906 Alpino motor strange sound

[electro]

I have just bought the Alpino 906 26". The bike is excellent, i have only made 50Km, but a strange sound is coming from the motor.

The sound is metallic, like rubbing one metal to another and always heard between 14 -17 Km/h. Under and over that limit it stops.

It is not the usual sound of the hub motor and it does not change the bikes performance in any way.

Has Anyone experienced anything like that. DO you believe that it is a motor fault that it will occur at a later time?

 

[Mussels]

I've not heard that, could it be the brake disc?

 

[electro]

At first i athought it would be that but the sound is not heard in 5km/h nor on 30 km/h, just between 14-17Km/h

Furthermore, when i lift the front wheel in the air and spin it with the throttle, then sound is not there.

Sthrange thing.

 

[Mussels]

I do get noise from mine but it's fairly clear it's just a motor under load and it happens over a greater speed range, I wouldn't like to guess what is causing your problem.

 

[Mussels]

I just looked at the photo on the Wisper site and the bars look adjustable, I can see the angle markers on the side of the stem.

 

[electro]

thank you for replying.

in case the motor brakes down after the warranty expires , does anyone know the cost to replace it?

 

[Mussels]

thank you for replying.

in case the motor brakes down after the warranty expires , does anyone know the cost to replace it?

No idea I'm afraid but I've found the motors to be very robust. My last bike had a SB rear hub motor and after about 15,000 miles the plastic gears broke but they are cheap and easy to replace.
Wisper would be able to give you a quote if you're worried as they supply spares direct and from what I've seen they aren't out to make a profit on them, reassured customers seem to be more important.

 

[tjay26]

I had a similar noise but found that it was as mussels said the brake mount was just a fraction too close to the disc. I also have found that with the 13G spokes, they tend to make quite a noise under load when loose.
I also have the 906 Alpino 2010 version and no issues with the motor, over 3000 km and still going well.

I cant recommend enough the service I have had with Wisper and the service support, if you contact them direct I am sure they will help you with prices etc.

 

[Mussels]

At first i athought it would be that but the sound is not heard in 5km/h nor on 30 km/h, just between 14-17Km/h

I experimented on the way home today and my motor makes a noise under load at roughly those speeds, it's probably the same noise and nothing to worry about.

 

[electro]

Thank you all. i will have the spokes and the brake pads checked.

 

[northlondon43]

Motor noise

Just to let you know that I bought the Alpino in May this year and had exactly the same issue with the noise at 15-19kmph. I had the front wheel replaced but it didnt resolve anything. Wisper just said it was one of those things.....very annoying noise :-(

 

[Kudoscycles]

Are your bikes fitted with the Dapush motor? We experimented with that motor on the latest Kudos Eco cycle,it took more amps than the old Suzhou Bafang motor,was noisier under load with some strange noises at certain speeds,also was heavy on battery usage but gave some additional hillclimbing power-we rejected it in favour of the well proven Bafang motor-as newbies to the electric bike world this seemed to us the historically proven option. I do think you guys are demanding more power from these nominal 250 watt motors which can only be achieved by increasing the controller amps,maybe pushing the envelope to extremes.
Kudos do not want to use this motor because of our loyalty to the LifePo4 battery,we would need to increase the battery Ah to 16 plus to achieve an acceptable range which would increase the battery weight to levels which would affect the handling of the bike and increase the battery cost to an unacceptably high price point,we are trying to keep replacement battery cost below £250.
Maybe,you are all just trying to get too much assistance from these small motors.
Dave
Kudos Cycles

 

[Mussels]

Are your bikes fitted with the Dapush motor? We experimented with that motor on the latest Kudos Eco cycle,it took more amps than the old Suzhou Bafang motor,was noisier under load with some strange noises at certain speeds,also was heavy on battery usage but gave some additional hillclimbing power-we rejected it in favour of the well proven Bafang motor-as newbies to the electric bike world this seemed to us the historically proven option. I do think you guys are demanding more power from these nominal 250 watt motors which can only be achieved by increasing the controller amps,maybe pushing the envelope to extremes.
Kudos do not want to use this motor because of our loyalty to the LifePo4 battery,we would need to increase the battery Ah to 16 plus to achieve an acceptable range which would increase the battery weight to levels which would affect the handling of the bike and increase the battery cost to an unacceptably high price point,we are trying to keep replacement battery cost below £250.
Maybe,you are all just trying to get too much assistance from these small motors.
Dave
Kudos Cycles

That's pretty much what I've found going from SB to Dapush, considering the price difference (I agree it needs a bigger battery) the SB is a good solid choice.
Something you didn't mention is drag, I can pedal higher than the motor top speed on the Dapush but couldn't on the SB. However my average journey times are down now so lack of drag feels good but doesn't do much for journey times.

