When you first decide to buy a road bike the choice can be very daunting. From bikes in the local supermarket costing £150 to those in specialist shops costing up to £5000 or more, what is the difference and what should you look for?
If you haven't ridden a road bike before, or not for many years, it is not easy to 'test drive' bikes, because they will all feel 'wrong' at first. The saddle will seem uncomfortable and too high, your back might hurt, and you won't know how to change gears. Don't be deterred!
For your first bike you are looking for a bike that will be a pleasure to ride, and will get you back on the road. There is no reason to pay dearly for a carbon-fibre frame and super light fittings quite yet. There are many road bikes in the £400 - £1,000 range that will do very well, from almost all the major manufacturers - Trek, Giant, Bianchi, Specialized etc.
The more expensive bikes will have lighter, more solid (rigid) frames and components. All should be satisfactory. There are plenty of £300-400 bikes available, and those in the £600 - £1100 range are really very good bikes, with many models falling between these two ranges.)
In truth a bike from any of the reputable manufacturers will be fine. None are going to have serious flaws, and the slight difference in weight is not crucial at this stage. I would not recommend buying an 'unbranded' bike since these will often have components - gears, brakes etc - that are not made to last, might well weigh a lot more, and could put you off cycling for ever.
Colour and appearance is important - psychologically at least. If you think the bike looks great you'll think you look great as well!
The most important thing of all is the size of the road bike. Riding the most expensive bike in the world will not be fun if it is the wrong size for you. See road bike sizing for more information.
Don't buy a bike in the sales because it is a bargain unless it is the right size!
Pedals are discussed elsewhere, but you might like to use 'old-fashioned' pedals at first, rather than clipless pedals, while you get used to the bike, and change them in due course.
One other choice that you will be confronted by - how many gears do you want. Many new and more expensive bikes have two rings at the front, and purists would ride nothing else. Many people are happier with three. Ironically it will often be the cheaper bikes that have three front rings. When you have been cycling a while you might find that you never use the smallest front ring, but if you plan to cycle many hills you might prefer the option. Going up a hill at the end of a long ride you might prefer to use the so-called granny-gear (the easiest gear on the bike).
If the shop sneer at you for wanting three rings, sneer back and go elsewhere. The choice is yours. The number of gears / rings at the back - usually 9 or 10 - is unlikely to be an issue.
Try and visit at least a couple of shops and get different opinions. Finding a good shop with helpful knowledgeable staff is an enormous help in the months and years to come.