The Tours Bike Leg: 87 Flat Kilometers Where the Half Is Won (or Lost)

The Course in a Nutshell

87.3 km in a single loop with a claimed 293 m of elevation gain. The organizer bills it as one of the fastest courses in France, and the numbers back it up: just over 3 meters of climbing per kilometer. You ride through vineyards and iconic Loire Valley landmarks, on roads that in 2025 were closed to traffic almost everywhere, except for roughly the last 5 km.

The single loop keeps things simple mentally: no repeated passes, no lapping slower riders in narrow sections. But heads up: there's no reliable data on local wind conditions in the sources consulted. On flat terrain along a river, wind can happen. Have a plan for that scenario too.

What "Flat" Really Means

A flat course isn't an easy course: it's a course with no breaks. There are no descents to give your back and neck a rest, no climbs forcing you to change position. You ride at steady power, in aero, for over two hours. That's a specific muscular and postural demand, different from a rolling course.

What to do in training: build in long blocks in the aero position at race pace. A concrete test: 2x30 minutes at target wattage, in aero, without ever coming out of position. If you can't hold that comfortably 6-8 weeks out from the race, you have a bike fit or pacing problem, not a fitness problem.

Risk Number One: Pushing Too Hard

A fast course tempts you to overdo it. You see high averages on your head unit, you feel good, you bump up the watts. Then the flat half marathon sends you the bill. The rule here is simple: hold your target wattage and let speed be a consequence. The flat run in Tours rewards whoever gets off the bike with fresh legs, not whoever posts the best bike split in their age group.

Aero Comfort: Don't Underestimate It

87 km almost entirely in position means prolonged friction. In 2025, chafing issues were reported on exactly this point. Two concrete actions before race day: verify your bike fit with long rides in full race setup (same tri suit, same saddle, same position) and test your anti-chafe cream in training, not on race day.

Aid Stations and Bike Nutrition

The official aid stations are at km 18, 47, and 72: well spaced, so you can start without overloading your bike. But there's a real case from 2025 worth more than a thousand theories: one athlete took in too many carbs and too much water on the bike, ending up with bloating and a bathroom stop. The lesson: dial in your hourly intake in training, on long rides at race pace, and don't exceed it on race day. On a fast course, the temptation to "load up" is strong because your hands are free and the pace is steady. Resist: more is not better.

Drafting: Clear Rules, Inconsistent Enforcement

Several signals from 2025 point to lax drafting enforcement. That's not an invitation to sit on wheels: penalties exist and can come your way. On a flat, fast course, packs form naturally; keep the legal gap and use passes to manage the situation, not to yo-yo back and forth.

The Last 5 km: Stay Switched On

In 2025 this was the only stretch not fully closed to traffic. You get there with over 80 km in your legs, your head already in T2, and the temptation to switch off. Don't: eyes open, clean lines, no risky moves until the dismount line.

Action Checklist

• 2x30' test in aero at race wattage within 6 weeks of race day
• Bike fit verified on long rides in full race setup
• Hourly nutrition plan tested and written down, with a hard cap
• Wind plan B: gearing and position for riding into the wind for long stretches
• Maximum attention in the last 5 km, possible traffic