{"$schema":"nativecad-dfm-pack/1","id":"bikes","title":"Bikes -- frames, drivetrain, cockpit, e-bikes, scooters and helmets","sector":"bikes","version":"2026-09-03","summary":"Frame tube and bottom-bracket standards, headset and dropout/axle sizing, disc-mount and boss dimensions, cockpit and seatpost diameters, e-bike/scooter/skateboard geometry, and the ISO/EN/CPSC/ASTM tests a bike, e-bike or helmet is held to.","aliases":["bike","bicycle","e-bike","ebike","scooter","e-scooter","skateboard","dropout","bottom bracket","bike headset","seatpost","handlebar","bottle cage","bike rack","helmet","sporting goods","fitness equipment"],"crossSector":false,"size":"full","sources":[{"id":"iso-4210","title":"ISO 4210 (all parts) Cycles -- Safety requirements for bicycles","url":"https://www.iso.org/search.html?q=ISO%204210","accessed":"2026-09-03"},{"id":"en-15194","title":"EN 15194 Cycles -- Electrically power assisted cycles (EPAC bicycles)","url":"https://standards.iteh.ai/search?q=EN+15194","accessed":"2026-09-03"},{"id":"en-1078","title":"EN 1078 Helmets for pedal cyclists and for users of skateboards and roller skates","url":"https://standards.iteh.ai/search?q=EN+1078","accessed":"2026-09-03"},{"id":"cpsc-1203","title":"16 CFR 1203 -- CPSC Safety Standard for Bicycle Helmets","url":"https://www.ecfr.gov/current/title-16/chapter-II/subchapter-C/part-1203","accessed":"2026-09-03"},{"id":"iso-6695","title":"ISO 6695 Cycles -- Saddles -- Concepts, dimensions and symbols","url":"https://www.iso.org/search.html?q=ISO%206695","accessed":"2026-09-03"},{"id":"astm-f2032","title":"ASTM F2032 Standard Specification for Helmets Used for BMX Cycling","url":"https://store.astm.org/f2032-22.html","accessed":"2026-09-03"},{"id":"park-tool-standards","title":"Park Tool -- bottom bracket, headset and frame standards reference pages","url":"https://www.parktool.com/en-us/blog/repair-help","accessed":"2026-09-03"},{"id":"sheldon-brown-glossary","title":"Sheldon Brown -- Bicycle Glossary and technical reference pages","url":"https://www.sheldonbrown.com/gloss_a-c.html","accessed":"2026-09-03"},{"id":"shimano-dealer-manual","title":"Shimano Dealer's Manual (bottom bracket, pedal, chainline, freehub specifications)","url":"https://si.shimano.com/","accessed":"2026-09-03"},{"id":"sram-standards","title":"SRAM Standards -- thru-axle and Boost hub/frame spacing reference","url":"https://www.sram.com/en/service/","accessed":"2026-09-03"},{"id":"matweb-materials","title":"MatWeb Material Property Data (frame steels, aluminium, titanium alloys)","url":"https://www.matweb.com/","accessed":"2026-09-03"},{"id":"iso-5775","title":"ISO 5775 Bicycle tyres and rims -- Designation, dimensions and marking","url":"https://www.iso.org/search.html?q=ISO%205775","accessed":"2026-09-03"}],"entries":[{"id":"frame-tube-steel-diameters","kind":"dimension","tier":1,"title":"Steel frame tube diameters and butted wall gauge","summary":"Steel (chromoly) frame tubes run 25.4, 28.6 or 31.8 mm OD, double-butted to a 0.8-0.9 mm centre wall (thicker at the welded ends) -- the standard top/down/seat-tube sizing for a lugged or TIG-welded steel frame.","applies":["frame","top tube","down tube","seat tube","steel frame"],"value":{"options":[25.4,28.6,31.8],"unit":"mm"},"basis":"Common steel-frame tubeset sizing (Reynolds/Columbus-style) referenced across Park Tool and Sheldon Brown frame-building pages","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["frame","tube","steel","chromoly","diameter"]},{"id":"frame-tube-alloy-diameters","kind":"dimension","tier":1,"title":"Aluminium frame tube diameters and wall gauge","summary":"Aluminium frame tubes oversize to 34.9 or 38.1 mm OD with a 1.2-1.6 mm wall -- larger diameter, thinner wall, trading steel's stiffness-per-weight for aluminium's lower modulus at similar mass.","applies":["frame","top tube","down tube","aluminium frame","alloy frame"],"value":{"options":[34.9,38.1],"unit":"mm"},"basis":"Common aluminium-frame tubeset OD/wall convention (6061/7005 hydroformed and butted tubing)","sources":["park-tool-standards"],"tags":["frame","tube","aluminium","diameter"]},{"id":"bb-shell-bsa","kind":"dimension","tier":1,"title":"BSA threaded bottom bracket shell","summary":"BSA (English) threaded BB shells are 68 mm (road/gravel) or 73 mm (MTB) wide, threaded 1.37 in x 24 TPI -- right (drive) side left-hand thread, left side right-hand thread, so the cups tighten rather than unscrew under pedalling.","applies":["bottom bracket","bb shell","crank"],"value":{"options":[68,73],"unit":"mm","table":[{"field":"thread","value":"1.37in x 24 TPI"}]},"basis":"BSA (British Standard Cycle) threaded bottom bracket shell width and thread