Downhill mountain biking is an exhilarating ride, but limited to bike parks and shuttled trails. All-mountain bikes open up endless trail possibilities to put your skills to the test. With some modifications, you can optimize your downhill bike to climb and shred all-mountain terrain.
Evaluating Your Downhill Bike’s Potential
Downhill bikes are built for speed, stability, and minimal pedaling on steep descents. Converting to all-mountain requires adding pedal-efficient, climb-friendly components. Assess your bike’s upgrade potential across these key areas:
- Reach and head tube angle – Long reach and slack head tube angle (63-65 degrees) provide downhill stability but make climbing challenging. Consider angle-adjust headsets and stems under 60mm to steepen the front end.
- Wheelbase – Shorter is better for snappy handling on climbs. Under 1200mm is ideal.
- Chainstays – Short (410-430mm) chainstays improve pedaling traction and handling.
- Bottom bracket height – Higher BBs (355mm+) improve pedal clearance on technical climbs. Lower BBs increase stability downhill.
- Cassette – Install a wide-range 10-50/52T cassette for easier climbing gears.
- Derailleur – Fit a long cage rear derailleur to accommodate the big cassette.
- Crankset – Swap in a 1x crankset with 30-32T chainring for optimal 1x gear range.
- Fork – 160-180mm travel downhill forks can work for all-mountain. Adjust air pressure for climbing efficiency.
- Shock – 200mm+ downhill shocks are fine. Tune compression for pedaling performance.
- Tires – Replace heavy downhill tires with wider all-mountain tires (2.3-2.6″) for grip and stability at speed.
- Brakes – Beefy downhill brakes have the power for all-mountain riding.
- Drivetrain – Swap in a tougher 1x drivetrain and clutch rear derailleur.
- Wheels – Strong downhill wheels support aggressive all-mountain riding.
- Cockpit – Cut the bars to 760-780mm width. Get a 50-70mm stem for snappier steering.
Step-by-Step Conversion Guide
With the right modifications, you can transform your downhill shred sled into a highly-capable all-mountain bike to open up a world of singletrack. Here are the key steps:
#1 Upgrade the Drivetrain
Start by converting your downhill bike’s drivetrain to a 1x setup with a wide-range gearing for optimal performance on steep climbs and rough terrain.
- Remove the front derailleur and large chainring, leaving only the small chainring. A 30-34T chainring is ideal.
- Install a 10-50/52T wide-range cassette on the rear wheel with easier climbing gears.
- Fit a long cage rear derailleur that has the capacity to handle the big cassette. Go for a clutched model to minimize chain slap.
- Swap the shifter for a single-click 1x shifter to control the rear derailleur.
- Install a narrow-wide chainring optimized for 1x drivetrains to prevent chain drops.
#2 Modify the Fork and Head Angle
Slack downhill bike geometries can make climbing a battle. Here’s how to optimize the fork and head tube angle for all-mountain capability:
- Install an angle-adjust headset using external cups to steepen the head tube angle by up to 1.5 degrees.
- Get an angle-adjust stem and/or look for shorter stem options (50-70mm). This will also quicken the steering response.
- For air-sprung forks, lower the pressure to increase sag around 20% for better small bump compliance and traction while climbing.
- Dial in rebound and compression damping on the fork and shock to balance pedaling efficiency with control on the descents.
#3 Upgrade the Wheelset
A bombproof downhill wheelset can handle aggressive all-mountain riding, but consider these tweaks:
- Replace heavy downhill tires with wider all-mountain tires in the 2.3-2.6″ range. Look for treads optimized for braking traction and cornering grip.
- Ensure the rims and hubs have clearance for the bigger tire volume.
- Optionally, build up a second lightweight wheelset for long climbs or less demanding trails.
#4 Fit All-Mountain Components
Dial in the cockpit and controls with components suited for all-mountain riding:
- Cut the wide downhill handlebars down to 760-780mm for greater climbing comfort and control.
- Install a short 50-70mm stem to quicken the steering.
- Set up wider platform pedals for maximum power transfer when pedaling and cranking through rough sections.
- Upgrade the seat post and saddle for long-distance comfort. A dropper post is highly recommended for getting the saddle out of the way on descents.
- Fine tune the brake lever reach for easy 1-finger braking control.
Optimizing Your Ride
Once your downhill bike is converted to all-mountain, it’s time to hit the trails. Here are tips to get the most from your bike across varied terrain:
- Lock out the suspension or set the climb switch for maximum pedaling efficiency on smoother climbs.
- Shift your weight forward and low on the bike for improved front wheel traction.
- Time your pedal strokes and shift your weight for maximum traction over roots and rocks.
- Drop the saddle and shift your weight back for confidence and control descending.
- Run the suspension open and soften your elbows and knees to absorb impacts.
- Lean back, stay relaxed, and let the bike move around underneath you.
- Lean the bike into corners, not your body, and look through the exit.
- Weight the outside pedal and drive your knees out for extra cornering grip.
- Brake before corners to maintain momentum. Modulate for controlled speed through the turn.
- Speed and momentum are your friends. Charge through rocks gardens and roots.
- Stay centered on the bike and let the wheels roll over obstacles.
- Loosen your grip, limbs, and hips to handle bumps. Stiff equals sketchy.
Frequently Asked Questions
What’s the biggest advantage of converting a downhill bike to all-mountain?
The biggest advantage is versatility. With an all-mountain setup, you can ride lifts and bike parks, shuttle runs or backcountry epics far beyond downhill terrain. The right mods optimize downhill performance and all-mountain capability.
What drivetrain should I run on a converted downhill bike?
A 1x drivetrain with a 30-34T chainring and 10-50/52T cassette gives the optimal gear range for steep ascents and gnarly descents. The narrow-wide chainring and clutch rear derailleur keep things quiet and chain retention secure.
Can I use my 200mm downhill fork for all-mountain riding?
Absolutely. Air-sprung forks in the 160-200mm range work great. Just be sure to run lower pressure/more sag (around 20%) to improve small bump sensitivity and traction for climbing over roots and rocks.
How much should I budget for converting my downhill bike?
Expect to spend $500-1000+ on parts and labor depending on components. Key upgrades like the drivetrain, stem, wheels and tires offer the biggest all-mountain performance gains. Shop sales and buy take-off parts to save.
How often should I service the suspension after converting to all-mountain use?
Servicing yearly or every 100 hours is recommended. The fork and shock see more varied terrain in all-mountain riding, so changing the oil, seals and bushings helps maintain optimal performance across long rides and different conditions.
With some thoughtful modifications and dialed components, converting your burly downhill bike to all-mountain is an extremely rewarding project. You unlock access to so much more terrain to push your riding. Just make the upgrades step-by-step and get familiar with how the bike handles new settings. Soon you’ll have a quiver-killer ready to shred it all, from bike park laps to backcountry epics. Now expand your possibilities and seek out new challenges!
Mahin Abrar is a passionate writer and outdoor enthusiast. As a regular contributor to Bikepics.net, Mahin shares his knowledge and experiences in the fields of biking, cycling, hiking, and camping. With a deep understanding of these activities and a keen eye for detail, he offers valuable insights and practical advice to help readers get the most out of their adventures. Whether you're a seasoned pro or just starting out, Mahin's writing is sure to inspire you and guide you on your journey.