Bike insurance is a recommended requirement for anyone riding a motorcycle on the road. It protects you against liability you may have if your bike is involved in an accident and damages another vehicle or injures another person.
Third party insurance is the cheapest option. It provides the basic motorcycle cover and pays out for damage to someone else or their property if your bike is involved in an accident. However, it doesn't cover repairing or replacing your motorcycle.
Third party, fire and theft insurance provides the same cover for your motorcycle as third party insurance, but in addition it covers the cost of repairing or replacing your bike if it's stolen or damaged by fire.
A no claim bonus is effectively a reward that an insurance company gives to policy holders who do not claim on their insurance policies for a specified period of time. The exact parameters, requirements, time periods and rewards vary from insurance company to insurance company. These bonuses are part of the benefits that insurers market to prospective clients and many people seek out specific bonus features as part of what they look for when sourcing an insurance company to tend to their insurance needs.
All motorcycle insurance policies will expect you to pay the first part of any claim, this is called a compulsory excess. How much this will be will depend on the individual policy and on the claim.
You may be able to reduce the cost of your motorbike insurance by paying a higher voluntary excess, an amount in addition to the compulsory excess. Generally speaking the more you agree to pay the cheaper your premium.