Roof bars (also called roof racks or crossbars) are the foundation of any roof-mounted cargo system. Before you can fit a roof box, bike rack, or any other roof accessory, you need the right roof bars for your vehicle. This comprehensive guide covers everything UK drivers need to know about choosing, fitting, and using roof bars
What Are Roof Bars?
Roof bars are horizontal bars that attach to your vehicle’s roof, creating a platform for mounting accessories like roof boxes, bike carriers, kayak racks, and ski holders. They’re also known as:
- Crossbars (American terminology)
- Roof racks (general UK term, though technically refers to the complete system)
- Load bars
- Transverse bars
A typical roof bar system consists of:
- Two parallel bars running across the width of your vehicle
- Mounting feet that attach to your vehicle’s roof
- Vehicle-specific fitting kit
- Locking system (on quality systems)
Types of Roof Bars
Square Bars
Traditional design with square/rectangular profile
Advantages:
- ✅ Most affordable option (£50-£100)
- ✅ Strong and durable
- ✅ Universal compatibility with most accessories
- ✅ Easy to source replacement parts
Disadvantages:
- ❌ Noisy at motorway speeds (whistling/humming)
- ❌ Poor aerodynamics increase fuel consumption
- ❌ Dated appearance
- ❌ Higher wind resistance
Best for: Budget-conscious buyers, occasional use, older vehicles
Aero/Wing Bars
Modern aerodynamic design with teardrop or wing-shaped profile
Advantages:
- ✅ Very quiet at high speeds
- ✅ Excellent aerodynamics reduce fuel consumption
- ✅ Sleek, modern appearance
- ✅ Lower wind noise and drag
- ✅ Often include integrated locks
Disadvantages:
- ❌ Higher cost (£120-£300)
- ❌ May require specific accessories
- ❌ Brand-specific designs
Best for: Regular users, long-distance drivers, premium vehicles, fuel efficiency
T-Track Bars
Professional-grade systems with integrated T-shaped channels
Advantages:
- ✅ Extremely secure accessory mounting
- ✅ Quick accessory changes
- ✅ Professional appearance and quality
- ✅ Excellent load distribution
- ✅ Compatible with wide range of accessories
Disadvantages:
- ❌ Most expensive option (£200-£400)
- ❌ Requires T-track compatible accessories
- ❌ Professional installation recommended
Best for: Professional use, commercial vehicles, frequent accessory changes
Roof Mounting Systems
How roof bars attach to your vehicle depends on your roof type:
Bare Roof (No Rails)
Many modern cars have completely bare roofs. Mounting systems include:
- Door frame mounts: Clamp to door frame channel
- Fixed point mounts: Bolt into pre-drilled mounting points
- Adhesive mounts: Stick-on pads (rare, not recommended for heavy loads)
Typical cost: £100-£250 (including vehicle-specific kit)
Raised Roof Rails
Traditional raised rails that run along the roof length. Common on:
- Estate cars
- SUVs
- MPVs
- Older vehicles
Mounting: Bars clamp directly onto the raised rails
Typical cost: £60-£150 (simpler installation)
Flush Roof Rails
Modern design where rails sit flush with the roof. Popular on:
- New SUVs
- Premium vehicles
- Sport models
Mounting: Special brackets that lift bars above the flush rails
Typical cost: £120-£280 (requires specific fitting kit)
Integrated Roof Bars
Factory-fitted bars integrated into the roof design. Found on:
- Some premium vehicles
- Commercial vans
- Purpose-built adventure vehicles
Benefit: No additional purchase needed, just add accessories
Major Roof Bar Brands
Thule (Premium)
Price range: £150-£350
Strengths:
- Industry leader from Sweden
- Excellent build quality and aerodynamics
- Comprehensive vehicle compatibility
- Strong warranty and customer service
- Wide accessory ecosystem
- City Crash tested for safety
Popular models:
- WingBar Evo: Premium aero bars, very quiet
- ProBar: Heavy-duty square bars
- SquareBar: Budget-friendly square option
- Edge: Flush rail specialist
Best for: Quality-focused buyers, regular users, premium vehicles
Yakima (Premium-Mid Range)
Price range: £120-£280
Strengths:
- American brand with strong reputation
- Good aerodynamics and build quality
- Innovative designs
- Competitive pricing vs Thule
- Excellent customer service
Popular models:
- JetStream: Aero bars with excellent noise reduction
- CoreBars: Mid-range aero option
- TimberLine: Heavy-duty steel bars
Best for: Value-conscious premium buyers
Halfords (Budget-Mid Range)
Price range: £50-£150
Strengths:
- UK high street availability
- Fitting service available in-store
- Good value for money
- Decent warranty
- Easy returns
Popular models:
- Advanced Roof Bars: Aero design, good value
- Universal Roof Bars: Budget square bars
Best for: Budget buyers, first-time users, UK convenience
Cruz (Mid Range)
Price range: £80-£180
Strengths:
- Spanish brand, popular in Europe
- Good build quality
- Wide vehicle compatibility
- Competitive pricing
Best for: Mid-range budget, European vehicles
Mont Blanc (Mid Range)
Price range: £90-£200
Strengths:
- French brand, solid reputation
- Good aerodynamics
- Reliable quality
- Wide accessory range
Best for: French vehicles, mid-range quality
Choosing the Right Roof Bars
1. Check Vehicle Compatibility
- Identify your roof type (bare, raised rails, flush rails)
- Check manufacturer compatibility charts
- Verify vehicle-specific fitting kit availability
- Confirm roof load limit in owner’s manual
2. Consider Intended Use
Occasional use (1-6 times/year):
- Budget square bars adequate
- Halfords or generic brands fine
- Focus on compatibility over features
Regular use (monthly):
- Invest in aero/wing bars
- Thule, Yakima, or premium brands
- Consider locking systems
- Fuel savings offset higher cost
