L2B - considering buying a road bike

[jumplead]

So up until now I've been doing what little training on a 1998 vintage fixed frame mountain bike (GT Palomar for those interested).

A work colleague who recently did a John O'Groats to Lands End ride offered to loan me his road bike to do the L2B on, but it appears that in the transport home the rear wheel has become buckled and may not be repaired in time.

So I'm thinking i'm just going to bike the bullet and buy myself a cheap road bike. But the question is, are the cheaper road bikes worth buying or would I just be better getting some slicks for the mountain bike? Also are these cheap bikes designed to be hauling my fat ass (18 stone) around?

Two that I've found in some very brief searching are:
http://www.evanscycles.com/products/claud-butler/c...
and
http://www.halfords.com/webapp/wcs/stores/servlet/...

[boolay]

I would stick to making the most out of the MTB and getting some skinny slick tyres, and maybe some aero bars for a bit more dynamic position. From the research I did, you need to spend around the 500 mark to get something reasonable.

[dubbs]

Aerobars? On a MTB? Can't see that being very helpful as the bike itself won't be aero, your MTB seating position isn't at the right angle for getting aero and the geometry would mean you'll be reaching too far forward in most instances so it'll knacker your back in no time.

I'd assume that to be the case, anyway.

[BliarOut]

I wouldn't alter bikes this close to the event, my (admittedly old(ish)) body would throw a right wobble if I changed anything now.

[Ken Sington]

Haven't done a L2B for a good few years but from my past experience it will be pretty mobbed with people who are not used to riding in big groups or in close proximity to others and the opportunities for getting up to high speed are few and far between so the upright position of a mtb that you are used to and easy reach of the brakes will probably serve you better than trying to change to something new this close to the event.