hemo wrote:....... a closed ebike system is one I won't entertain due to lack of being able to maintain it.
Seem to be parts available for Bosch motors... https://www.performancelinebearings.com ... it-bdu2xx/
Replacement bearings, gears etc. If its a circuit board or module you have to go back to Bosch anyway. After all it isnt something very simple like a normal bike where you can replace parts easily.
Hemo's point is a good one: many e-bikes seem rather too monolithic and difficult to deal with should something of the motor, battery or gearbox go wrong. Many seem to use a very small front chainring too, which is surely going to be a weak point. And if the motor or battery goes defunct during a ride, the monolithic e-bikes tend to weigh rather a lot.
For this and other reasons I'll once more mention the Fazua Evation e-bike design, which carries the motor and battery as an easily-splittable and dropout-able module in the down tube, with a normal chainset attached to a BB gearbox connecting the motor to that chainset. This has several advantages over more monolithic e-bike designs.
* The motor/battery can be dropped out of the frame with one button press, in a second. The bike then functions as an ordinary bike. Most manufacturers of bikes with the fazua motor/battery offer a blanking plate to put over the empty chamber in the down tube, although the bike is structurally rideable without.
* Because the bike itself needs very little if any additional bits to cope with the motor, Fazua bikes can be light compared to BB motor bikes. 13-16 Kg is typical, depending on the other component and frame weights. This drops by 3.5 kg if the bike is used with the motor/battery out.
The battery can be taken in one second so it can be removed elsewhere to charge. This is a great benefit if your bike cannot be kept near an electricity source for the charger; or id kept in an environment (such as an outdoor shed) that might be detrimental to the charger and battery.
* Should the battery or motor fail, they can be replaced with another motor or battery module. No tools needed. The simple gearbox in the BB is also a module although that needs tools to remove and replace. The failed motor module, should you ever have one, is light enough to post away to Fazua for a fix or replacement if still under guarantee.
* If a significantly better battery or motor became available, the modular design would allow an easy "upgrade".
Some hub motored e-bikes have similar advantages, although many seem to embed the battery in the frame in a way that doesn't make it easy to get in and out. In addition, a new motor needs a new wheel or wheel rebuild.