Whether you’re a super fit or leisurely rider, new to mountain biking or seasoned expert, there are great trails along the valley floor where you can ride without needing a lift pass.
For example, following the river path upstream you can enjoy the low level trails of the Petit Balcon Sud or Petit Balcon Nord. Both trails are well signposted and accessible without having to take any lifts or deal with bad weather higher in the hills. These trails can still be fairly technical with rocks and rooty sections but it’s never too sustained so you can hop off and walk those bits if you'd prefer. A circuit of both Balcons is well worth it, at 16kms in length it takes around 3-4 hours to complete the loop. Check out the routes on the Chamonix Mountain Bike Trails maps in the link above.
If you're staying in the centre of Chamonix and fancy a lung and leg-busting climb, then you can head up the 4 x 4 track close to Les Planards and the summer luge. You follow the trail into the woods and up and up in the direction of the Mer de Glace where you'll get a great view. The last 200m are not too easy on a bike, so push along until you get to the view and the buvet where you can buy some hard earned refreshments before turning round to enjoy the descent. Alternatively take the earlier hair pin off the 4 x 4 trail up to your right and on to the Caillet chalet. From here it's technical downhill all the way, just don't forget to look out for hikers and runners who also like this route!