Regretable a Dawes bike owner

[Kevin Davies]

Hi

Can anyone help?

We are the owners of a Dawes Suburbia electric bike.

Its about two years old and hardly used.
Back in September of 2016 it was taken out for a ride and the motor stopped working.
Support from Dawes to rectify this situation has not been straight forward.

We live in Poole and looking for a replacement wheel, or motor of equal or better spec.

Thank you in advance.

Kevin

 

[Nealh]

Are you sure its the motor ?
Start with the battery, charge it first and check the voltage output with a volt meter.

 

[Kevin Davies]

yes, there are horrible sounds coming from it for the couple of seconds it bursts into life

 

[Kevin Davies]

The specs for the motor can be found here.
http://www.syimotor.com/products_detail/&productId=7313d96f-a0e6-41a9-8008-16235901a3ea.html

 

[Nealh]

For a 2 year old bike hardly used a motor issue seems uncommon as they are quite robust. What makes you say a definite yes !!!
Have you ruled out a weak battery, blown fuse and checked all wiring connections esp the motor connection.

 

[Kevin Davies]

I quite agree, yes the items you mentioned have been thoroughly checked over.

Feeling very sick over the whole process.

 

[Deleted member 4366]

The noise from the motor is often caused by electrical problems outside of the motor. To check whether the motor is faulty, you need to disconnect the cable, then rotate it by hand forwards. It should turn freely. Then, turn it backwards. You should feel a slight resistance and roughness. The roughness is more notchiness as each magnet passes each coil.

If it works as described above, connect the motor cable and turn the motor backwards. It should feel the same as it did before. If there's a totally different feel (jamming), there's a problem in the cable or in the motor controller.

If both those tests are OK, open up the box at the front of the battery where the motor controller sits and pull apart all the motor connectors, then reconnect them to see if the problem goes.

The biggest cause for rough running is when the bike falls over and the motor cable gets damaged where it comes out of the axle, so check it there carefully.

 

[cyclebuddy]

We live in Poole and looking for a replacement... ...motor of equal or better spec.

If you're convinced it definitely is the motor, and you've already identified the actual motor you need as being from Syimotor, why not email them? The link you give shows their website is dual language (i.e. they speak English!), has both email and live-chat, and, if they won't sell/ship you one direct, their world-map of resellers for their motors shows they have importers/sellers throughout Europe (inc the UK). Just a thought.

 

[Kevin Davies]

emailed them numerous times, no reply...

 

[Kevin Davies]

The noise from the motor is often caused by electrical problems outside of the motor. To check whether the motor is faulty, you need to disconnect the cable, then rotate it by hand forwards. It should turn freely. Then, turn it backwards. You should feel a slight resistance and roughness. The roughness is more notchiness as each magnet passes each coil.

If it works as described above, connect the motor cable and turn the motor backwards. It should feel the same as it did before. If there's a totally different feel (jamming), there's a problem in the cable or in the motor controller.

If both those tests are OK, open up the box at the front of the battery where the motor controller sits and pull apart all the motor connectors, then reconnect them to see if the problem goes.

The biggest cause for rough running is when the bike falls over and the motor cable gets damaged where it comes out of the axle, so check it there carefully.

I'm more inclined to open the motor up, remove the 'Grit' which could be broken ball bearings....

 

[Alan Quay]

I'm more inclined to open the motor up, remove the 'Grit' which could be broken ball bearings....

If you perform the tests that D8veh has taken time to describe you will solve your problem quickly and with least cost.



Sent from my HTC 10 using Tapatalk

 

[cyclebuddy]

emailed them numerous times, no reply...

It seemed surprising to me that the motor maker Shengyi didn't respond. So I tried emailing them myself using sales@syimotor.com and using the details of the motor you needed from the web-site link you gave. I said...

"Hi.
I need to buy a replacement DGW07C-RA 36-volt 250 watt hi-speed motor. I am in the UK. Can you supply direct or is there a UK or European partner I can buy from?
Many Thanks"

And they replied:

Shengyi is willing to provide you DGW07 motor

Dear (my name deleted),

Thank you for your contact. Yes, we can provide you the motor DGW07 directly. Which company do you buy from? The E-bike manufacture in China?

Kind regards,
Daniel Dai

International market
SuZhou Shengyi Motor CO.,LTD
Tel : +86-512-65977525
Fax : +86-512-65975022
Web: www.syimotor.com

I'm guessing Dawes gave you the name of the motor supplier, and maybe Shengyi are asking which Chinese factory produced the bike for Dawes so they can check which specific motor of the many variants they make and supplied for that model. It's a response, and progress if you decide you do need to buy a new replacement.

 

[Deleted member 4366]

I'm more inclined to open the motor up, remove the 'Grit' which could be broken ball bearings....

There is no grit in there, so you can't remove it.

Do the tests to find the cause of your problem. Don't bother the motor manufacturer or waste your money on a new motor until you know the cause of the problem.

Just because it feels like there's a problem in the motor, it doesn't mean that there is something wrong with it. 9 times out of 10, the cause is outside the motor. You need to read up on how a three-phase sensored motor works.

 

[Deleted member 4366]

All 250w rear hub-motors work the same. There's just two main differences: sensorless (less than 8 wires) or sensored (8 or more wires); however, even if you bought a replacement from Shengyi, there's no guarantee that it'll be directly compatible with your bike because the same designation motor can be fitted with or without an internal speed sensor and they fit a range of different connectors and cables for different manufacturers.

You need to determine whether your bike has a free-hub or freewheel gear-set (13 or 14 teeth on top gear is freewheel, 11T is free-hub), what length of cable from the motor to the first connector and exactly which connector you have and the number of pins, then you can use any motor with that configuration, which gives the opportunity to get one in the UK and/or a better one.

As I said above. Order a motor if you want to waste your time and money and get further grief/frustration, otherwise, find out what's wrong with your bike first.

 

[awol]

My motor sometimes makes a horrible juddering sound when one of my phase wire connection comes loose and sometimes I when have a bad connection in my hall sensor pins connector so it is worth taking the above advice on those checks first.