Sprint - loud noise

[Jeanette Morgan]

Any ideas what the problem could be ?- if, indeed, it is a problem.

My husband was climbing a steep hill in pedelec mode, the bike was straining and he came to a halt - I think it is possible the automatic cut out on the motor (I believe there is one) came in as he could not get the motor going again, despite the green light on the switch. However, he had forgotten about E-mode, so this could be why the bike motor seemed to fail him at that moment. He pushed the bike to the top of the hill and after after letting the bike stand for a short while (he 'phoned me at work !!). I advised him to switch into E-mode and turn the throttle and, thank goodness, he had power and happily cycled home.

Today the bike worked fine but there it is not as silent as it was, in fact it was very noisey. It is very loud when pulling in the power (it settles once going along), the motor seems to be pulling well, and I am curious that in fact it is a vibration of something as pushing and pulling various "bits" did seem to almost cure the problem. He can't remember the noise yesterday but he was rather worried about getting home so did not notice that aspect.

Does this sound as if he has caused a problem to the motor? Any suggestions?

It's good to share concerns on this site, I do hope that it will settle down. This is a brand new Sprint our two had to be changed out by 50 Cycles due to a "product recall" as prevoiusly mentioned in other threads. Could it be that they do just get noiser as they run in?

 

[Ian]

Hi Jeanette,

it is most likley that that bike stopped due to the battery voltage falling to the cut off point, this can happen when the bike is working hard even with a fully charged battery. When this happens the controller must be reset before the motor will operate, this simply means turning off the key, and after a few seconds turning it back on, it must be the key switch though and not the handlebar mounted switch.
As for the noise it's difficult to tell without hearing it, but motor noises do vary, a certain amount of vibration at certain speeds and throttle settings is normal, and results from the motor being switched on and off very rapidly to regulate its power, this in turn can cause muguards and other fittings to vibrate and add to the noise, and there's also a psycological aspect to it, once you've heard it once you'll listen for it. If the bike can still deliver full power and is still smooth at low speeds it is probably performing normaly. The Sprint has a powerful, normaly very reliable motor which in the UK version operates at well below its potential maximum output and is unlikey to have been damaged.

Ian.

 

[Jeanette Morgan]

Dear Ian,

Thanks for your thoughts, in fact he did turn the key so I am sure you are correct. Will see how the noise goes, hopefully it will disappear, and as you say, we should try to ignore it as much as possible. It is reassuring to know that the motors are hardy, which is what I had hoped you would say.

I'll keep an eye on it an post again on progress.

Jeanette