Yes, it is possible you can be found 100% fault for your bicycle accident; or, you can be held liable under California law as an "apportionment of fault."  For example, you can be found 0%, 50%, 60%, or 25% at fault, depending on the facts of the accident.  Also, your bike injury may be due to a product, or mechanical defect of the bike itself, or to unsafe roadways, in addition to unsafe motorists.  If a mechanical bike defect, or unsafe roadway is alleged, this needs to be reviewed and confirmed by an expert.