convention","sources":["park-tool-standards","shimano-dealer-manual"],"tags":["bottom-bracket","bsa","threaded","shell-width"]},{"id":"bb-shell-pf30","kind":"dimension","tier":1,"title":"PF30 press-fit bottom bracket shell","summary":"PF30 press-fit shells bore to 46 mm ID over a 68 mm shell width, pressing the bearing cups directly into the frame shell rather than threading them -- wider bearing spacing than BSA for a stiffer, lower-friction bottom bracket.","applies":["bottom bracket","bb shell","press fit"],"value":{"table":[{"field":"boreID","value":46},{"field":"shellWidth","value":68}],"unit":"mm"},"basis":"PF30 press-fit bottom bracket standard bore and shell width","sources":["park-tool-standards"],"tags":["bottom-bracket","pf30","press-fit"]},{"id":"bb-shell-t47","kind":"dimension","tier":1,"title":"T47 threaded bottom bracket shell","summary":"T47 threads a 47 mm ID cup directly into a PF30-width (68 or 73 mm) shell -- combining PF30's wide bearing stance with a threaded interface that avoids press-fit creak.","applies":["bottom bracket","bb shell","t47"],"value":{"value":47,"unit":"mm","table":[{"field":"shellWidth","value":"68 or 73"}]},"basis":"T47 threaded bottom bracket standard cup ID and shell width options","sources":["park-tool-standards"],"tags":["bottom-bracket","t47","threaded"]},{"id":"bb-shell-bb86-92","kind":"dimension","tier":1,"title":"BB86/BB92 press-fit bottom bracket shell","summary":"BB86 (road, 86.5 mm shell) and BB92 (MTB, 89.5-92 mm shell) press-fit bearings directly into a 41 mm ID shell bore -- narrower bore than PF30 because the bearings press straight into carbon-moulded cups rather than into an aluminium insert.","applies":["bottom bracket","bb shell","bb86","bb92"],"value":{"value":41,"unit":"mm"},"basis":"Shimano BB86/BB92 press-fit bottom bracket shell bore specification","sources":["shimano-dealer-manual","park-tool-standards"],"tags":["bottom-bracket","bb86","bb92","press-fit"]},{"id":"headset-steerer-diameters","kind":"dimension","tier":1,"title":"Fork steerer diameters: 1-1/8 in straight and 1.5 in tapered lower","summary":"A standard 1-1/8 in steerer is 28.6 mm; a tapered fork's larger lower bearing race seats a 1.5 in (39.8 mm) steerer section, giving the head tube more stiffness where steering loads are highest.","applies":["headset","fork","steerer"],"value":{"table":[{"field":"steerer1-1/8in","value":28.6},{"field":"taperedLower","value":39.8}],"unit":"mm"},"basis":"Standard 1-1/8 in threadless steerer OD and the tapered (1-1/8-to-1.5 in) fork's lower steerer-race diameter","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["headset","steerer","fork","tapered"]},{"id":"headset-cup-id-table","kind":"dimension","tier":1,"title":"Integrated headset cup/head-tube ID by standard (ZS44/ZS56/IS42/IS52/EC34)","summary":"Head tube or cup ID by integrated headset standard: ZS44 44 mm, ZS56 56 mm, IS42 42 mm, IS52 52 mm, EC34 34 mm -- get the wrong ID and the bearing cup either falls through the head tube or never seats.","applies":["headset","head tube","integrated headset"],"value":{"table":[{"standard":"ZS44","id_mm":44},{"standard":"ZS56","id_mm":56},{"standard":"IS42","id_mm":42},{"standard":"IS52","id_mm":52},{"standard":"EC34","id_mm":34}],"unit":"mm"},"basis":"Common zero-stack (ZS) / integrated (IS) / external-cup (EC) headset head-tube-ID naming convention","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["headset","zs44","zs56","is42","is52","ec34"]},{"id":"dropout-qr-old","kind":"dimension","tier":1,"title":"Quick-release dropout over-locknut distance and axle diameter","summary":"Quick-release hubs space to 100 mm over-locknut distance (OLD) front, 135 mm rear, on a 9 or 10 mm skewer/axle diameter -- the legacy hub-spacing pair that thru-axle standards replaced.","applies":["dropout","hub","quick release","axle"],"value":{"table":[{"field":"frontOLD","value":100},{"field":"rearOLD","value":135},{"field":"axleDia","value":"9 or 10"}],"unit":"mm"},"basis":"Standard quick-release front/rear over-locknut spacing and skewer diameter","sources":["sheldon-brown-glossary","park-tool-standards"],"tags":["dropout","quick-release","old","axle"]},{"id":"dropout-thru-axle-sizes","kind":"dimension","tier":1,"title":"Thru-axle diameter x OLD combinations and thread pitches","summary":"Thru-axles run 12x100 (front road), 12x142 (rear road/gravel), 12x148 Boost (rear MTB) and 15x110 Boost (front MTB), threaded M12x1.0, M12x1.5 or M12x1.75 depending on brand -- diameter x OLD must match the frame/fork exactly, thread pitch only has to match the axle's own nut.","applies":["dropout","thru axle","hub","boost"],"value":{"options":["12x100","12x142","12x148","15x110"],"unit":"mm","table":[{"field":"threadPitch","value":"M12x1.0 / M12x1.5 / M12x1.75"}]},"basis":"Common