Ensuring that your new Tarmac is properly fit to you is an important step in preparing for your first ride.  Your Authorized Specialized Retailer will be able to provide a basic fit, ensuring that you are able to ride your Tarmac comfortably and efficiently. Specialized also offers Retül Fit, a data-driven bicycle fitting tool designed to improve comfort, prevent injury, and increase performance.

Retül can help you estimate your Tarmac bike size and saddle height here

Frame Geometry

Detailed measurements can be found in the geometry chart below.

 Click here to expand...

Frame Size

Crank length165mm165mm170mm172.5mm172.5mm175mm175mm
Stem length70mm80mm90mm100mm100mm110mm110mm
Seatpost length300mm300mm300mm380mm380mm380mm380mm
Head tube length93mm102mm113mm131mm151mm178mm198mm
Head tube angle 70.5°71.75°72.5°73°73.5°73.5°74°
BB height 266mm266mm266mm268mm268mm268mm268mm
BB drop74mm74mm74mm72mm72mm72mm72mm
Fork length, full366mm
Fork rake/offset47mm47mm47mm44mm44mm44mm44mm
Front center572mm574mm577mm579mm592mm606mm613mm
Chainstay length410mm
Bike stand-over height723mm735mm746mm768mm786mm808mm834mm
Seat tube length435mm447mm458mm475mm496mm517mm547mm
Seat tube angle 75.5°75.5°74°74°73.5°73.5°73°
Top tube length (horizontal)496mm509mm531mm541mm563mm577mm595mm


The Tarmac's use of fully integrated cables within the bars, stem, and frame mean that it's important to determine your drivetrain first (electric or manual) before cockpit assembly.

After you choose your drivetrain, select the proper headset cover: 

  • Integrated Tarmac Stem with electronic shifting
  • Integrated Tarmac Stem with mechanical shifting
  • Universal cap for a standard stem and round spacers with either electronic or mechanical shifting

All three headset covers are included in the small parts box, or can be ordered as the plastic parts kit S202500009.

Lower headset cover-mechanicalLower headset cover-electricLower headset cover-non Tarmac stem

If the rider is using a Tarmac stem, there are three 10mm spacers and one 5mm spacer available. The upper headset transition cover is placed on top of the spacers (if used). There is no upper headset transition cover if the rider is using a non-Tarmac stem. These are also included in the small parts box and the plastic parts kit S202500009. These spacers can be used to fine-tune fit.

Upper headset cover5mm spacer10mm spacer

Stem adjustment

If you wish to install a longer or shorter stem on your Tarmac, the internally routed Tarmac stem is available in sizes ranging from 70mm to 140mm, with 6 or 12 degrees of rise. Contact your Specialized retailer if you wish to purchase an additional stem, or you can purchase one online at Please note that the Tarmac stem uses a non-standard torque pattern as shown below.  The upper bolts must be tightened and torqued so there is no gap at the top of the stem faceplate (1 in image below) before the bottom bolts are tightened and torqued.

Image of stem torque requirements -click to enlarge

After the stem is installed, the Tarmac uses a top cap (same part as the Venge) S182500012.

There are two stem cover options: open and closed. If a rider chooses to cut their steerer flush with the stem, they should use the closed stem cover. If the rider wishes to use an additional spacer above the stem, they should use the open stem cover.  Both Stem Covers are included in the plastic parts kit (S202500009).

Closed stem coverOpen stem cover

Saddle height 

To adjust the saddle height, begin by moving the rubber grommet up the seatpost to expose the seatpost wedge bolt.  Loosen the seatpost wedge bolt using a 5mm hex.  Apply grease to the seatpost wedge ramp faces and bolt.  Apply carbon paste to the seatpost at the clamping area.  Adjust the saddle height as needed.  Ensure that the seatpost insertion is within the range shown below.  Damage to frame and seatpost may occur if the seatpost insertion exceeds the value listed.  Torque the seatpost wedge bolt to 6.2Nm (55 in-lbf) and slide the rubber seatpost grommet back onto the frame.

SizeMinimum insertionMaximum insertion

Image of seatpost wedge -click to enlarge

Tire Pressure & Tubeless Conversion

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