidence is clearly shown but they don't seem to fear any form of prosecution. Many ebike kits have a fallback legal mode.

Many of the ebikes sold as 250W in the UK are sold as 350W elsewhere outside Europe etc, its the same motor etc just in the UK they are stating 250W and limiting it to 25kph.

On the popular Voilamart kits the direct drive motor is the same across many wattages; i.e. 500W, 1000W, 2000W it is just the control box that is different allowing more power.
Richard D
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Re: Converting an old bike to an ebike

Post by Richard D »

It'll be the motor controller's firmware that keeps it within the EU/UK limit. The same manufacturer will sell a motor rated for 350W/500W/1000W - same motor, but different firmware (raising the current draw for more power, possibly updating the controller circuitry to handle the increased current, increasing the top speed, removing the requirement to turn the pedals etc).

Is it possible to flash the firmware to create a more powerful ebike? Yes it is. And it’s not particularly difficult. Except that you’re not creating a more powerful ebike, you’re creating an electric motorbike in the eyes of the law, so unless you fancy wearing a helmet/registering it/obtaining insurance then you shouldn’t do it.

I have no intention of flashing the firmware on the motor I’ve just fitted to increase the speed/power. 15mph is plenty. But I MIGHT flash the firmware to get around a known bug with this particular unit, that the power assist cuts out at around 90RPM (a limit around 105-110RPM would be more useful and realistic - noting that at such a high cadence you're not going to be applying much torque to the pedals, therefore won’t be getting much assist anyway).
Richard D
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Re: Converting an old bike to an ebike

Post by Richard D »

Jdsk wrote: 12 Jun 2021, 9:29am
Richard D wrote: 12 Jun 2021, 9:24am I’ve just fitted a 250w torque-sensing Tongsheng motor and 48v battery to my wife’s Dawes Karakum. It was pretty straightforward; if you know how to service a bottom bracket or install Dynamo lights this is no harder.
That's a useful way of describing it.
Of course, I should be careful not to describe it as easy. I’m *not* a trained - or even amateur - bike mechanic. I can however fettle brakes, swap cables, tune the derailleurs (though I haven’t completely tamed one of my FDs yet - they are finicky beasts, after all), and over Xmas I replaced my groupset on the summer bike (done with the aid of YouTube videos and a great deal of swearing). In the course of which I’ve picked up a few specialist tools (like pedal spanners) and a little bit of knowledge.

In terms of the conversion, fitting the rear rack and battery was no harder than fitting ANY pannier rack. Four Allen bolts and a bit of fiddling. Ditto placing the controller on the handlebars and cable-tying the wires out of the way. Actually installing the motor wasn’t at all tricky - once the old chain set was off and out, and the BB she’ll cleaned up a bit, it was simply a case of putting it through the hole, doing up three or four Allen bolts and screwing the crank arms and pedals on.

It was all common sense stuff, but again there are loads of YouTube videos where people walk you through the process,

The only tough bit was removing the old crankset. This needed a crankset puller (I didn’t have one, so that was £8 spent at Wiggle. And using a BB removal tool - which I DID already have (in a cheap Lidl cycling tool kit). But the ruddy thing was on TIGHT. I've rarely had to push so hard on something to get it to shift - and that was using a 1/2” square drive long arm torque bar I had lying around, from a cheap Aldi car toolkit. Oddly enough, it was in my junk box waiting for me to take it to the tip; so glad I'd not got around to it, and I'll be keeping that particular part of the toolkit now I know how useful it is!
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