# Bicycle Accessories

“Bicycle accessories” bundles unrelated product types — helmets, locks, lights, pumps, racks and panniers, computers, bottle cages, child seats — each judged against its own safety standard or spec, not a shared one. What to ask depends entirely on which accessory the buyer means.

## How it works

Each accessory solves one specific risk or need of riding a bike, by a different mechanism: a helmet's foam liner crushes to absorb impact energy; a lock's hardened steel resists cutting, picking and leverage; a light makes the rider visible to traffic rather than lighting the road like a car's headlamp; a rack and panniers carry load off the body without shifting the bike's balance; a computer reads speed, cadence or GPS sensors and displays the result. Because the mechanisms differ, the spec that signals quality in one type — certification, security rating, lumens — says nothing about another.

## How an expert narrows the choice

```mermaid
timeline
  section 1 · Accessory type
    helmet : ask Safety certification, Rotational impact protection, Helmet form : skip Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position
    lock : ask Lock form, Security rating, Shackle or chain material : skip Safety certification, Rotational impact protection, Helmet form, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position
    light : ask Front or rear, Light output, Runtime per charge : skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position
    pump_or_repair_kit : ask Pump or tool form, Valve compatibility : skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position
    rack_or_pannier : ask Rack mount, Pannier attachment, Pannier size class : skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Connectivity, Sensor ecosystem, Cage material, Mount position
    bike_computer_or_gps : ask Connectivity, Sensor ecosystem : skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Cage material, Mount position
    bottle_cage : ask Cage material : skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Mount position
    child_seat : ask Mount position : skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material
  section 2 · Riding context
    touring_bikepacking : ask Rack mount, Pannier attachment, Pannier size class
    mountain_trail : ask Helmet form
    ebike : ask Sensor ecosystem
```

1. **Accessory type.** Helmet, lock, light, pump, rack, computer, bottle cage, or child seat?
   Each type is judged on a completely different spec — a helmet's certification has no equivalent in a bottle cage — so this fork decides which facet set even applies.
   If helmet: ask Safety certification, Rotational impact protection, Helmet form; skip Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position.
   If lock: ask Lock form, Security rating, Shackle or chain material; skip Safety certification, Rotational impact protection, Helmet form, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position.
   If light: ask Front or rear, Light output, Runtime per charge; skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position.
   If pump_or_repair_kit: ask Pump or tool form, Valve compatibility; skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material, Mount position.
   If rack_or_pannier: ask Rack mount, Pannier attachment, Pannier size class; skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Connectivity, Sensor ecosystem, Cage material, Mount position.
   If bike_computer_or_gps: ask Connectivity, Sensor ecosystem; skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Cage material, Mount position.
   If bottle_cage: ask Cage material; skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Mount position.
   If child_seat: ask Mount position; skip Safety certification, Rotational impact protection, Helmet form, Lock form, Security rating, Shackle or chain material, Front or rear, Light output, Runtime per charge, Pump or tool form, Valve compatibility, Rack mount, Pannier attachment, Pannier size class, Connectivity, Sensor ecosystem, Cage material.
   Skip if already known: a query that already names the accessory ('bike lock', 'helmet', 'bike computer'), an earlier answer naming a certification, security rating, or lumen figure.

2. **Riding context.** Commuting, road riding, mountain trails, touring, or an e-bike?
   Riding context shifts what matters inside a type: a tourer weighs rack and pannier capacity heavily, a mountain rider often wants a full-face or MIPS helmet, an e-bike rider sometimes needs sensor compatibility.
   If touring_bikepacking: ask Rack mount, Pannier attachment, Pannier size class.
   If mountain_trail: ask Helmet form.
   If ebike: ask Sensor ecosystem.
   Skip if already known: an earlier answer naming a riding style or bike type, accessory_type answered as lock, light, pump_or_repair_kit, bottle_cage, or child_seat — riding discipline changes nothing for these.

## What to surface

### Accessory type

Which bicycle accessory the listing actually is: helmet, lock, light, pump or repair kit, rack or pannier, computer or GPS, bottle cage, or child seat. This leaf bundles products an expert would never compare to each other. Asking it first avoids asking about a security rating on a helmet or a lumen count on a bottle cage. [1] [2] [4] [9] [8] [10]

Values: helmet, lock, light, pump_or_repair_kit, rack_or_pannier, bike_computer_or_gps, bottle_cage, child_seat.
Question to ask: Helmet, lock, light, pump, rack, computer, bottle cage, or child seat?

