Strange grinding noise from back wheel

[dodgyal]

I've had my Wisper 905se for about 6 months now and love it! I dont even think about getting in my car for work anymore, rain or shine!

I have noticed a high piched grinding / rubbing noise coming from the back wheel at speeds over 18mph which seems to get worse the faster I go. during this speed I've turned the power off just to make sure its not related to the power, but its still the same. I've check the usual, brakes tyre etc, I've also noticed when I pick up the back wheel and spin it the hub looks off centre to the outer rim, I get a slight bounce up and down, but the wheel is not buckled.

Anyone else expeienced this? Know what it could be?

 

[Mussels]

Is the noise continuous, rythmic or occasional?

 

[Blew it]

dodgyal

Two things you need to check as a matter of urgency!.

Make sure the motor cable is not rubbing against the tyre, if it is, re-secure it with a cable tie. This can be found on the chainside of the machine.

Wisper 905 wheels need a little attention during the first 400 miles. Starting at the valve, pluck each spoke with a fingernail....it should give a nice "ting". If it's more like a "thunk" then the spokes need re-tensioning, Preferably by a bike mechanic as it's easy to pull the wheel out of true.

The "bobbing" is quite normal on bicycles and is due to the weight of the valve un-balancing the wheel.

As a matter of interest, sometimes the high frequency vibration from the motor, particularly when running fast, will create a "zinging" sound from the wheel.....even if the spokes are correctly tensioned.

Regards

Bob

 

[dodgyal]

Thanks Blew it, I'll check my spokes tonight, I have made sure the motor cable is secure, it has a cable tie on already, I checked this when I puchased after reading the forum.

Mussels, the noise starts occasional and the faster I go it becomes permanent, it almost sounds bearing related (simmilar to my campervan which also needs its front bearings changing! )

 

[Andrew harvey]

Lift the rear wheel of the floor and check for any side to side play on the wheel.
It sometimes happens that the bearing cups work loose over the first few hundread miles. If there is any play in the wheel the bearing cups need to be retightened, you will need to very slim spanners, or if you pass abike shop they should be able to tighten them for you in about 5 minutes.

 

[Wisper Bikes]

Grinding noise

Hi Al

Can you lift the back wheel off the ground and throttle it to full power, is noise still there? If not it maybe a gear problem in the motor.

Try all the suggestions that others have made as well as they are pretty comprehensive. If you still get the problem we may need to get the bike back to renew the gears for you. It is unusual on the Bafang A but it can happen.

You can also talk directly to our service manager Norman on;

service.wisper@wisperbikes.com

All the best David

 

[dodgyal]

Hi Al

You can also talk directly to our service manager Norman on;

service.wisper@wisperbikes.com

All the best David

Thanks David, no real noise from the motor when I use the grip with the wheel off the floor. I've sent norman a mail as I have another problem now too.

 

[Wisper Bikes]

Another problem?

Hi Al, you seem to be going through the mill!

Can you tell me what the other problem is?

Best regards David

 

[dodgyal]

Hi David, Yes the lock cylinder has fallen through into the battery. I can't use the bike anymore.

I've had no response from Norman yet.

 

[Wisper Bikes]

Problems

Hi Al

Sorry to hear about your problems.

I have asked Norman to contact you directly.

All the best David.

 

[dodgyal]

Thanks Norman for your prompt attention and getting me back on the road, now I just need to work out what is wrong with the back wheel.