Velopedia Bicycle Archive
2025 Polygon Tambora A4
Cyclocross/Gravel bicycle from the Velopedia specification archive.
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What Velopedia knows
- Model year
- 2025
- Category
- Gravel & Cyclocross
- Original MSRP
- $1,799.00
- Sizes
- S, M, L, XL
- Colors
- Charcoal
- Geometry
- 8 manufacturer sizes · Geometry context
- Record coverage
- 21 preserved details · archived image · original MSRP · preserved geometry
- Archive ID
- 900001842
Frameset
| Frame Construction | ALX XC Trail Frame |
|---|---|
| Frame Material | Aluminum |
| Fork | Carbon Rigid |
| Fork Material | Carbon Fiber |
Drivetrain
| Shifters | Shimano GRX ST-RX600, 2X11-Speed Brifter |
|---|---|
| Rear Derailleur | Shimano GRX RD-RX810 |
| Crankset | Prowheel RPZ C701X TT, 48-31T |
| Bottom Bracket | BSA, 68mm |
| Cassette | Shimano CS-HG700, 11-34T |
| Chain | KMC X11 |
Brakes
| Brakes | Shimano GRX Hydraulic Disc; Levers: Shimano ST-RX600; Rotors: Shimano RT-CL700, 160mm |
|---|
Cockpit & Contact Points
| Headset | Token TK156SP-36 W/ Sealed Bearing, ZS 56/28.6 | ZS 56/40 |
|---|---|
| Handlebar | Polygon Expert, W: 420mm (S, M) / 440mm (L, XL), BB: 31.8mm, R/D: 125mm, B/R: 77mm |
| Stem | POLYGON EXPERT, EXT: 90mm (S, M) / 100mm (L, XL) , BB: 31.8mm, R/D: 7degree |
| Saddle | Linc Flux 2 |
| Seatpost | Polygon Expert, DXL: 27.2X400mm |
Wheels & Tires
| Hubs | F: Novatec D791SB 12x100mm 32H CL / R: Novatec D792SB 12x142mm 32H CL for Sprocket |
|---|---|
| Wheels | Alloy Double Wall 32H |
| Rims | F: Alloy Double Wall FV H: 20 622 32H TLR / R: Alloy Double Wall FV H: 20 622 32H TLR |
| Front Tire | Maxxis Pursuer 700x32C |
| Rear Tire | Maxxis Pursuer 700x32C |
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 · All Road | M · All Road | L · All Road | XL · All Road | S · Gravel | M · Gravel | L · Gravel | XL · Gravel |
|---|---|---|---|---|---|---|---|---|
| Seat tube | 404 mm | 448 mm | 492 mm | 535 mm | 404 mm | 448 mm | 492 mm | 535 mm |
| Effective top tube | 526 mm | 550 mm | 581 mm | 610 mm | 526 mm | 551 mm | 581 mm | 611 mm |
| Head tube | 143 mm | 163 mm | 193 mm | 221 mm | 143 mm | 163 mm | 193 mm | 221 mm |
| Head-tube angle | 70.25° | 71.77° | 72.06° | 72.26° | 70° | 71.5° | 71.8° | 72° |
| Seat-tube angle | 74.75° | 74.26° | 73.76° | 73.26° | 74.5° | 74° | 73.5° | 73° |
| Actual seat-tube angle | 74.75° | 74.26° | 73.76° | 73.26° | 74.5° | 74° | 73.5° | 73° |
| Chainstay / rear center | 415 mm | 415 mm | 415 mm | 415 mm | 425 mm | 425 mm | 425 mm | 425 mm |
| Wheelbase | 997 mm | 1003 mm | 1026 mm | 1048 mm | 1017 mm | 1022 mm | 1045 mm | 1067 mm |
| Bottom-bracket drop | 79 mm | 79 mm | 79 mm | 79 mm | 78 mm | 78 mm | 78 mm | 78 mm |
| Bottom-bracket height | 265 mm | 265 mm | 265 mm | 265 mm | 280 mm | 280 mm | 280 mm | 280 mm |
| Reach | 371 mm | 383 mm | 400 mm | 415 mm | 369 mm | 381 mm | 397 mm | 412 mm |
| Stack | 566 mm | 591 mm | 621 mm | 648 mm | 568 mm | 593 mm | 622 mm | 650 mm |
| Standover height | 701 mm | 741 mm | 784 mm | 819 mm | 716 mm | 755 mm | 798 mm | 833 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
All Road
Archive context: The chainstay of 415 mm sits toward the shorter rear-center end. Its wheelbase of 997 mm sits toward the shorter end. The seat angle of 74.8° sits somewhat steeper than typical.
Compared with 87 distinct cyclocross/gravel 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 · All Road geometry M geometry
All Road
Archive context: The chainstay of 415 mm sits toward the shorter rear-center end. Its wheelbase of 1003 mm sits toward the shorter end. The seat angle of 74.3° sits toward the steeper end.
