Velopedia Bicycle Archive
2025 Polygon Siskiu D7
Mountain bicycle from the Velopedia specification archive.
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What Velopedia knows
- Model year
- 2025
- Category
- Mountain
- Original MSRP
- $1,499.00
- Sizes
- 27.5” SM, 27.5” MD, 29” MD, 29” LG, 29” XL
- Colors
- Blue White, Green Black
- Geometry
- 5 manufacturer sizes · Geometry context
- Record coverage
- 22 preserved details · 2 archived images · original MSRP · preserved geometry
- Archive ID
- 900001804
Frameset
| Frame Construction | ALX XC Trail Frame |
|---|---|
| Frame Material | Aluminum |
| Fork | RockShox Recon Silver RL 120mm Travel |
| Rear Shock | RockShox Deluxe Select Plus E2E: 190x45mm |
Drivetrain
| Shifters | Shimano 1X11-Speed Trigger |
|---|---|
| Rear Derailleur | Shimano 11-speed |
| Crankset | 170mm, 32T |
| Bottom Bracket | Threaded 68/73mm |
| Cassette | Shimano 11-50T |
| Chain | KMC Chain |
| Pedals | Alloy Cage Pedal W/ Reflector |
Brakes
| Brakes | Shimano Hydraulic Disc; Levers: Shimano Lever; Rotors: Rotor: Front:180mm Rear:160mm Center-Lock |
|---|
Cockpit & Contact Points
| Headset | Threadless Zero Stack Headset, ZS 44/28.6 | ZS 56/40 |
|---|---|
| Handlebar | Polygon Xpert, Alloy |
| Stem | Polygon Xpert, Alloy |
| Saddle | Linc Void Saddle |
| Seatpost | Tranz X Dropper 150mm |
Wheels & Tires
| Hubs | F: Shimano HB-MT400 Thru Axle 15x100mm 32H Center Lock / R: Shimano FH-MT400 Thru Axle 12x148mm 32H Center Lock |
|---|---|
| Wheels | Alloy Double Wall |
| Rims | Alloy Double Wall 584 / 622-30 32H for Tyre 584 / 622-54/76 |
| 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″) | M (29″) | L (29″) | XL (29″) |
|---|---|---|---|---|---|
| Seat tube | 395 mm | 435 mm | 435 mm | 487 mm | 522 mm |
| Effective top tube | 572.7 mm | 595.1 mm | 603.9 mm | 624.3 mm | 646.7 mm |
| Head tube | 102 mm | 105 mm | 102 mm | 112 mm | 122 mm |
| Head-tube angle | 67° | 67° | 67.5° | 67.5° | 67.5° |
| Seat-tube angle | 75.5° | 75.5° | 76° | 76° | 76° |
| Actual seat-tube angle | 70° | 70° | 68.7° | 68.7° | 68.7° |
| Chainstay / rear center | 432 mm | 432 mm | 436 mm | 436 mm | 436 mm |
| Wheelbase | 1133 mm | 1157 mm | 1165 mm | 1189 mm | 1213 mm |
| Bottom-bracket drop | 27 mm | 27 mm | 47 mm | 47 mm | 47 mm |
| Bottom-bracket height | 326 mm | 326 mm | 326 mm | 326 mm | 326 mm |
| Reach | 425 mm | 445 mm | 445 mm | 465 mm | 485 mm |
| Stack | 571.2 mm | 580.4 mm | 606.7 mm | 615.9 mm | 625.2 mm |
| Standover height | 676 mm | 696 mm | 698 mm | 733 mm | 761 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: Its stack of 571.2 mm sits toward the lower end. Its wheelbase of 1133 mm sits toward the shorter end. The head angle of 67° sits toward the steeper end.
Compared with 180 distinct mountain geometries in the Small-equivalent size cohort from model years 2023–2027 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 stack of 580.4 mm sits toward the lower end. Its wheelbase of 1157 mm sits toward the shorter end. The head angle of 67° sits toward the steeper end.
Compared with 186 distinct mountain geometries in the Medium-equivalent size cohort from model years 2023–2027 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 M (29″) geometry
Archive context: The head angle of 67.5° sits toward the steeper end. Its wheelbase of 1165 mm sits toward the shorter end. Its stack of 606.7 mm sits somewhat lower than typical.
Compared with 186 distinct mountain geometries in the Medium-equivalent size cohort from model years 2023–2027 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: The head angle of 67.5° sits toward the steeper end. Its stack of 615.9 mm sits toward the lower end. Its wheelbase of 1189 mm sits somewhat shorter than typical.
Compared with 179 distinct mountain geometries in the Large-equivalent size cohort from model years 2023–2027 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 stack of 625.2 mm sits toward the lower end. The head angle of 67.5° sits toward the steeper end. Its reach of 485 mm sits toward the shorter end.
Compared with 158 distinct mountain geometries in the XL-equivalent size cohort from model years 2023–2027 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 (29″) geometry Parts & serviceability
Find replacement parts
CassetteShimano 11-50TNamed component · published drivetrain speed — verify exact version
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 and shock were last serviced. Check the stanchions for damage, look for oil at the seals, cycle both units through their travel and test the suspension pivots for 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
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: 2025 Polygon Siskiu D7 · Mountain · Published sizes: 27.5” SM, 27.5” MD, 29” MD, 29” LG, 29” XL
Frame and fork
Inspect the frame and fork →Archived: Frame: ALX XC TRAIL FRAME · Fork: ROCKSHOX RECON SILVER RL 120MM TRAVEL
Suspension
Evaluate the suspension →Archived: Fork: ROCKSHOX RECON SILVER RL 120MM TRAVEL · Rear shock: ROCKSHOX DELUXE SELECT PLUS E2E: 190x45MM
Drivetrain
Check drivetrain wear →Archived: Shifters: SHIMANO 1x11-SPEED TRIGGER · Rear derailleur: SHIMANO 11-SPEED · Crankset: 170mm, 32T · Bottom bracket: THREADED 68/73mm · Cassette: SHIMANO 11-50T · Chain: KMC CHAIN
Brakes
Inspect the brakes →Archived: Brakes: SHIMANO HYDRAULIC DISC; Levers: SHIMANO LEVER; Rotors: ROTOR: FRONT:180MM REAR:160MM CENTER-LOCK
Wheels and tires
Check wheels and tires →Archived: Wheels: ALLOY DOUBLE WALL · Rims: ALLOY DOUBLE WALL 584 / 622-30 32H FOR TYRE 584 / 622-54/76 · Hubs: F: SHIMANO HB-MT400 THRU AXLE 15x100mm 32H CENTER LOCK / R: SHIMANO FH-MT400 THRU AXLE 12X148mm 32H CENTER LOCK · 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: THREADLESS ZERO STACK HEADSET, ZS 44/28.6 | ZS 56/40 · Handlebar: POLYGON XPERT, ALLOY · Stem: POLYGON XPERT, ALLOY · Seatpost: TRANZ X DROPPER 150mm · Saddle: LINC VOID SADDLE · Pedals: ALLOY 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.