Bicycle parking: Detailed planning guide

This section describes what types of bicycle racks are acceptable for installation and how to refer to them in plans, codes, and other instructions.

1.1. The idea of an “acceptable” rack

An acceptable bicycle rack is a high‑security rack that physically supports the bicycle frame (often called a “support‑type” rack). Such a high-security support-type rack is designed so that a user can secure their bicycle frame and at least one wheel to the rack with a personal u-lock while keeping the bike upright and stable.

In practice, manufactured high-security support-type racks generally accomodates two bicycle per rack. An unusual exception to a 2-sided rack a rack that is custom-designed, such as a work that is also an art installation, provided it meets key criteria.

“High‑security” for a bicycle rack means:

• The rack is made from robust, tamper‑resistant materials (e.g., thick steel) that resist cutting and bending.
• It is permanently and securely anchored to a solid base with tamper‑resistant hardware, so the rack itself is not the weak point.
• Its geometry is compatible with secure locks, so users can realistically use a U‑lock (or equivalent) to secure the frame and at least one wheel.

“Support‑type” for a bicycle rack means:

• The rack physically supports the bicycle frame, not just a wheel.
• It provides two or more points of contact so the bicycle remains upright and does not easily tip, twist, or roll.
• The contact points are located where typical bicycle frames can rest securely, across a wide range of bicycle types.

1.2. Functional requirements

Acceptable racks meet all the following criteria:

• Enable secure locking of the frame: The rack allows the bicycle frame and at least one wheel to be locked to the rack with a standard U‑lock (or equivalent high‑security lock).
• Provide stable two‑point support: The rack supports the bicycle at two or more points so that it remains upright and does not easily twist, tip, or roll.
• Be durable and securely anchored: The rack is permanently and securely anchored to a hard surface (e.g., concrete) with tamper‑resistant hardware. Materials are strong, weather‑resistant, and vandal‑resistant.
• Avoid damage to bicycles: The rack has no sharp edges, pinch points, or shapes likely to bend wheels or scratch frames with normal use.
• Be accessible to all kinds of users and bicycles: Contact surfaces are smooth and compatible with a wide range of bicycles (including step‑through frames, some cargo bikes, and kids’ bikes).
• Provide realistic capacity: Each usable bicycle space must permit independent locking and removal of that bicycle without moving other bikes.

Any rack or installation of a rack that does not meet these criteria is not acceptable, regardless of manufacturer capacity claims.

1.3. Acceptable rack designs

The following types of rack designs are acceptable when they meet the functional performance standard above and the dimensional/spacing standards elsewhere in this guide.

1.3.1. Inverted‑U racks (and equivalent)

Other common names: Inverted‑U rack, hoop rack, staple rack, U‑rack.

Description: A simple upside‑down “U” made of steel tubing, anchored at both ends, generally bolted into concrete. Designed to hold two bicycles, one on each side.

Acceptability: Considered the preferred standard rack type. Fully supports all bicycle designs, easily accommodates u‑locks, and is simple and intuitive to use.

Acceptable variations:

• Subtly different shapes: Racks that are similar to an upside-down “U” shape but have rounder or squarer corners, or other slight differences. A couple of those are included in the following entries.
• Inverted‑U with cross member: An additional horizontal bar between the legs to provide another convenient locking point, especially for smaller frames and step‑through bikes. Acceptable so long as it easily accomodates locking locking the frame and wheel for bicycles of all sizes and shapes.
• Multiple inverted‑Us on a rail (“racks on rails”): Modules consisting of several inverted‑U racks mounted on a shared base or rail. Acceptable where the module is permanently and securely anchored and individual U‑racks maintain required spacing.

Bottom line: Inverted‑U racks are the “gold standard” of racks as they provide the simplest, strongest, most accessible options for different sizes and shapes of bicycles and user needs. Most installers should simply select the inverted U.

1.3.2. Half‑circle / hoop‑style racks

Description: A semi‑circular or arched hoop anchored at both ends, forming a curved support between two bases.

Acceptability: Acceptable where rhe curved portion reaches the main frame area of a bicycle (not just the wheel), and bikes can lean on the hoop and be locked by the frame and wheel to the hoop.

Bottom line: Half‑circle or hoop‑style racks are acceptable where they provide stable support to the bicycle frame and allow secure locking of the frame and at least one wheel. They are essentially a variation of the inverted U.

1.3.3. Short S‑curve (“swerve”) racks

Description: A short, S‑shaped tube anchored at both ends, forming a gentle curve between two bases. Intended to serve two bicycles, one on each side, similar to an inverted‑U.

Acceptability: Acceptable where each side can be used like an inverted‑U (securely locking the frame and wheel on both sides), and the rack provides two‑point support and does not rely on wheel slots.

