Insurance or accept cash to repair it myself?

[agricola]

An assessor should come to look at the bike damage. He'll sent the info with an estimate to the insurers. You will be made an offer. You can refuse the offer and try to get it revised upwards. You should try this as the insurers will try to get away with the least cost to themselves. They are not interested in you. They are just trying to save money.

Good luck with it