Folding Bike Gears Explained

Understanding gear ratios and ranges

Gears allow you to pedal efficiently at different speeds and on varying terrain. Lower gears make pedaling easier (for hills), higher gears enable faster speeds (for flat ground).

Gear range explained

Gear range (expressed as percentage) indicates the spread between lowest and highest gears:

• 200%: Highest gear is 2x harder to pedal than lowest gear
• 300%: Highest gear is 3x harder to pedal than lowest gear
• 500%: Highest gear is 5x harder to pedal than lowest gear

Wider range provides more versatility but often requires more gears or complexity.

Gear steps

How evenly gears are spaced affects riding smoothness. Well-spaced gears allow small adjustments. Large jumps between gears feel awkward, requiring significant effort changes.

Types of gearing systems

Hub gears

Gears contained inside the rear hub. Chain runs in straight line, shifting happens internally.

Advantages:

• Low maintenance (sealed from weather and dirt)
• Can shift when stationary (useful at traffic lights on hills)
• Protected from damage in folding and transport
• Long-lasting with minimal attention
• Clean operation (no exposed moving parts)

Disadvantages:

• Heavier than derailleur systems
• More expensive initially
• Limited gear range in compact designs
• Internal servicing requires specialist knowledge
• Less efficient (small power loss through mechanism)

Common hub gear options:

• Sturmey Archer 3-speed: ~180% range, simple, reliable
• Brompton BWR 3-speed: ~190% range, designed for folders
• Shimano Alfine 8-speed: ~307% range, excellent for urban use
• Shimano Alfine 11-speed: ~409% range, wide range internal hub

Best for: Urban commuting, minimal maintenance needs, year-round riding, stop-start traffic

Derailleur gears

External system where chain moves between multiple sprockets. Visible mechanism with exposed moving parts.

Advantages:

• Lighter weight than hub gears
• Wide gear ranges available (7-11 speeds typical)
• Less expensive than hub gears
• Easier to repair and service (standard bicycle knowledge)
• More efficient power transfer

Disadvantages:

• Requires regular maintenance (adjustment, cleaning)
• Exposed to weather, dirt, and damage
• Cannot shift when stationary
• Can be damaged in transport or folding
• Needs periodic cable replacement

Common derailleur options:

• Shimano Tourney 7-speed: ~240% range, entry-level budget
• Shimano Altus 8-speed: ~280% range, reliable mid-range
• Shimano Claris 8-speed: ~300% range, good quality
• Microshift 9-speed: ~305% range, budget-friendly wide range
• Shimano Sora 9-speed: ~340% range, excellent performance

Best for: Varied terrain, recreational riding, weight-conscious riders, budget options

Combined systems

Some folders combine hub gear and derailleur for wider range in compact package.

Examples:

• Brompton 6-speed: 2-speed hub + 3-speed derailleur = 270% range
• Brompton 12-speed: 3-speed hub + 4-speed derailleur = ~440% range

Advantages:

• Wide range without large external derailleur
• Can shift hub gear when stationary
• Compact packaging

Disadvantages:

• More complex with two systems to maintain
• Heavier than derailleur alone
• More expensive than either system alone

Best for: Hilly areas needing wide range, Brompton owners wanting maximum versatility

How many gears do you actually need?

Single speed (1 gear)

Fixed gear ratio, no shifting.

Suitable for:

• Completely flat cities (Amsterdam, Cambridge)
• Short commutes under 3 miles
• Riders wanting absolute simplicity
• Minimalist approach

Limitations:

• Any hill becomes very difficult
• No ability to adjust to conditions
• Less efficient across varied speeds

Recommendation: Only for genuinely flat routes. Most UK riders need gears.

3-speed hub gear

Simple hub gear, typically 180-200% range.

Suitable for:

• Mostly flat with occasional gentle hills
• Short urban commutes under 5 miles
• Riders prioritizing simplicity
• Minimal maintenance preference

Limitations:

• Narrow range struggles on moderate hills
• Large steps between gears
• Top gear may feel limiting for faster riding

Recommendation: Works for flat London, Cambridge. Inadequate for Bristol, Edinburgh.

6-8 speed

Either 6-7 speed derailleur or combination system. Typically 240-300% range.

Suitable for:

• Most UK commutes including moderate hills
• Mixed urban and suburban terrain
• 5-10 mile commutes
• Reasonably fit riders

Coverage:

• Lowest gear handles moderate hills at walking pace
• Highest gear comfortable at 20-25mph on flat
• Well-spaced steps for smooth transitions

Recommendation: Sweet spot for most riders. Handles varied terrain adequately.

9-11 speed

Advanced derailleur or high-end hub gear. Typically 300-400% range.

Suitable for:

• Hilly areas (Sheffield, Bristol, Bath, Edinburgh)
• Long rides over 10 miles
• Varied terrain including steep sections
• Riders wanting optimal gear for every situation

Coverage:

• Very low gears handle steep hills
• High gears support fast riding
• Small steps between gears

Recommendation: Worthwhile for genuinely hilly areas or long-distance riding.

12+ speed

Premium systems like Brompton 12-speed. Typically 400-500%+ range.

