We are super excited to host our first big ride from our new shop in Louisville, Colorado. Lennard has been hosting Gran Fondo's from his house for ages, but after he developed his heart arrhythmia, riding over 200 miles in a day became a non-starter. Now that he's been training on his gravel e-bike for years, he's ready to bring back the Fondo, this time, a gravel version.
We are super excited to host our 2nd big ride from our shop in Louisville, Colorado. Lennard has been hosting Zinn Gran Fondos from his house for ages, but after he developed his heart arrhythmia, riding over 200 mountainous miles in a day became a non-starter. Now depending on his gravel e-bike, he's brought back the Zinn Fondo* as a metric century on gravel roads in the mountains above Boulder. We had a great turnout in 2025, so let's make it bigger in 2026.
The Zinn Fondo (largely) mountain gravel ride will start and finish at the Zinn Cycles shop in Louisville. Riders can choose one of three loops of approximately 60km, 85km, and 100km in length. There will be a ride leader for each loop. All three loops will be primarily on bike paths and dirt roads. The “Corto” (short loop) goes up Chapman Dr. and down Flagstaff Rd. The “Medio” (medium loop) goes up to Gold Hill via Fourmile Canyon Dr. and Gold Run Dr. and returns via Sunshine Canyon Dr. The “Lungo” (long loop) follows the Medio loop with the addition of a left turn at Salina to continue along Fourmile Creek to Pennsylvania Gulch and up Switzerland Trail to Gold Hill Rd., rejoining the Medio loop at the Gold Hill Store.
Zinn Fondo Gravel technical details:
Corso Corto (short loop): 59km, 2,300 feet of climbing (start/finish at Zinn Cycles shop)
OR, with alternative start/finish in Boulder at Eben G. Fine Park: 20km, 1,300 feet of climbing
Corso Medio (medium loop): 87km with 4,200 feet of climbing (start/finish at Zinn Cycles shop)
OR, with alternative start/finish in Boulder at Eben G. Fine Park: 37km, 3,200 feet of climbing
Corso Lungo (long course): 98km with 4,700 feet of climbing (start/finish at Zinn Cycles shop)
OR, with alternative start/finish in Boulder at Eben G. Fine Park: 48km, 3,700 feet of climbing
Climbing Switzerland Trail entails significant technical challenge on a road or gravel bike.
The descents of Sunshine Canyon and Flagstaff Mountain are not to be taken lightly—use appropriate caution. You and only you are responsible for your safety.
Start time 8AM at Zinn Cycles, 1655 Cannon Cir. Suite 100 in Louisville. When you get back there will be burgers and brats grilling for you and ice cold drinks.
Alternative meeting/start time is approximately 9-9:15AM at Eben G. Fine Park bathrooms.
This is an unofficial ride with no entry fees and no feed stations. Riders are welcome to start and stop wherever and whenever they want and to join and leave the ride wherever and whenever they want. Some riders will stop to eat and drink at the Gold Hill Store. E-bikes welcome.
*The Zinn Fondo ride started 38 years ago, in 1988, on Lennard Zinn’s 30th birthday. The idea was to ride in the mountains from dawn to dusk (or later!), enjoying companionship and great views with good friends. Many routes were used. The original route, sometimes repeated, was the “Grand Loop” from Boulder, comprising 369km (229 miles), 19,000 feet of climbing, and two crossings of the Continental Divide via Estes Park, Trail Ridge Rd., Granby, Winter Park, Berthoud Pass, Idaho Springs, Peak to Peak Highway, and Nederland, finishing back in Boulder.
Zinn Fondo distances and elevation gain have moderated now, as Lennard is turning 68 and has a heart arrhythmia and an e-bike. What hasn't changed is enjoying a friendly ride in the mountains with good people, and now, the course isn't changing, either. In the interest of keeping a known, wonderful, favorite route of Lennard's that our friends can count on and put on their calendars, it makes sense to keep it the same for now. We hope you'll join us!