No Products in the Cart
The stack-to-reach ratio is one of the most valuable โ yet overlooked โ tools in bike fitting. It tells you how upright or aggressive your position will be on a given frame and helps compare geometries across bikes of different sizes, styles, and brands.
Stack = Vertical distance from bottom bracket to top of head tube
Reach = Horizontal distance from bottom bracket to top of head tube
Stack-to-Reach Ratio = Stack รท Reach
This gives a normalized indicator of a bike's fit posture โ useful across brands and frame sizes.
โ
Higher ratio โ More upright, comfort-oriented geometry
โ
Lower ratio โ Lower, aggressive, race-style fit
โ
Great for comparing road, gravel, endurance, or touring bikes
โ
Eliminates confusion between inconsistent size labels (like "54 cm" or "M")
Bike Type | Stack-to-Reach Ratio | Fit Style |
---|---|---|
Aero Race Bike | 1.35 โ 1.45 | Low, stretched, aggressive |
Standard Road Bike | 1.45 โ 1.55 | Balanced performance |
Endurance Road Bike | 1.55 โ 1.65+ | Upright, comfort-focused |
Gravel / Touring | 1.60 โ 1.75+ | Relaxed and upright |
Flat Bar / Hybrid | 1.70 โ 1.90+ | Maximum upright comfort |
๐ก For long-distance comfort, aim for 1.55 or higher โ ideally 1.60+.
Stack: 580 mm
Reach: 370 mm
S:R = 1.57 โ Comfort-oriented for long rides
Stack: 520 mm
Reach: 390 mm
S:R = 1.33 โ Aggressive, efficient but less forgiving
Stack: 610 mm
Reach: 360 mm
S:R = 1.69 โ Ideal for relaxed posture and long touring days
๐ Check geometry charts before buying โ donโt rely only on frame size labels
๐ Use S:R ratio to compare bikes across brands
๐ง Helps guide decisions on stem length or bar height adjustments
๐ฒ Especially important for gravel, endurance, and touring riders
If comfort is your top priority โ whether for commuting, endurance rides, or multi-day touring โ aim for a stack-to-reach ratio of 1.55 or above. It promotes a more upright position that reduces strain on your neck, back, and wrists, especially over long distances.
โ๏ธ While low-ratio frames work for racing, most riders benefit from a fit that balances performance with all-day comfort โ and S:R ratio is the key.