Important caveat: This rack is different than the a similarly-sounding rack that is not acceptable–Long multi‑wave “schoolyard” racks that are counted as many spaces but do not provide stable frame support for each bicycle are unacceptable.

Bottom line: Short S‑curve (‘swerve’), like half‑circle / hoop‑style racks, work essentially the same as an inverted‑U rack, allowing secure frame‑and‑wheel locking on both sides and providing two‑point support. Long multi‑wave racks with only single‑point support or wheel‑only locking are not acceptable.

1.3.4. Post‑and‑ring racks (or ring‑and‑post)

Description: A vertical or leaning post with one or two rings (or other closed shapes, such as a rectangle) at approximately frame height. Bikes lean against the ring and lock the frame and wheel to the ring/post.

Acceptability: Acceptable where the ring is large enough to accept a U‑lock around the frame and wheel (allowing U‑lock attachment around the bicycle frame and wheel and the rack provides stable two‑point support) and the post and ring assembly is robust and permanently anchored.

Important caveat: Post-and-ring racks are prone to having rings that are not large enough to accept all sizes and shapes of bicycles, especially when two are locked on either size.

Custom racks (sculptural or other artful racks)

Description: Custom-built racks, typically used to present a sculpture or other artful decoration that doubles as useful bicycle rack.

Acceptability: Acceptable where the functional geometry of the design allows U‑locks to secure the frame and at least one wheel, provides two‑point support so the bicycle stands upright, and is constructed and anchored to the same standards as a conventional rack.

Pitfall to avoid: Racks that are primarily sculpture and only offer wheel‑only locking or single contact points are not acceptable, regardless of artistic merit.

Bottom line: Artistic or custom racks are acceptable when they meet the same functional criteria as standard high‑security, support‑type racks: frame‑and‑wheel lockability, two‑point support, durable construction, and permanent anchoring.

Other support‑type racks

Other support‑type forms (for example, A‑frame or triangle racks that operate like wide inverted‑U’s) may be acceptable if they clearly meet all functional criteria in Section 1. These should be evaluated explicitly against those criteria, with an emphasis on high‑security construction and U‑lock‑compatible geometry.

1.4 Unacceptable rack types (do not use)

The following rack types are not acceptable according to the conesus of bicycle security professionals. They should generally be avoided and retired in favor of acceptable designs.

1.4.1. Wheel‑slot (“comb” or “toaster”) racks: Do not use

Description: Racks with parallel slots or thin hoops into which only the front wheel (or sometimes the rear wheel) is intended to be inserted.

Why they are unacceptable:

• Typically allow wheel‑only locking; the frame cannot easily be secured with a U‑lock.
• Provide poor support; bikes are easily knocked over.
• Frequently bend or damage wheels when bikes are pushed or fall.

1.4.2. Long multi‑wave (“schoolyard”) racks counted by crest: Do not use

Description: Continuous wave‑shaped racks marketed as multi‑bike racks, often counted as one space per crest or valley of the wave.

Why they are unacceptable:

• Typically do not allow independent, secure frame‑and‑wheel U‑locking for each “advertised” space.
• In practice, bikes usually contact the rack at a single point, leading to instability.
• The practical capacity is much lower than the nominal capacity.
• Are generally not of high-security construction; furthermore, are prone to one point of failure exposing many bicycles to theft.

1.4.3. Coathanger racks: Do not use

Description: Racks that resemble a “coat hanger” bar with multiple angled arms or short protrusions intended to hold bikes by the top tube or to hang them partially off the ground.

Why they are unacceptable:

• Typically not allow easy frame‑and‑wheel U‑locking to a robust, continuous element.
• Typically support the bike at a single point, often only by the top tube.
• Create usability and accessibility issues for many riders: They can be difficult or impossible for many people to lift bikes into position; incompatible with many frame types (step‑through, some e‑bikes, cargo bikes, kids’ bikes, some adaptive cycles), and cause bikes to swing into each other, increasing the risk of damage.

1.4.4. Single posts or bollards without rings: Do not use

Description: Simple posts or bollards without any ring, hoop, or extended element to stabilize and secure the bicycle.

Why they are unacceptable:

• Rarely allow secure U‑lock attachment to the frame and wheel in a stable position.
• Offer very limited support; bikes are prone to tipping and twisting.

1.4.5. Low wheel stands: Do not use

Description: Very low hoops, spring‑loaded wheel clamps, or short fixtures that contact only the lower wheel and do not extend up to the frame triangle.

Why they are unacceptable:

• Do not reach the frame triangle and therefore do not support frame‑and‑wheel U‑locking.
• Provide minimal stability and can damage wheels.

