what bike is this aaand...

[lectro]

..and why doesn't it go? Haha

Hi all,

newbie here, from north London, just got this electric bike but having some problems with it. First of all if I'm not wrong this is a Thompson electric bike?

There is a problem either with the batteries or the motor, need ur advice on this people, I've charged the batteries for couple of hours, under light throttle the wheel turns, when riding it enough to keep the momentum but when u try to accelerate, say more than half throttle it makes a vibrating noise, as if something slipping inside the motor. Can't figure out if its weak battery or weak motor is there a way of testing it? I've removed the rear wheel, I just need to find someone who can run a test and take it to them if its not a known fault..

Here's a picture, thanks everyone

Neil.

 

[neptune]

From what you have told us it is difficult to give a definitive answer, but at first glance, this sounds like a motor fault. One possibility is worn reduction gears, if indeed this is a geared motor. What you do next depends on your mechanical ability. Does anyone know if spares are available for this motor wheel?

 

[flecc]

It isn't a Thompson, their three models at the top on this link have scarcely changed over the last 10 years. All use internally geared rear-wheel brushless hub-motors, at first 180 watts and later 200 watts.

The front wheel motor on your one looks like it could be a direct drive one without internal gears. If it is internally geared they may be failing as Neptune says. Alternatively, if it's a Hall sensor motor with eight wire connection is could be one of the sensor or phase leads intermittent, connection failing on higher currents. Hopefully someone will recognise the make to help further, but I suspect it's one of the Chinese brands that only made it here in a small batch a while ago.

 

[lectro]

Front? No, there is no motor in the front, its on the rear wheel..

I'm good with mechanical things but never opened up an electric motor of this sort so I'm a bit hesitant.. I will take it apart to see how it works once I'm sure the motor is faulty tho, not anything else.. I'll take some better pics and post it up in a minute..

Thanks for the support

 

[flecc]

I guess that's just a large brake in the front wheel then, huge for a bike brake if so. That rear hub does look like an internally geared hub motor, so it's worth opening it up to check the internal gears. Also check the wiring into it at both ends and any connector that might be inline to ensure there's no poor connections.

I can't tell which motor type from that photo, but it's construction looks a bit like the one used in the Cyclamatic. Hopefully one of that bike's many owners can advise on stripping it.
.

 

[lectro]

Yea it looks like a Chinese brand, is Ebay the best place to look for spares?

No idea if the motor is geared but certainly the bike ain't ..I'll take more pics when I open it up

 

[flecc]

Thanks for the pic, that makes it much clearer, the construction looks like the usual Suzhou Bafang motor type. If you take out the 8 perimeter screws on the sprocket side and remove the innermost spindle nut on the other side, a sharp tap on the left hand end of the spindle should release the side plate from the shell to enable the innards to be withdrawn. If it's the internally geared type as I suspect, you'll see the epicyclic gears on the left hand side and be able to check them.

 

[lectro]

Right, I had time to open up the motor but I couldn't understand anything whether its geared or not lol.. Had a quick look, took coupe of pics and closed it back up. If I'm right its not geared and it looks fine to me. Anything unusual on the pics guys?

Cheers,

Neil

 

[morphix]

I've seen motors like this with similar spoked wheels being sold by Chinese suppliers online..so you may be able to get a suitable replacement fairly cheap and swap the wheel out, but it depends on what sort of motor is.. you may have to replace the controller too to go with a new motor.. Are you sure you want to keep this bike to send money on it, assuming it's not a simple fault like flecc suggested which you can put right?

That bike looks more like it's for Chinese domestic market than UK..it's the typical moped style bike!

 

[flecc]

It's not internally geared, it's a typical direct drive motor. The problem may be Hall sensor failure or a connection intermittent failure in the leads to the controller. Since it runs ok at low power but vibrates at higher levels, a poor connection may well be the problem , so check the lead and any connector continuities first.

 

[Deleted member 4366]

Shame you couldn't have shown us a photo big enough to see. Can you take a photo looking down on it, upload it to photobucket or whatever you use, and post a link?

Assuming that it's a three phase motor, that sort of pproblem is often a weak connection to the phase wires - especiallly if you have those cheapo bullet connectors that come standard on most Chinese motors. If you have this type, pull them apart, crimp the barrel a bit so that it's a much tighter fit, and re-connect.

 

[lectro]

Ooh I thought you can enlarge the pic by clicking on it.. I'll upload one thru another web site when I get home..

Eerm, not really looking to spend money to be honest, if I can pin point the problem I'll have a go fixing it, otherwise I'm not looking to spend anything, probably put it on egay without a reserve.. I like the foldable electric bikes, want one of em

 

[lectro]

Right... its on Ebay, not prepared to spend money, time and space so decided to get rid of it and just get a new one.

Might be good for spares to someone..

http://pages.ebay.com/link/?nav=item.view&id=160904388226

Thank you everyone for your help and support with this bike.

Neil