Velopedia Bicycle Archive

2025 Polygon Siskiu T27 EVO

Mountain bicycle from the Velopedia specification archive.

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What Velopedia knows

Model year
2025
Category
Mountain
Original MSRP
$1,999.00
Sizes
XS
Colors
Cream
Geometry
1 manufacturer size · Geometry context
Record coverage
22 preserved details · 6 archived images · original MSRP · preserved geometry
Archive ID
900001778
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Manufacturer catalog

Published sizes and colors

1 size · 1 color

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

Published sizes

XS

Published colors

Cream

Frameset

Frame ConstructionALX Trail 140mm Travel
Frame MaterialAluminum
ForkRockShox Recon Silver-RL 150mm Travel
Rear ShockRockShox Deluxe Select Plus, E2E: 210x55mm

Drivetrain

ShiftersShimano Deore SL-M6100, 1X12-Speed Trigger
Rear DerailleurShimano Deore RD-M6100-SGS Direct Attach
CranksetShimano FC-M6120-1 Boost, 32T
Bottom BracketShimano 2-Piece Crankset BSA Threaded
CassetteShimano Deore CS-M6100-12, 10-51T Microspline
ChainKMC New X-12
PedalsAlloy Flat Pedal W/ Replaceable PIN & Reflector

Brakes

BrakesShimano Hydraulic Disc Brakes; Levers: Shimano BL-M4100; Rotors: Shimano SM-RT54, 180mm Center-Lock

Cockpit & Contact Points

HeadsetFSA no.57E for Taper H/T, ZS 44/28.6 | ZS 56/40
HandlebarPOLYGON EXPERT, W: 720mm, BB: 35mm, R/D: 30mm, B: 9 degree
StemPOLYGON EXPERT, E: 35mm, BB: 35mm, R/D: 0 degree
SaddleFizik Terra Alpaca X5
SeatpostDropper Post Xfusion Manic LC 100mm Travel, DXL: 30.9 X 314mm

Wheels & Tires

HubsF: Shimano HB-TC500-15-B Thru Axle 15x110mm 32H Center-Lock, R: Shimano FH-TC500-MS-B Thru Axle 12x148mm 32H Center-Lock for Microspline
WheelsPolygon MT6
RimsAlloy Double Wall H: 18mm W: 29mm 584-27.5 32H for Tyre 584-54/76 TL Ready
Front TireMaxxis Dissector 27.5"X2.40"
Rear TireMaxxis Dissector 27.5"X2.40"

Size-specific frame data

Geometry

1 size · 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.

MeasurementXS
Seat tube375 mm
Effective top tube559.2 mm
Head tube90 mm
Head-tube angle65°
Seat-tube angle76.5°
Actual seat-tube angle71°
Chainstay / rear center425 mm
Wheelbase1146.4 mm
Bottom-bracket drop20 mm
Bottom-bracket height335 mm
Reach420 mm
Stack579.87 mm
Standover height666 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

XS geometry

Archive context: The chainstay of 425 mm sits toward the shorter rear-center end. Its stack of 579.9 mm sits toward the lower end. Its reach of 420 mm sits somewhat longer than typical.

Compared with 56 distinct mountain geometries in the XS-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 XS geometry

Parts & serviceability

Find replacement parts

3 top part searches
ChainKMC New X-12Exact archived model
CassetteShimano Deore CS-M6100-12, 10-51T MicrosplineExact archived model
More qualified parts (6)
Bottom bracketShimano 2-Piece Crankset BSA ThreadedNamed archived component — verify dimensions
SaddleFizik Terra Alpaca X5Named archived component — verify exact version
CranksetShimano FC-M6120-1 Boost, 32TExact archived model
Rear derailleurShimano Deore RD-M6100-SGS Direct AttachExact archived model
ShiftersShimano Deore SL-M6100, 1X12-Speed TriggerExact archived model
Seatpost30.9 mm dropper postDropper post identified — select the published travel for your frame size

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 →
  • 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 the full range under light load, measure chain wear and inspect the cassette or freewheel teeth. Skipping or hesitation can indicate wear, poor adjustment or mismatched parts.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: 2025 Polygon Siskiu T27 EVO · Mountain · Published sizes: XS

Archived: Frame: ALX TRAIL 140mm TRAVEL · Fork: ROCKSHOX RECON SILVER-RL 150mm TRAVEL

Archived: Fork: ROCKSHOX RECON SILVER-RL 150mm TRAVEL · Rear shock: ROCKSHOX DELUXE SELECT PLUS, E2E: 210x55mm

Archived: Shifters: SHIMANO DEORE SL-M6100, 1x12-SPEED TRIGGER · Rear derailleur: SHIMANO DEORE RD-M6100-SGS DIRECT ATTACH · Crankset: SHIMANO FC-M6120-1 BOOST, 32T · Bottom bracket: SHIMANO 2-PIECE CRANKSET BSA THREADED · Cassette: SHIMANO DEORE CS-M6100-12, 10-51T MICROSPLINE · Chain: KMC NEW X-12

Archived: Brakes: SHIMANO HYDRAULIC DISC BRAKES; Levers: SHIMANO BL-M4100; Rotors: SHIMANO SM-RT54, 180mm CENTER-LOCK

Archived: Wheels: POLYGON MT6 · Rims: ALLOY DOUBLE WALL H: 18mm W: 29mm 584-27.5 32H FOR TYRE 584-54/76 TL READY · Hubs: F: SHIMANO HB-TC500-15-B THRU AXLE 15x110mm 32H CENTER-LOCK, R: SHIMANO FH-TC500-MS-B THRU AXLE 12x148mm 32H CENTER-LOCK FOR MICROSPLINE · Front tire: MAXXIS DISSECTOR 27.5"x2.40" · Rear tire: MAXXIS DISSECTOR 27.5"x2.40"

Controls and contact points

Archived: Headset: FSA NO.57E FOR TAPER H/T, ZS 44/28.6 | ZS 56/40 · Handlebar: POLYGON EXPERT, W: 720mm, BB: 35mm, R/D: 30mm, B: 9 degree · Stem: POLYGON EXPERT, E: 35mm, BB: 35mm, R/D: 0 degree · Seatpost: DROPPER POST XFUSION MANIC LC 100mm TRAVEL, DxL: 30.9 x 314mm · Saddle: FIZIK TERRA ALPACA X5 · Pedals: ALLOY FLAT PEDAL W/ REPLACEABLE PIN & 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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