From the Manizales bypass, a couple of kilometers past the Villamaría junction, to the Letras páramo (12,064 ft / 3,677 m) it is 19.6 miles (31.6 km) at an average of 5.7%: about 5,900 ft (1,800 m) of climbing. This is the short side of Alto de Letras: less than half as long as the Mariquita side, but with a more sustained grade and without the descents along the way on the other side.
What the climb is like
- Km 0-5 (4.2%). A warm-up on the road to Mariquita.
- Around km 7. A long straight at 7.7%, the hardest kilometer on this side.
- Km 7-14.5 (6.4%). A steady grade with no standout pitches, through Andean cloud forest, much of it now pasture.
- Km 14.5-16. The only clear break, with a short descent.
- Km 16-25.5 (6.7%). The toughest section: 5.9 miles (9.5 km) with the steepest pitches between km 20 and 23, short and never above 10%. Around 10,800 ft (3,300 m) the valley opens up.
- Last 3.7 miles (6 km) (5.8%). Long straights across the páramo and a final stretch at 4%. Around km 27 is the turnoff to Los Nevados National Natural Park.
Wikipedia gives 19.6 miles (31.6 km) at 5.7% with a maximum of 10% and the summit at 12,064 ft (3,677 m). Altimetrías de Colombia describes a good 31 kilometers, with no pitch above 10% and the summit at 12,070 ft (3,679 m).
Its history
Along with La Línea and the Loma del Escobero, Letras is one of Colombia’s mythical climbs, and it has featured many times in the country’s big races; its history is told on the page for the Mariquita side. This side climbs from the Cauca river valley toward the Nevado del Ruiz massif, the volcano whose 1985 eruption buried the town of Armero under a mudflow.
When to go, weather, water and traffic
You can ride it all year, although in the rainy months (April-May and October-November) fog is almost guaranteed on the middle section. Manizales sits above 6,500 ft (2,000 m) and has a cool climate; up on the páramo the wind is strong and cold. Bring a jacket and gloves for the descent. At 12,064 ft (3,677 m) the air holds about a third less oxygen than at sea level.
The pavement is in very good shape. It is the road between Manizales and Mariquita, with buses and trucks: use a rear light. Stock up on water and food in Manizales: up on the páramo there are very few services.
What gearing to use
With a steady grade of 6 to 7%, a 34x28 is enough at 3 W/kg (watts per kilogram of body weight): on 6.7% you ride about 8.1 mph (13 km/h) at 84 rpm. If you feel the altitude, a 34x30 or 34x32 gives you some margin near the top. Check your combinations in the gear calculator.
Tips
- Pace yourself until km 16: the hard part comes after the only break.
- Go in the morning; in the afternoon fog closes in on the middle section.
- If you have energy left, descend toward Fresno and come back: you will get a good chunk of the Mariquita side.
Frequently asked questions
How long does it take to climb Alto de Letras from Manizales?
A 159 lb (72 kg) rider on a 21 lb (9.5 kg) bike takes about 2 hr 09 min at 3 W/kg (216 W), 2 hr 33 min at 2.5 W/kg and 1 hr 40 min at 4 W/kg. Work out your own time with your weight and power in the calculator on this page.
Which side of Letras is harder?
The Mariquita side, at almost 50 miles (80 km) with about 11,730 ft (3,575 m) of total climbing. The Manizales side is less than half as long (19.6 miles / 31.6 km) but steeper on average: 5.7% versus 4.5%.
What is the hardest section of Letras from Manizales?
Km 16 to 25.5: 5.9 miles (9.5 km) at 6.7% on average, with the steepest pitches between km 20 and 23. Even so, none goes past 10%.