Recommended specification language

For use in codes, standards, RFPs, and drawings, the following language can be used summarize these requirements:

Racks allow users to lock the bicycle frame and at least one wheel with a standard U‑lock or equivalent (NACTO, 2014; Boulder, B.R.C. §9‑9‑6(e) 2025).

Inverted‑U (“staple”) racks are intended to serve bikes on both sides of the rack. Layouts provide space for that two‑sided use.

Racks support the bicycle in at least two points of contact so it does not tip over or twist (NACTO, 2014).

Rack placement and spacing avoids interference between adjacent bikes: handlebars, pedals, baskets, and trailers do not routinely collide if users park normally (Boulder, B.R.C. §9‑9‑6(e) 2025).

Racks are designed and finished to avoid damage to bicycless—no sharp edges, rough welds, or abrasive contact surfaces (Boulder, B.R.C. §9‑9‑6(e) 2025).

Clearances prevent frequent scraping of bikes against walls, posts, or other racks (NACTO, 2014).

Racks are securely anchored to concrete or similarly durable paving with tamper‑resistant anchors, so racks cannot be easily removed (Boulder, B.R.C. §9‑9‑6(e) 2025).

Racks are of solid, vandal‑resistant construction, resistant to rust, corrosion, and cutting or prying with common tools (Boulder, B.R.C. §9‑9‑6(e) 2025; NACTO, 2014).

As an alternative, here is a summary statement that combines all those items: “Bicycle parking shall be provided using high‑security, support‑type, U‑lock‑compatible racks that allow the bicycle frame and at least one wheel to be locked with a standard U‑lock, provide at least two points of support to prevent the bicycle from tipping, and are constructed of durable materials and permanently anchored. Acceptable rack types include inverted‑U racks and their variations, post‑and‑ring racks, short S‑curve (‘swerve’) racks that function equivalently to inverted‑U racks, half‑circle/hoop racks, and art racks whose functional geometry meets these criteria. Wheel‑slot (‘comb’/‘toaster’) racks, long multi‑wave racks that permit only wheel‑locking or single‑point support, coathanger‑type racks, single‑post stands without rings, and low wheel‑only stands are not permitted as compliant bicycle parking.”

This section describes where and how to site a bicycle parking area.

1.2.1. Location

Within 50 ft of main building entrances, measured along a practical pedestrian path (Boulder, B.R.C. §9‑9‑6(e) 2025).  

Outside the building and adjacent to the sidewalk or public space, unless an equally convenient and visible indoor option is clearly signed (Boulder, B.R.C. §9‑9‑6(e) 2025).  

On the primary public‑access level, without requiring elevators or long ramps (Boulder, B.R.C. §9‑9‑6(e) 2025).

In a place with good passive surveillance—for example, in front of storefront windows or along busy walkways, not hidden at the back of sites or in unlit corners (Boulder, B.R.C. §9‑9‑6(e) 2025; NACTO, 2014).

1.2.3. Urban design and visibility

Racks are located in convenient, highly visible, active, and well‑lighted areas; they are not hidden in remote corners (Boulder, B.R.C. §9‑9‑6(e) 2025; NACTO, 2014).  

Racks do not block pedestrian movement, building entrances, curb ramps, transit stops, or accessible routes (Boulder, B.R.C. §9‑9‑6(e) 2025; NACTO, 2014).  

If the bike parking area is not visible from the main entrance, it is marked with wayfinding signs (Boulder, B.R.C. §9‑9‑6(e) 2025).

Figures in this section provide measurements for designating a bicycle parking area and then placing one or more inverted U racks in that area.

Measurements typically refer to the distance from the centerpoint or centerline of the rack to something else (e.g., bicycle area boundary, wall, or other rack).

Measurements assume the use of standard inverted‑U racks, with each rack holding bicycles on both sides (i.e., 2 spaces per rack).

1.3.1. Rules of thumb

A single rack accommodating one bicycle on each side requires about 24 square feet of floor area, or 12 feet per bicycle. That is based on 6 feet of length by 4 feet of width (two feet on each side of the rack).

When multiple racks are placed side by side, the per-space requirement is less. That is because racks can be placed as close to two feet apart, and the space between two racks can accomodate two bicycles (whereas the minimum distance between the rack and the outside boundary of the bicycle area is also two feet, and in that case only one bicycle will fit between the rack and the boundary). Using 6 feet in length, that comes out to 6 square feet per bicycle.

As another rule of thumb, the size of a typical car parking space (usually at least 9 by 18 feet)) can accomodate 9 racks holding 18 bicycles. That is based on a configuration of three rows of two racks side by side.

1.3.2. One standalone inverted‑U rack

This describes a single inverted‑U rack by itself accomodating two bicycles, one on each sides. The depth and width dimensions designate exclusive access for bicycle parking that is separated from motor vehicle parking and driving and does not obstruct sidewalks, multiuse paths, or other uses.

