In reply to thomasmcalonan:
I did the relentless a couple of years ago, in much the same condition as you describe yourself (reasonably fit, team of 4). Here's what I learned:
- Look after yourself properly. I didn't hydrate very well and ended up with horrible cramps on one lap. A few people didn't eat well (the sleeplessness can mess with your appetite) and had some shocking laps. Keep warm when you're off the bike.
- Try to get there early to set up your team camp, as good space is at a premium. If you have a can or caravan that will make your life a million percent better in terms of having somewhere good to recover between laps.
- The route tends to be a figure of eight with two climbs on it. They're not super long but it will help if you practice some intense climbs.
- Get lots of night-riding practice in. It's amazing how different the course becomes in the dark.
- When I did it it was dry, but it's Fort William in October so expect to get wet - bring as much spare clothing as you can.
It's a really cool race. You'll have a blast!