Before you go any further, let us clarify one point - You are not the worst cyclist in the UK
, I am the worst cyclist and I have earnt this award the hard way... so there
You will need a 'road bike',
NOT a mountain bike. I have very little idea what all the cycle experts are talking about (Allan T and others) with regards cogs and gears and thingies, but you don't want a mountain bike - even I can see that.
I purchased my "road bike" only a month before the event (£425 and the wheels go round and that's all I can tell you). I managed most of it, but my inexperience (and age, longest in the tooth) ground me to a halt just before the end. Without doubt I would have managed the cycling a couple of months later, or slightly slower
.
So, you need a road bike. You
definately need granny gears ( unless you are a 'proper cyclist'). You probably need those special shoes and peddley thingies. You need a couple of months of practice, or more.
Both days about 60 miles on bikes (all road) and 2 x running mountains each day . Snowdon and Cadair/ Pumlumon and Pen y fan.
The hard bit is eating and drinking in between
.