Originally published at: World Triathlon Updates Hydration Rules - Slowtwitch News
World Triathlon has announced updated guidelines regarding the controversial hydration rules, aiming to provide additional clarity for professional and age-group athletes alike.
The rules, which came into effect earlier this year, limited the number and amount of liquid that could be carried within bottles both in front of and behind the rider. IRONMAN adopted these rules as well, adding further clarifying language around what constituted a bottle being mounted to a surface “around the steering axis.” But then the German triathlon federation DTU took it a step further, with nine additional pages of regulations on hydration carriers.
This puts everyone back on the same page — the announcement on the revised rules starts with “after extensive meetings with DTU, the World Triathlon Technical Committee, and the bike manufacturers’ industry, World Triathlon has developed a rule interpretation document on the World Triathlon Fairing rules.” It is expected that IRONMAN will follow suit, given the ongoing rules harmonization between IRONMAN and World Triathlon.
Here are the key clarifications made by the revised rules.
Handlebars and Attachments to Them
World Triathlon has officially adopted the extension rule that IRONMAN had previously gone through, prohibiting extensions from reaching beyond the leading edge of the front wheel. This measurement will include the absolute tip of the extension — meaning that if you have a Dura-Ace friction TT shifter, the end of that shifter is considered the tip.
All attachments — whether it be hydration, mounts, nutrition boxes, etc. — now must effectively fit within a box. It is our understanding that a measurement jig is being created so as to effectively create a pass/fail method of inspection. Those points of reference are measured from the lowest edge of the arm support, and must fit within a box that is:
- a maximum of 250 mm in the direction of the saddle
- a maximum of 200 mm in height
- no further than the foremost point of the handlebars or clip-ons
- a maximum of 20 mm from the highest point of the front wheel
Computers are specifically excluded from this measurement.
The other key clarification here is on anything mounted above the arms — it is specifically prohibited. The arms must remain uncovered at all times. Call it the Joe Skipper rule.
Hydration: Limits on Fluid Volume, Bottle Counts
The updated ruleset provides some further clarity on the front and rear hydration rules. Front hydration that mounts around the steering axis may not exceed 2 liters of total capacity. There is not a limit on the number of bottles used to reach that figure.
With rear carriers, there’s another imaginary 30cm x 30cm box that the mount, cage/carrier, etc. must fit into. Bottles are specifically excluded from that measurement. Athletes may carry a maximum of two liters of fluid across two bottles with an individual capacity of one liter. It makes things somewhat standardized.
We say somewhat there because, if you are an athlete with a bike that has frame hydration built in, your rules are different. Your frame hydration is limited to a total capacity of two liters. Crucially, though, you are not allowed to then have rear hydration carriers. Ventum One, Specialized Shiv Tri, etc. owners, be aware!
When Will New Rules Be In Force?
World Triathlon’s rules, although announced yesterday, are in effect as of April 15th. IRONMAN, in general, will give a notice period to athletes regarding rule changes such as these. We would anticipate that rules won’t take effect until 30 days after an announcement from the brand, making either races towards the tail end of May, or early June, as races where would expect to see these things evolve.

