The calculated distance (air line) between Saint-Cyr-sur-Mer and Grenoble is approximately 138 miles respectively 222 kilometers.
By car or train, the actual journey to Grenoble is certainly longer, as only the direct route (as the crow flies) between Saint-Cyr-sur-Mer and Grenoble has been calculated here.
Air line (approximately)
222 kilometers
120 nautical miles