Racers and fit riders who want Giant's race geometry without Propel's deep tubes.
Giant's lightweight race bike: compact sloping top tube, sharp steering, and a fit that has been a stack/reach reference for a long time. Less aero drama than Propel.
Fast road riders who want Orbea aero. Orca if you care more about weight.
Aero Orbea race bike. Deeper tubes than Orca, same size run so many riders can twin the two on stack/reach.
Racers and fast club riders who want the modern Tarmac. If you came off an SL7, check that the stack/reach still matches your size.
The current Specialized race bike: lighter than SL7, still aero, and famously 'it just disappears' if the fit is right. Size by stack/reach — the 54/56 split is where a lot of riders hop.
| Measurement | StevensArcalis 2012 |  GiantTCR Advanced 2027 |  OrbeaOrca Aero 2022 |  SpecializedTarmac SL8 2025 |
|---|---|---|---|---|
| Stackmm | 562 | 562 | 542−20 | 544−18 |
| Reachmm | 393 | 393 | 388−5 | 384−9 |
| Head tube angle° | 73.0 | 73.0 | 72.8−0.2 | 73.0 |
| Seat tube angle° | 73.0 | 73.0 | 73.5+0.5 | 74.0+1.0 |
| Chainstaymm | 408 | 405−3 | 408 | 410+2 |
| Wheelbasemm | 1000 | 991−9 | 980−20 | 978−22 |
| BB dropmm | 70 | 67−3 | 68−2 | 72+2 |
| BB heightmm | — | — | — | 268 |
| Standovermm | — | — | — | 768 |
| Part | Arcalis 56 | TCR Advanced ML | Orca Aero 53 | Tarmac SL8 54 |
|---|---|---|---|---|
| Stem | 100 mm | 100 mm | 90 mm | 100 mm |
| Bar | 420 mm | 420 mm | 400 mm | 420 mm |
| Crank | 172.5 mm | 172.5 mm | 170 mm | 172.5 mm |
Is The Science Wrong? Which Bike Actually Climbs Faster? Global Cycling Network · 270K views ; 2022 Orbea Orca Aero Road Bike Review | *Aero Lunchbox Not ...
The Orbea Orca Aero is just sublime once up to speed; it cuts through the air with ease and holds momentum in much the same way as a time trial bike. Swapping ...
That spec retails for £8,250 and is said to weigh 7.16kg in a size 56. You can read Sam's full review here. The Specialized Tarmac SL8 will be at the ...
# Specialized Tarmac SL8 Expert #### VERDICT: - Very Good - Quite good - Not so good ### Specialized SL8 Expert: Ride The SL8 was noticeably comfortable, but there was a sense o…