Professional/daily use:
- T-track or heavy-duty systems
- Premium brands essential
- Professional installation
- Extended warranties
3. Budget Considerations
Budget tier (£50-£100):
- Basic square bars
- Generic/Halfords brands
- Manual locks or no locks
- Basic fitting kits
Mid-range tier (£100-£200):
- Entry-level aero bars
- Cruz, Mont Blanc, Halfords Advanced
- Integrated locks
- Better aerodynamics
Premium tier (£200-£350):
- Top-spec aero bars
- Thule WingBar Evo, Yakima JetStream
- Advanced locking
- Excellent aerodynamics and noise reduction
- Long warranties
Installation Guide
Tools Needed
- Torque wrench (if specified)
- Allen keys (usually supplied)
- Soft cloth (protect roof finish)
- Stepladder (for taller vehicles)
- Owner’s manual (for roof load limits)
Basic Installation Steps
- Read instructions thoroughly – Each system differs
- Identify mounting points – Check vehicle manual
- Attach mounting feet – Follow specific vehicle guide
- Position bars correctly – Equal distance from front/rear
- Space bars appropriately – Check accessory requirements
- Tighten to specification – Use torque wrench if required
- Check alignment – Bars should be parallel and perpendicular
- Test security – Apply pressure, check for movement
- Activate locks – If equipped with locking system
- Recheck after 50 miles – Fittings can settle
Correct Bar Spacing
Spacing depends on what you’ll carry:
- Roof boxes: 60-90cm apart (check box manual)
- Bikes: As wide as possible (stability)
- Kayaks: 60-75cm apart
- Skis: Manufacturer specification
- General cargo: Maximum stable distance
Safety & Weight Limits
Understanding Roof Load Limits
Dynamic roof load: Maximum weight while vehicle is moving
- Includes bars + accessories + cargo
- Typically 50-100kg depending on vehicle
- Found in vehicle owner’s manual
- Never exceed this limit
Static roof load: Maximum weight when stationary
- Usually much higher (200kg+)
- Relevant for roof tents
- Not relevant for roof boxes
Roof Bar Load Ratings
Quality roof bars specify maximum load capacity:
- Budget bars: 50-60kg typical
- Mid-range bars: 75kg typical
- Premium bars: 75-100kg typical
- Heavy-duty bars: 100kg+ (commercial use)
Important: Use the lower value between your vehicle’s roof limit and the bar’s rating.
Maintenance & Care
Regular Checks
- Tighten fittings every 3 months
- Check after 50 miles of any long journey
- Inspect rubber pads for wear
- Lubricate locks annually
- Check for corrosion on steel components
Cleaning
- Wash with vehicle using car shampoo
- Dry thoroughly to prevent corrosion
- Avoid harsh chemicals
- Clean mounting points when removing bars
Storage When Not in Use
- Remove bars when not needed (reduce wear, improve MPG)
- Store in dry location
- Keep fitting kit components together
- Protect from moisture to prevent corrosion
Legal Considerations UK
- Height limits: Total vehicle height must not exceed 4.57m (15ft)
- Width limits: Roof load must not exceed 2.9m width
- Overhang: Front overhang max 2m, rear overhang max 1m beyond vehicle
- Secure loading: Legal requirement that load is properly secured
- Insurance: Inform insurer about roof bars (usually no premium change)
- MOT: Roof bars don’t affect MOT unless they obscure lights/number plate
Common Problems & Solutions
Wind Noise/Whistling
Causes:
- Square bar design
- Incorrect fitting
- Missing wind deflectors
Solutions:
- Upgrade to aero bars
- Add wind deflector strips
- Check bar positioning and alignment
- Ensure end caps are fitted
Corrosion
Prevention:
- Choose aluminium or stainless steel bars
- Clean and dry after use in salt/winter
- Apply corrosion protection spray
- Remove bars during winter storage
Loosening Over Time
Prevention:
- Use torque wrench for initial fitting
- Recheck after 50 miles
- Regular tightening schedule
- Replace worn rubber components
Impact on Fuel Consumption
Empty roof bars impact:
- Square bars: 5-10% MPG reduction
- Aero bars: 2-5% MPG reduction
- T-track bars: 3-6% MPG reduction
With roof box fitted:
- Additional 15-25% MPG reduction
- Total impact: 17-35% depending on bar type and speed
Fuel saving tips:
- Remove bars when not in use
- Choose aero bars for regular use
- Drive at moderate speeds (fuel consumption increases exponentially above 60mph)
- Remove roof box immediately after trip
Buying vs Renting Roof Bars
Buy Roof Bars If:
- You use roof accessories regularly (monthly+)
- You need bars year-round
- You want specific brand/quality
- Long-term cost savings important
Cost analysis: £100-£300 one-time purchase vs £10-£25/week rental
Rent (With Roof Box) If:
- Occasional use (1-6 times/year)
- Don’t want storage hassles
- Want to test different systems
- Need complete solution (bars + box)
Benefit: Many roof box rental services include compatible roof bars, saving purchase cost and hassle
Conclusion
Roof bars are a crucial investment for anyone needing to carry extra cargo on their vehicle’s roof. The key decisions are:
- Verify compatibility with your specific vehicle
- Choose bar type based on usage frequency and budget
- Select quality brand appropriate to your needs
- Install correctly following manufacturer guidelines
- Maintain properly for safety and longevity
For occasional users, renting a complete roof box system (including bars) often makes more economic sense than buying. For regular users, investing in quality aero bars from brands like Thule or Yakima provides the best balance of performance, fuel efficiency, and longevity.
Need roof bars for a roof box rental? Many services include compatible roof bars with your rental, providing a complete solution without the purchase commitment.