Velopedia Bicycle Archive
2021 Polygon Xtrada 7
Mountain bicycle from the Velopedia specification archive.
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What Velopedia knows
- Model year
- 2021
- Category
- Mountain
- Original MSRP
- $799.00
- Sizes
- 27.5” SM, 27.5” MD, 27.5" LG, 29” MD, 29” LG, 29” XL
- Colors
- Purple White, Grey Black
- Geometry
- 6 manufacturer sizes · Geometry context
- Record coverage
- 20 preserved details · archived image · original MSRP · preserved geometry
- Archive ID
- 900001798
Model history 1 other year
Frameset
| Frame Construction | ALX XC Trail |
|---|---|
| Frame Material | Aluminum |
| Fork | SR Suntour XCR32 Air LOR 120mm (27.5" & 29") Travel |
Drivetrain
| Shifters | Shimano Deore SL-M6100-R, 1X12-Speed Trigger |
|---|---|
| Rear Derailleur | Shimano Deore RD-M6100-SGS Direct Attach |
| Crankset | Shimano Deore FC-M6120 1X12 SP |
| Bottom Bracket | Shimano 2-Piece Crankset BSA Threaded 73mm |
| Cassette | 12 Speed, 10-51T |
| Chain | KMC X-12 |
| Pedals | PP Flat Pedal W/ Reflector |
Brakes
| Brakes | Shimano MT-201 Hydraulic Disc Brakes; Levers: Shimano BL-MT201 Hydraulic Disc Brakes; Rotors: Shimano SM-RT10 160mm Center-Lock |
|---|
Cockpit & Contact Points
| Headset | Zero Stack (ZS) Sealed Bearing for Taper Head Tube, ZS 44/28.6 | ZS 56/40 |
|---|---|
| Handlebar | Polygon Xpert Alloy, W: 760mm, BAR Bore: 31.8mm, Rise/Drop: 12mm, Bend: 6DEGREE |
| Stem | Polygon Xpert Alloy, EXT: 40mm, BAR Bore: 31.8mm, Rise/Drop: 7DEGREE |
| Saddle | Polygon, Steel Ø 7mm |
| Seatpost | Polygon Xpert Alloy, DXL: 27.2 X 350mm, Seat Clamp: 31.8mm W/ QR |
Wheels & Tires
| Wheels | Alloy Wheels |
|---|---|
| Rims | Alloy Double Wall H:23mm W: 30mm 584 32H for Tyre 584-68/622-68 |
| Front Tire | Performance Tire 27.5"X2.25" / 29"X2.25" |
| Rear Tire | Performance Tire 27.5"X2.25" / 29"X2.25" |
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 (27.5″) | M (27.5″) | L (27.5″) | M (29″) | L (29″) | XL (29”) |
|---|---|---|---|---|---|---|
| Seat tube | 385 mm | 425 mm | 460 mm | 425 mm | 460 mm | 500 mm |
| Effective top tube | 569 mm | 590 mm | 612 mm | 598 mm | 619 mm | 640 mm |
| Head tube | 95 mm | 100 mm | 105 mm | 95 mm | 100 mm | 105 mm |
| Head-tube angle | 67° | 67° | 67° | 67° | 67° | 67° |
| Seat-tube angle | 75° | 75° | 75° | 75° | 75° | 75° |
| Actual seat-tube angle | 75° | 75° | 75° | 75° | 75° | 75° |
| Chainstay / rear center | 425 mm | 425 mm | 425 mm | 435 mm | 435 mm | 435 mm |
| Wheelbase | 1106 mm | 1128 mm | 1150 mm | 1147 mm | 1169 mm | 1191 mm |
| Bottom-bracket drop | 45 mm | 45 mm | 45 mm | 65 mm | 65 mm | 65 mm |
| Bottom-bracket height | 310 mm | 310 mm | 310 mm | 309 mm | 309 mm | 309 mm |
| Reach | 410 mm | 430 mm | 450 mm | 430 mm | 450 mm | 470 mm |
| Stack | 593.8 mm | 599.3 mm | 603 mm | 629.3 mm | 633.2 mm | 637.8 mm |
| Standover height | 663 mm | 697 mm | 726 mm | 693 mm | 715 mm | 751 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 (27.5″) geometry
Archive context: The chainstay of 425 mm sits toward the shorter rear-center end. Its wheelbase of 1106 mm sits toward the shorter end. Its stack of 593.8 mm sits toward the lower end.