thru-axle diameter/OLD combinations and the thread-pitch variation across axle brands","sources":["sram-standards","park-tool-standards"],"tags":["dropout","thru-axle","boost","old"]},{"id":"dropout-hanger-derailleur","kind":"fastener","tier":1,"title":"Derailleur hanger bolt hole","summary":"A rear derailleur hanger mounts on a dia10 mm hole tapped M10x1, threaded into the dropout's replaceable hanger tab -- the hanger is meant to bend or snap before the derailleur or frame does in a chain/spoke strike.","applies":["dropout","derailleur hanger","rear derailleur"],"value":{"value":"M10x1","unit":"mm","table":[{"field":"holeDia","value":10}]},"basis":"Standard replaceable derailleur hanger mounting bolt and hole diameter","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["dropout","derailleur-hanger","m10"]},{"id":"disc-mount-standards","kind":"dimension","tier":1,"title":"Disc-brake caliper mount standards (IS, post mount, flat mount)","summary":"IS mounts on two M6 bolts 51 mm apart; post mount bolts direct on a 74 mm M6 spacing; flat mount bolts to the frame/fork face on 140 or 160 mm rotor-matched spacing -- an adapter converts between them but never swaps rotor size.","applies":["disc brake","caliper","frame mount","fork mount"],"value":{"table":[{"standard":"IS","spacing_mm":51,"bolt":"M6"},{"standard":"post mount","spacing_mm":74,"bolt":"M6"},{"standard":"flat mount","spacing_mm":"140 or 160"}],"unit":"mm"},"basis":"Common disc-brake caliper mounting standards and their bolt spacing","sources":["park-tool-standards","sram-standards"],"tags":["disc-brake","is-mount","post-mount","flat-mount"]},{"id":"bottle-cage-boss","kind":"fastener","tier":1,"title":"Bottle-cage boss thread and spacing","summary":"A bottle cage bolts to two M5 threaded bosses spaced 64 mm apart on the frame -- the universal bottle-cage mounting standard across steel, aluminium and carbon frames.","applies":["bottle cage","frame boss"],"value":{"value":"M5","unit":"mm","table":[{"field":"spacing","value":64}]},"basis":"Universal bottle-cage boss thread size and hole spacing","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["bottle-cage","boss","m5"]},{"id":"handlebar-diameters","kind":"dimension","tier":1,"title":"Handlebar grip and clamp diameters","summary":"Handlebar grip area is 22.2 mm; the stem clamp area is 31.8 mm (standard) or 35 mm (oversize, higher-torque MTB stems) -- a stem sized for the wrong clamp diameter cannot torque to spec and will slip.","applies":["handlebar","stem","grip"],"value":{"table":[{"field":"gripDia","value":22.2},{"field":"clampDia31_8","value":31.8},{"field":"clampDia35","value":35}],"unit":"mm"},"basis":"Standard handlebar grip and clamp diameter convention","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["handlebar","grip","clamp","diameter"]},{"id":"seatpost-diameters","kind":"dimension","tier":1,"title":"Seatpost diameters and frame clamp sizes","summary":"Seatposts run 27.2, 30.9 or 31.6 mm OD to match the frame's seat-tube ID; the external seat-tube clamp collar closes on 31.8 or 34.9 mm -- post diameter and clamp diameter are two different numbers, don't confuse them.","applies":["seatpost","seat tube","seat clamp"],"value":{"options":[27.2,30.9,31.6],"unit":"mm","table":[{"field":"clampDia","value":"31.8 or 34.9"}]},"basis":"Standard seatpost OD sizes and the external seat-clamp collar diameters they pair with","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["seatpost","diameter","clamp"]},{"id":"saddle-rail-dimensions","kind":"dimension","tier":1,"title":"Saddle rail diameter and spacing","summary":"Standard round saddle rails are dia7 mm, spaced 44 mm apart -- the pair every two-bolt and single-bolt seatpost clamp is machined to grip; carbon/titanium oval or bladed rails deviate and need a matching clamp.","applies":["saddle","seatpost clamp","rails"],"value":{"table":[{"field":"railDia","value":7},{"field":"railSpacing","value":44}],"unit":"mm"},"basis":"ISO 6695 standard round saddle rail diameter and spacing convention","sources":["iso-6695"],"tags":["saddle","rail","iso-6695"]},{"id":"pedal-thread-size","kind":"fastener","tier":1,"title":"Pedal spindle thread: 9/16-20 TPI","summary":"Bicycle pedal spindles thread 9/16 in x 20 TPI into the crank arm -- an inch thread because ISO 4210-8 and pedal manufacturers still publish it that way; the right pedal is right-hand thread, the left pedal is left-hand thread to resist unscrewing under pedalling.","applies":["pedal","crank arm"],"value":{"value":"9/16-20","unit":"in"},"basis":"ISO 4210-8 pedal thread specification, published in inches","sources":["iso-4210","shimano-dealer-manual"],"tags":["pedal","thread","9-16","crank"]},{"id":"crank-spindle-chainline","kind":"dimension","tier":2,"title":"Crank