Which size or configuration labels have geometry for the 2021 Specialized Sirrus 1.0?

Geometry is listed for XXS, XS, S, M, L, and XL.

What are the reach and stack of the 2021 Specialized Sirrus 1.0 in size M?

In size M, reach is 398 mm and stack is 593 mm.

What is the head tube angle of the 2021 Specialized Sirrus 1.0?

The head tube angle is 71 degrees in size M.

What does the 2021 Specialized Sirrus 1.0 ship with?

The stock build includes Shimano EF500, Specialized Roadsport, Specialized Flowset, and Specialized Bridge Sport.

Which years of the Specialized Sirrus are on Quiver?

Quiver has the Specialized Sirrus for 2021, 2023, 2022, 2020, 2019, 2018, 2017, 2015, 2014, 2013, 2012, 2011, 2010, 2009, and 2008.

2021

2021 Specialized Sirrus 1.0

Commuter

The 2021 Specialized Sirrus 1.0 sits more aggressive than most commuter bikes. Reach 373 to 414 mm, stack 536 to 632 mm. The Sirrus 1.0 build comes with Shimano Altus shifting and Specialized Roadsport tires.

Compare with 730+ commuter bikes

Source: specialized.com. Checked Sep 5, 2026.

Key facts

Brand: Specialized
Model: Sirrus
Model year: 2021
Frame: 1.0
Type: Commuter
Geometry labels: XXS, XS, S, M, L, and XL
Drivetrain: Shimano Altus
Geometry: Complete for every size
Source: specialized.com
Checked: Sep 5, 2026

Geometry by size

Geometry drawing, size S, to scale.

2021 Specialized Sirrus 1.0 geometry by size
Measurement	XXS	XS	S	M	L	XL
Reach(mm)	373	388	393	398	402	414
Stack(mm)	536	555	562	593	608	632
Head tube angle(°)	69.5	70	70	71	71	71
Seat tube angle(°)	73.5	73.5	73.5	73.5	73.5	73.5
Chainstay length(mm)	440	440	440	440	440	440
Wheelbase(mm)	1036	1053	1061	1066	1075	1096
Standover(mm)	692	715	745	775	805	827
Seat tube length(mm)	360	395	440	470	510	530
Fork length(mm)	395	395	395	395	395	395
Head tube length(mm)	121	139	147	175	191	217

How to read a geometry chart

Stock build

9 parts

Drivetrain

Shimano EF500

Shifter

Shimano Altus

DerailleurActuation type Mechanical

Shimano Tourney FD-TY710

Derailleur

Shimano HG200

Cassette

KMC X8

Chain

Shimano Tourney

Crankset

Wheels & Tires

Specialized Roadsport

Tire

Cockpit

Specialized Flowset

Stem

Seatpost & Saddle

Specialized Bridge Sport

Saddle

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Manufacturer

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Quick answers

Which size or configuration labels have geometry for the 2021 Specialized Sirrus 1.0?: Geometry is listed for XXS, XS, S, M, L, and XL.
What are the reach and stack of the 2021 Specialized Sirrus 1.0 in size M?: In size M, reach is 398 mm and stack is 593 mm.
What is the head tube angle of the 2021 Specialized Sirrus 1.0?: The head tube angle is 71 degrees in size M.
What does the 2021 Specialized Sirrus 1.0 ship with?: The stock build includes Shimano EF500, Specialized Roadsport, Specialized Flowset, and Specialized Bridge Sport.
Which years of the Specialized Sirrus are on Quiver?: Quiver has the Specialized Sirrus for 2021, 2023, 2022, 2020, 2019, 2018, 2017, 2015, 2014, 2013, 2012, 2011, 2010, 2009, and 2008.