Filthy Fifty Mountain Bike Race 2025
October 25
The Annual Filthy 50+ mountain bike race takes place in San Diego and travels through various sections of San Dieguito River Park and Black Mountain Park. The race offers two different lengths, 30 miles, and 50 miles.
Organized by Quick n’ Dirty Mountain Bike Racing, the ride is suitable for all skill levels and is fully marked with pink flags and red arrows. There are two courses: a 30-mile ride and a 50+ mile ride that continues on to the Black Mountain Park area where riders will encounter a lollipop and new trails. Fully stocked feed stations will be placed throughout the course to keep riders fueled up.
There will also be a kid’s ride supported by Team Quick n’ Dirty, and awards will be given out immediately following the ride. Riders are reminded to pay attention to other riders, hikers, and horseback riders on the trails, especially when riding the switchbacks portion of the course.
Here’s the full list of classes:
- Expert Men Open – 50+ Miles
- Expert Women Open – 50+ Miles
- Sport Men Open – 50+ Miles
- Sport Women Open – 50+ Miles
- Beginner Men Open – 50+ Miles
- Beginner Women Open – 50+ Miles
- Single Speed Open – 50+ Miles
- Drop Bar Open (Gravel/CX/Road) – 50+ Miles
- Big Boned (200+) – 50+ Miles
- 55+ Men/Women Open – 50+ Miles
- 30 Mile Ride Open – 30 miles
- 30 Mile Ride School Boy 12-15
- 30 Mile Ride School Girl 12-15
- Kids Ride – 1-3 Miles Beginner/Sport/Expert
The race takes place on public trails with other mountain bikers, hikers, and equestrians likely to be encountered on the trails. Riders are encouraged to be careful and respectful of other users of the trails. The trails are marked for the race and feed stations available along the way for refueling.
Registration for the event is limited to 400 riders.
Filthy 50+ is one of several San Diego County races that Quick n’ Dirty puts on. Check out their website for a full list of events.
Here’s a video about the 2022 race: