I need to replace the brake pads of my Batavus (make) Cambridge (model) bicycle. They're drum brakes, so I don't know what's inside until I take it apart and it would be most convenient if I could do that after buying the replacement pads. Apparently there are different types/shapes. I've looked to no avail for information online. I'm surprised (and very annoyed) that Batavus don't provide online manuals. I hope that someone here might have the same bike or knows where to direct me for information online. Thanks in advance for any advice offered.