Original sentence: Hardcore cyclists prefer to use the grid roads, but the dual carriageways, roundabouts and 60 mph limits makes this an option best suited to the very confident and highly experienced.There have been fatal collision accidents on the main roads but none on the redways.Using the Redways can be frustrating for experienced cyclists, because they tend to go under or over the roads, rather than vice versa
Edited sentence: Hardcore "ultra" cyclists prefer to use the grid roads, but the dual carriageways, roundabouts and 60mph limits makes this only an option for the very confident and highly experienced (and insured.Using the Redways can be frustrating for inexperienced cyclists, because they tend to go under or over the roads, rather than vice versa