What test do I need to take?
There are 3 categories of full licence to aim for:

Category P – moped.

Sub-Category A1 – light motorcycle licence, which restricts riders to any bike up to 125cc and a power output of 11kW.

Category A – standard motorcycle licence.
Moped and Motorcycle tests normally consist of 2 separate parts – a theory test and a practical test.

Theory Test

You will probably need to pass a Theory Test before taking a practical test for a moped or a motorcycle.

You do not need to take a theory test if you already hold a full licence for another category of motorcycle or have passed a moped test since 1 July 1996.

The Theory Test Pass Certificate is valid for 2 years. The practical test must be passed within this period otherwise the Theory Test will have to be taken again.

Practical Test
Category P, the practical test can be taken on any moped.

Sub-category A1, the practical test must be taken on a bike of between 75cc and 125cc.

Category A
The practical test is taken on a bike of between 121cc and 125cc and capable of at least 100 kph. After passing the standard motorcycle practical test you will be restricted for 2 years to riding a bike of up to 25kW and a power/weight ratio not exceeding 0.16kW/kg. After this you may ride any size of bike.

Riders over the age of 21, or those who reach 21 before their 2-year restriction ends, have further test options:

Direct Access
Those who do not already hold a full motorcycle licence may, after taking CBT and the Theory Test, if necessary, take the practical test on a motorcycle with a power output of at least 35kW. A pass will allow you to ride any size of bike.

All or part of the CBT course may be taken on either a learner bike or a large bike.

You may practise for the practical test on bikes larger than the learner bike specification provided:

You are accompanied at all times by a qualified instructor on another bike and in radio contact.
You wear fluorescent or reflective clothing and follow all other provisional licence restrictions.

Accelerated Access
Riders who already hold a full licence and reach age 21 while still within the 2 year restricted period and wish to ride bikes larger than 25kW, may practise and take a further test on a large bike.

The same test and practise conditions for Direct Access riders will apply.

Although you revert to learner status while practising, test failure will not affect your existing motorcycle licence entitlement.

Sidecars
Learners who wish to ride with a sidecar can practise on a combination with a power/ weight ratio not exceeding 0.16kW/kg.

On obtaining a standard licence (category A), you will be restricted to a combination with the above power/weight ratio for two years.

At age 21 learners may, only within Direct or Accelerated Access provisions, practise on a larger combination. But the test must be taken on a solo bike (physically disabled riders may take a test on sidecar combination, but their licence will limit them to riding combinations).

Note
1 bhp = 0.75kW
100 km/h = 62 mph (approx.)
1kg = 2.2lbs

Examples
11kW = 14.6 bhp
25 kW = 33 bhp
35kW = 46.6 bhp
bhp = brake horse power