Used as: top-level split, filter. Data: derived from listing fields, backfill cost low. Look for it as: Derive from the product title and category breadcrumb; these products are almost never miscategorized.
Title keyword match covers nearly every listing.

### Riding context

The kind of riding the accessory is bought for: commuting, road/fitness, mountain/trail, touring or bikepacking, or an e-bike. Context changes which value within a type matters: a tourer needs a rack rated for panniers and a low-rider mount, a mountain rider wants a full-face or MIPS helmet, and an e-bike rider needs a computer or sensor that speaks to the motor's own electronics. [9] [1] [8]

Values: commuting_urban, road_fitness, mountain_trail, touring_bikepacking, ebike.
Question to ask: Commuting, road riding, mountain trails, touring, or an e-bike?

Used as: top-level split, filter. Data: needs research, backfill cost medium. Look for it as: Rarely a stated field; inferred from the product's marketed use case in the title or description.
Keyword-match against the five values; default to commuting_urban for lights, locks and racks with no stated use case, since that is the largest buyer segment.

### Lock form

The lock's physical form: rigid U-lock/D-lock, folding lock, chain, cable, frame/ring lock, disc rotor lock, or a smart/app-connected lock with keyless unlock. Form decides what the lock can physically secure and how it is carried: a U-lock resists leverage and cutting best but only fits smaller objects; a chain wraps irregular racks and poles but its security depends entirely on the chain's own hardness; a cable is light and long but the weakest of the group used alone. [2]

Values: u_lock_or_d_lock, folding_lock, chain_lock, cable_lock, frame_ring_lock, disc_rotor_lock, smart_lock.
Question to ask: A rigid U-lock, a folding lock, a chain, or a cable?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Always stated in the product title.
Title keyword match covers essentially every listing.

### Front or rear

Whether the light is a front (white) light, a rear (red) light, or sold as a combo set of both. Front and rear lights serve opposite purposes and are legally distinct in most jurisdictions — front must be white, rear red — and a buyer asking for 'a bike light' usually needs to know this splits into two separate products, not one. [4]

Values: front, rear, front_and_rear_set.
Question to ask: Front light, rear light, or a set of both?

Used as: top-level split, filter. Data: on the listing, backfill cost low. Look for it as: Always in the title; color (white/red) is a reliable cross-check.
Title keyword match.

### Light output

The light's rated brightness in lumens, typically stated per mode (low/medium/high/boost). A be-seen light for a lit city street needs only tens of lumens; a light meant to actually illuminate an unlit road or trail at speed needs output in the hundreds to low thousands, comparable to a car's own headlamp. Lumens is the one number brands report consistently, but it trades directly against runtime at the same battery size. [5] [4]

Question to ask: Just to be seen, or bright enough to light the road?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated per-mode in the spec bullets; the title usually leads with the top-mode figure.
Numeric extraction from the title or spec table; when only a model name is given, look up that model's published lumen rating.
Chart: position on a brightness axis.

### Pump or tool form

The form the inflation tool takes: a floor-standing pump with a gauge, a frame-mounted or hand-held mini pump, or a single-use CO2 inflator. A floor pump with a gauge is what lets a rider hit a precise pressure at home and is the fastest way to inflate; a mini pump is what actually gets carried on the bike for a roadside flat but takes far more strokes per psi; a CO2 inflator fills a tire in seconds but each cartridge is single-use, so it is a race-day or emergency tool, not a everyday one. [6]

Values: floor_pump, mini_or_frame_pump, co2_inflator, multi_tool_with_pump.
Question to ask: A pump to keep at home, carry, or CO2 cartridges?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated in the title; floor pumps are distinguished by an included pressure gauge.
Title keyword match.

