Defining the optimal dimensions of a frame it’s always a fascinating challenge. Even more so is calculating the optimal measurements of the entire bicycle, that is, that set of geometries that lead to a total harmony of ergonomics and handling, from the saddle point to the hoods (hand points) and to the pedal (shoe points).
Traditionally, designing custom bicycles requires the physical presence of the cyclist at the manufacturer’s headquarters or the retailer, which can be limiting and can make the tailor-made accessible to a very small subgroup of amateurs, not only for economic reasons but also for logistics and time.
The world of bike fitting has developed over the years a series of “recipes”, empirical methods refined and handed down over the years, evolved as new equipment has entered the bike fitter’s study, but often oriented towards the ultimate goal of adapting the athlete to an existing frame. Usually, replacements and/or micro-adjustments of the saddle, stem and handlebars are proposed to improve the posture, rarely achieving perfection only when the starting point already falls within the ideal values… it is certainly not possible to compensate starting from a frame with inadequate measurements.
Here’s why sizing of the frame is important, whether it’s identifying the most suitable standard size or, better yet, starting from a blank sheet of paper and setting up the project for a new tailor-made special.
But what is Gregario’s proposal on this subject? Well, it all depends on your starting point…
Case A) Do you already have clear ideas?
Chances are you already have a trusted bike fitter or a dealer equipped and capable of defining your ideal contact points… or let’s say you have an old bike that fits you like a glove and you want to replicate that exact positioning on a modern monocoque but does not match with standard sizes… or let’s finally suppose that you already have your ideal measurements in your head because your great-great-grandmother told them to you in a dream. Well in all these cases no sizing method is necessary, you’ll just have to communicate us these essential data clearly, i.e. those reported in the following table in reference to the diagrams below:
| Xs |
Horizontal distance from BB center to saddle contact point
(approximately where the saddle is wide 70 mm) |
| Zs |
Vertical distance from BB center to saddle contact point (see above) |
| Xc |
Horizontal distance from BB center to hand contact point
(hoods, approximately at the point of support in the palm at the base of the thumb) |
| Zc |
Vertical distance from BB center to hand contact point (see above) |
| W |
Handlebar width (measured at the center of the controls) |
If necessary, also provide information on the driving style you prefer, so we will take this into account during the design phase to set the length of the stem. Our cockpit also provides the possibility of adjustment of the stem angle, but the basic reference is with horizontal stem (parallel to the ground) and any variations in the angle are intended for micro-adjustments (e.g. seasonal) as well as the saddle adjustments: up to ± 3 cm in height and the classic forward/backward depending on the chosen saddle model. These are the reference schemes for the measures to be provided if you already have all the tools to define them independently.
