My First Bike - tough decision...

I bought a Specialized Allez (alloy) with claris as my first, then a Giant TCR (carbon) with 105 as my 'race' bike.

I still get just as much fun out of the Allez, although I did spend £15 upgrading the derailleur and mech to Sora (runs a little smoother and still works with the claris shifters once properly tuned).

The main problem you will have is whether to go for a racier or sportive(r) oriented bike. The former will give you more responsive handling and put the power down more satisfyingly. The latter will iron out the bumps and allow for a more upright position (although thats not upright like a city bike, just in comparison with a race bike). A test ride with both types normally sets people clear on what they want.

Basically, race bikes are longer and have a lower front end for that proper 'Pro' head and hands down, bum in the air positioning that you mentioned with the huge seatpost stickout. A bike with 'endurance' geometry tend to have a higher front end and shorter top tube for a slightly more sit-up-and-beg position.

If you're starting road cycling, I'd definitely start with an 'endurance' bike until you get fitter and more into it. I've been back into cycling for about 3 years (8,000 miles) and love riding my Giant Defy which is very much an 'endurance' bike but hired a proper race bike abroad recently and loved it. My next n+1 will probably be more race orientated than endurance.

So Jim, now you've got everyone's opinion, where do you stand??!!

If I were you, I'd get the lowest gears possible. Prioritise your recovery from surgery over looks!

Also, people who say "XX/XX gears are fine for any hill" probably don't live near any hills.

To be the fly in the ointment... forget 105, forget future proofing, maybe even forget a road bike. After a long time not riding and recuperating from injury the most important thing is comfort. That means big tyres, wide range of gears, the right size bike and trying before you buy. You'll get bored of the track and winter is coming... The roads are gonna be shit. Go to Halfords and try a Voodoo Bizango mountain bike. £600 or regularly on sale for £480.

If you must have a road bike or hybrid go cheaper; £300 or so.

Why?

Even if you buy all your clothes from Aldi (pretty much cheapest) you're looking at minimum £200 for clothes. Jacket or Jackets. Midlayer Jersey. Baselayer. Bib tights or shorts and legwarmers. If you wanna be comfortable you need a chamois pad. Socks and shoes. If you buy a new bike they often don't have pedals. Helmet and gloves. As it gets warmer you'll need clothes for better weather.

Are you gonna take care of the bike? Chain lube, multi-tool, inner tubes, puncture kit.. this is minimum. Bikes are like a shitty car - money traps.

Just buy a bike that fits, you like and what you can afford. If you get a chance test ride a few before making a commitment. Good luck. 

I wouldn't buy that 56cm. I'm 5' 11" and ride a 57cm. It would be a real compromise that would always niggle you. If you keep searching ebay you'll find something  suitable eventually.

Like what SP says

A good frame is a solid basis for upgrades.

Newish second hand will get you a lot more bicycle for your money, but there are risks.

Don't discount looks. If you get that little frisson of happiness whenever you look at your bike then you are more likely to want to ride it and look after it.

Don't loose sight of the reason you are buying the bike. To help you recover from an injury. Which to my mind makes comfort and lower gearing somewhat a higher priority.

No chance of borrowing the MTB back from your Dad is there?

Well worth a look at Decathlon's Triban 540. And if you feel like you got the wrong size they'll change it for you too. 

Definitely consider Decathlon's Btwin range. Great value and appear to be good quality. A friend has one and likes it. Plus a local shop means it should be easier to try/ look at in the flesh/ take back in the event of issues.

Also remember that although they're known as budget bikes in the UK (you are on a budget after all!), they've got a good reputation on the continent - in France they sell some pretty high end stuff under the Btwin range.

You aren't going to get much cred from the Rapha crowd, but £650 gets you 105 and Aksiums at Decathlon:

http://www.decathlon.co.uk/triban-540-road-bike-105-red-blue-id_8364452....

Don't be ashamed to buy a triple if you don't want to be huffing and puffing. 30t small ring and a 32t on the back would be great for beginners. If you're stronger than you thought then you've still got plenty of gears to take it at a greater pace. Also think about your knees. Better to spin with less torque if you're coming off surgery.

Don't fret too much detail. First bike, and with your history, get any old thing (that fits) and see how it goes. If you buy second hand for £500 and don't like it after a year then a) you'll sell it for about the same as you bought it for and b) you'll have a much better idea what your second bike is gonna be.

I bought my first road bike 4 years ago, but was already a keen mountain biker, and chose well. I'm now the proud owner of an Enigma Esprit titanium bike worth about £4,000 and don't regret a single penny.