I have signed up to the London to Brighton off road event in September. It's 75 miles on bridleways, old railway tracks and a bit of woodland singletrack I believe. I would appreciate some opinions regarding tyre choice. I'd be looking for something light and fast rolling that I could use afterwards for the extremely rare occasions that the trails are dry. I'll be doing it on my Trance X3 which has 26 inch tyres currently on the Giant standard rims.