### Connectivity

How the computer gets its data: a wired magnet sensor, a wireless sensor using ANT+ or Bluetooth, or built-in GPS. A wired computer is the cheapest and never drops signal but only reads wheel speed, not location; a wireless or GPS unit can log a full ride route and pull in heart rate or power meter data, but depends on a radio connection that a smartphone's Bluetooth alone handles less reliably than a dedicated ANT+ radio. [8]

Values: wired_sensor, wireless_ant_or_bluetooth, gps_built_in.
Question to ask: Just speed and distance, or do you want GPS route tracking too?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated in the title or spec bullets; GPS units are marketed on that feature prominently.
Keyword match; default to wired_sensor for the cheapest unlabeled units.

### Helmet form

The helmet's build for its riding discipline: road (lightweight, ventilated, sometimes aero-tailed), mountain/trail (extended rear coverage, sometimes a visor), commuter (rounder, often with a light mount or visor), or full-face (covers the chin, for downhill/BMX). A road helmet trades rear-head coverage for ventilation and weight; a mountain helmet extends down the back of the skull for the kind of backward falls common off-road; a full-face helmet is the only one of the four built for a direct face impact, and is not interchangeable with the others for that use. [1]

Values: road, mountain_trail, commuter, full_face.
Question to ask: Road, mountain trail, everyday commuting, or full-face for downhill?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Almost always in the title or category name.
Title keyword match against the four values; default to road for an unlabeled lightweight vented helmet.

### Runtime per charge

How many hours the light lasts on a single charge or battery at a given mode. Runtime falls steeply as output rises on the same battery, so the headline lumen figure alone overstates what a rider gets on a long ride: the same light that runs under an hour at its brightest boost mode can run most of a day at its dimmest. [5]

Range: 0.9 to 18 hours.
Question to ask: A short commute, or a long ride or multi-day trip?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated per-mode alongside the lumen figure in the spec table.
Numeric extraction from the spec table; pair with the mode it was measured at, since runtime without a mode is close to meaningless.
Chart: position on a runtime axis, inverse of brightness.

### Pannier size class

Whether the pannier is a single small commuter bag, a smaller front/low-rider pair sized to sit ahead of the front wheel, or a larger rear touring pair. Touring riders deliberately run a smaller pair up front and a larger pair at the rear to keep the heaviest gear low and centered rather than high and to one side; a commuter buying a single bag for a laptop has a completely different sizing need from either. [9]

Values: single_commuter_bag, front_low_rider_pair, rear_touring_pair.
Question to ask: One bag for commuting, or a front-and-rear pair for a loaded tour?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Usually stated as 'single' vs 'pair' in the title, with front/rear named for touring-specific models.
Keyword match on 'pair'/'single' and 'front'/'rear'/'low-rider'.

### Mount position

Whether the child seat mounts to the handlebar/stem at the front, to the rear rack or frame at the back, or is a towed trailer instead of a seat. A front-mounted seat sits on the stem ahead of the adult rider, suits only the youngest and lightest children, and lets the adult watch the child while riding; a rear-mounted seat on the rack or frame suits an older child who can sit upright unsupported and is the more common choice once the child outgrows the front seat. Both are sold today as genuinely distinct product lines, not a size variant of one product. [10] [11]

Values: front_mounted, rear_rack_or_frame_mounted, towed_trailer.
Question to ask: A seat in front, behind, or a towed trailer?

Used as: top-level split, filter. Data: on the listing, backfill cost low. Look for it as: Always in the title ('front-mounted', 'rear child seat').
Title keyword match.

### Security rating

The lock's independent security certification, most commonly the UK's Sold Secure scale: Diamond, Gold, Silver or Bronze, or unrated. Sold Secure rates a lock against a specific set of attack tools and a time limit rather than the seller's own claim: Diamond resists the most determined, well-equipped thief and is recommended for high-value bikes in high-risk areas, while Bronze is only a deterrent against an opportunistic grab. The rating, not the lock's price or weight, is the closest thing to an objective security number this category has. [3] [2]

Values: diamond, gold, silver, bronze, unrated.
Question to ask: How valuable is the bike, and how risky is the area?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated as a named rating with the Sold Secure logo when certified; otherwise look for an ART (Dutch) rating as an alternative scale.
Keyword/logo match against the four tiers; default to unrated when neither Sold Secure nor ART is mentioned.
Chart: position on a security axis, Diamond highest.

