Can you insist on travelling with your bike?
No. According to the 'National Conditions of Carriage' by which all train operating companies are bound, the operator can refuse an item of luggage if:

• It might cause injury or inconvenience or damage to property
• There is not enough room for it
• The loading and unloading of the luggage may cause delay to the train
• The luggage is not carried or packaged in a suitable manner

In other words, the operating companies have a number of options to prevent you from taking a bicycle aboard. Rail-replacement buses can cause extra problems. Even if the railway company actively welcomes bikes, the bus driver is not obliged to carry it, so it's essential to be as concilliatory as you can. In practise, most are willing to stow the bike in the luggage hold if there's space, but you may need to remove various bits and pieces.

Folding bikes
British railway passengers are permitted to carry up to three items of luggage free of charge, including two large items (such as a folding bike) and one small item, such as a briefcase of handbag. Folding bicycles travel by rail as hand luggage under archaic rules that permit a package of up to one metre cubed with no dimension exceeding one metre. Until recently folding bicycles were required to be carried in a 'container or case', but following the break up of the system and the arrival of new compact bikes, this regulation has generally lapsed. Even where it remains in force, the cyclist is now most unlikely to be challenged. The only regulation applying across the system is, reasonably enough, that folding bikes should be completely folded down.
However, a bag or cover is still essential when carrying a folding bike on Underground trains (particularly in the central London area) and on buses. The rules for the carriage of folding bikes on buses are slightly different to those by rail, because bus companies leave the bus driver or conductor a great deal of discretion. If a bike, or any other large item of luggage, looks likely to inconvenience other passengers, the bus driver can refuse to carry it. Generally, drivers are a little more generous when buses are used as rail replacement vehicles during engineering works.
Folding bike rules obviously vary a great deal elsewhere in the world. From the feedback we receive at A to B Magazine, it seems you can safely transport a folding bike just about anywhere by rail, but if conventional bikes are banned locally it's best to be cautious. Once a railway official has made a decision not to allow you aboard, it's usually an irreversible decision, so if in doubt, always fold and cover the bike before entering the station premises.

Conventional bikes
Not quite so easy. For a brief period, bicycles were welcomed free of charge on most rail services, but in the lead-up to railway privatisation, bikes were virtually banned in many areas.
Fortunately, most of the privatised companies have shown a slightly more enlightened attitude, but with more than 20 different companies, there are now more than 20 separate rule books covering different parts of the country and - in a few cases - similar trains from the same platform. In general terms, the situation is improving, as the railway companies try to attract new business, but the latest generation of rail vehicles offer very little space for bikes and as older vehicles are withdrawn, the situation is getting worse. The good news is that the rules have been liberalised since changes to the Conditions of Carriage in the summer of 2006, and the only remaining blanket ban covers scooters, mopeds and motorcycles. This means tandems, electric bikes, trailers and tricycles are all carried, but subject to local condtions. In practise, few rail companies are willing to carry tandems or tricycles.
Some companies require a compulsory bicycle reservation. This is usually free, but if you intend to buy your tickets in advance on the internet, remember that it is no longer possible to reserve a bicycle space this way, and it may be difficult to match a cycle reservation with a seat reservation at a later date. Worse still, after six months of 'teething problems' the computerised railway booking system is still unable to reliably offer advance tickets by phone or over the counter, and without a ticket you cannot reserve space for your bike.

A code of practice
Cycle path construction charity Sustrans, the Cyclist's Public Affairs Group and the Cyclists Touring Club have introduced a code of practice for UK rail operators. In brief, the code suggests that Train Operating Companies:

• Provide customer information in advance of travelling
• Improve cycle access to stations
• Provide cycle parking
• Offer 'sufficient' onboard storage space for bicycles
• Provide at-station information and facilities for cyclists

Operators meeting these objectives are awarded a Cycle Mark, which can be renewed on an annual basis - assuming the operator continues to meet the standards. All cyclists are invited to help provide feedback to the scheme. If you have any positive or negative comments about the cycle policy of UK rail operators, you can pick up a copy of the 'Passenger Feedback Form' from: Cycle Mark, 35 King Street, Bristol BS1 4DZ