 

[electro]

Now, i have done 350km. The sounds continue but i am used to it. The Dapush motor looks to work perfectly altough the many different noises it produces
I am generally very happy with the bike. It has a lot of power and i get 40- 50km out of a full charged battery in full assist.

 

[Mussels]

That's pretty much what I've found going from SB to Dapush, considering the price difference (I agree it needs a bigger battery) the SB is a good solid choice.
Something you didn't mention is drag, I can pedal higher than the motor top speed on the Dapush but couldn't on the SB. However my average journey times are down now so lack of drag feels good but doesn't do much for journey times.

I've put a lower power controller in it now, it seems faster and quieter.

 

[Wisper Bikes]

Hi North London

I am delighted you are enjoying your Wisper Alpino, although I am sorry to read about the noise you are experiencing between 14 and 16kph.

We totally stand by the Dapu motor it is absolutely superb, we have had it independently tested and we now believe it is the best electric bike motor on the market today. We use it on our premium models because it will take a much higher current than the Bafang without overheating, will produce more power, and has a very much lower resistance when being cycled without power. Although more expensive than the Bafang it is certainly worth the extra investment.

We have recently manufactured a new output fuse cap holder having found the standard unit we were using was restricting the current. If you would like to drop me a line I will send you a new one, hopefully this will reduce any noise you are experiencing. We have also just finished reprogramming the controller to give a higher output and to allow more power to be sent to the motor without the motor protection system cutting the power. If the fuse cap holder mod does not cure the noise the new controller certainly will.

Bafang make a great motor, very reliable, we still use it on our standard se and eco bikes and will continue to do so for the foreseeable future.

Please drop me a line with your address and I will get a new fuse cap holder out to you.

Best regards

David

 

[ColinJH]

I appreciate that this is now an old thread, but have recently acquired a new Alpino 906 (end November) with 28inch wheels and a also experiencing a noise from the hub around 17 to 19 kph. I have mentioned it to my dealer who advised that it could still be a matter of the hub running in ( have so far only covered 110 kilometres), but am now concerned that this is the same problem being experienced by others. In fact an online magazine review dating back to 2010 mentioned a hub resonance at these speeds, but this was reported as being something that Wisper were aware of and had resolved. The resonance certainly stops once past the 21kph point, but should I be concerned and go back to my dealer?

 

[Deleted member 4366]

Nothing to worry about. It's covered by warranty for a long time yet. It's not unusual to get resonance noises from motors. If that's what it is, it'll probably go away sometime in the future. You can check it's not the brake by applying the brake slightly when it's making the noise.

 

[ColinJH]

Nothing to worry about. It's covered by warranty for a long time yet. It's not unusual to get resonance noises from motors. If that's what it is, it'll probably go away sometime in the future. You can check it's not the brake by applying the brake slightly when it's making the noise.

Thanks d8veh,
It's definitely nothing rubbing as front wheel spins cleanly, it's only when the bike reaches this particular speed range, the sound then goes when passing this or if I decellerate. As you say plenty of time on warranty still, just baffled that a supposedly fixed problem has arisen on a brand new bike of latest vintage.

Otherwise thoroughly pleased with the bike, it's a great piece of machinery

 

[Pharisee]

I had a similar screeching 'resonance' on my 905 City. It turned out to be the plastic chainguard. The chainguard was made in two parts, one sliding inside the other to give some length adjustment. The two parts being clamped together with a screw and nut. At certain frequencies, the two parts rubbed / vibrated against each other producing the annoying screech. The solution was simply to glue the two parts together once the correct length had been established.