Would a recumbent bike be allowed at an ultra endurance event? & Why is no one using one? When I look at ultra-endurance races, for example, https://www.transcontinental.cc/ I always think two things:


Wow! I want to do this
This is ideal for a recumbent bike! 




So, I wonder: Would this be allowed? I kind of assume there is no rule forbidding it so: Why is not everyone doing this? Recumbents are a lot more comfortable for long distance and at least in the flat they are a lot faster, two.

Rules for the transcontinental:


Ride from start to finish via controls listed here
No third party support, resupply or lodgings
No drafting (other than with pairs partner)
All forward travel must be self powered
Travel by ferries only by approved routes
All riders must maintain evidence of their ride
Inactive for 2+ days without contact = scratch
No insurance, no helmet, no lights = scratch
Riders must know and obey local traffic laws
Ride in the spirit of self reliance &amp; equal opportunity
The TCR is a race (strictly speaking a time trial).  In that specific case, Wikipedia states that recumbents and tandems are not allowed (no citation is given).  I suspect that races will either say that or have a separate category (as is the case for the race across America.  I can't find a definitive answer for the Race ACross Europe as the you appear to have to sign up to get the rule book, but I have found implications that they are allowed.

For the more generic events in your title (of which there are many more), the case is likely to be more permissive. The TransOz (certificate error) for example, is run under Audax Australia rules, which state "A  rider  may  ride  any  type  of  cycle  on  a  ride  provided  it  is  only  capable  of  being  propelled solely by human effort and complies with the road rules*." Many such events (1200km and above) are listed by the Randonneurs Mondiaux.

Wikipedia has a note of interest in the article on Ultra-distance cycling (the admittedly vague definition there includes much shorter rides than those in the question, right down to the sort of distances I ride). "There are no longer any true ultra-distance bike races (i.e., that are longer than 300 kilometres (190 mi)) that are affiliated with cycling's main governing body, the UCI" so we can't really blame the UCI directly for the lack of recumbents on such rides.  The oldest ultra-distance cycling event (Paris-Brest-Paris definitely allows them.  This isn't technically a race any more, but first place finisher is a prestigious position.



* From other context on the site, this seems to be referring to local law for road usage, rather than, e.g., the UCI rules for road bike races (which would forbid recumbents).