Suitable for:

• Very hilly terrain with steep grades
• Touring and long-distance folding
• Riders wanting maximum versatility
• Those who can justify premium pricing

Coverage:

• Extreme low gears for steepest hills
• Very high gears for maximum speed
• Tiny steps between gears

Recommendation: Overkill for most riders. Justifiable for extreme terrain or touring.

Matching gearing to your terrain

Flat cities (London, Cambridge, Norwich)

Elevation gain: Minimal (under 50m per 10km)

Recommended gearing: 3-6 speed adequate

Reasoning: Limited climbing means simple gearing works. Priority is simplicity and reliability. Hub gears ideal for urban stop-start patterns.

Models: Brompton 3-speed, budget 6-speed derailleurs

Gentle hills (Manchester, Birmingham, Leeds)

Elevation gain: Moderate (50-150m per 10km)

Recommended gearing: 6-8 speed recommended

Reasoning: Regular gentle climbs benefit from wider range. 3-speed struggles, 6-8 speed comfortable for fit riders.

Models: Brompton 6-speed, 7-8 speed derailleur folders

Moderate hills (Bristol, Newcastle, Nottingham)

Elevation gain: Significant (150-250m per 10km)

Recommended gearing: 8-10 speed strongly recommended

Reasoning: Regular moderate climbs demand lower gears. 6-speed adequate for very fit riders, 8-10 speed more comfortable.

Models: 8-9 speed derailleur folders, Brompton 6-speed (minimum)

Steep hills (Edinburgh, Bath, Sheffield, coastal towns)

Elevation gain: Major (250m+ per 10km, steep grades)

Recommended gearing: 10-12 speed or consider electric

Reasoning: Steep climbs require very low gears. 8-speed struggles on steepest sections. Electric assistance may be better solution than extreme gearing.

Models: Brompton 12-speed, 10-11 speed derailleur folders, electric folders

Mixed terrain

Commute includes flat sections plus occasional steep hill

Recommended gearing: Based on steepest regular hill, not average

Reasoning: Gearing must handle worst-case scenario. Gear for hills, accept being over-geared on flats.

Maintenance requirements by gearing type

Hub gear maintenance

Routine:

• Weekly: Check shifting operates smoothly
• Monthly: Check cable tension
• Annually: Professional service recommended (£40-60)
• Every 2-3 years: Internal service/oil change (£60-100)

Costs: Lower long-term due to sealed design. Parts last longer.

Derailleur maintenance

Routine:

• Weekly: Clean chain if riding in wet/dirt
• Monthly: Check derailleur adjustment, clean thoroughly
• Quarterly: Cable replacement often needed (£5-10)
• Annually: Chain replacement (£12-18), possibly cassette (£25-40)

Costs: Higher frequency but lower individual costs. DIY-friendly.

Choosing your gearing: decision framework

Step 1: Map your typical route

Use mapping tools to check elevation profile. Note:

• Total elevation gain
• Steepest gradient encountered
• Whether hills avoidable via alternative routes

Step 2: Consider your fitness

Honest assessment:

• Regularly cycle or exercise: Can manage with fewer gears
• Moderate fitness: Standard gearing appropriate
• Low fitness or health limitations: Err toward more/lower gears
• Unknown fitness: Choose more gears initially

Step 3: Evaluate maintenance preferences

• Want minimal maintenance: Hub gears preferred
• Happy with regular attention: Derailleur acceptable
• DIY maintenance: Derailleur easier to self-service
• Professional service only: Either works

Step 4: Consider budget

• Under £600: Derailleur systems dominate this price
• £600-1,200: Both available, derailleur offers more gears
• Over £1,200: Premium options in both categories

Step 5: Make decision

Combine factors:

• Flat + low maintenance preference = 3-speed hub
• Moderate hills + budget under £700 = 7-8 speed derailleur
• Steep hills + premium budget = Brompton 12-speed or 10-speed derailleur
• Very hilly + moderate budget = Consider electric assistance instead

Common gearing mistakes to avoid

• Choosing too few gears for hills: Test your actual route before assuming 3-speed adequate
• Choosing too many gears for flat terrain: Complexity without benefit
• Prioritizing gear count over gear range: 6-speed with 270% range better than 7-speed with 240% for hills
• Ignoring maintenance implications: Derailleur gears need regular attention
• Assuming hub gears always better: Weight, cost, and range trade-offs exist
• Not testing gearing before buying: Test ride on actual hills if possible
• Forgetting wheel size affects gearing: 16-inch wheels need different ratios than 20-inch

Can you change gearing later?

Changing gearing systems is difficult and often impractical:

• Hub to derailleur: Requires new wheel, derailleur, shifters. Expensive, rarely worthwhile
• Derailleur to hub: Requires new wheel, shifters, frame modifications possibly. Very expensive
• Adding gears within same system: Limited options, expensive
• Changing gear ratios: Possible by changing sprockets but limited range

Recommendation: Choose appropriate gearing initially. Upgrades are rarely cost-effective.

Final gearing selection advice

• Be honest about actual terrain, not occasional hills
• Test ride on representative hills if possible
• When uncertain, choose more gears rather than fewer
• Match gearing to worst regular hill, not average
• Consider fitness realistically (you may not improve)
• Factor maintenance willingness into hub vs derailleur choice
• Remember: inadequate gearing ruins daily riding experience
• Electric assistance may be better solution than extreme gearing for very hilly areas

Related guides: How to choose | Wheel size comparison | Best folding bikes