If you do one practical thing before an Alpine trip, make it this. Not new wheels. Not a crash training plan. Gears.
The right gearing is the cheapest upgrade in cycling, and it’s the difference between spinning up a col and grinding to a halt on one. Flat-land riders arrive over-geared every week of the season, and they pay for it on the first climb. Here’s how not to be one of them, with the actual numbers.
Why your home gearing fails in the mountains
On the flat, your gears let you pedal at a comfortable 85 to 95 rpm and your speed follows. On a long 8 or 9% ramp it flips. The gradient sets your speed, maybe 7 or 8 km/h, and your gear then decides your cadence whether you like it or not.
Run the numbers. At 8 km/h, a bottom gear of 34×34 lets you pedal at about 60 rpm. Spinning, sustainable, kind to the knees. A bottom gear of 39×28, common on older road bikes, forces you down to about 45 rpm. That’s not pedalling, that’s a leg press, repeated a few thousand times, and it burns exactly the muscles you’ll need again tomorrow.
One climb like that is hard. A week of them is what breaks people.
The target: a bottom gear of 1:1 or lower
The test takes ten seconds. Divide the teeth on your smallest chainring by the teeth on your biggest cassette sprocket. 34 at the front, 34 at the back: 1.0. That’s the target. At or below 1:1, almost any fit rider can spin up almost any paved col. Above about 1.2, you’re packing a grind.
| Setup | Bottom gear | Verdict |
|---|---|---|
| 53/39 with 11-28 | 1.39 | Race gearing. Leave it at home |
| 52/36 with 11-30 | 1.20 | Still a grind on the steep ramps |
| 50/34 with 11-32 | 1.06 | Workable, just |
| 50/34 with 11-34 | 1.00 | The sensible Alpine baseline |
| Sub-compact, e.g. 46/33 or 43/30 with 10-36 | 0.92 to 0.83 | Spinning room to spare |
How to get there
The cheapest fix is usually the cassette. Swapping to one with a 32, 34 or 36-tooth sprocket transforms a bike for a fraction of the price of anything else. Two caveats. A bigger cassette usually needs a longer chain, and it can exceed your rear derailleur’s capacity, so count your teeth and ask your shop before you buy. For any mechanic it’s a routine job.
The next step up is a compact chainset, 50/34, if you’re riding 52/36 or older 53/39 rings. And many modern endurance bikes come Alpine-ready out of the box, so before spending anything, count what you already have. Smallest ring at the front, biggest sprocket at the back, divide. You might be fine.
Whatever you change, change it weeks before you fly, and ride it. Never take an untested bike to the mountains.
Hiring? Ask one question
If you’re hiring in the Alps instead, the question for the shop is “what’s the lowest gear?” Ask for a compact chainset with at least a 32-tooth sprocket, and ideally a 34. Good Alpine hire shops fit exactly this as standard, because they know what their roads ask. It’s one of the reasons hiring can beat bringing an over-geared bike from home, and we weigh up that whole decision in getting to Annecy for cycling.
Low gears aren’t cheating
Some riders resist easy gears as if they’re an admission of weakness. The professionals settled that argument years ago. Watch any mountain stage and you’ll see the best climbers in the world on wide-range cassettes, spinning.
Here’s the way to think about it. You don’t have to use your easiest gear. But you can’t use a gear you don’t have, and the moment you need it is the moment it’s too late to fit one. Fit the easy gear. Hope to ignore it.
Tom, Founder and Head Coach, said, “One of the most common things I see on our Alpine trips isn’t a lack of fitness-it’s gearing.
One rider I remember particularly well arrived on a modern aero bike with a 53/39 chainset and an 11-28 cassette. He’d been riding mostly in the UK and had no trouble on short, steep climbs at home. On paper, he was a strong rider too, around 300 watts FTP.
Everything looked fine until we reached the Col de la Madeleine.
About halfway up, where the gradient sits around 8–9% for long stretches, his cadence had dropped below 60 rpm. Instead of riding smoothly, he was grinding every pedal stroke. This may be fine for some over geared efforts, but definitely not on a long Alpine climb. It puts so much fatigue into your legs.
The issue wasn’t fitness-it was gearing.
For most riders tackling Alpine sportives or week-long trips, I’d much rather see a setup that lets you maintain 75–90 rpm on the longer climbs. Something like a 50/34 or 46/33 (Sram) compact chainset paired with a 11-34 or 10-36 cassette gives you options when gradients increase or fatigue sets in. I’ve never heard anyone on our trips say they had too many light gears – ever!
The interesting thing was that once we talked about it, he realised he’d chosen his gearing almost entirely based on what looked “fast” rather than where he actually rode.
The following season he came back with lower gearing. He climbed more smoothly, finished each day feeling fresher, and enjoyed the descents more because he wasn’t arriving at the summit completely spent.
Sometimes the biggest performance gain isn’t more training—it’s having the right setup for the terrain.”
What the right gears free you to do
Lower gearing isn’t only about getting up. With a gear that lets you spin, your effort stays aerobic and repeatable, your knees stop taking the strain, and you have the spare attention to eat, drink and look at where you are. Gearing is the foundation the other mountain skills stand on. How to pace a long Alpine climb and how to fuel a big day in the mountains both quietly assume you can spin.
Keep reading
Your first Alpine col: what to expect is where most riders put their new gears to work. For the bigger picture, and which Alpine base fits your level, see Cycling in the French Alps.
Plan your trip
Not sure what your bike needs, or whether to bring it at all? Send us your setup and we’ll give you a straight answer. Get in touch. It’s exactly the kind of question we like.