Photo by Brian Wangenheim on Unsplash
Straight to the point A background in metrology — the study of measurement — means Dave Archer, President of UK-based Arch Design Works and designer of the Velo Angle system, knows more than most about what points are of interest when measuring a bike.
W
ithin Cycling, point definition is not
stack heights would allow simple translation from
trivial, as there isn’t universal
the BB.
agreement as to what locations should serve as references. Using the BB-saddle-handlebar/arm pad
The saddle reference is the most problematic corner of the triangle, as the appropriate spot is both difficult to reliably locate and difficult to
triangle as an example, the bottom bracket is the
agree upon where it’s located. Early conventions
only location that is universally defined.
like the saddle tip or in-line with the seat tube
Unfortunately, as it is not a point of rider contact,
were driven more by convenience than function.
it is the least functional of the three. This
More recent suggestions, such as a distance
illustrates the common situation where history,
from the tip as a proportion of overall saddle
convenience or other considerations influence
length, are improvements, but not directly tied to
convention.
anatomical features that determine position.
The bottom bracket is the logical origin for
Latest suggestions of referencing the saddle
dimensions convenient for frame selection.
at a particular width, (most published suggestions
However, the majority of riders seeking
are between 70 and 80 mm) appear a logical
professional fits will apply the results to existing
attempt at setting a more effective convention for
bikes. The ideal reference would be the surface
rider position, particularly if saddle changes are
of the shoe insole. While this may seem
contemplated. Figure 1 (next page) depicts a
impractical, a compilation of pedal/cleat and shoe
