Folding Bike Size Guide

How fold dimensions are measured

Folded dimensions follow format: Length x Width x Height (or Depth). These measurements indicate the rectangular space the folded bike occupies.

What affects fold size

• Wheel size: Primary determinant. 16-inch wheels fold smaller than 20-inch
• Frame design: How frame folds affects compactness
• Handlebar type: Some handlebars fold flatter than others
• Pedals: Folding vs non-folding pedals affect dimensions
• Accessories: Mudguards, racks, bags add to dimensions
• Configuration: Seat height, handlebar position when folded

Manufacturers measure with bike optimally folded. Real-world dimensions may be slightly larger.

Folding bike size comparison

Dimensions are approximate and may vary by configuration. Always verify with current manufacturer specifications before purchasing.

Understanding size categories

Ultra-compact (Brompton category)

Typical size: 58.5 x 56.5 x 27cm

Volume: Approximately 0.09 cubic meters

Characteristics:

• Smallest fold available for adult riders
• Achieved through 16-inch wheels and decades of engineering
• Essentially only Brompton at this size for quality adult bikes
• Rolls when folded using rear wheel
• Fits spaces impossible for other folders

Best for: Crowded peak-hour trains, tiny storage spaces, taking inside venues, frequent carrying

Compact (premium 20-inch category)

Typical size: 70-75 x 64-68 x 36-38cm

Volume: Approximately 0.17-0.19 cubic meters (roughly 2x Brompton)

Examples: Tern BYB, higher-end compact designs

Characteristics:

• 20-inch wheels with optimised folding mechanisms
• Still considered compact but noticeably larger than Brompton
• Better ride quality than 16-inch while maintaining portability
• Typically more expensive due to premium design

Best for: Moderate train use, hallway storage, balancing ride quality with fold size

Standard (typical 20-inch category)

Typical size: 79-81 x 68-72 x 38-40cm

Volume: Approximately 0.21-0.23 cubic meters

Examples: Tern Link series, Dahon Vybe, Decathlon Tilt, most mid-range folders

Characteristics:

• Most common fold size for 20-inch wheels
• Practical for car boots and moderate storage
• Wide price range from budget to mid-premium
• Good ride quality with acceptable fold

Best for: Car boot transport, off-peak trains, home hallway storage, primarily-cycling commutes

Large (24-inch and relaxed designs)

Typical size: 85-95 x 70-80 x 42-48cm

Volume: Approximately 0.25-0.36 cubic meters

Examples: 24-inch wheel folders, some relaxed 20-inch designs

Characteristics:

• Larger wheels prioritise ride quality over compactness
• Fold is practical but not particularly compact
• Better suited to car transport than train
• Ride quality approaches full-size bikes

Best for: Car-only transport, large storage spaces, recreational riding priority

Where folded bikes fit: practical scenarios

Train travel

Under seats (most UK trains):

• Typical clearance: 60-65cm length, 25-30cm height
• Fits: Ultra-compact folders only (Brompton)
• Tight fit but workable: None, requires ultra-compact
• Does not fit: All other folders

Overhead luggage racks:

• Typical clearance: 90cm length, 35cm depth, varies height
• Fits: Ultra-compact and compact folders easily
• Fits with care: Standard folders (80cm) if positioned carefully
• May not fit: Large folders (85cm+)

Luggage areas at carriage ends:

• Varies significantly by train type
• Fits: All folders off-peak
• Challenging: Standard and large folders during peak hours
• Best: Ultra-compact and compact folders always manageable

Floor space by doors:

• Acceptability varies by train crowding
• Off-peak: All folders acceptable
• Peak hours: Larger folders may obstruct other passengers
• Recommendation: Observe your specific route and times before committing

Car boot storage

Small cars (Fiat 500, Mini Cooper, Toyota Aygo):

• Boot dimensions approximately: 185 x 75 x 65cm
• Fits: Ultra-compact folders easily
• Fits with rear seats down: Compact and some standard folders
• Challenging: Standard folders with rear seats up
• Recommendation: Measure your specific boot, consider ultra-compact

Medium cars (VW Golf, Ford Focus, Vauxhall Astra):

• Boot dimensions approximately: 380 x 100 x 70cm
• Fits: Ultra-compact, compact, and standard folders comfortably
• Fits multiple bikes: 2 x ultra-compact or 1 x standard
• Recommendation: Most folders work well

Large cars and estates:

