The London to Brighton is a good ride, my flatmate and I did it last year. I would advise you keep on the smaller roads, there are a coupe of prefered routes but most go over ditchling beacon, if you are fixed then you may need to walk up - also there are some fairly long hills to go down, I would't want to do it on a small gear and I'd be careful if you are breakless tho I rode with one of the couriers who was doing it brakeless.
As far as mountain bikes are concerned I would have thought they should be able to keep up as they can coast down the hills and will find it easier going up, even if they will have to work on the flat,
Tell them to pump their tyres up though.
I only have the option to do it fixed anyway, others will be opting for the freewheel. My gear ratio will be 46x16 so I'm anticipating some walking on the way.
Thanks Chris for the advice :)
I've found a few routes on the net like this one : http://www.freewebs.com/cycleroutes/
I only have the option to do it fixed anyway, others will be opting for the freewheel. My gear ratio will be 46x16 so I'm anticipating some walking on the way.