Hopper Urban/ Coyote Connect/ Viking Harrier Problem?

[dedPiksil]

Hi all!

Please be gentle as I'm a complete newbie to the forum and to electric bikes in general! I've been trawling the forums looking for something similar to the problem I have but couldn't find anything so I was wondering if someone could help?

Here is the bike: https://www.tesco.com/direct/hopper-urban-electric-bike-burgundy/730-7949.prd?source=others

From when I bought it, it didn't feel like it was giving me much power when I'm pedalling even on high level assist. I came from a Dillenger Comfort so I know when an electric bike gives me a boost! After riding it for a week or so (a little less than 20 miles a day), I noticed the battery hadn't worn down much, just by one notch (80% - 100% on the battery light). I suspected that there was something wrong so on inspection - flipping it over and pedalling using hands - I found out two things:

- The motor didn't seem to kick in until after pedalling quite fast (in 1st or any gear)

- When it did kick in, it moved at a slow pace, as in not spinning fast as I guess I expected

Based on deduction - please tell me if you think I'm wrong - the battery seems normal as from the approx 100 miles I've rode, it's gone down a notch from full charge. I'm guessing this is the consequence of a small amount of assist if that makes sense, as opposed to the (idealistic) 25 miles I'm supposed to get with full pedal assist.

This leaves either the motor, controller or wiring... again, please correct me if I'm wrong!

Is there some kind of test/ repair/ replace motor etc. I could do? I think I'm competent enough to delve into it.

Unfortunately and very frustratingly, the seller is not willing to return the full amount I paid but is willing to give some back towards its repair.

Thank you in advance!

 

[signwave]

When did you buy this bike?
When did you take delivery of it?

 

[dedPiksil]

Hi Signware, sorry I was sure I mentioned it was preowned, I got it from Facebook marketplace.

 

[signwave]

Ah... I was going to suggest that as it appeared to be less than 30 days since purchase then you could reject the thing as not conforming to contract under The Consumer Rights Act 2015.

But if it was bought from a private individual, that does not apply.

 

[dedPiksil]

I was going to ask about the small claims court in case there was a chance but figured if the fault is easily fixable, I'd rather do that.

 

[Nealh]

Turn the bike upside down and have a look at the pas sensor and magnet disc, it should be on the underside or to the side of the bottom bracket. It consists of a round plastic disc with usually 5 - 12 magnets on it, attached to the bottom bracket or frame should be a small wired sensor that senses the magnet disc as it rotates. Some sensors have a red led and this should light when a magnet is sensed and indicates the pas is working. Ensure that the gap is about 1mm between the magnet disc and sensor and try to see if this helps the motor kicking in, it is possible they don't align correctly so may need repositioning. Some sensors have a small red led this should light up as a magnet is sensed, if of this type it should confirm the pas works. Whilst at it follow the wiring to the controller and check that the connector is mated properly as well as checking the wire along its run for any signs of damage.

Does the bike have a throttle if so does it work ?
Let us know how you get on then we can try other fault diagnosis if the issue isn't corrected.

 

[dedPiksil]

Hi Nealh thank you for the advice, I really appreciate it! I'll give this a go when I'm back home and will update.

I don't think it has an led but will check it. Throttle wise, it doesn't unfortunately. I was in two minds on whether to buy one to test it further as I understand it, the controller should have one of those 3 wire connectors for it. Didn't want to tinker in case the bike was under warranty.

Regarding the wires being connected properly, would the panel with the assist and battery level be an indication of whether it is connected properly or not? It seems to light up fine when turning it on but I guess to get the thing to work you'd have to turn it on no?

 

[Deleted member 4366]

Check out the pedal sensor as above to eliminate it as a possible cause because it's a quick and easy test; however, I don't think that's the cause of your problem. It sounds like you're permanently stuck on level one, which is the default setting when there's no signal from the control panel.It should kick in within two rotations of turning the crank, so if it doesn't there could be more than one problem. Can you confirm how far you have to turn the crank before the motor starts?

You can test the control panel to see if it's giving the right signal. There's 4 wires, normally red (battery voltage), blue (battery voltage when the panel is switched on), black (ground) and green (signal to the controller.

The green should have 1v on level 1, 2v on level 2, 3v on level 3 and 4v when you press the 4km/h button (if you have one). Test the voltage between black and green. The panel must be switched on. You have to open the compartment in the front of the battery to get at the controller, where you can get your probes up the back of the connector . Don't disconnect the connectors for testing.

 

[dedPiksil]

Ok guys, so it was a lot simpler than we thought.


Part of the 5 magnet disk was snapped off. Any idea how this could have happened? The disk itself is in an non obtrusive place so I can't see how it could have been broken by the rider.

Anyhow, the magnets missing from the disk were stuck to the front derailleur so I managed to align it in the gap with the disk properly adjusted (1mm - thanks @Nealh) and hey presto! Good power to the motor.

Took it out to work and it was a easy ride. It gave me a great boost every now and then but not consistent.

Is this normal or do you guys think it's because the disk isn't 100% in the correct place yet?

Also, I found a replacement on banggood for £4 - win!

When replacing the broken disk, apart from the 1mm gap between the pas sensor and the disk, how much of a gap should there be between the derailleur and the disk, if any?

 

[Nealh]

Good to hear that the fix was simple, always best to start with the very basics before buying lots of unnecessary parts.
A disc with 8 or more magnets should give a better smoother pulse and iron out the intermittent pas, though that could just be down to incorrect alignment with the sensor.
I think you mean the gap between disc and chain ring, it doesn't matter. On my hub kits the disc is attached direct to the chain ring as I have hollow tech bottom brackets with outer bearings shells.

 

[Deleted member 4366]

They break and/or get knocked out of line when the chain comes off.

 

[dedPiksil]

I think you mean the gap between disc and chain ring,

Ah yes, sorry I meant front chain ring. Great, I'll just snap it on and adjust the sensor and thank you for the 8 magnet advice. I give it a go and report back when it's all done.

They break and/or get knocked out of line when the chain comes off.

Thank you @d8veh that's good to know. I noticed that there were a couple o-rings wedged by the disk which I guess were used as spacers between the chain ring and sensor. Hopefully, by attaching the disk directly to the chain ring it should be less of a problem should the chain come off!