- Spect Mira
- 48
- Stack 508, Reach 362
- Trek Madone Gen 8
- XS
- Stack 507, Reach 370
Stack: practically identical
Reach: 8 mm longer
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: these frames put you in effectively the same position, so geometry will not decide this pair. What can: the sourced differences below and, once you enter your measurements, your size and setup on each frame.
Spect Mira: race geometry. Trek Madone Gen 8: race geometry.
The frame standards line up and we hold no sourced weight or performance claim that separates them. What is left to decide is your size and setup on each frame.
Trek Madone Gen 8 is the dearer of the two, going by the cheapest build you can buy of each; Spect Mira 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.
Start with the decision you are making. We will ask only for the details needed to answer it.
Step 1/1
Your answer decides which questions follow and what the result focuses on.
Geometry does not separate these bikes: matched sizes put the rider in effectively the same position.
Typical difference across matched sizes: frame front height 1 mm, forward length 0 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.
See the closest size matches and the differences in stack, reach, and riding position.
Stack: practically identical
Reach: 8 mm longer
Stack: 11 mm taller
Reach: practically identical
Stack: 4 mm taller
Reach: practically identical
Stack: 3 mm lower
Reach: 3 mm shorter
Stack: 6 mm lower
Reach: 7 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.
TrainCraft plans
Set a goal, choose when you can ride, and get a structured plan that adjusts as your fatigue and availability change.