When was the last TDF where riders were allowed to ride with no helmet?
Was this mandated across all grand tours at the same time?
Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It only takes a minute to sign up.Sign up to join this community
Helmets were entirely optional until 5 May 2003.
On 5 May 2003 the following rules were introduced https://web.archive.org/web/20160304090208/http://oldsite.uci.ch/english/news/news_2002/20030502i.pdf
During competitions on the road, a hard shell crash helmet shall be worn. Except where there are legal provisions to the contrary, riders taking part in international events for elite men of class 4 and above may, at their own risk, remove their helmet during the final climb when the finish of the event or stage is on or at the summit of that climb, subject to the following conditions: 1) the climb in question is at least 5 km in length, 2) the helmet may not be removed before the start of the climb,
3.2 Rider taking the start without the required helmet
- Elite men's road races in class 4 and above 200 to 10 000 [CHF fine], plus 50 points deducted from the UCI individual classification [a TdF win is 1000 points]
- Other cases: start refused
3.3 Rider removing the obligatory helmet during an event
- Elite men's road races in class 4 and above 200 to 10 000 [CHF fine], plus 50 points deducted from the UCI individual classification
- Other cases: expulsion from the race and 100
Therefore helmets were mostly compulsory, but elite riders could remove the helmets legitimately on a climb, however they had to be retrieved immediately by a team member.
This rule was certainly in place for 2003 & 2004 https://web.archive.org/web/20040804001045/http://www.letour.fr/2004/docs/reglement_us.pdf
This was changed either on 1 August 2004 (post 2004 TDF) or 1 January 2005
Except where legal provisions determine otherwise, riders taking part in UCI WorldTour events may, at their own risk, refrain from wearing a helmet during individual time trial races taking place entirely on a mountainous course. Every discussion regarding the qualification «entirely on a mountainous course» will be decided by the commissaires’ panel.
This meant that organisers COULD designate a climb where helmets were not required, but this was not necessarily the case.
It appears from video evidence that for 2005 helmets were optional on certain climbs, but from 2006 onwards this was no longer the case.
The provision was deleted entirely from 1 January 2015
Starting with https://en.wikipedia.org/wiki/Andrey_Kivilev
In March 2003, he crashed during the Paris–Nice race and subsequently died of his injuries. His death was the trigger for the UCI to implement the compulsory wearing of helmets in all endorsed races.
The UCI moved very quickly with a change in regulations:
After Kivilev's death, the UCI made the wearing of helmets compulsory. They had previously tried to introduce this requirement in 1991, but some riders protested this at the Paris–Nice race, so the rule was not introduced. The nature of Kivilev's death, in that he was a lead rider, in one of the top French cycling teams, racing in a top stage race, coupled with advances in helmet technology, brought the debate back to the fore and conclusively so for the UCI. Whilst many riders were initially still against compulsory helmet use, the UCI ensured the rules requiring helmets to be worn at all times would be in place for the 2003 Giro d'Italia, which started just eight weeks after Kivilev's death. Dissension to the rule was initially high, but the new rules were affirmed in October 2003. Whilst at first the rule was loose and not tightly enforced, especially on mountain-top finishes, it has since been enforced more strictly and helmet-wearing is now ubiquitous in the peloton.
I can't find specific mention of all Grand Tours, but a UCI rule change would apply to all UCI events. You could assume that helmets were officially mandatory in all UCI events after Saturday, 10 May 2003, the day the Giro started.
UCI regs of the day may be found here https://web.archive.org/web/20110623174023/http://www.uci.ch/Modules/BUILTIN/getObject.asp?MenuId=MTkzNg&ObjTypeCode=FILE&type=FILE&id=34028&LangId=1