spindle type and chainline range","summary":"ISIS splined and 24 mm (Hollowtech-II style) are the two common external-bearing crank spindle interfaces; chainline (chainring centreline to frame centreline) runs 43.5-52 mm -- outside that band the chain runs at an angle that skips or wears fast.","applies":["crank","spindle","chainline"],"value":{"min":43.5,"max":52,"unit":"mm"},"basis":"Common road/MTB chainline range across BSA/PF30/BB86 bottom bracket widths","sources":["shimano-dealer-manual","park-tool-standards"],"tags":["crank","spindle","chainline","isis"]},{"id":"ebike-battery-pack-dims","kind":"dimension","tier":2,"title":"E-bike downtube battery pack voltage and envelope","summary":"E-bike downtube battery packs run 36 V or 48 V nominal and occupy roughly 90 x 70 x 370 mm -- a downtube frame section built to fit an internal battery must clear this envelope plus a few mm for the mounting rail and latch.","applies":["e-bike","ebike","battery","downtube"],"value":{"table":[{"field":"voltage","value":"36 or 48 V"},{"field":"width","value":90},{"field":"depth","value":70},{"field":"length","value":370}],"unit":"mm"},"basis":"Common internal downtube e-bike battery pack voltage and physical envelope","sources":["en-15194"],"tags":["e-bike","battery","downtube","voltage"]},{"id":"ebike-middrive-bb-width","kind":"dimension","tier":2,"title":"Mid-drive e-bike motor bottom-bracket shell width","summary":"Popular mid-drive motors (Bosch, Bafang BBS02) mount through a 68 or 73 mm BB-shell-width bracket -- the same shell widths as a standard threaded BSA bottom bracket, so a mid-drive conversion still fits a conventional frame.","applies":["e-bike","mid drive","bosch","bafang"],"value":{"options":[68,73],"unit":"mm"},"basis":"Bosch and Bafang BBS02 mid-drive motor mounting bracket width, matched to standard BB shell widths","sources":["en-15194","park-tool-standards"],"tags":["e-bike","mid-drive","bosch","bafang","bottom-bracket"]},{"id":"helmet-impact-en1078-cpsc","kind":"test","tier":1,"title":"Bicycle helmet impact test (EN 1078 / CPSC 1203)","summary":"Drop the helmeted headform 1500 mm onto flat and kerbstone anvils; EN 1078 and CPSC 1203 both cap transmitted acceleration at 250 g, and CPSC additionally requires the retention strap to hold 500 N without more than 25 mm of extension.","applies":["helmet","bicycle helmet"],"value":{"table":[{"field":"dropHeight_mm","value":1500},{"field":"maxAccel_g","value":250},{"field":"strapLoad_N","value":500}]},"basis":"EN 1078 and CPSC 16 CFR 1203 helmet impact-attenuation and retention-system test requirements","sources":["en-1078","cpsc-1203"],"tags":["test","helmet","impact","en-1078","cpsc-1203"]},{"id":"ebike-hubmotor-dropout-widths","kind":"dimension","tier":2,"title":"E-bike hub-motor dropout widths and anti-rotation flats","summary":"E-bike hub motors slot into 100 mm (front), 135 mm or 142 mm (rear) dropout widths -- the same OLD family as pedal-bike hubs -- and key against rotation with a pair of dia10 mm flats machined into the motor axle where it seats in the dropout slot.","applies":["e-bike","hub motor","dropout"],"value":{"options":[100,135,142],"unit":"mm","table":[{"field":"axleFlat","value":10}]},"basis":"Common hub-motor dropout width and axle-flat anti-rotation convention","sources":["en-15194","sram-standards"],"tags":["e-bike","hub-motor","dropout","flat"]},{"id":"scooter-wheel-deck-stem","kind":"dimension","tier":2,"title":"Kick/e-scooter wheel size, deck width and stem diameter","summary":"Kick and e-scooter wheels run 8, 8.5 or 10 in, decks are 150-180 mm wide, and the folding stem tube is 32-35 mm OD -- a wider deck and larger wheel trade portability for stability at speed.","applies":["scooter","e-scooter","kick scooter"],"value":{"table":[{"field":"wheelSize_in","value":"8 / 8.5 / 10"},{"field":"deckWidth_mm","value":"150-180"},{"field":"stemDia_mm","value":"32-35"}]},"basis":"Common kick and e-scooter wheel, deck and folding-stem dimensions","sources":["park-tool-standards"],"tags":["scooter","e-scooter","wheel","deck","stem"]},{"id":"skateboard-truck-hole-pattern","kind":"dimension","tier":2,"title":"Skateboard truck mounting-hole pattern and axle diameter","summary":"Standard skateboard trucks bolt on a 2.125 x 1.625 in rectangular hole pattern into the deck, and run an 8 mm axle -- the same hole pattern across nearly every mass-market deck and truck brand.","applies":["skateboard","truck","deck"],"value":{"value":"2.125 x 1.625","unit":"in","table":[{"field":"axleDia","value":"8 mm"}]},"basis":"Universal skateboard truck mounting-hole spacing and axle diameter convention","sources":["park-tool-standards"],"tags":["skateboard","truck","axle","hole-pattern"]},{"id":"dropout-plate-thickness","kind":"dimension","tier":2,"title":"Dropout