Compared with 98 distinct cyclocross/gravel 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 · All Road geometry L geometry
All Road
Archive context: The chainstay of 415 mm sits toward the shorter rear-center end. Its wheelbase of 1026 mm sits toward the shorter end. The head angle of 72.1° sits toward the steeper end.
Compared with 69 distinct cyclocross/gravel 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 · All Road geometry XL geometry
All Road
Archive context: The chainstay of 415 mm sits toward the shorter rear-center end. The head angle of 72.3° sits toward the steeper end. Its wheelbase of 1048 mm sits toward the shorter end.
Compared with 74 distinct cyclocross/gravel 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 · All Road geometry S · Gravel geometry
Archive context: Its reach of 369 mm sits toward the shorter end. The seat angle of 74.5° sits toward the steeper end. Its wheelbase of 1017 mm sits toward the shorter end.
Compared with 98 distinct cyclocross/gravel geometries in the Medium-equivalent size cohort from model years 2023–2027 in the Velopedia archive.M · Gravel geometry
Archive context: Its reach of 381 mm sits toward the shorter end. Its wheelbase of 1022 mm sits toward the shorter end. The seat angle of 74° sits toward the steeper end.
Compared with 69 distinct cyclocross/gravel geometries in the Large-equivalent size cohort from model years 2023–2027 in the Velopedia archive.L · Gravel geometry
Archive context: Its wheelbase of 1045 mm sits toward the shorter end. Its reach of 397 mm sits toward the shorter end. The head angle of 71.8° sits somewhat steeper than typical.
Compared with 74 distinct cyclocross/gravel geometries in the XL-equivalent size cohort from model years 2023–2027 in the Velopedia archive.XL · Gravel geometry
Archive context: Its stack of 650 mm sits toward the taller end. The head angle of 72° sits somewhat steeper than typical. Its reach of 412 mm sits somewhat longer than typical.
Compared with 20 distinct cyclocross/gravel geometries in the XXL-equivalent size cohort from model years 2024–2027 in the Velopedia archive.Parts & serviceability
Find replacement parts
ChainKMC X11Exact archived model
CassetteShimano CS-HG700, 11-34TExact archived model
Front tireMaxxis Pursuer 700x32CNamed tire and published size
More qualified parts (3)
Rear derailleurShimano GRX RD-RX810Exact archived model
ShiftersShimano GRX ST-RX600, 2X11-Speed BrifterExact archived model
Seatpost27.2 mm seatpostPublished diameter — verify length and setback
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 →
- 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. If it is set up tubeless, confirm both tires hold pressure and ask when the sealant was last refreshed.Check wheels and tires →
- Bottom bracketTurn the cranks slowly, feel for rough bearings and check for side-to-side play. Creaking under load deserves investigation but does not identify the source by itself.Inspect the bottom bracket and shell →
Bike-specific inspection checklist 20 checks based on 5 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 Tambora A4 · Cyclocross/Gravel · Published sizes: S, M, L, XL
Frame and fork
Inspect the frame and fork →Archived: Frame: ALX XC TRAIL FRAME · Fork: CARBON RIGID · Carbon Fiber
Drivetrain
Check drivetrain wear →Archived: Shifters: SHIMANO GRX ST-RX600, 2x11-SPEED BRIFTER · Rear derailleur: SHIMANO GRX RD-RX810 · Crankset: PROWHEEL RPZ C701X TT, 48-31T · Bottom bracket: BSA, 68mm · Cassette: SHIMANO CS-HG700, 11-34T · Chain: KMC X11
Brakes
Inspect the brakes →Archived: Brakes: SHIMANO GRX HYDRAULIC DISC; Levers: SHIMANO ST-RX600; Rotors: SHIMANO RT-CL700, 160mm
Wheels and tires
Check wheels and tires →Archived: Wheels: ALLOY DOUBLE WALL 32H · Rims: F: ALLOY DOUBLE WALL FV H: 20 622 32H TLR / R: ALLOY DOUBLE WALL FV H: 20 622 32H TLR · Hubs: F: NOVATEC D791SB 12x100mm 32H CL / R: NOVATEC D792SB 12x142mm 32H CL FOR SPROCKET · Front tire: MAXXIS PURSUER 700X32C · Rear tire: MAXXIS PURSUER 700X32C
Controls and contact points
Archived: Headset: TOKEN TK156SP-36 W/ SEALED BEARING, ZS 56/28.6 | ZS 56/40 · Handlebar: POLYGON EXPERT, W: 420mm (S, M) / 440mm (L, XL), BB: 31.8mm, R/D: 125mm, B/R: 77mm · Stem: POLYGON EXPERT, EXT: 90mm (S, M) / 100mm (L, XL) , BB: 31.8mm, R/D: 7degree · Seatpost: POLYGON EXPERT, DxL: 27.2x400mm · Saddle: LINC FLUX 2
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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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.