Removing the 905SE rear wheel to replace the freewheel

[Mussels]

The design of these has changed over time so yours may not be quite the same, but it probably is.
To remove the freewheel you need a special tool, this is a socket that needs to be slid all the way down the motor cable. It should be simple but there's a plug and socket to make connecting the hall sensors easy. The plug won't fit through the tool needed to change the freewheel, no wonder normal bike shops don't want to touch electric bikes.
I found in the end I was able to dismantle the plug without causing any damage or a lot of work, if you slide a small hex (Allen) key down the side of the pin it pushes the retainer spring back and enables the connector blade to be taken out of the back of the plug. This then leaves you with 5 thin wires and 3 bullet connectors which can be guided through the middle of the tool and down to the freewheel, remember to take the wheel nut and washer off first. All the electrical work is done gently, if you are using force then something is up.
Whole thing can be completed in an hour, have fun.

 

[Phil the drill]

Hi Mussells
Not sure which model year your Wisper is, but mine is April 2008. I found that the following freewheel removal tool works fine (I used it to change my rear cluster to an 11-34t one).
Cyclepro Multi Freewheel Remover Shimano Uniglide Cycle Accessories Workshop Bicycle Tools General Maintenance Cyclepro Multi Freewheel Remover Shimano Uniglide
The square hole, designed to fit a standard 1/2" socket set is big enough to allow the connectors through without dismantling the plug. Cheaper than most others too .
Cheers, Phil

 

[Mussels]

Hi Mussells
Not sure which model year your Wisper is, but mine is April 2008. I found that the following freewheel removal tool works fine (I used it to change my rear cluster to an 11-34t one).
Cyclepro Multi Freewheel Remover Shimano Uniglide Cycle Accessories Workshop Bicycle Tools General Maintenance Cyclepro Multi Freewheel Remover Shimano Uniglide
The square hole, designed to fit a standard 1/2" socket set is big enough to allow the connectors through without dismantling the plug. Cheaper than most others too .
Cheers, Phil

My bike was delivered at the same time as yours and I bought the same tool in your link and there is no way the plug would fit through the tool, there's a photo that shows it next to the crank dust cap.

 

[Phil the drill]

My bike was delivered at the same time as yours and I bought the same tool in your link and there is no way the plug would fit through the tool, there's a photo that shows it next to the crank dust cap.

Interesting, I've got a different plug arrangement on my Wisper, so problem was easier to solve. However, as you say, it isn't that difficult to remove the connectors from the plug if necessary.

Phil