plate thickness","summary":"A machined or forged dropout plate runs 5-8 mm thick -- thick enough to carry the thru-axle/QR clamping load and the derailleur hanger's cantilevered bending without the plate itself flexing under a chain-suck or crash load.","applies":["dropout","frame"],"value":{"min":5,"max":8,"unit":"mm"},"basis":"Common forged/machined dropout plate thickness across steel and aluminium frames","sources":["park-tool-standards"],"tags":["dropout","thickness","plate"]},{"id":"rack-fender-eyelet","kind":"fastener","tier":2,"title":"Rack and fender mounting eyelets","summary":"Frame and fork rack/fender eyelets thread M5, with rear-rack eyelets typically spaced 100 mm apart at the dropout -- matching the M5 boss standard shared with bottle cages so a frame builder threads one size across the whole accessory set.","applies":["rack","fender","eyelet","bike rack"],"value":{"value":"M5","unit":"mm","table":[{"field":"rackSpacing","value":100}]},"basis":"Common rack/fender eyelet thread size and rear rack mounting-tab spacing","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["rack","fender","eyelet","m5"]},{"id":"handlebar-stem-clamp","kind":"dimension","tier":2,"title":"Stem steerer clamp diameter","summary":"A threadless stem's steerer clamp bore matches the 1-1/8 in (28.6 mm) steerer from headset-steerer-diameters -- an oversize 1.5 in lower steerer needs a tapered-specific stem or a reducer, it will not clamp a 1-1/8 in stem directly.","applies":["stem","steerer","headset"],"value":{"value":28.6,"unit":"mm"},"basis":"Standard 1-1/8 in threadless stem steerer-clamp bore","sources":["park-tool-standards"],"tags":["stem","steerer","clamp"]},{"id":"crank-isis-spline","kind":"dimension","tier":2,"title":"ISIS splined bottom-bracket spindle interface","summary":"ISIS Drive splines a 10-groove, involute-tooth spindle onto the crank interface -- an open standard alternative to Shimano's square-taper and external-bearing spindles, common on older MTB and tandem cranksets.","applies":["crank","spindle","isis"],"value":{"value":10,"unit":"count"},"basis":"ISIS Drive splined bottom bracket interface specification (10-spline)","sources":["park-tool-standards","sheldon-brown-glossary"],"tags":["crank","isis","spline","bottom-bracket"]},{"id":"skateboard-bearing-608-see-robotics","kind":"feature","tier":2,"title":"Skateboard wheel bearing: 608","summary":"Skateboard (and inline-skate and scooter) wheels press-fit a pair of 608 deep-groove ball bearings per wheel -- see robotics/bearing-common-sizes-table for the 8x22x7 mm bore/OD/width the wheel's bearing bore must be machined or moulded to.","applies":["skateboard","wheel","bearing"],"basis":"608 is the near-universal skate/scooter/skateboard wheel bearing size, shared with the robotics pack's bearing table rather than restated","sources":["park-tool-standards"],"tags":["skateboard","bearing","608"],"see":["robotics/bearing-common-sizes-table"],"value":{"options":["see robotics/bearing-common-sizes-table for the 608 bore/OD/width (8x22x7mm)"]}},{"id":"disc-rotor-bolt-pattern","kind":"dimension","tier":2,"title":"Disc rotor 6-bolt pattern","summary":"A 6-bolt disc rotor mounts on six M5 bolts on a 44 mm PCD around the hub flange -- the alternative to a splined Center Lock rotor, and the pattern a hub-motor or custom hub flange must reproduce to accept off-the-shelf rotors.","applies":["disc brake","rotor","hub"],"value":{"value":"M5","unit":"mm","table":[{"field":"pcd","value":44},{"field":"boltCount","value":6}]},"basis":"Standard 6-bolt (ISO) disc rotor mounting pattern","sources":["park-tool-standards","sram-standards"],"tags":["disc-brake","rotor","6-bolt","pcd"]},{"id":"wheel-rim-bead-seat-diameters","kind":"dimension","tier":2,"title":"Common rim bead-seat diameters (700c/650b/20in)","summary":"ISO 5775 bead-seat diameter (BSD) is the number that actually matches a tyre to a rim regardless of marketing name: 622 mm (700c/29in), 584 mm (650b/27.5in) and 406 mm (20in BMX/folding) are the common bike bead-seat diameters.","applies":["wheel","rim","tyre"],"value":{"table":[{"name":"700c/29in","bsd_mm":622},{"name":"650b/27.5in","bsd_mm":584},{"name":"20in","bsd_mm":406}]},"basis":"ISO 5775 bead-seat-diameter designation, the size that actually determines tyre/rim compatibility","sources":["iso-5775"],"tags":["wheel","rim","bsd","iso-5775"]},{"id":"frame-material-chromoly-4130","kind":"material","tier":1,"title":"4130 chromoly steel frame tubing","summary":"4130 chromoly is the standard steel frame-tube alloy: yield ~460 MPa in the normalized/drawn condition, density 7.85 g/cm3, weldable and butts thin without cracking -- the