boucle St Martin de Fressengeas 18 km variante 252.6 260.4 258.7 259 261.9 263.9 266 266.6 265.9 269.7 276.6 279 287.3 286.8 284.4 284.5 288.1 288 285.4 283.4 284 283.6 280.8 276.2 274.5 273 271.2 270.9