Mountain biker Adele Mitchell continues to venture out on her first road bike. This month, the sportive gauntlet is well and truly thrown down.

An email arrives from my local cycling club:

How would you like to join us for the Prudential RideLondon-Surrey 100?

Hmm. When I picked up my road bike a few months ago I hadn’t quite anticipated that it would lead to an invitation to take part in August’s inaugural Prudential Ride 100 – a 100 mile jaunt from London to Surrey and back again along with 20,000 other cyclists. However and despite being nowhere near road-fit enough and having precisely zero sportive experience, I knew I couldn’t let this opportunity pass.

There was only one thing for it: start training.

Step one? A bike fit.

When you ride a mountain bike you rarely sit still on the saddle for long so although it’s important that the bike fits you, you’re less likely to suffer chronic, body-part numbing ride issues than you are on a road bike, where you stay in one position for longer.

A few miles into each ride I was noticing neck and knee pain and suffering with numb hands. After 100 miles I’d probably have to be straightened out on a rack!

To combat these niggling aches, I took myself and my bike to the Specialized Concept Store in Kingston for a geometry fit. Working on the theory that it’s easier to alter a bike than it is a body (so thrilled it isn’t the other way round!), I was videoed riding (never realised I talked so much until it was played back!), measured and tested for flexibility before some expert fine-tuning took place.

Bike fitter Luke identified that I was sitting too far back and not tracking straight, so he moved my seat forward and up a fraction, fitted a shorter stem, adjusted my cleats and added new shoe inserts. He also lowered the gear levers to take the pressure off the nerves in my palms. I rode home – 20 miles (in the pouring rain – get me!) – and was amazed at the difference: no numb hands and an infinitely more comfortable back and pair of knees. I did have very wet feet though.

A geometry fit isn’t cheap (£200 plus parts) but I can heartily recommend it if you’re looking at regularly riding any distance.

Step two? Get some expert riding advice.

A 55 mile ‘Tour de Surrey Hills’ with ex-racer Jackie Roberts from Beyond Mountain Bikes was the perfect opportunity to pick up some road riding tips.

I’d imagined our ride would be a roll around the local lanes, chatting about padded shorts and gel bars with the occasional stop to admire the view and decide where to next.

How wrong could I be! Everytime I tried to use a little light conversation to distract Jackie from the relentless pace she’d set, it was pointed out that the next climb was a Strava segment and wouldn’t it be fun to try for QOM?

All I could do was stuff another energy sweet into my mouth, try to keep up and tell myself that, as I’d managed the pain of childbirth three times, I was probably going to survive this too.

We then barreled along part of the Olympic route – flat, thankfully – at a pace that would have convinced onlookers that we were actually in contention for medals where I discovered the joy of slipstreaming and even overtook a male roadie. I would have punched the air had I not been gripping the handlebars so tightly.

What did I learn on the ride? That I was capable of going much faster and for much longer than I had ever thought – even if I did have to go straight to bed afterwards!

Step three? Become a little bit obsessed.

A hundred miles is a long way and, as I’m sure many riders find, it’s not easy to fit in a six hour plus training ride, in fact, to date, its been impossible. However, to take the sting out of the three Ride 100 climbs, all of which I happen to live very close to, I decided that if I can’t get out on long rides I will at least do quite a few hilly ones.

As a result my friends have stopped asking me how the road cycling is going for fear of expiring through boredom as they have to listen to me compare the differences between Box Hill (not so steep, very smooth but longish) and Leith Hill (steeper, lumpier, shorter).

The lure of the road – and the challenge of Ride 100 – is hooking me in.