Because they want to sell the new avinox system, that will be presented in March, with 1000 WH battery
That could be the case, but seems a little short sighted if that is really their thought process. Avinox already offers lighter weight 600WH main batteries for people looking to keep the bike as light as possible, so they recognize there is variation in how many WH people need. It seems like for any given battery size bike there are users who may want to add more juice for their particular use cases.
To my mind, the range extender could be a way for them to make more money, not less, as it could be an "add-on" sale for both current users with either the 600 or 800 WH battery, or next-gen users with the 700WH or 1000WH battery. You might be a current user with the 600WH battery, who likes to keep the bike lighter for your weeknight rides, but wants to add the range extender for the big weekend epics. Even on the next-gen stuff, you might have the big daddy 1000WH battery, but if you weigh 100kg and want to do a big ride in the mountains with 6000ft+ of vert, you still might want additional capacity beyond what the new bikes will max out at. My point is, offering the extender could basically be an easy upsell for a significant number of users.
@TrailwattsUK Thanks for the update on your development process, and I will be keeping an eye out for further updates and end-user reports. The lack of a range extender is one thing that has made me hesitate about getting an Avinox-equipped bike, so if your setup proves to be a reliable option, it would make me more likely to buy into that ecosystem. Regarding the warranty aspect, I wouldn't hesitate to use one on a motor that was out of warranty. On an in-warranty motor, I'd still use one,
IF the modifications could be reversed without leaving a trace in the event that I needed motor work to be done by a dealer. On that point, if I remember correctly, on your current kits that require a loom swap, one needs to modify the stock wiring harness by splicing in the new loom. I don't know how easy it is to acquire complete wiring harnesses or have compatible ones manufactured but, to keep things reversible for "in-warranty" motors, I'd prefer the option to buy a whole new dedicated wiring harness with your loom. That way, the stock one could be kept unaltered for refitment if needed.