• Boot dimensions: 400cm+ length
• Fits: All folders easily
• Multiple bikes: 2-3 folders depending on size
• Recommendation: Fold size not limiting factor

Home storage

Under bed storage:

• Typical clearance: 200cm length, 25-35cm height
• Fits: Ultra-compact folders only (and only just)
• Does not fit: All other categories too tall
• Note: Dust and inconvenience make this suboptimal anyway

Hall cupboard:

• Typical dimensions: 60-90cm width, 40-60cm depth, 180cm+ height
• Fits: Ultra-compact folders easily
• Fits: Compact folders in generous cupboards (70cm+ depth)
• Challenging: Standard folders (80cm length) in typical cupboards
• Recommendation: Measure cupboard depth precisely

Corner of room/hallway:

• Depends on hallway width and tolerance for obstruction
• Narrow hallways (80cm): Ultra-compact and compact folders best
• Standard hallways (100cm+): All folders acceptable
• Wide hallways (120cm+): All folders comfortable

Wardrobe storage:

• Typical wardrobe depth: 55-60cm
• Fits: Ultra-compact folders (58.5cm with care)
• Does not fit: Compact folders (65-68cm depth)
• Does not fit: Standard folders (70-72cm depth)
• Recommendation: Very few folders small enough for wardrobes

Office storage

Under desk:

• Typical desk clearance: 70cm width, 50cm depth, 60-70cm height
• Fits: Ultra-compact folders in most desk spaces
• Fits: Compact folders in generous desk spaces
• Challenging: Standard folders (typically too wide or tall)
• Alternative: Store beside desk if under-desk does not work

Beside desk/in corner:

• Depends on office layout and policies
• All folders fit physically
• Smaller folders less obtrusive and more likely accepted
• Check office policies before assuming storage

How to measure your spaces accurately

Tools needed

• Tape measure (3m minimum)
• Notepad for recording dimensions
• Phone camera for reference photos

Measuring process

1. Measure Length, Width, Height of available space
2. Subtract 5-10cm from each dimension for comfort margin
3. Note any obstructions (pipes, walls, shelves)
4. Consider access (can you maneuver folded bike into space?)
5. Measure multiple spaces (train, car, home) if applicable
6. Use smallest measured space as your size constraint

Common measuring mistakes

• Not adding clearance margin: Tight fits frustrate daily use
• Measuring empty space without bike shape consideration: Rectangular bikes do not use triangular spaces efficiently
• Forgetting door opening dimensions: Space may exist but bike cannot fit through door
• Not accounting for other items: Car boots contain other luggage
• Measuring once rather than verifying: Measure twice to confirm
• Assuming specifications match reality: Bikes may be slightly larger with accessories

Choosing the right size for your needs

If you need ultra-compact (Brompton size)

Required scenarios:

• Storing under train seats during crowded peak hours
• Tiny flat with only wardrobe or very small cupboard space
• Taking bike inside shops, restaurants, offices regularly
• Frequent carrying through crowded spaces
• Storage space under 60 x 60 x 30cm

Options: Brompton C Line, P Line, or T Line (£1,500-4,500)

Trade-offs: Higher price, 16-inch wheels, less comfortable for long rides

Browse: Brompton range

If compact folders suit you

Suitable scenarios:

• Moderate train use, not always peak hours
• Hall cupboards with 70cm+ depth
• Under generous office desks
• Want better ride quality than 16-inch while maintaining portability

Options: Tern BYB, premium compact designs (£1,200-1,800)

Trade-offs: Still premium pricing, fewer options than standard category

If standard folders work

Suitable scenarios:

• Car boot transport primary
• Off-peak or occasional train use
• Home hallway or corner storage (100cm+ width)
• Prioritise ride quality and value over absolute compactness

Options: Tern Link series, Dahon, Decathlon (£400-900)

Trade-offs: Larger fold, may struggle in peak-hour trains

Browse: 20-inch folders

Final sizing advice

• Always measure your most restrictive space first
• Add 5-10cm clearance to published dimensions for real-world use
• If possible, see folded bike physically before buying
• Consider that you will improve at folding compactly with practice
• Remember fold size affects price: ultra-compact costs premium
• Prioritise your 80% use case, not occasional edge cases
• If uncertain between sizes, observe your actual train/storage for a week
• Used Brompton provides ultra-compact at mid-range pricing

Compare sizes: 16 vs 20 inch | Brompton vs Tern | Best folding bikes