My insurer have asked for an assessment of my damaged bike, the shop has recommended a new bike as this offers the best value (sum of parts etc). Assuming that the insurer agrees to this assessment and pays for the replacement what happens to the old bike? Do I get to keep it? Some parts are serviceable and would make good upgrades/spares for the new bike. I cant imagine why the insurer would want the old bike, what are peoples experiences?

the old bike would belong to the insurance co. You can probably buy it back for pennies tho

Technically the property of the insurance company but they are unlikely to want it. Wait till they’ve paid out then ask what they want you to do with it. Chances are you will get to dispose of it