How this site is researched

Most cycling sites will tell you Sa Calobra is 9.4 km, or 9.5 km, or 10 km; that it gains 668 m, or 654 m, or 682 m; that it averages 6.3%, or 7.0%, or 7.1%. All of those numbers are published somewhere. Almost none of them say how they were worked out, which is why they disagree and why you cannot tell which one to believe.

This page explains how every figure on the site is produced. It is linked from the foot of every page, so the other pages can stick to the riding.

Why the figures are measured

Everything on the site is worked out from measurement and from published sources you can check yourself: public datasets, official publications and operators’ own pages. The advantage is consistency. The geometry of a road, the altitude of a pass, the distance from a town to the foot of a climb and the rank of one climb against every other are all worked out the same way, for every road on the island at once, and checked again the following month.

When a page here describes a climb, it gives you what the road measures: its true gradient, its real steepest kilometre, and where it stands against every other climb on the island. A ride report tells you how a climb felt to one person on one Tuesday in March. These figures come out the same for everyone.

Where the numbers come from

Every climb figure on the site is produced by one script, run over the same two public datasets:

• Road geometry: the centreline of the actual road, from OpenStreetMap (ODbL). Using the mapped road instead of a GPS trace of somebody’s ride keeps a rider’s wandering line, stops and lost signal out of the numbers.
• Elevation: Spain’s national 5 m digital terrain model, IGN Elevacion4258_5 (CC BY 4.0 scne.es). Phone and bike-computer barometers are not used.

The rules the script applies are published in full on the climbs atlas, because two figures can only be compared when both were produced the same way. In summary: the list of climbs is drawn from OpenStreetMap by a query; roads tagged as closed to the public are removed before any route is worked out; elevation is sampled every 10 m; tunnels and bridges are interpolated in a straight line between their two ends, because a terrain model reads the mountain above a tunnel and the valley beneath a bridge; height gained is the summit minus the lowest point on the road, not a running total of every rise; and the steepest kilometre is the largest gain over any 1,000 m stretch, checked in steps of 10 m.

Every change made by hand to what the query returned, whether a rename, a moved start point or an exclusion, is listed on the atlas with its reason, row by row, so you can check which climbs are in the list and why.

How the figures are checked

A method can be consistent and still be wrong, so the figures are compared with independent sources and the comparison is published. Every pass here has an elevation tag in OpenStreetMap, entered by other mappers. Three summits were also measured from the Mallorca 312 organiser’s official GPX: barometric and GPS elevations recorded on the road, with no connection to the LiDAR terrain model. The full comparison table shows every difference, including the three that are more than ten metres apart and the one place the measurement disagrees with every published source.

How rankings and verdicts are worked out

Some things here are judgements rather than measurements: rankings, the difficulty index, which side of a pass to take, which climbs are worth a day. Each one is calculated from criteria published next to it. None is assigned by hand.

• The difficulty index is height gained squared, divided by ten times the length in metres. The formula is printed in full, so you can check it and disagree with it.
• A climb page’s verdict leads with whichever of three measures (height gained, steepest kilometre, length) that climb ranks highest on against every other climb here, counting each direction up a pass separately. If a climb sits mid-table on all three, the verdict says so. None of its inputs has anything to do with a commercial relationship.
• Editorial calls, such as what a region is best for or what the riding is like, are labelled as ours where they appear.

How the site stays up to date

Every fact here carries the date it was last checked and how often it is re-checked. Once that interval has passed, the page shows its age and points you to the source for the current status. Re-checking, which means re-reading sources and fixing broken links, is a regular part of the work, so the numbers stay current.

A check date tells you when somebody last looked. It does not tell you how long the thing was valid in the first place. An offer runs to a deadline, a timetable to the end of its season, a fares scheme to the end of its year, and the pages that publish them stay online afterwards, unchanged. So the dates a source gives for itself are recorded alongside it, and when the day you are planning for falls outside them, the page says so next to the figure. For example, if the race is in April 2027 and a discount code was advertised for bookings made by June 2025, you get the code, because it may still work, and you are told how old it is.

Anything that changes too often to keep current in the text, such as opening hours, live prices and road status, is not written into it. The page points you to a live source instead: an official feed or the operator’s own page. Where two authorities disagree, you get both, each with its name and date. The Formentor traffic restriction, for example, ends on 18 October according to the DGT and on 15 October according to the Consell de Mallorca. Picking one of them would claim a certainty that does not exist.

How the site makes money

Some links here are affiliate links: if you book a hire car or somewhere to stay through one, we may earn a commission, and it costs you nothing extra. Every one is marked at the point of the link, and the disclosure appears above the first on any page that carries them.

Commission has no effect on the content. No ranking, comparison, verdict or difficulty score on this site uses a commercial relationship as an input; they are calculated only from the criteria above and the measured figures. Where there is no partner in a category, the page says so and does not invent a recommendation. The full terms are on the affiliate disclosure page.

Corrections

Spot a wrong number? Every figure comes from a script and a dataset, so fixing the source usually corrects every page that uses it. Email hello@mallorcavelo.com.