baseline steel-frame material this pack's tube sizes assume.","applies":["frame","tube","steel"],"value":{"table":[{"property":"yield","value":460,"unit":"MPa"},{"property":"density","value":7.85,"unit":"g/cm3"}]},"basis":"MatWeb 4130 chromoly steel (normalized) property data, the standard bicycle frame steel","sources":["matweb-materials"],"tags":["material","4130","chromoly","steel"]},{"id":"frame-material-aluminum-6061-7005","kind":"material","tier":1,"title":"6061-T6 and 7005 aluminium frame tubing","summary":"6061-T6 (yield ~276 MPa) needs post-weld heat treatment to reach full strength; 7005 (yield ~290 MPa) age-hardens naturally at room temperature after welding -- 7005 is the more common as-welded aluminium frame alloy for exactly that reason.","applies":["frame","tube","aluminium"],"value":{"table":[{"material":"6061-T6","yield_MPa":276},{"material":"7005","yield_MPa":290}]},"basis":"MatWeb 6061-T6 and 7005-T6 aluminium property data, the two common welded bicycle frame alloys","sources":["matweb-materials"],"tags":["material","6061","7005","aluminium"]},{"id":"material-titanium-3al-25v","kind":"material","tier":2,"title":"Ti 3Al-2.5V titanium frame tubing","summary":"Ti 3Al-2.5V (the common titanium frame-tube alloy) yields around 725 MPa at 4.48 g/cm3 density -- roughly steel's strength at half the weight, at a cost and weld-complexity premium that keeps it a niche frame material.","applies":["frame","tube","titanium"],"value":{"table":[{"property":"yield","value":725,"unit":"MPa"},{"property":"density","value":4.48,"unit":"g/cm3"}]},"basis":"MatWeb Ti-3Al-2.5V property data, the standard titanium bicycle frame-tube alloy","sources":["matweb-materials"],"tags":["material","titanium","3al-2.5v"]},{"id":"material-carbon-fiber-frame","kind":"material","tier":2,"title":"Carbon fibre composite frame layup","summary":"A carbon frame is a laid-up composite: unidirectional/woven carbon-epoxy plies at roughly 1.6 g/cm3, tensile strength 600-3500 MPa fibre-direction depending on fibre grade and layup -- properties are layup-dependent, never one number like an alloy's.","applies":["frame","carbon fiber","composite"],"value":{"min":600,"max":3500,"unit":"MPa","note":"fibre-direction tensile strength range across carbon fibre grades"},"basis":"Typical carbon/epoxy composite fibre-direction tensile strength range for bicycle-frame-grade layups","sources":["matweb-materials"],"tags":["material","carbon-fiber","composite"]},{"id":"material-aluminum-6082-forgings","kind":"material","tier":2,"title":"6082 aluminium forgings for stems, cranks and dropouts","summary":"6082-T6 (yield ~250 MPa) is the common forged-aluminium alloy for stems, crank arms and dropout plates -- higher-strength forging grade than 6061, chosen where the part is hot-forged rather than tube-formed.","applies":["stem","crank","dropout","forging"],"value":{"value":250,"unit":"MPa"},"basis":"MatWeb 6082-T6 property data, a common forged-component aluminium alloy in bicycle components","sources":["matweb-materials"],"tags":["material","6082","aluminium","forging"]},{"id":"material-pom-bushings","kind":"material","tier":2,"title":"POM for bushings, cable guides and bearing seals","summary":"POM (Delrin/acetal), density 1.41 g/cm3, is the default low-friction plastic for pedal bushings, cable guides and bearing seal lips -- self-lubricating against steel and dimensionally stable in the temperature range a bike sees.","applies":["pedal","bushing","cable guide"],"value":{"value":1.41,"unit":"g/cm3"},"basis":"MatWeb POM copolymer property data, the standard low-friction bushing plastic","sources":["matweb-materials"],"tags":["material","pom","bushing"]},{"id":"standard-iso-4210","kind":"standard","tier":2,"title":"ISO 4210 -- bicycle safety requirements (multi-part)","summary":"ISO 4210 is the multi-part bicycle safety standard: Part 6 covers frame and fork test methods, Part 8 covers pedal and drive-system test methods, and the series as a whole sets the fatigue, static-load and braking requirements a complete bicycle is certified against.","applies":["bicycle","frame","fork","pedal"],"basis":"The base bicycle safety standard series this pack's frame-fatigue and pedal-force test entries are drawn from","sources":["iso-4210"],"tags":["standard","iso-4210","safety"]},{"id":"standard-en-15194","kind":"standard","tier":2,"title":"EN 15194 -- electrically power assisted cycles (EPAC)","summary":"EN 15194 sets the safety and test requirements for e-bikes (EPAC): continuous rated motor power capped at 250 W, assistance cutting out above 25 km/h, plus battery, wiring and mechanical/electrical safety requirements layered on top of ISO 4210's bicycle