I rode the A25 to Sevenoaks last night and I'm not sure if you'll be using it, but thought you may like some feedback. Whilst it's a good road for training on your own I don't necessarily think it works for a CG: -
- it's too hilly from Redhill until Westerham to manage Thru & Off
- from Westerham - Sevenoaks it flattens out, but is too narrow to safely ride 2 abreast or T&O plus the surfaces get's pretty bad
- A25 is almost all unlit so an actually CG with T&O is not advisable unless you
all have very powerful lights
We've looked at different options for CGs in our area over the last few years and it is quite tricky to be honest. The only option for main lit roads is the A23 basically which is far from ideal although it has worked in the past. If you were to use the A25 I would suggest you could only do it with a long line, taking long turns on the front and you should still really use powerful lights (ie 2x Fenix or better) in which case you may as well go on a quiet country lane circuit.
The CGs I've done recently which have worked have been with groups where every rider has very powerful lights as this is the only safe way that you can do T&O in the dark and even then it is risky if you are having CG newbies along etc. However most people it seems are prepared to dump £150+ on some lights so it is more feasible than you may first think.
I would also echo Andrew G's comments to wear bright clothing and have several rear LEDs in case one fails. Also try to angle flashing LEDs so they don't point into the face of the rider behind
Good luck tonight and let us know how you get on.
Marcus (NP)