Which size or configuration labels have geometry for the 2021 Jamis PORTAL C4?

Geometry is listed for L/19", M/17", S/15.5", and XL/21".

What are the reach and stack of the 2021 Jamis PORTAL C4 in size S/15.5"?

In size S/15.5", reach is 418 mm and stack is 606 mm.

What is the head tube angle of the 2021 Jamis PORTAL C4?

The head tube angle is 67.5 degrees in every size.

What does the 2021 Jamis PORTAL C4 ship with?

The stock build includes Fox 34 Series Float 29” Rhythm, Shimano Deore, Vittoria Mazza 29 x 2.4”, and Shimano MT420 4-Piston Hydraulic Disc.

Which years of the Jamis PORTAL C4 are on Quiver?

Quiver has the Jamis PORTAL C4 for 2021.

2021

2021 Jamis PORTAL C4

Reach 418 to 482 mm, stack 606 to 634 mm. The PORTAL C4 build comes with Vittoria Mazza 29 x 2.4” tires.

Compare geometry

Source: bikecatalogs.com. Checked Oct 4, 2026.

Key facts

Brand: Jamis
Model: PORTAL C4
Model year: 2021
Geometry labels: L/19", M/17", S/15.5", and XL/21"
Fork: Fox 34 Series Float 29” Rhythm
Geometry: Complete for every size
Checked: Oct 4, 2026

Geometry by size

Geometry drawing, size M/17", to scale.

2021 Jamis PORTAL C4 geometry by size
Measurement	L/19"	M/17"	S/15.5"	XL/21"
Reach(mm)	461	439	418	482
Stack(mm)	625	615	606	634
Head tube angle(°)	67.5	67.5	67.5	67.5
Seat tube angle(°)	74.5	74.5	74.5	74.5
Effective top tube(mm)	635	610	585	660
Chainstay length(mm)	437	437	437	437
Wheelbase(mm)	1198	1173	1148	1224
BB drop(mm)	33	33	33	33
Standover(mm)	754	749	754	774
Head tube length(mm)	125	115	105	135

How to read a geometry chart

Stock build

14 parts

Suspension

Fox 34 Series Float 29” Rhythm

Fork

Drivetrain

Shimano Deore

ShifterSpeeds 12

Shimano Deore M6100

Cassette

KMC X12

Chain

Race Face Ride

CranksetCrank length 170 / 175mmSpeeds 12

Race Face BSA

Bottom bracket

Wheels & Tires

Vittoria Mazza 29 x 2.4”

Tire

Brakes

Shimano MT420 4-Piston Hydraulic Disc

Brake

Cockpit

Race Face Ride

HandlebarWidth 760mm

Race Face Ride

StemBar clamp diameter 31.8mmSteerer diameter 1 1/8"Rise 6°Material Aluminum

Jamis Lock-On

Grips

FSA Orbit IS Integrated

Headset

Seatpost & Saddle

KS Rage Dropper

Seatpost

WTB Volt

SaddleWidth 135 / 142 / 150mmLength 265mm

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Quick answers

Which size or configuration labels have geometry for the 2021 Jamis PORTAL C4?: Geometry is listed for L/19", M/17", S/15.5", and XL/21".
What are the reach and stack of the 2021 Jamis PORTAL C4 in size S/15.5"?: In size S/15.5", reach is 418 mm and stack is 606 mm.
What is the head tube angle of the 2021 Jamis PORTAL C4?: The head tube angle is 67.5 degrees in every size.
What does the 2021 Jamis PORTAL C4 ship with?: The stock build includes Fox 34 Series Float 29” Rhythm, Shimano Deore, Vittoria Mazza 29 x 2.4”, and Shimano MT420 4-Piston Hydraulic Disc.
Which years of the Jamis PORTAL C4 are on Quiver?: Quiver has the Jamis PORTAL C4 for 2021.

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