Quiver

2024 Specialized Tarmac SL8 Pro Shimano vs 2026 Trek Madone SLR Gen 8

The M is the Trek Madone SLR Gen 8 size closest to your 54 Specialized Tarmac SL8 Pro Shimano. We match frame stack and reach. This is a geometry comparison, not a fit recommendation; stem, spacers, handlebars and saddle setup also affect your riding position.

What changes on the Trek Madone SLR Gen 8

Compared with the Specialized Tarmac SL8 Pro Shimano in 54, the Trek Madone SLR Gen 8 in M places the top of the head tube 6 mm lower and 3 mm further forward, relative to the bottom bracket. Its wheelbase is 3 mm longer, which can contribute to stability at speed.

Frame stack
−6 mm
Lower front end
Frame reach
+3 mm
Longer frame reach
Wheelbase
+3 mm
Longer: steadier at speed
Head angle
−0.1°
About the same head angle
Chainstays
±0 mm
About the same

The two frames

2024 Specialized Tarmac SL8 Pro Shimano (54)The Specialized Tarmac SL8 Pro Shimano frame drawn to scale.J 978

Only the Specialized Tarmac SL8 Pro Shimano is drawn. The Trek Madone SLR Gen 8 numbers we have for size M are missing the seat angle.

Geometry side by side

MeasurementSpecialized Tarmac SL8 Pro Shimano 54Trek Madone SLR Gen 8 MDifference
Reach381mm384+3 mm
Stack552mm546−6 mm
Head tube angle73°72.9°−0.1°
Seat tube angle74°not listed
Chainstay length410mm410±0 mm
Wheelbase978mm981+3 mm
BB drop72mm70−2 mm
BB height268mmnot listed
Standover768mm762−6 mm
Seat tube length473mm476+3 mm
Fork length370mmnot listed
Head tube length137mm136−1 mm
Effective top tubenot listed545

Differences are the Trek Madone SLR Gen 8 minus the Specialized Tarmac SL8 Pro Shimano. Full charts: 2024 Specialized Tarmac SL8 Pro Shimano, 2026 Trek Madone SLR Gen 8.

Where each sits in its class

Specialized Tarmac SL8 Pro ShimanoTrek Madone SLR Gen 8

AggressivePositionUpright
CalmSteeringQuick
PlayfulBalancePlanted

Each bike is ranked against the other road bikes on Quiver, on frame geometry alone. Not your hand position or ride feel.

What each ships with

The stock build of each bike's first listed trim. Parts that match are dimmed.

PartSpecialized Tarmac SL8 Pro ShimanoPro - Shimano Ultegra Di2Trek Madone SLR Gen 8SLR 7 AXS Gen 8
FrameSpecialized Tarmac SL8 FACTnot listed
ShifterShimano Ultegra R8170 Di2not listed
DerailleurShimano Ultegra R8150 Di2not listed
CassetteShimano Ultegranot listed
ChainShimano Ultegranot listed
CranksetShimano Ultegra R8100not listed
WheelsetRoval Rapide CL IIBontrager Aeolus Pro 51
TireSpecialized S-Works TurboPirelli P Zero
BrakeShimano Ultegra R8170 Di2not listed
HandlebarRoval RapideTrek RSL
SeatpostSpecialized S-Works Tarmac SL8not listed
SaddleSpecialized Powernot listed
Forknot listedTrek Madone Gen 8 one-piece

Know what is on every bike.

Add your bike to Quiver. Keep its parts, setup, and service history together, then share your build.

Explore the app
A Transition Relay build sheet: frame, fork, shock and drivetrainThe Relay’s ride photo galleryThe Relay’s ride spectrum and 2D frame geometryThe garage: five bikes and 99 recorded partsA Specialized Tarmac SL8 road build sheet