### Valve compatibility

Which tube valve type the pump head or adapter fits: Presta, Schrader, Dunlop, or a chuck that converts between them. Presta is the narrower (6 mm), high-pressure valve common on road and performance bikes; Schrader is the wider (8 mm) valve shared with car tires and common on cheaper or kids' bikes. A pump head built for one will not seal on the other without an adapter, so this is the single most common reason a pump fails to work on a given bike. [6] [7]

Values: presta_only, schrader_only, dunlop, presta_and_schrader_switchable.
Question to ask: A thin Presta valve, or a wider Schrader valve?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated in the spec bullets; a switchable head is usually marketed as 'fits both valve types'.
Keyword match; most quality floor pumps today are switchable, so default to presta_and_schrader_switchable when the listing is silent.

### Rack mount

How the rack attaches to the bike: to rear frame eyelets, clamped to the seatpost, or bolted to a specific frame mount point. A frame with rear eyelets takes the sturdiest, highest-capacity rack; a bike without eyelets (common on many road and some disc-brake bikes) is limited to a seatpost-clamp rack, which carries less weight and can shift under load. This single compatibility check determines whether a given rack will fit the bike at all. [9]

Values: frame_eyelet_mount, seatpost_clamp_mount, disc_brake_compatible_mount, front_fork_mount.
Question to ask: Does your bike have rack eyelets near the rear axle?

Used as: filter, shown on the card. Data: on the listing, backfill cost medium. Look for it as: Stated in the spec bullets; a seatpost-mount rack is usually named as such in the title.
Keyword match; when silent, a rack sold with a weight capacity over about 25 kg is almost always eyelet-mount.

### Safety certification

The mandatory or regional safety standard the helmet is certified to: US CPSC, European EN 1078, Australian/NZ AS/NZS 2063, or none stated. CPSC certification is legally required for any helmet sold in the US; a helmet without it is not just inferior, it is not legal to sell as a bicycle helmet. EN 1078 and AS/NZS 2063 are the equivalent mandatory marks elsewhere, so the right one to look for depends on the buyer's country. [1]

Values: cpsc, en_1078, as_nzs_2063, multiple, unspecified.
Question to ask: Do you need it certified for the US, EU, or Australia/NZ?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Usually printed on the helmet's inner liner sticker and repeated in the listing's safety or compliance bullet.
Most helmets sold into a region already carry that region's mark; default to cpsc for US-market listings with no stated certification, since it has been mandatory there since 1999.

### Rotational impact protection

Whether the helmet adds a rotational-impact protection system such as MIPS, over and above the standard foam liner. CPSC and EN 1078 testing only measures linear acceleration and ignores rotational acceleration, which is large enough in real angled falls to cause concussion and brain injury on its own. MIPS adds a low-friction layer that lets the helmet shift slightly on impact to cut that rotational force, so two helmets that both pass the same certification can still differ here. [1]

Values: mips_or_equivalent, none_stated.
Question to ask: Want the added rotational-impact layer (MIPS), or is standard certification enough?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Called out by name in the title or a dedicated bullet when present ('MIPS', 'WaveCel' or similar); otherwise assume absent.
Brand-name keyword match; it is always marketed when present since it costs more to include.
Chart: position on a rotational-protection axis.

### Shackle or chain material

What the lock's load-bearing metal is made of: hardened or case-hardened steel, boron-alloy steel, or an unhardened/lightweight alloy used mainly for cable and low-security chain. Case-hardened steel resists bolt cutters and hacksaws far better than the mild steel found in a hardware-store chain; a lock advertised as a security product almost always states this, and its absence is itself a signal the lock is not built to resist a determined cut. [2]

Values: hardened_or_case_hardened_steel, boron_alloy_steel, standard_alloy, unspecified.
Question to ask: Hardened steel, or a lighter alloy for convenience over top security?

Used as: filter, shown on the card. Data: on the listing, backfill cost medium. Look for it as: Usually in the spec bullets ('hardened steel shackle', 'boron alloy'); absent on basic cable locks.
Keyword match; when missing, infer standard_alloy for cable locks and hardened_or_case_hardened_steel for anything marketed with a Sold Secure rating above Bronze.

