Two road frames can have exactly the same reach and put the front of the bike at very different heights. The medium 2021 Giant TCR Advanced SL Disc 1 and the medium 2027 Canyon Endurace CF SLX 9 Di2 records make a useful example: both list 388 mm of frame reach, but the Endurace has 41 mm more stack.
That is a substantial difference in the frame’s starting position. It does not mean the rider’s hands will be exactly 41 mm higher; the cockpit still matters.
The numbers behind the difference
These are the specific builds and medium sizes preserved in the Archive. They come from different model years, so this is a comparison of two frames, not a claim about how all road bikes have changed.
| Measurement | 2021 TCR | 2027 Endurace | Endurace difference |
|---|---|---|---|
| Reach | 388 mm | 388 mm | 0 mm |
| Stack | 545 mm | 586 mm | 41 mm higher |
| Wheelbase | 980 mm | 1,009 mm | 29 mm longer |
| Head-tube angle | 73° | 72.5° | 0.5° slacker |
Reach locates the top of the head tube horizontally from the bottom bracket. Stack locates it vertically. Look at those two coordinates together: in these charts, the Endurace’s head-tube top sits directly above the TCR’s when both frames are aligned at the bottom bracket.
Check the calculation
Stack difference: 586 − 545 = 41 mm. Reach difference: 388 − 388 = 0 mm. Wheelbase difference: 1,009 − 980 = 29 mm. These are direct subtractions of the recorded measurements, with no estimated dimensions added.
Why equal reach does not guarantee equal fit
Canyon’s geometry guidance distinguishes frame stack and reach from the position where your hands actually hold the bars. Stem length and angle, spacers, handlebar shape and hood placement all contribute to that final position.
Our inference from the two charts is narrower: the Endurace offers a taller frame starting point at the same horizontal reach. Whether that helps a particular rider depends on the position they need and the adjustment available on each bike.
The wheelbase and steering angle also differ. Matching one fit coordinate therefore does not make the two bikes geometrically identical. Nor do these numbers establish which bike rides better; this comparison includes no ride test.
Use the chart before choosing a size
If you are moving from a bike that fits well, record its frame size and cockpit setup. Compare both stack and reach in the candidate frame, then check whether its cockpit can put your hands where you want them.
The practical lesson from this pair is simple: a matching reach number is a useful starting point, but you still need the vertical coordinate. “Medium” by itself answers neither question.
Open the TCR geometry chart and the Endurace geometry chart to check other sizes. Select the actual published size before using the Geometry Analyzer.
Sources
- Giant: 2021 TCR Advanced SL Disc 1 — manufacturer geometry chart; the medium values also match the Velopedia record. The regional page is used for geometry, not U.S. pricing.
- Velopedia: 2027 Canyon Endurace CF SLX 9 Di2 — the archived build and size chart used here.
- Canyon: road bike geometry explained — frame coordinates and cockpit position.