
Velopedia Bicycle Archive
2021 Kona Unit
Original manufacturer specifications including 29" wheels, geometry for 4 published sizes.
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What Velopedia knows
- Model year
- 2021
- Category
- Mountain
- Original MSRP
- $1,249.00
- Sizes
- S, M, L, XL
- Colors
- Satin Fatgue Green w/ Gloss Yellow, Nicotine & Flame Fade Decals
- Geometry
- 4 manufacturer sizes · Geometry context
- Record coverage
- 24 preserved details · archived image · original MSRP · preserved geometry
- Archive ID
- 900001983
Model history 11 other years
Frameset
| Frame Construction | Reynolds 520 Butted Cromoly |
|---|---|
| Frame Material | Steel |
| Fork | Kona Plus fork 110mm spacing |
| Rear Shock | n/a |
Drivetrain
| Shifters | n/a |
|---|---|
| Front Derailleur | n/a |
| Rear Derailleur | n/a |
| Crankset | FSA Comet Modular; Chainring: 32t |
| Bottom Bracket | FSA MegaExo 73mm |
| Cassette | Joytech 18t |
| Chain | KMC Z1 Narrow |
| Pedals | Kona JS2 |
Brakes
| Brakes | Brake Calipers: Shimano MT201 Hydraulic; Front Brake Rotor: Shimano RT26 180mm; Rear Brake Rotor: Shimano RT26 160mm; Brake Levers: Shimano MT201 Hydraulic |
|---|
Cockpit & Contact Points
| Headset | TH ZST no.10 |
|---|---|
| Handlebar | Kona XC/BC Riser |
| Stem | Kona XC |
| Saddle | WTB Volt |
| Seatpost | Kona Thumb w/Offset 31.6mm |
Wheels & Tires
| Hubs | (F) Formula 110x15mm / (R) Formula 148x12mm |
|---|---|
| Rims | WTB ST I30 TCS 2.0 |
| Spokes | Stainless Black 14g |
| Front Tire | WTB Ranger TCS 29x2.6" |
| Rear Tire | WTB Ranger TCS 29x2.6" |
| Wheel Size | 29" |
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 | 370 mm | 420 mm | 470 mm | 530 mm |
| Top tube | 582 mm | 610 mm | 637 mm | 675 mm |
| Head tube | 110 mm | 120 mm | 130 mm | 140 mm |
| Head-tube angle | 68° | 68° | 68° | 68° |
| Seat-tube angle | 75° | 75° | 75° | 75° |
| Chainstay / rear center | 430 mm | 430 mm | 430 mm | 430 mm |
| Wheelbase | 1115 mm | 1144 mm | 1173 mm | 1211 mm |
| Bottom-bracket drop | 65 mm | 65 mm | 65 mm | 65 mm |
| Bottom-bracket height | 310 mm | 310 mm | 310 mm | 310 mm |
| Reach | 425 mm | 450 mm | 475 mm | 510 mm |
| Stack | 588 mm | 597 mm | 606 mm | 615 mm |
| Standover height | 695 mm | 731 mm | 768 mm | 810 mm |
| Fork offset / rake | 50 mm | 50 mm | 50 mm | 50 mm |
| Front center | 693 mm | 722 mm | 750 mm | 789 mm |
| Fork length / axle-to-crown | 470 mm | 470 mm | 470 mm | 470 mm |
Geometry source: Kona first-party archive 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 bottom-bracket drop of 65 mm sits toward the deeper-drop end. Its stack of 588 mm sits toward the lower end. Its wheelbase of 1115 mm sits somewhat shorter than typical.
Compared with 86 distinct mountain geometries in the Small-equivalent size cohort from model years 2019–2023 in the Velopedia archive.M geometry
Archive context: Its bottom-bracket drop of 65 mm sits toward the deeper-drop end. Its stack of 597 mm sits toward the lower end. Its wheelbase of 1144 mm sits somewhat shorter than typical.
Compared with 86 distinct mountain geometries in the Medium-equivalent size cohort from model years 2019–2023 in the Velopedia archive.L geometry
Archive context: Its bottom-bracket drop of 65 mm sits toward the deeper-drop end. Its stack of 606 mm sits toward the lower end. Its wheelbase of 1173 mm sits somewhat shorter than typical.
Compared with 79 distinct mountain geometries in the Large-equivalent size cohort from model years 2019–2023 in the Velopedia archive.XL geometry
Archive context: Its bottom-bracket drop of 65 mm sits toward the deeper-drop end. Its stack of 615 mm sits toward the lower end. The chainstay of 430 mm sits somewhat shorter than typical.
Compared with 71 distinct mountain geometries in the XL-equivalent size cohort from model years 2019–2023 in the Velopedia archive.Parts & serviceability
Find replacement parts
More qualified parts (3)
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 →- FrameCheck paint chips, vent holes and the inside of the seat tube for corrosion. Also look for dents, bent tubes and cracking around welded or brazed joints.Inspect the frame and fork →
- BrakesTest each brake separately and confirm it stops firmly and releases cleanly. Inspect the pads and braking surfaces for wear or contamination, and check the cables or hoses for damage.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.Check wheels and tires →
Bike-specific inspection checklist 19 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: 2021 Kona Unit · Mountain · Published sizes: S, M, L, XL
Frame and fork
Inspect the frame and fork →Archived: Frame: Reynolds 520 Butted Cromoly · Fork: Kona Plus fork 110mm spacing
Drivetrain
Check drivetrain wear →Archived: Crankset: FSA Comet Modular; Chainring: 32t · Bottom bracket: FSA MegaExo 73mm · Cassette: Joytech 18t · Chain: KMC Z1 Narrow
Brakes
Inspect the brakes →Archived: Brakes: Brake Calipers: Shimano MT201 Hydraulic; Front Brake Rotor: Shimano RT26 180mm; Rear Brake Rotor: Shimano RT26 160mm; Brake Levers: Shimano MT201 Hydraulic
Wheels and tires
Check wheels and tires →Archived: Wheel size: 29" · Rims: WTB ST i30 TCS 2.0 · Hubs: (F) Formula 110x15mm / (R) Formula 148x12mm · Front tire: WTB Ranger TCS 29x2.6" · Rear tire: WTB Ranger TCS 29x2.6"
Controls and contact points
Archived: Headset: TH ZST No.10 · Handlebar: Kona XC/BC Riser · Stem: Kona XC · Seatpost: Kona Thumb w/Offset 31.6mm · Saddle: WTB Volt · Pedals: Kona JS2
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.