### Pannier attachment

How the pannier bag clips to the rack: a hook-and-latch or elastic cord system that grips the rack's top rail, or a quick-release claw system proprietary to one brand of rack. A hook-on pannier generally works on any rack with a round or flat top rail, while a brand's own quick-release claw system (fastest on and off) usually only clicks onto that brand's matching rack, so mixing brands can mean the bag does not fit the rack at all. [9]

Values: universal_hook_and_latch, proprietary_quick_release, strap_on.
Question to ask: Fit any rack, or match one specific rack brand?

Used as: filter, shown on the card. Data: on the listing, backfill cost medium. Look for it as: Stated in the spec bullets; proprietary systems are named by brand ('QL system', 'Snapit').
Keyword/brand match; default to universal_hook_and_latch, the more common system, when unstated.

### Sensor ecosystem

Whether the computer can pair with external ANT+ or Bluetooth Low Energy sensors (cadence, heart rate, power meter) beyond its own built-in speed sensor. A rider training seriously wants to add a cadence or power sensor later without replacing the head unit, so this decides whether the computer is a closed, single-purpose device or the hub of a small sensor network; it also matters for e-bikes, whose own speed sensor sometimes needs a specific compatible head unit. [8]

Values: expandable_ant_plus_or_ble, fixed_sensor_only.
Question to ask: Will you want to add sensors like cadence or power later?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Stated in the spec bullets as 'ANT+ compatible' or similar; absent on the most basic wired units.
Keyword match for 'ANT+' or 'Bluetooth Low Energy' sensor support.

### Cage material

What the bottle cage is made of: molded plastic/composite, aluminum, carbon fiber, or stainless/chromoly steel. Carbon and aluminum cages are lightest and hold the bottle most securely over rough ground but cost the most and can mark a bottle's finish; molded plastic is cheapest and gentlest on the bottle but flexes more and can let a bottle eject on a hard hit; steel is heaviest but most durable and resists UV degradation that plastic cages eventually show. [9]

Values: molded_plastic_composite, aluminum, carbon_fiber, steel.
Question to ask: Lightest possible, or durable and cheap?

Used as: filter, shown on the card. Data: on the listing, backfill cost low. Look for it as: Almost always in the title.
Title keyword match; default to molded_plastic_composite, the most common and cheapest option, when unstated.
Chart: position on a weight axis, carbon lightest.

## What you give up

- The same light burns through its battery far faster at its brightest setting: the NiteRider Lumina 1200 Boost runs about 55 minutes at its full 1,200-lumen boost mode but close to 18 hours at a 75-lumen walk setting, so the headline lumen figure alone overstates what a rider gets on a long ride. [5] Board branch: "More output, much less runtime".
- A higher Sold Secure tier is earned with thicker hardened steel and more metal overall, so a Diamond-rated U-lock is meaningfully heavier to carry than a Bronze-rated cable; Sold Secure itself frames the choice as matching the tier to the bike's value and the area's risk, not buying the top tier by default. [3] [2] Board branch: "More security, more weight to carry".

## Words you will meet

- **MIPS**. A low-friction layer inside some helmets that lets the shell shift slightly on impact to cut rotational force on the brain.
- **CPSC**. The US Consumer Product Safety Commission; its bicycle helmet standard has been mandatory for helmets sold in the US since 1999.
- **EN 1078**. The European Union's mandatory bicycle helmet safety standard.
- **Sold Secure**. A UK lab that rates locks Diamond, Gold, Silver or Bronze by timing how long they resist a set of real theft tools.
- **Case-hardened steel**. Steel heat-treated so its outer layer resists cutting tools much better than plain mild steel of the same thickness.
- **Presta valve**. The narrower (6 mm), high-pressure tube valve common on road and performance bikes; needs a compatible pump head or an adapter.
- **Schrader valve**. The wider (8 mm) tube valve shared with car tires, common on cheaper and kids' bikes.
- **Lumens**. The unit a light's total brightness is rated in; higher means more light but shorter runtime at the same battery size.
- **ANT+**. A low-power wireless radio standard built into most dedicated bike computers for talking to sensors without dropping signal.
- **Cadence sensor**. A sensor that measures how many times per minute the rider is pedaling.
- **Pannier**. A bag built to hang off the side of a bicycle rack rather than ride on the rider's back.
- **Low-rider mount**. A rack mount point near the front axle, used for a smaller pair of front panniers that sit low to keep weight centered.
- **Frame eyelet**. A small threaded hole near a bike's rear axle or fork, built specifically for bolting on a rack.
- **AS/NZS 2063**. The mandatory bicycle helmet safety standard for Australia and New Zealand, parallel to CPSC and EN 1078.
- **ART**. The Dutch ART Foundation, a lock-testing body whose own security rating is used as an alternative to the UK's Sold Secure scheme.
- **Dunlop valve**. An older bicycle tube valve type, distinct from Presta and Schrader, that needs a Dunlop- or Schrader-style pump chuck or an adapter.
- **Smart lock**. A bicycle lock unlocked by a phone app or Bluetooth key fob instead of a physical key or combination.