mechanics.","applies":["e-bike","ebike","epac"],"value":{"table":[{"field":"ratedPower_W","value":250},{"field":"cutoffSpeed_kmh","value":25}]},"basis":"EN 15194 EPAC power and assist-cutoff limits, the defining numbers of an EU-legal e-bike","sources":["en-15194"],"tags":["standard","en-15194","e-bike","epac"]},{"id":"standard-en-1078","kind":"standard","tier":2,"title":"EN 1078 -- pedal cycle, skateboard and roller-skate helmets","summary":"EN 1078 covers helmets for pedal cyclists and for skateboard/roller-skate users: shell coverage area, retention system and the impact-attenuation test this pack's helmet-impact entry cites.","applies":["helmet","skateboard"],"basis":"The EU helmet standard behind this pack's impact-test entry, also covering skateboard helmets","sources":["en-1078"],"tags":["standard","en-1078","helmet"]},{"id":"standard-cpsc-1203","kind":"standard","tier":2,"title":"16 CFR 1203 -- US bicycle helmet safety standard","summary":"16 CFR 1203 is the mandatory US federal safety standard for bicycle helmets: coverage area, peripheral vision, retention system strength and the impact test this pack's helmet-impact entry cites -- no bicycle helmet may be sold in the US without meeting it.","applies":["helmet"],"basis":"The mandatory US federal helmet standard behind this pack's impact-test entry","sources":["cpsc-1203"],"tags":["standard","cpsc-1203","helmet"]},{"id":"standard-iso-6695-saddle","kind":"standard","tier":2,"title":"ISO 6695 -- saddle concepts, dimensions and symbols","summary":"ISO 6695 defines saddle terminology and the standard rail diameter/spacing this pack's saddle-rail entry cites, so a seatpost clamp and a saddle from different manufacturers still fit together.","applies":["saddle","seatpost"],"basis":"The saddle dimensioning standard behind this pack's saddle-rail entry","sources":["iso-6695"],"tags":["standard","iso-6695","saddle"]},{"id":"standard-iso-4210-8-pedals","kind":"standard","tier":2,"title":"ISO 4210-8 -- pedal and drive-system test methods","summary":"ISO 4210-8 sets the pedal, crank and drive-system test methods within the ISO 4210 series: static and dynamic pedal-force fatigue, crank/pedal thread engagement and drivetrain durability.","applies":["pedal","crank","drivetrain"],"basis":"The part of ISO 4210 this pack's pedal-force fatigue test entry is drawn from","sources":["iso-4210"],"tags":["standard","iso-4210-8","pedal"]},{"id":"test-frame-fatigue-iso4210-6","kind":"test","tier":2,"title":"Frame fatigue test, horizontal force (ISO 4210-6)","summary":"Clamp the frame at the head tube and rear dropouts and cycle a 1200 N horizontal force at the front dropout/fork crown 100,000 times; a frame that cracks, or a weld that fails, before 100k cycles does not pass ISO 4210-6.","applies":["frame","fatigue"],"value":{"value":100000,"unit":"cycles","table":[{"field":"force","value":1200,"unit":"N"}]},"basis":"ISO 4210-6 frame fatigue test method: horizontal force amplitude and required cycle count","sources":["iso-4210"],"tags":["test","frame","fatigue","iso-4210-6"]},{"id":"test-pedal-force-iso4210-8","kind":"test","tier":2,"title":"Pedal and crank fatigue test (ISO 4210-8)","summary":"Apply an alternating 1100 N pedal force through a crank arm at the pedal-thread axis and cycle to the standard's required count; a crank, spindle or pedal thread that fails before then fails ISO 4210-8's drivetrain durability clause.","applies":["pedal","crank","drivetrain"],"value":{"value":1100,"unit":"N"},"basis":"ISO 4210-8 pedal/crank fatigue force amplitude","sources":["iso-4210"],"tags":["test","pedal","crank","iso-4210-8"]},{"id":"test-ebike-en15194","kind":"test","tier":2,"title":"E-bike assist cutoff and rated power test (EN 15194)","summary":"Ride the e-bike up through 25 km/h under load while logging motor power and road speed: continuous rated power must not exceed 250 W and pedal assist must taper to zero at or before 25 km/h -- a control unit that assists past that speed or power fails EN 15194 outright.","applies":["e-bike","ebike","epac"],"value":{"table":[{"field":"maxPower_W","value":250},{"field":"cutoffSpeed_kmh","value":25}]},"basis":"EN 15194 EPAC compliance test for assist cutoff speed and continuous rated motor power","sources":["en-15194"],"tags":["test","e-bike","en-15194"]},{"id":"test-handlebar-seatpost-static-iso4210","kind":"test","tier":2,"title":"Handlebar and seatpost static load test (ISO 4210)","summary":"Clamp the handlebar/stem or seatpost/frame at its interface and hold a 1000 N static load at the grip or saddle-rail position without fracture or excess permanent set -- a static strength check, separate from the frame's fatigue test.","applies":["handlebar","seatpost","stem"],"value":{"value":1000,"unit":"N"},"basis":"ISO 4210 static load test method applied