Velopedia Bicycle Archive

2021 Polygon Heist X7

Cyclocross/Gravel bicycle from the Velopedia specification archive.

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What Velopedia knows

Model year
2021
Category
Gravel & Cyclocross
Original MSRP
$799.00
Sizes
S, M, L, XL
Colors
Dark Brown
Geometry
4 manufacturer sizes · Geometry context
Record coverage
21 preserved details · archived image · original MSRP · preserved geometry
Archive ID
900001840
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Manufacturer catalog

Published sizes and colors

4 sizes · 1 color

Manufacturer-published sizes and colors; availability and exact size/color pairings may vary by market or production run.

Published sizes

SMLXL

Published colors

Dark Brown

Frameset

Frame ConstructionAL6 Urban Cross, 12x142mm O.L.D. 2HRU
ForkSuntour NCX Air, Air Spring, Preload Adjuster, Hydraulic Lock OUT, Straight 1-1/8" Threadless
Rear Shock-

Drivetrain

ShiftersShimano Deore SL-5100, 1X11 Speed Trigger
Rear DerailleurShimano Deore RD-M5100 Direct Attach
CranksetProwheel Charm 36T 2-Piece-Crank, Crank ARM: 170mm
Bottom BracketThreaded BB, BSA Threaded 68mm
CassetteShimano , 11-speed 11-51T
ChainKMC X11-1
PedalsPP Cage Pedal W/ Reflector

Brakes

BrakesShimano BR-MT400 Hydraulic Disc Brake; Levers: Shimano BR-MT400 Hydraulic Disc Brake; Rotors: Shimano SM-RT56 160mm 6-Bolts

Cockpit & Contact Points

HeadsetIntegrated W/ Sealed Bearing for Taper Head Tube, IS 42/28.6 | IS 52/40
HandlebarEntity Xpert, W: 700mm, BAR Bore: 31.8mm, Rise/Drop 0mm, Bend: 6DEGREE
StemEntity Xpert, EXT: 60mm (400, 431) / 80mm (470, 516), Bare Bore: 31.8mm, Rise/Drop: 7DEGREE
SaddleEntity Saddle, Steel Ø 7mm
SeatpostEntity Xpert, DXL: 27.2X350mm, Offset: 15mm, Seat Clamp: 31.8mm W/ QR

Wheels & Tires

Hubs-
WheelsAlloy Double Wall
Rims-
Front TireWTB Riddler Tire 700x45C
Rear TireWTB Riddler Tire 700x45C

Size-specific frame data

Geometry

4 sizes · 13 measurements

Manufacturer-published geometry normalized for consistent archival comparison. Effective top tube and reach remain separate measurements because they describe different aspects of fit.

MeasurementSMLXL
Seat tube400 mm431 mm470 mm516 mm
Effective top tube563.12 mm593.12 mm620.8 mm648.54 mm
Head tube90 mm90 mm100 mm110 mm
Head-tube angle71°71°71°71°
Seat-tube angle74°74°74°74°
Actual seat-tube angle74°74°74°74°
Chainstay / rear center440 mm440 mm440 mm440 mm
Wheelbase1063.12 mm1093.12 mm1121.43 mm1149.63 mm
Bottom-bracket drop70 mm70 mm70 mm70 mm
Bottom-bracket height289.5 mm289.5 mm289.5 mm289.5 mm
Reach385 mm415 mm440 mm465 mm
Stack621.18 mm621.18 mm630.64 mm640.1 mm
Standover height688.3 mm708.7 mm742.5 mm781.5 mm

Geometry source: Polygon first-party metric geometry table ↗ Measurements can vary by configuration, wheel size, or flip-chip position where noted by the manufacturer.

Geometry tools

Analyze a published size

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S geometry

Archive context: Its stack of 621.2 mm sits toward the taller end. Its reach of 385 mm sits toward the longer end. Its wheelbase of 1063.1 mm sits toward the longer end.

Compared with 30 distinct cyclocross/gravel geometries in the Small-equivalent size cohort from model years 2022–2023 in the Velopedia archive.
Want to go deeper?Open this exact published size and configuration in the Velopedia Geometry Analyzer, then complete any measurements the manufacturer did not provide.
Analyze S geometry

Parts & serviceability

Find replacement parts

3 top part searches
ChainKMC X11-1Exact archived model
CassetteShimano , 11-speed 11-51TNamed component · published drivetrain speed — verify exact version
Front tireWTB Riddler Tire 700x45CNamed tire and published size
More qualified parts (3)
Brake padsShimano BR-MT400 Hydraulic Disc BrakeBrake model identified — verify pad shape
Rear derailleurShimano Deore RD-M5100 Direct AttachExact archived model
ShiftersShimano Deore SL-5100, 1X11 Speed TriggerExact archived model

Searches use the archived manufacturer specification, not the components currently installed on a particular bicycle. Confirm the exact model, size and fit before ordering. As an Amazon Associate I earn from qualifying purchases. Velopedia may also earn from qualifying eBay purchases. Velopedia may also earn from qualifying retailer purchases. Commercial relationships do not influence Archive specifications or analysis.

