Above posts are not quite right/clear IMHO
1)you do not pay your excess if they claim of your insurance
2)It's likely both parties will be sharing responsibilty so you have to fight for 'repair your own' (as you know)
3) If you get left with a small % liability - you won't nesessarily lose NCB ask you insurance company what their policy is 10%???
4)If you're at fault your claims history will reflect value of pay out but maybe worth claiming for your bike if your
yellow curvy is w/o and you buy back salvage 
5) Give Riders support a call 020 8246 4900