to handlebar/stem and seatpost/frame assemblies","sources":["iso-4210"],"tags":["test","handlebar","seatpost","iso-4210"]},{"id":"test-helmet-astm-f2032-bmx","kind":"test","tier":2,"title":"BMX helmet impact test, extended coverage (ASTM F2032)","summary":"ASTM F2032 tests a BMX helmet over a larger shell-coverage area than EN 1078/CPSC 1203 (down to the skull base and around the ears) at the same 1500 mm drop height, since BMX racing carries higher head-impact risk than street riding.","applies":["helmet","bmx"],"value":{"value":1500,"unit":"mm"},"basis":"ASTM F2032 Standard Specification for Helmets Used for BMX Cycling: extended-coverage impact test at the standard drop height","sources":["astm-f2032"],"tags":["test","helmet","bmx","astm-f2032"]},{"id":"recipe-thru-axle-dropout-plate","kind":"recipe","tier":2,"title":"Recipe: thru-axle dropout plate with derailleur hanger","summary":"Build a 45x70x6 mm dropout plate with a dia12 mm thru-axle bore and a tapped M10 derailleur-hanger hole, combining dropout-thru-axle-sizes and dropout-hanger-derailleur into one buildable plate.","applies":["dropout","thru axle","derailleur hanger"],"basis":"Combines dropout-thru-axle-sizes, dropout-plate-thickness and dropout-hanger-derailleur into one buildable plate","sources":["sram-standards","park-tool-standards"],"tags":["recipe","dropout","thru-axle","derailleur-hanger"],"recipe":{"prompt":"Model a 45x70x6mm thru-axle dropout plate with a 12mm axle bore and a tapped M10 derailleur hanger hole","steps":[{"tool":"cad_box","args":{"dx":45,"dy":70,"dz":6},"note":"dropout plate, 45x70mm, 6mm per dropout-plate-thickness"},{"tool":"cad_drill_hole","args":{"of":"$0","type":"drill","diameter":12,"center":[22.5,15]},"note":"12mm thru-axle bore, through"},{"tool":"cad_drill_hole","args":{"of":"$1","type":"tapped","size":"M10","center":[22.5,55]},"note":"tapped M10x1 derailleur hanger hole, through"}],"expect":{"volume":17880.95,"faceCount":10,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}},{"id":"recipe-bottle-cage-mount-block","kind":"recipe","tier":2,"title":"Recipe: bottle-cage mount block","summary":"Build a 20x74x6 mm mount block with two tapped M5 holes 64 mm apart, matching bottle-cage-boss's spacing exactly.","applies":["bottle cage","frame boss"],"basis":"Combines bottle-cage-boss's M5 thread and 64mm spacing into one buildable mount block","sources":["park-tool-standards"],"tags":["recipe","bottle-cage","boss"],"recipe":{"prompt":"Model a 20x74x6mm bottle-cage mount block with two tapped M5 holes 64mm apart","steps":[{"tool":"cad_box","args":{"dx":20,"dy":74,"dz":6},"note":"mount block, 20x74x6mm"},{"tool":"cad_hole_pattern","args":{"of":"$0","type":"tapped","size":"M5","pattern":{"kind":"linear","origin":[10,5],"step":[0,64],"count":2}},"note":"2x tapped M5 bosses, 64mm apart per bottle-cage-boss"}],"expect":{"volume":8713.75,"faceCount":10,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}},{"id":"recipe-seatpost-clamp-collar","kind":"recipe","tier":2,"title":"Recipe: seatpost clamp collar","summary":"Build a dia40x40 mm collar bored to 31.6 mm for the seatpost, slotted through the wall to let it pinch closed, and drilled with a tapped M5 clamp-bolt hole.","applies":["seatpost","seat clamp","collar"],"basis":"Combines seatpost-diameters' 31.6mm post OD with a cut slot and an M5 clamp bolt into one buildable collar","sources":["park-tool-standards"],"tags":["recipe","seatpost","clamp","collar"],"recipe":{"prompt":"Model a seatpost clamp collar: dia40x40mm cylinder bored to 31.6mm, slotted through the wall, with a tapped M5 clamp bolt hole","steps":[{"tool":"cad_cylinder","args":{"r":20,"h":40},"note":"dia40mm collar blank, 40mm tall"},{"tool":"cad_drill_hole","args":{"of":"$0","type":"drill","diameter":31.6,"center":[0,0]},"note":"31.6mm bore for the seatpost, through"},{"tool":"cad_box","args":{"dx":3,"dy":25,"dz":40,"origin":[-1.5,0,0]},"note":"3mm slot-cutting tool, from centre out past the OD"},{"tool":"cad_boolean_subtract","args":{"of":"$1","tool":"$2"},"note":"cut the pinch slot through the wall"},{"tool":"cad_drill_hole","args":{"of":"$3","type":"tapped","size":"M5","axis":[1,0,0],"start":[-20,10,20],"depth":40},"note":"tapped M5 clamp-bolt hole straight through both walls"}],"expect":{"volume":18223.54,"faceCount":576,"watertight":true,"note":"measured 2026-09-19: representation change, not geometry: pinned while the boolean published a TESSELLATED B-rep (one planar face per triangle) and it now publishes an analytic one — faceCount 1168 -> 576, volume 0.012%. 576 is STILL a tessellation DENSITY, not a topology fact (a Ø31.6 bore and an M5 cross-tap through a Ø40 collar): a future move in it is a re-tiling unless the volume moves with it"}}}]}