## Where we made a call

- CPSC and EN 1078 helmet testing ignores rotational acceleration, which real angled falls can produce in concussion-causing amounts. (confidence medium). Single-sourced to Wikipedia's bicycle helmet article, which itself cites biomechanics literature; the underlying papers were not independently fetched this run. [1]
- A Sold Secure Gold-rated lock is not theft-proof: a magazine test broke two Gold-rated locks in just 10 seconds. (confidence low). Single-sourced to Wikipedia's citation of a Cycle magazine test; the original magazine article was not independently fetched this run. [2]

## References

1. [Bicycle helmet](https://en.wikipedia.org/wiki/Bicycle_helmet) (primer). Supports: CPSC mandatory US helmet standard took effect March 1999; EN 1078:1997 is the EU standard; AS/NZS 2063 for Australia/NZ; MIPS reduces rotational violence to the brain from angled impacts; CPSC and EN 1078 test only linear, not rotational, acceleration; 96% of studied helmets on children were found incorrectly fitted.
2. [Bicycle lock](https://en.wikipedia.org/wiki/Bicycle_lock) (primer). Supports: Defines U-lock, folding, chain, cable, frame and disc rotor lock forms; Case-hardened security chain resists cutting better than hardware-store chain; Two Sold Secure Gold-rated locks in a Cycle magazine test withstood only 10 seconds.
3. [Sold Secure Pedal Cycle bike lock ratings](https://soldsecure.com/ratings/pedal-cycle) (spec sheet). Supports: Four rating tiers for bikes: Diamond, Gold, Silver, Bronze; Each tier is matched to bike value and area theft risk, not a default top choice.
4. [Bicycle lighting](https://en.wikipedia.org/wiki/Bicycle_lighting) (primer). Supports: LED output ranges from a few lumens to levels comparable to an automotive headlamp; Front lights are white, rear lights red, by convention and law in most places.
5. [NiteRider Lumina 1200 Boost product page](https://www.niterider.com/products/lumina-1200-boost) (spec sheet). Supports: 1,200 lumen max output; run times from 0:55h at 1,200 lumens to 18:00h at 75 lumens.
6. [Presta valve](https://en.wikipedia.org/wiki/Presta_valve) (primer). Supports: Presta valve is 6 mm diameter, narrower than Schrader/Dunlop's 8 mm; Presta is commonly used on high-pressure bicycle inner tubes and tubeless setups.
7. [Schrader valve](https://en.wikipedia.org/wiki/Schrader_valve) (primer). Supports: Schrader valve is the wider, automotive-style valve also used on many bicycles.
8. [Bicycle computer](https://en.wikipedia.org/wiki/Bicycle_computer) (primer). Supports: Computers read wired or wireless speed, cadence and heart-rate sensors; Dedicated units use ANT+ for reliable multi-sensor connection vs. phone Bluetooth.
9. [Pannier (bicycle section)](https://en.wikipedia.org/wiki/Pannier) (primer). Supports: Panniers hook onto a rack's top rail via a latch or elastic mechanism; Touring setups pair smaller front low-rider panniers with larger rear panniers.
10. [Bicycle child seat](https://en.wikipedia.org/wiki/Bicycle_seat) (primer). Supports: Front-mounted seats attach at the handlebar stem, for the youngest/lightest children; Rear-mounted seats attach to the rack or frame, for older children.
11. [Thule child bike seats category](https://www.thule.com/en-us/us/learn/child-bike-seats) (spec sheet). Supports: Front-mounted and rear-mounted child bike seats are sold as separate product lines.