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Used-bike inspection

If you’re buying this bike used

Before any test ride: both brakes should stop the bike firmly and release cleanly; both wheels should run true and be securely attached; tires should have no casing damage; and the headset, handlebar, stem, cranks and pedals should have no looseness or play.

Follow the full used-bike inspection order →
  • FrameInspect the complete frame and fork in bright light for cracks, dents, distortion, corrosion, impact marks, suspicious paint differences or signs of repair. Check the head tube, bottom-bracket area, dropouts, joints and clamped surfaces especially closely.Inspect the frame and fork →
  • BrakesBoth levers should feel firm and return cleanly. Check for fluid around the levers and calipers, inspect pad thickness and contamination, and look for worn or bent rotors.Inspect the brakes →
  • SuspensionAsk when the fork was last serviced. Check the stanchions for damage, look for oil at the seals and make sure the fork moves smoothly without bushing play.Evaluate the suspension →
  • DrivetrainShift through every gear under light load and measure chain wear. Confirm that the shifter, derailleur, chain and cassette belong to the same 11-speed system.Check drivetrain wear →
  • Wheels & tiresSpin both wheels and watch the rims for side-to-side or vertical movement. Check for dents, cracks, loose or uneven spokes and hub play, then inspect both tire casings for cuts, cracking or exposed threads.Check wheels and tires →
Bike-specific inspection checklist 22 checks based on 6 archived component groups Open checklistClose checklist
0 of 22 checked Progress stays in this browser for this bike.

This checklist uses the archived equipment for this bike. It cannot confirm the condition, service history or later component changes of the example in front of you.

Archived: 2021 Polygon Heist X7 · Cyclocross/Gravel · Published sizes: S, M, L, XL

Archived: Frame: AL6 URBAN CROSS, 12x142mm O.L.D. 2HRU · Fork: SUNTOUR NCX AIR, AIR SPRING, PRELOAD ADJUSTER, HYDRAULIC LOCK OUT, STRAIGHT 1-1/8" THREADLESS

Archived: Fork: SUNTOUR NCX AIR, AIR SPRING, PRELOAD ADJUSTER, HYDRAULIC LOCK OUT, STRAIGHT 1-1/8" THREADLESS · Rear shock: -

Archived: Shifters: SHIMANO DEORE SL-5100, 1x11 SPEED TRIGGER · Rear derailleur: SHIMANO DEORE RD-M5100 DIRECT ATTACH · Crankset: PROWHEEL CHARM 36T 2-PIECE-CRANK, CRANK ARM: 170mm · Bottom bracket: THREADED BB, BSA THREADED 68mm · Cassette: SHIMANO , 11-SPEED 11-51T · Chain: KMC X11-1

Archived: Brakes: SHIMANO BR-MT400 HYDRAULIC DISC BRAKE; Levers: SHIMANO BR-MT400 HYDRAULIC DISC BRAKE; Rotors: SHIMANO SM-RT56 160mm 6-BOLTS

Archived: Wheels: ALLOY DOUBLE WALL · Rims: - · Hubs: - · Front tire: WTB RIDDLER TIRE 700X45C · Rear tire: WTB RIDDLER TIRE 700X45C

Controls and contact points

Archived: Headset: INTEGRATED W/ SEALED BEARING FOR TAPER HEAD TUBE, IS 42/28.6 | IS 52/40 · Handlebar: ENTITY XPERT, W: 700mm, BAR BORE: 31.8mm, RISE/DROP 0mm, BEND: 6degree · Stem: ENTITY XPERT, EXT: 60mm (400, 431) / 80mm (470, 516), BARE BORE: 31.8mm, RISE/DROP: 7degree · Seatpost: ENTITY XPERT, DXL: 27.2X350mm, OFFSET: 15mm, SEAT CLAMP: 31.8mm W/ QR · Saddle: ENTITY SADDLE, STEEL ø 7mm · Pedals: PP CAGE PEDAL W/ REFLECTOR

Before and during the test ride

Follow the full used-bike inspection order →

Build relationships are limited to the archived manufacturer specifications. Confirm exact fit and standards before ordering parts or performing service.

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Specifications are presented as a reference. Components may vary by market, size, production run, or later manufacturer revisions.

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