I'm no expert - this was the first Grasstrack meet we've promoted - but the basic formula:
Where
Grasstrack racing used to be fairly popular all over the UK - it's particularly big in Scotland where it's often incorporated in a number of the Highland Games held there; there are even riders who make a semi-professional living out of grasstracj racing at these games.
In the rest of the UK nowadays there is a national grasstrack series and around a dozen or so open meetings held each year during the season.
The track
Mark out an oval for the track on a fairly flat patch of land. Most tracks are approx 300-400m round.
The inside line of the track is marked with a painted line. Coloured pegs and string are then placed around the line to stop riders taking a shorter route round the turns. There's no banking.
The bikes
Riders almost exclusively use old skool traditional steel track bikes - the racing can be hard and crashes are fairly frequent, so a tough, dependable (and cheap to repair) bike is essential. The other major consideration is tyre clearance - most modern alloy/carbon frames don't have enough clearance under the fork and at the rear for the wider grasstrack tyres used.
Grasstrack tyres used to be more readily available but are really hard to find nowadays. Alternatives include Vittoria and Tufo dry CycloCross tyres with a minimal tread. tyres usually are sized 28-32mm and top riders will have several sets depending on how soft / dry / hard the track is. Because of the cornering forces exerted on the tyres on the non-banked track, a few sheets of fabric / tape are wrapped round the tyres and the rim to help keep the tyres glued onto the rim.
Wheels are almost always trad large-flange Campy / SUntour / Shimano track hubs laced 32h or 36h to old-skool track tubular rims. You don't see many composite tri-spokes at these races
Gearing will vary depending on the track conditions but I understand that this is uaually in the 76-80 inch range (eg 44x16 to 48x16).
Cranks will generally be short (165mm) for clearance when cornering.
The rest of the bike is pretty much the same as for regular hard track racing on a velodrome.
The racing
It's insane!! The emphasis is on short, full-gas sprints eg 800m. Riders are held on teh start line and pushed off by holders - as the racing is so fast and short its important to get a good start, so it pays to practice with an experienced pusher-offer.
Racing tends to err on the side of the physical too, as riders use shoulders, heads and elbows to fight for teh inside line on the sketchy corners.
Races are similar to hard track, ie sprints, handicaps, devil-takes-the-hindmost, points and scratch races. Due to the lack of banking cornering at speed in a tight packed bunch on a fixed gear bike takes some skill and nerve, and slideouts usually bring half of the field down with them!
It's a cool and slightly dangerous form of track racing, but y'all should give it a go. Just mark out a 300m oval in yr local park, swipe some traffic cones or similar to mark the inside line, put the widest set of tyres you can fit into yr frame and let rip. When you start off its like being a kid again bombing around the park trying to knock yr mates off their bikes whilst trying to hold the rear wheel from sliding out...! As well as being a blast it'll also probably do wonders for yr bike handling skills.
Cheers
mickster