Mostly we take multiple C100 masts as the reference of various brands as, in general, those represent the most accurate bend curve for those sails, which are designed to perform best on those C100 masts.
We also found quite big differences in tolerances regarding production with all brands.
Fluctuations of bend curves and stiffness from +/- 1-2 points (bend curve) prove that none of the brands are 100% consistent.
So we measure several masts per brand and take the average of those measurements into account when constructing the Mast Selector Matrix Tool.
In general brands don't have much interest in renewing bend curves year-on-year since compatability issues will arise across sail/mast combinations from previous seasons that will cause conflict for their regular customers.
We follow the market based on feedback we gather as well rumors we pick-up on upcoming changes. (Some of those are due to happen soon.)
When there are strong signals we will investigate deeper by sourcing product in the market and take measurements and update our mast selector using version numbers.
In general, to obtain correct data, ideally we would like to measure 3 of the same type of masts (since each brand face inconsistencies in production, to have an average result) although for practical reasons this is not always possible.
SPANNING THE SPECTRUM
We use 3 dots to mark the bendcurve of different brands to help clarify which bend curve is more preferable in marginal situations where one brand's bend curve is close to another category of curve.
We show 5 blocks representing the same curve color simply because all brands, including our own, will face prodution tolerances during production.
These variances are simply unavoidable and any manufacture telling you that they do not have a range of tolerances is not telling the truth.
In general these tolerance are acceptable in terms of performance, although specific brands want to claim differently.
PLEASE MOST OF THE PEOPLE MOST OF THE TIME
According to our knowledge, we feel about 90-95% of customers who purchased Unifiber masts are happy with the performance of their sails and have bought a product with a sensible average of curve characteristics to use on a range of sail brands they may buy in the coming seasons.
Additionally, windsurfers who compete or are heavily into sail tuning have options to tube their sails for specific conditions, e.g., for speed sails, in general a Flex Top mast for a Constant-Curve design sail can work beneficially in terms of performance.