Polygon Cascade 20

Name: Polygon Cascade 20
Brand: Polygon

2026 YouthMountain youth Manufacturer page

Last known price: $499

Prices shown first for United States
Fork travel: 40 mm
Wheels: 20″
Drivetrain: 1 × 7 30t / 14–28t
Gear range: 200%
Frame: Aluminum
Brakes: Mechanical disc

Sizes

Size guide

3'7" to 4'5"

The manufacturer did not publish rider heights for these sizes.

Components

8 of 22 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

AL6 Aluminium Rigid Frame, Internal Cable Routing (Front), IS Disc Mount 160mm, Threaded BSA 68mm Bottom Bracket, Rear Spacing 135mm (M10), 31.8mm Seat Clamp, Kickstand Mount (Bolt-On Centre Chainstay) Not identified

Suspension

1 part

Fork

Suspension Fork, 40mm Travel, Coil Spring, Alloy Crown & Lowers, Straight 1-1/8" Threadless Steerer, Post Mount Disc 160mm, QR 9x100mm Spacing Not identified

Drivetrain

6 parts

Bottom bracket

BSA, 68mm, threaded Not identified
Cassette

7-Speed Freewheel, 14–28T Not identified
Chain

Meile M70 Not identified
Crankset

30T Not identified
Rear derailleur
- Shimano Tourney RD-TY200 7 speeds
RD-TY200
Shifters
- Shimano Tourney

Brakes

2 parts

Brakes
- Tektro MD-M280
MD-M280
Disc rotors
- Tektro

Wheels and tires

4 parts

Front hub
- Race Face Vault J-Bend Hub - 32H
Rear hub
- Race Face Vault J-Bend Hub - 32H
Rims

20" Alloy Double Wall Rims, 32H, 20mm Height, 21mm Internal Width Not identified
Tires
- Kenda

Cockpit and contact points

7 parts

Grips

Standard Rubber Grips Not identified
Handlebar

Steel Handlebar, 560mm Width, 25.4mm Clamp, 7° Rise, 6° Backsweep Not identified
Headset
- Cane Creek Headset Bearings
Pedals

One-Piece PP Body Pedals Not identified
Saddle

Youth Saddle, Steel Rail 7mm Not identified
Seatpost

Steel Seatpost, 27.2x300mm Not identified
Stem

Alloy Stem, 40mm Length, 25.4mm Clamp Not identified

Other components

1 part

Kickstand

Included Not identified

Sizes and geometry

1 size Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 3'7" to 4'5"

Table

Reach 305mm

Stack 454mm

Wheelbase 845mm

Head angle 70.0°

Seat angle 72.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 20″ wheel; exact published values are in the table below.

Size Reach Stack

Complete manufacturer geometry table 1 published size

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	305
Stackmm	454
Top tube lengthmm	453
Seat tube lengthmm	254
Head tube lengthmm	100
Head tube angle	70°
Seat tube angle	72°
Chainstay lengthmm	350
Wheelbasemm	844.8
Front centermm	499
Bottom bracket dropmm	-42.5
Bottom bracket heightmm	215
Standover heightmm	476
Fork rakemm	11
Stack/reach ratio	1.49
Suspension and parts
Crank lengthmm	110
Handlebar widthmm	560
Stem lengthmm	40

Not published by the manufacturer: Trail, Front travel, Rear travel, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Fork material: Aluminum

Suspension

Suspension configuration: Hardtail
Front travel: 40 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 30
Largest chainring: 30
Rear sprockets: 7
Smallest sprocket: 14
Largest sprocket: 28
Lowest gear: 21.4 in
Highest gear: 42.9 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Mechanical disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Bottom bracket standard: BSA
Fork spring: Coil
Tire clearance: Maximum tire width: 1.95″
Tire width: 1.95″
Wheel material: Aluminum
Wheel size: 20″

Technical analysis

1 measure

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Shifting

Mechanical

9 of 321 bicycles with this information use electronic shifting.

Cohort: Youth / Mountain youth Model year: 2026
Sample: 321 bicycles with this information
Coverage: 100.0% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 8.2 km/h
Highest gear: 16.4 km/h

Total gear range 200%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 21.4–42.9 gear inches

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2026 builds

Differences across 2026 builds
Specification	This bicycle Polygon Cascade 20	Polygon Cascade 2	Polygon Cascade 24	Polygon Cascade 3	Polygon Cascade 4	Polygon Cascade 5
Frame
Fork material	Aluminum	Not informed	Aluminum	Not informed	Not informed	Not informed
Suspension
Suspension configuration	Hardtail	Hardtail	Hardtail	Full suspension	Hardtail	Hardtail
Front travel	40 mm	100 mm	50 mm	100 mm	100 mm	100 mm
Rear travel	Not informed	Not informed	Not informed	135 mm	Not informed	Not informed
Drivetrain
Front chainrings	1	3	1	1	1	1
Smallest chainring	30	24	32	36	36	36
Largest chainring	30	42	32	36	36	36
Rear sprockets	7	7	7	8	10	10
Smallest sprocket	14	14	14	11	11	11
Largest sprocket	28	28	28	45	46	48
Lowest gear	21.4 in	23.6 in	27.4 in	23.2 in	22.7 in	21.8 in
Highest gear	42.9 in	82.5 in	54.9 in	94.9 in	94.9 in	94.9 in
Brakes
Brake type	Mechanical disc	Mechanical disc	Mechanical disc	Hydraulic disc	Hydraulic disc	Hydraulic disc
Other specifications
Bottom bracket standard	BSA	Not informed	BSA	Not informed	Not informed	Not informed
Suspension	Hardtail	Hardtail	Hardtail	Full suspension	Hardtail	Hardtail
Tire clearance	Maximum tire width: 1.95″	Maximum tire width: 2.25″	Maximum tire width: 2.1″	Not informed	Maximum tire width: 2.25″	Maximum tire width: 2.25″
Tire width	1.95″	2.25″	2.1″	2.25″	2.25″	2.25″
Wheel size	20″	27.5″	24″	27.5″ / 29″	27.5″ / 29″	27.5″ / 29″