Velopedia Bicycle Archive
2021 Polygon Heist X5
Cyclocross/Gravel bicycle from the Velopedia specification archive.
Selling this bike? Create a Bike History Report
What Velopedia knows
- Model year
- 2021
- Category
- Gravel & Cyclocross
- Original MSRP
- $719.00
- Sizes
- S, M, L, XL
- Colors
- Cream
- Geometry
- 4 manufacturer sizes · Geometry context
- Record coverage
- 21 preserved details · archived image · original MSRP · preserved geometry
- Archive ID
- 900001838
Frameset
| Frame Construction | AL6 Urban Cross, 12x142mm O.L.D. 2HRU |
|---|---|
| Fork | Suntour NVX, Preload Adjuster, Hydraulic Lock OUT, Straight 1-1/8" Threadless |
| Rear Shock | - |
Drivetrain
| Shifters | Shimano Deore SL-M6000/SL-M4100, 1X10 Speed Trigger |
|---|---|
| Rear Derailleur | Shimano Deore RD-M6000/RD-M4120 Direct Attach |
| Crankset | Prowheel Charm 36T 2-Piece-Crank, Crank ARM: 170mm |
| Bottom Bracket | Threaded BB, BSA Threaded 68mm |
| Cassette | Shimano CS-HG500, 10-speed 11-42T |
| Chain | KMC X10-1 |
| Pedals | PP Cage Pedal W/ Reflector |
Brakes
| Brakes | Shimano BR-MT201 Hydraulic Disc Brake; Levers: Shimano BR-MT201 Hydraulic Disc Brake; Rotors: Shimano SM-RT26 160mm 6-Bolts |
|---|
Cockpit & Contact Points
| Headset | Integrated W/ Sealed Bearing for Taper Head Tube, IS 42/28.6 | IS 52/40 |
|---|---|
| Handlebar | Entity Xpert, EXT: 700mm, BAR Bore: 31.8mm, Rise/Drop: 0mm, Bend: 6DEGREE |
| Stem | Entity Xpert, EXT: 60mm (400, 431) / 80mm (470, 516), BAR Bore: 31.8mm, Rise/Drop: 7DEGREE |
| Saddle | Entity Saddle, Steel Ø 7mm |
| Seatpost | Entity Xpert, DXL: 27.2X350mm, Offset: 15mm, Seat Clamp: 31.8mm W/ QR |
Wheels & Tires
| Hubs | - |
|---|---|
| Wheels | Alloy Double Wall |
| Rims | - |
| Front Tire | WTB Riddler Tire 700x45C |
| Rear Tire | WTB Riddler Tire 700x45C |
Size-specific frame data
Geometry
Manufacturer-published geometry normalized for consistent archival comparison. Effective top tube and reach remain separate measurements because they describe different aspects of fit.
| Measurement | S | M | L | XL |
|---|---|---|---|---|
| Seat tube | 400 mm | 431 mm | 470 mm | 516 mm |
| Effective top tube | 563.12 mm | 593.12 mm | 620.8 mm | 648.54 mm |
| Head tube | 90 mm | 90 mm | 100 mm | 110 mm |
| Head-tube angle | 71° | 71° | 71° | 71° |
| Seat-tube angle | 74° | 74° | 74° | 71° |
| Actual seat-tube angle | 74° | 74° | 74° | 71° |
| Chainstay / rear center | 440 mm | 440 mm | 440 mm | 440 mm |
| Wheelbase | 1063.12 mm | 1093.12 mm | 1121.43 mm | 1149.63 mm |
| Bottom-bracket drop | 70 mm | 70 mm | 70 mm | 70 mm |
| Bottom-bracket height | 289.5 mm | 289.5 mm | 289.5 mm | 289.5 mm |
| Reach | 385 mm | 415 mm | 440 mm | 465 mm |
| Stack | 621.18 mm | 621.18 mm | 630.64 mm | 640.1 mm |
| Standover height | 688.3 mm | 708.7 mm | 742.5 mm | 781.5 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
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 M geometry
Archive context: Its stack of 621.2 mm sits toward the taller end. Its reach of 415 mm sits toward the longer end. Its wheelbase of 1093.1 mm sits toward the longer end.
