New Road Bike

I would highly recommend going to a proper bike shop like Sigma or a Specialized Concept Store and getting a good "fit" on a bike and having it adjusted to your needs to make sure its 100% right for you

I would not get consumed by having the highest specification parts; as a well fitted bike is a joy to ride, whereas a badly fitted bike (with nice bits) is horrible to ride and may ruin your enjoyment of riding

I am a specialized fan, and would rather have a well fitted Allez Elite than a badly fitted Tarmac Comp, as an example (I've had both!)

2nd hand is to be avoided, unless you are a bike mechanic and know exactly what you are buying, or have enough experience as a seasoned rider to make a good choice

A really good idea is to set some of that money aside for a proper fitting. It's amazing how much more comfortable you will be if the seat angle is right, the size of bike is right, if the handlebars are in such a position so as not to put too much pressure on your wrists and so on.

As above really. £1500 is a serious budget - so expect choice and proper service: remember that you're doing the shop a favour by giving them your business so if they don't seem to want it or you feel you're being fobbed off walk away!

Some sensible comments above. My tuppence is to suggest you try a number of different bikes to see what you like best in real life (irrespective of what the reviews tell you)

When I was in the market for my race bike, I tried at least 5 bikes that were all roughly in the right price range. And actually, I avoided looking at reviews.

Getting some advice from Sigma and/or other shops is a good thing to do, but there's no real substitute for trying different bikes (over a few miles - not just a pootle round the car park), perhaps trying your favourite one or two more than once on different days. And then choose the one that puts the biggest smile on your face. At the end of the day, the bike that makes you happiest is likely to get you out riding the most. That will have a bigger impact on your performance/enjoyment than one reviewer's perceptions of bottom bracket stiffness...

For reference, some years later, I still really, really love my race bike (I did upgrade wheels at some point). But I have never got on quite so well with my winter bike (which I bought blind), even though it is set up as best I can tell exactly the same as the race bike (and even when I fully take into consideration the fact that it will never be as light/fast as the race bike).

+1 for Sigma Sport. Really looked after me when I bought from there. Worth travelling to from other parts of London.

If you have a budget of £1500 and no real idea what you want get to one of the major dealers near you. See you're in London so Sigma Sport in Hampton Wick, stop sniggering at the back, would be a good starting point.

They carry a good range of makes and models and have always treated me courteously whenever I've been in either to browse or actually buy something.

Buying off the internet when you're not sure what you want and can't see before you commit is a bit risky.

Whatever else you do, get to ride a selection of bikes before you part with your cash. And don't get fobbed of with 'Women's Specific Design' as being the only choices available to you. With a bit of component swapping, and a half-decent sales person, almost any bike could be suitable if it is sized properly.