Compared with 48 distinct mountain geometries in the Small-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 S (27.5″) geometry M (27.5″) geometry
Archive context: Its wheelbase of 1128 mm sits toward the shorter end. Its stack of 599.3 mm sits toward the lower end. The chainstay of 425 mm sits toward the shorter rear-center end.
Compared with 52 distinct mountain geometries in the Medium-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 M (27.5″) geometry L (27.5″) geometry
Archive context: Its stack of 603 mm sits toward the lower end. The chainstay of 425 mm sits toward the shorter rear-center end. Its wheelbase of 1150 mm sits toward the shorter end.
Compared with 44 distinct mountain geometries in the Large-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 L (27.5″) geometry M (29″) geometry
Archive context: Its bottom-bracket drop of 65 mm sits toward the deeper-drop end. Its wheelbase of 1147 mm sits toward the shorter end. Its reach of 430 mm sits toward the shorter end.
Compared with 52 distinct mountain geometries in the Medium-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 M (29″) geometry L (29″) geometry
Archive context: Its bottom-bracket drop of 65 mm sits toward the deeper-drop end. Its reach of 450 mm sits toward the shorter end. Its wheelbase of 1169 mm sits toward the shorter end.
Compared with 44 distinct mountain geometries in the Large-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 L (29″) geometry XL (29”) geometry
Archive context: Its reach of 470 mm sits toward the shorter end. Its stack of 637.8 mm sits toward the lower end. Its bottom-bracket drop of 65 mm sits toward the deeper-drop end.
Compared with 14 distinct mountain geometries in the XXL-equivalent size cohort from model years 2021–2025 in the Velopedia archive.Parts & serviceability
Find replacement parts
ChainKMC X-12Exact archived model
Bottom bracketShimano 2-Piece Crankset BSA Threaded 73mmNamed archived component — verify dimensions
CranksetShimano Deore FC-M6120 1X12 SPExact archived model
More qualified parts (2)
Rear derailleurShimano Deore RD-M6100-SGS Direct AttachExact archived model
ShiftersShimano Deore SL-M6100-R, 1X12-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.
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 →- FrameLook closely for dents and hairline cracks around welds, the head tube and bottom-bracket area. Cosmetic scratches matter less than a change in shape or a crack line.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 12-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 20 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 Xtrada 7 · Mountain · Published sizes: 27.5” SM, 27.5” MD, 27.5" LG, 29” MD, 29” LG, 29” XL
Frame and fork
Inspect the frame and fork →Archived: Frame: ALX XC TRAIL · Fork: SR SUNTOUR XCR32 AIR LOR 120mm (27.5" & 29") TRAVEL
Suspension
Evaluate the suspension →Archived: Fork: SR SUNTOUR XCR32 AIR LOR 120mm (27.5" & 29") TRAVEL
Drivetrain
Check drivetrain wear →Archived: Shifters: SHIMANO DEORE SL-M6100-R, 1x12-SPEED TRIGGER · Rear derailleur: SHIMANO DEORE RD-M6100-SGS DIRECT ATTACH · Crankset: SHIMANO DEORE FC-M6120 1x12 SP · Bottom bracket: SHIMANO 2-PIECE CRANKSET BSA THREADED 73mm · Cassette: 12 SPEED, 10-51T · Chain: KMC X-12
Brakes
Inspect the brakes →Archived: Brakes: SHIMANO MT-201 HYDRAULIC DISC BRAKES; Levers: SHIMANO BL-MT201 HYDRAULIC DISC BRAKES; Rotors: SHIMANO SM-RT10 160mm CENTER-LOCK
Wheels and tires
Check wheels and tires →Archived: Wheels: ALLOY WHEELS · Rims: ALLOY DOUBLE WALL H:23mm W: 30mm 584 32H FOR TYRE 584-68/622-68 · Front tire: PERFORMANCE TIRE 27.5"X2.25" / 29"X2.25" · Rear tire: PERFORMANCE TIRE 27.5"X2.25" / 29"X2.25"
Controls and contact points
Archived: Headset: ZERO STACK (ZS) SEALED BEARING FOR TAPER HEAD TUBE, ZS 44/28.6 | ZS 56/40 · Handlebar: POLYGON XPERT ALLOY, W: 760mm, BAR BORE: 31.8mm, RISE/DROP: 12mm, BEND: 6degree · Stem: POLYGON XPERT ALLOY, EXT: 40mm, BAR BORE: 31.8mm, RISE/DROP: 7degree · Seatpost: POLYGON XPERT ALLOY, DXL: 27.2 x 350mm, SEAT CLAMP: 31.8mm W/ QR · Saddle: POLYGON, STEEL ø 7mm · Pedals: PP FLAT 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.