1.3.2.1. Minimum depth

Minimum depth of the bike parking area:  

• Mark a rectangle on the ground that defines where bikes are allowed to extend on both sides of the rack.  
• This rectangle is at least 6 ft (1.8 m) deep, measured from the front edge of the bike area to the back edge (NACTO, 2014).  
• The rack will sit inside this 6‑ft‑deep area.

Position of the rack within that depth:

• From the centerline of the rack to the front edge of the bike area is at least 2 ft 4 in (0.71 m).  
• From the centerline of the rack to the back edge of the bike area is also at least 2 ft 4 in (0.71 m) (Boulder, DCS Tech Drawings 2009).  
• With these clearances on both sides, the total bike area depth is at least 6 ft and functions properly for two‑sided short‑term parking.

1.3.2.2. Minimum width

Side clearance from rack to walls or obstructions:  

• From the closest point of the rack to any side wall, curb, fence, planter, or other obstruction there is at least 2 ft (0.6 m) on each side (Boulder, DCS Tech Drawings 2009).

Clear pedestrian path nearby:  

• If the rack is on a sidewalk, there is at least 5 ft (1.5 m) of unobstructed sidewalk, measured from the outer edge of any parked bike to the nearest obstruction (building face, curb, pole, etc.) (NACTO, 2014).

Separation from motor vehicle lanes or parking: 

• If the rack is near a travel lane or parking space, there is at least 2 ft (0.6 m) of clear horizontal space from the outer edge of any parked bike to the curb or edge of the motor vehicle lane (NACTO, 2014).

1.3.2.3. Vertical clearance

• At least 6 ft 8 in (2.0 m) of clear height above the entire bike parking area (NACTO, 2014).

1.3.3. Multiple racks next to one another in a row (side‑by‑side), bikes on both sides

Use this configuration when installing two or more inverted‑U racks in a row, with bikes on both sides of each rack.

1.3.2.1. Depth of the bike parking area and rack position

Total depth of bike area, front to back: 

• Mark a rectangular bike area that is at least 6 ft (1.8 m) deep, measured from the front edge of where bikes can extend to the back edge (NACTO, 2014).
• The depth for this configuration is the same as described for a standalone rack.

Distance from rack centerline to front and back edges:  

• From the centerline of each rack to the front edge of the bike area is at least 2 ft 4 in (0.71 m).  
• From the centerline of each rack to the back edge of the bike area is also at least 2 ft 4 in (0.71 m) (Boulder, DCS Tech Drawings 2009).  
• With these clearances, a 6‑ft‑deep bike area functions well for two‑sided short‑term parking on each rack.

1.3.2.2. Side clearance and distance between racks

Side clearance from racks to boundaries/obstructions:  

• From the closest point of any rack to any side boundary, wall, curb, fence, planter, or similar obstruction must be at least 2 ft (0.6 m) on each side (Boulder, DCS Tech Drawings 2009).

Distance between adjacent racks in the row: 

• From the centerline of one rack to the centerline of the next rack along the row must be at least 3 ft 6 in (1.07 m) (Boulder, DCS Tech Drawings 2009).  
• This spacing provides at least about 2.5 ft of functional width per bicycle along the row (NACTO, 2014).

Note: Ensure that this spacing holds if using a prefabricated inverted U “racks on rails design.”

1.3.2.3. Two facing rows (aisle between them)

If there are two rows of racks facing each other (for example, back‑to‑back aisles in a garage or plaza):  

• Measure the distance between the front edges of the bike envelopes (where front wheels/handlebars will extend) of the two rows.  
• This clear aisle must be at least 5 ft (1.5 m) wide (NACTO, 2014).  
• You can approximate this by measuring from the front edge of the marked bike area on one side to the front edge on the opposite side.

1.3.4. Racks aligned end‑to‑end (one after another)

Use this configuration when racks are lined up along a curb, wall, or path, one after another along their length.

Side clearance from rack to boundaries:  

• From the closest point of each rack to any side boundary or obstruction is at least 2 ft (0.6 m) on each side (Boulder, DCS Tech Drawings 2009).

Distance between racks along the line (end‑to‑end): 

• From the centerline of one rack to the centerline of the next rack along the line must be at least 6 ft (1.8 m) (Boulder, DCS Tech Drawings 2009).  
• This gives each bike a full 6 ft length of bike area (NACTO, 2014).

Distance from rack centerline to front and rear boundaries:  

• From the centerline of each rack to the front boundary of the bike area is at least 2 ft 4 in (0.71 m).  
• From the centerline to the rear boundary is at least 2 ft 4 in (0.71 m) (Boulder, DCS Tech Drawings 2009).