wisper one week on

[Beej]

I have had my Wisper se for just over a week and despite the weather have managed 50 or 60 miles, including a 20+ mile trip with my trailer for the weekly shop (includes heavy items like spuds and a gallon of scrumpy, so quite good going). Apart from an annoying squeak from the bottom bracket region (any ideas?) it is fine.

The rolling resistance seems quite high and quite variable, almost as if the motor is opposing the freewheel sometimes?

What exactly does the assist sensor sense? Does it provide variable assist or is it effectively just a motor on/motor off device? I suppose what I am getting at is - is there a riding strategy for achieving maximum economy/range, as when driving a car, or do you just get what you get regardless?

Beej

 

[Mussels]

I have had my Wisper se for just over a week and despite the weather have managed 50 or 60 miles, including a 20+ mile trip with my trailer for the weekly shop (includes heavy items like spuds and a gallon of scrumpy, so quite good going).

Good to hear.

Apart from an annoying squeak from the bottom bracket region (any ideas?) it is fine.

My sprung seat post has an annoying squeak even after I strip it and apply grease, is it that?

The rolling resistance seems quite high and quite variable, almost as if the motor is opposing the freewheel sometimes?

There is an internal freewheel so the motor doesn't drag like on some other bikes, however without power pedaling feels a bit like swimming in treacle. I have improved this by changing the chainring but you can't avoid the fact that it is a heavy bike.

What exactly does the assist sensor sense? Does it provide variable assist or is it effectively just a motor on/motor off device? I suppose what I am getting at is - is there a riding strategy for achieving maximum economy/range, as when driving a car, or do you just get what you get regardless?

Beej

The pedal assist kicks in when the pedals turn forward and IIRC it offers about 80% of available power up to 15mph. Maximum efficiency is achieved at higher speeds using just pedelec, pretty obvious as you are pedaling quite hard then. The motor is not at it's best under 10mph but I don't know the exact optimum speeds.
I could quite easily sit here and drink the whole gallon right now.

 

[flecc]

Even though the motor has a freewheel, when pedalling without power the orbital gears in the hub still have to be turned by your effort since the freewheel only disconnects the motor. Hence the drag.
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[wibble]

I had an annoying click on my Wisper at the start. It was coming from the righthand side, near the crank area. I wasn't sure if it was the chainwheel, crank, chain or pedal. So I took a guess at the pedal and added a little grease to the thread and bingo!. Problem solved!

and yep, I also thought that there was considerable drag when going down slight hills. But I thought that maybe it was just me needing an haircut. So nice to hear somebody else has noticed it too!.

 

[Mussels]

Even though the motor has a freewheel, when pedalling without power the orbital gears in the hub still have to be turned by your effort since the freewheel only disconnects the motor. Hence the drag.
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Would this affect freewheeling or just when pedaling? There seems to be little rolling resistance unless I'm trying to pedal.

 

[flecc]

Would this affect freewheeling or just when pedaling? There seems to be little rolling resistance unless I'm trying to pedal.

There is always some rolling resistance in these hubs when gliding or pedalling without power. The hub shell has a toothed gear ring inside and three orbital gears run on that, in turn rotating against the gear wheel at the centre. The orbital gears are mounted on a frame fixed to the stationary spindle so have to rotate as the wheel and hub turn.
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[flecc]

P.S. to above post. On my Torq Talk site linked below you can see a colour coded drawing of the principle internals with a description of the working of these Suzhou Bafang motors. In addition there's an animation of a Hall motor with a description of how it works, and the animation can be stepped through slowly to aid understanding.

There's also three photos of a stripped Suzhou Bafang motor with a description of it's parts and working.

Motor details
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[JohnInStockie]

... Apart from an annoying squeak from the bottom bracket region (any ideas?)

It might be an idea to tighten you pedal crank, I found a rythmic '..errkk' developing on a couple of the bikes Ive had in the past and it was always that the pedal arm wasnt on straight / tightly.

hth

John

 

[fcurran]

It might be an idea to tighten you pedal crank, I found a rythmic '..errkk' developing on a couple of the bikes Ive had in the past and it was always that the pedal arm wasnt on straight / tightly.

hth

John

It's a good idea to check and tighten all nuts and bolts including crank arms etc after a short period of purchasing a new bike. This is common practise in the cycle industry and quite a few shops will offer a free 4 week check on new bikes where this sort of thing is checked. They will also adjust brake and gear cables as all new bikes will have some form of cable stretch.

Regards

FrankC

 

[Beej]

I seem to have cured the squeak. It seemed to come from under the bottom bracket, where what I presume is the sensor is adjacent to a disc which goes around with the pedals. A liberal dose of WD40 has done the trick.

Other thoughts:

I may well end up replacing the seat pillar (I am tall, with arms like Mr Tickle). Why don't Wisper offer a choice of seat pillars and handlebar stems to obviate the problem of a one-doesn't-quite-fit-anyone frame?

The battery lights seem very vague. I can get it to show just the red while pedalling, even though it shows green when freewheeling. I am hoping that the freewheeling reading is the more reliable indicator of how much juice I have left?

I have already replaced the wireless speedo, which just generated random numbers (it was cheaper than going back to Bristol to sort the problem).

Beej

 

[Mussels]

I seem to have cured the squeak. It seemed to come from under the bottom bracket, where what I presume is the sensor is adjacent to a disc which goes around with the pedals. A liberal dose of WD40 has done the trick.

Other thoughts:

I may well end up replacing the seat pillar (I am tall, with arms like Mr Tickle). Why don't Wisper offer a choice of seat pillars and handlebar stems to obviate the problem of a one-doesn't-quite-fit-anyone frame?

I'm an average height and have the seat post past the max marks, it is all pretty low.

The battery lights seem very vague. I can get it to show just the red while pedalling, even though it shows green when freewheeling. I am hoping that the freewheeling reading is the more reliable indicator of how much juice I have left?

It's more of a volt meter, accurate battery life meters don't really exist and what you have is the norm it seems.

I have already replaced the wireless speedo, which just generated random numbers (it was cheaper than going back to Bristol to sort the problem).

Beej

I've just replaced mine with a cheap wired one and it's nice to have a reliable speedo.