There are many ways to get to Bude , but one thing we must point out there is NO train station in Bude. If you are using public transport to get to the start / B&B then the nearest station is Okehampton , which is a good part of 30 mile away. There is a bus service one an hour , week day only but I doubt if you would be allowed to take your bike on it.
Driving from London , we would suggest, M4, M5 head for Okehampton through the town centre and follow the signs to Bude. Driving from the North Driving from North , take the M5 , Exeter , Okehampton , Bude.