BH Aerolight vs Specialized Tarmac SL9: which bike is right for you?

Compare ride character, intended rider, geometry, and fit. Add your measurements to see which bike suits you better and which size to choose on each.

Fit verdict: the frame positions are close, a few millimetres apart. The frame alone will not decide this; use your measurements to see which size and setup gets nearer to your position on each bike.

Compare them for meCompare geometry and sizes

In one look

BH Aerolight: race geometry. Specialized Tarmac SL9: race geometry.

  • The frame front of Specialized Tarmac SL9 is slightly higher, by about 3.6 mm. That difference alone does not settle your position.
  • The forward length of the frame is nearly the same across matched sizes.

These two split on cockpit; the sourced values are below. What each difference means for your size, your setup and the riding you describe is in the full comparison.

  • CockpitDiffersSource 1Source 2
    BH Aerolight
    Two-piece integrated
    Specialized Tarmac SL9
    One-piece integrated bar and stem

    A one-piece cockpit is cleaner and faster, but changing bar width or stem length means buying a whole new unit.

  • Price

    Specialized Tarmac SL9 is the dearer of the two, going by the cheapest build you can buy of each; BH Aerolight starts lower.

Subjective findings from independent tests on stock or near-stock builds. Tyres, pressure and size change how a frame feels.

We compare differences at frame and model level. Components, current price, and availability depend on the exact build and seller.

2026 • race geometry
BH Aerolight
Size guide and geometry for the BH Aerolight
2026 • race geometry
Specialized Tarmac SL9
Size guide and geometry for the Specialized Tarmac SL9

Fit and size differences

The matched frame measurements differ by only a few millimetres, so stem and spacer choices can matter more than the frame.

Typical difference across matched sizes: frame front height 3.6 mm, forward length 1.6 mm.

For a personal answer, the fit-and-size path uses your measurements to show only the relevant frame sizes. The full chart remains available as a reference.

View geometry for every size

How do BH Aerolight and Specialized Tarmac SL9 sizes compare?

See the closest size matches and the differences in stack, reach, and riding position.

BH Aerolight
XS
Stack 510.5, Reach 368.4
Specialized Tarmac SL9
49
Stack 514, Reach 375

Stack: 3.6 mm taller

Reach: 6.6 mm longer

BH Aerolight
SM
Stack 523.4, Reach 374.9
Specialized Tarmac SL9
52
Stack 527, Reach 380

Stack: 3.6 mm taller

Reach: 5.1 mm longer

BH Aerolight
MD
Stack 538.9, Reach 382.4
Specialized Tarmac SL9
54
Stack 544, Reach 384

Stack: 5.1 mm taller

Reach: practically identical

BH Aerolight
LA
Stack 554.1, Reach 389.6
Specialized Tarmac SL9
54
Stack 544, Reach 384

Stack: 10.1 mm lower

Reach: 5.6 mm shorter

BH Aerolight
XL
Stack 576, Reach 398.9
Specialized Tarmac SL9
56
Stack 565, Reach 395

Stack: 11 mm lower

Reach: 3.9 mm shorter

The same size label can create a different position on each frame. Stack and reach are one part of the decision; the personalized comparison connects them to your body and each bike’s ride character.

FAQ

Can the same rider take different sizes on these two bikes?
Yes. Frame labels are not standardized, so the same rider may need different sizes. This comparison deliberately avoids a generic matched-size answer and hands your measurements to Bike Fit instead.
Which frame has the higher front: BH Aerolight or Specialized Tarmac SL9?
The frame front of Specialized Tarmac SL9 is slightly higher, by about 3.6 mm. That difference alone does not settle your position.

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