Cycling in the Alps

If I remember correctly the TGV has restrictions on bikes. I think they have to be in a case and it has to be of a certain size - you may struggle with some bike cases - check the website - use Google Translate for anything that is in French (ie most of it!)
The best way is to fly out and hire a car - make certain it is big enough to take the bike though. It is quicker and gives you more time to ride other than the sportive.
We are driving down in the summer and stopping off in Dijon which is about 4 hours drive from the Bourg d'Oisans area. The best bit is the hotel will let you take the bike in overnight, so no worries in the morning. Check hotel availabilities as a lot of people do the same and once you get into June it is very difficult to get a room so that may influence your travel decision.
Either way have fun and enjoy the ride and plan your next trip soon as you will definitely be going back!!

That train/bus/taxi trip sounds like it would be hard work - add in a bike bag/box (I assume) and it sounds pretty challenging! If you can afford it, fly and get a hire car (Grenoble, Turin, Marseille all about 2-3 hr drive) - or drive the whole way. As others say you can take a break as and when. There is usually a transfer you could arrange if you want to fly but not drive, though it might be pricey.

It's always a mission to get there, but it's all worth it when you roll out on your 1st ride, with (hopefully) the sun on your backs....

Never tried it but a friend of mine said it was great. Might be worth a look.

http://www.bike-express.co.uk/Tour/Med_A_Out_with_any_Return_inc_Atlanti...

Self drive from the UK , Dover to Dunkirk is about 90 quid return then either use the motorways and pay about 50 quid in tolls (avoid Lyon/Paris stretch) or use the "A" roads

Me and my brother have done the trip from south Wales to bourg d'oissans a number of times and did the way mentioned above as its cheaper and easier plus you get to stop as and when you want to

Btw in regards to alpine climbs count on an hour minimum for most up to about 10 mile if not longer , there is simply nothing in the UK that can compare imho

That sounds like an expensive and slow route! I'd fly to Geneva and hire a transfer to take you from there.... oh, I just checked the map. Quite a long way from Geneva! Erm. Fly then hire a car? Might still be cheaper and more useful...