«I didn't have a low enough gear»... This is the most frequent regret at the top of a mountain pass. Choosing the right development is yet one of the keys to climbing comfortably, saving your knees and avoiding agony on steep sections. Here is how to choose the right gear ratio for climbing the passes of the Oisans.
Bracket, development: what is it all about?
The bracket corresponds to the ratio between the chainring (at the front) and the sprocket (at the rear). A «low» gear (small chainring, large sprocket) is easy to turn and ideal for climbing; a «high» gear is used for speed on the flat. What matters in the mountains is having a gear that is supple enough to maintain a high cadence (around 70-90 revolutions per minute) even at low speed.
Why prefer flexibility in the mountains
Spinning at a high cadence places more demand on the heart and lungs, but spares the muscles and joints. Conversely, pushing a heavy gear at a low cadence tires the legs and damages the knees. On sustained climbs such as those of’Oz-en-Oisans (nearly 11 %) or Villard-Notre-Dame (up to 17 %), if the process takes too long, it can literally bring you to a standstill.
What equipment should I choose?
- The compact crankset (50/34 teeth) is now the standard for the mountains, much more suited than the traditional double.
- The cassette tape make the real difference: choose a generous large sprocket of 28, 30, 32 teeth or more depending on the gradient and your fitness.
- Modern single-chainring (1x) drivetrains offer very wide-range cassettes that simplify the choice.
Simply put: it's better to have a gear that's too low than not low enough. You'll never regret having a spare sprocket on the final hairpins of a mountain pass.
Adapt the gear ratio to the climb
For a long, steady climb like the Col du Lautaret, standard development is enough. For a short, steep wall, or for the end of a big day like The Marmotte, allow some margin: tired legs call for a lower gear. Consult the mile by mile of each pass on our info sheets to anticipate difficult sections.
Frequently asked questions
What gearing for climbing Alpe d'Huez?
A compact crankset (50/34) combined with an 11-30 or 11-32 cassette is suitable for most cyclists tackling the 8 % average of the’Alpe d'Huez.
Is it better to spin or to push a big gear on a climb?
Pedalling at a high cadence is preferable: it saves the muscles and joints over the course of a mountain pass.
Is using a 32 or 34-tooth cassette «cheating»?
Not at all: it’s a smart choice that allows you to climb for longer and with greater peace of mind, even for experienced climbers.
Before your next climb, study the detailed gradient of your col on the Oisans mountain passes page to choose the right development.