Compared with 26 distinct cyclocross/gravel geometries in the Medium-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 M geometry L geometry
Archive context: Its reach of 440 mm sits toward the longer end. The seat angle of 74° sits toward the steeper end. Its stack of 630.6 mm sits toward the taller end.
Compared with 20 distinct cyclocross/gravel geometries in the Large-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 L geometry XL geometry
Archive context: The seat angle of 71° sits toward the more relaxed end. Its reach of 465 mm sits toward the longer end. Its wheelbase of 1149.6 mm sits toward the longer end.
Compared with 20 distinct cyclocross/gravel geometries in the XL-equivalent size cohort from model years 2021–2023 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 XL geometry Parts & serviceability
Find replacement parts
ChainKMC X10-1Exact archived model
CassetteShimano CS-HG500, 10-speed 11-42TExact archived model
Front tireWTB Riddler Tire 700x45CNamed tire and published size
More qualified parts (1)
Brake padsShimano BR-MT201 Hydraulic Disc BrakeBrake model identified — verify pad shape
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.
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 10-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
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.
Identity and fit
Follow the full used-bike inspection order →Archived: 2021 Polygon Heist X5 · Cyclocross/Gravel · Published sizes: S, M, L, XL
Frame and fork
Inspect the frame and fork →Archived: Frame: AL6 URBAN CROSS, 12x142mm O.L.D. 2HRU · Fork: SUNTOUR NVX, PRELOAD ADJUSTER, HYDRAULIC LOCK OUT, STRAIGHT 1-1/8" THREADLESS
Suspension
Evaluate the suspension →Archived: Fork: SUNTOUR NVX, PRELOAD ADJUSTER, HYDRAULIC LOCK OUT, STRAIGHT 1-1/8" THREADLESS · Rear shock: -
Drivetrain
Check drivetrain wear →Archived: Shifters: SHIMANO DEORE SL-M6000/SL-M4100, 1X10 SPEED TRIGGER · Rear derailleur: SHIMANO DEORE RD-M6000/RD-M4120 DIRECT ATTACH · Crankset: PROWHEEL CHARM 36T 2-PIECE-CRANK, CRANK ARM: 170mm · Bottom bracket: THREADED BB, BSA THREADED 68mm · Cassette: SHIMANO CS-HG500, 10-SPEED 11-42T · Chain: KMC X10-1
Brakes
Inspect the brakes →Archived: Brakes: SHIMANO BR-MT201 HYDRAULIC DISC BRAKE; Levers: SHIMANO BR-MT201 HYDRAULIC DISC BRAKE; Rotors: SHIMANO SM-RT26 160mm 6-BOLTS
Wheels and tires
Check wheels and tires →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, EXT: 700mm, BAR BORE: 31.8mm, RISE/DROP: 0mm, BEND: 6degree · Stem: ENTITY XPERT, EXT: 60mm (400, 431) / 80mm (470, 516), BAR 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.
Have you owned this bike?Help preserve its real-world history by sharing your owner experience.
Share the details that would help another rider understand how this model fits, rides and holds up over time. Velopedia reviews every contribution before publication.
Already contributed? Send me a fresh private edit link
For privacy, Velopedia shows the same confirmation whether or not an experience exists.
Recently checked marketplace data
Market Snapshot
Velopedia did not find a close used eBay listing in the latest snapshot. New and used listings remain separate.
Evidence standard
Fixed-price and Best Offer item prices only
Shipping and tax excluded
Active asks, not completed sales
No close current matches found. Velopedia did not find an eBay listing confident enough to include in the latest snapshot.
Listings shown have not passed their eBay-supplied end time. Velopedia rechecks matched bicycles on a protected weekly cycle; availability can still change between checks. Price calculations use active fixed-price and Best Offer item prices before shipping and tax. Auction bids, auction-only prices, classified ads, lower-confidence Review candidates and ended listings are excluded. These observations are not completed-sale prices, a certified appraisal or a guarantee of value.
Specifications are presented as a reference. Components may vary by market, size, production run, or later manufacturer revisions.