However it is easy to understand when there are two separate governing bodies involved. The FIM have always protected two and three wheeled sport (1909) and the FIA has (eventually) been there for the four or more wheeled folk (1898, but now 1935 rules).
Probably not wise for me to try to correct Malcolm, but 'Pedant' is my middle name ...
My notes suggest that the earliest records (1898-1904) were under the authority of the ACF. And yes 'F' is France. The AIACR was formed in 1904 (and included the USA) but didn't define rules for land speed records until 1908. The FIA did not come into existence until October 1946, but I'm not sure whether this was regarded as a new organisation or simply the AIACR renamed.
As for the FIM it was originally the FICM (also formed in 1904) and became the FIM in 1949. I am less sure of the details of its history though.
in facts, a lot of this comments are right....but I like to clarify some notes for better understanding...the whole history behind this association can really confuse....
first...four wheeler
the very first World Speed Record was set by a French motorist close to Paris....someone has to take care...the closest "organization" was the French automotive "club"...
by the way...first records was slower than the bicycle records....means human power.....to this time
there was not too much rules....for this first record attempt the distance was set to one kilometer...the racer was a electric vehicle...at high speed the battery didn't last much longer...there was also in the early days a mile to set a record....but the speed was so slow...that the record breakers didn't accelerate anymore...worse...they slowed down...so it didn't make sense to go over a longer distance....different in the US...kilometer...what's that....they knew miles....and the famous how much miles the minute became there very popular...
the first challenger was coming from Belgian....and very quick there was more "foreigner" going for the record....and this French "regulator" wasn't always fair....so in 1904 they changed the first time the name of the organization to get the whole automotive organization an international touch....also the US was included....
But there was still no proper rules....this organization done it very simple...due to missing rules the just said, yes we certify this record or they said no....simple....
sometimes the explanation why they didn't accept could be understand - like the attempt from one of the owners of Rolls Royce company....this fellow run downhill's...
but other nobody could understand....in 1906, Ormond Beach, Daytona....a steam car set some records...but they only accept the slower speed.....
so finally around 1908 they start to write the first proper rules....with the first major change in 1911...the two way records became the base to set a record...the last record under the old rule was set 1909 at Brooklands....at the same place...in 1914 the first two way record was set....this record was slower than the 1909 one way record...but it was now the bench mark...and it was the first record which run over the mile distance....
with this new rule in 1911 the discussion about the fastest began....reason....running in Europe the record attempts used the two way....in the US, here especially Daytona....the American Automobile Club still run one way....so a lot speed records....some of them faster than the official record was not certified from the still in Paris based organization....
in Europe the confusion wasn't better...in 1924 a record was only accept over the mile, albeit the kilo was faster...
when the tracks in Europe start to be too short for setting faster speeds, it was Segrave using the 1000 hp Sunbeam, who runs at Daytona Beach for the outright record...and the first two way record in the states....also the first over 200 mph....
not to much changes in the rule book....one was the turn around time....first 1/2 hour...later 1 hour....that the racer didn't need anymore a reverse gear.....and one percent rule...
after the war the organization was still the same and based in Paris....but they gave himself a more clear name....FIA....
to the two and three wheeler....the "motorcycle" organization was found later....the same year when the four wheeler changed their name for the first time...
but was not found to certify speed records...it was for the motorcycle races....the first world speed record was finally in the 20's announced....
after the WW II, when the AIACR became FIA, the FICM, that it matched, became FIM....but they was still two different organization, to today....
Both was still in Paris....but later they moved to a neutral country....Switzerland....a country with more or less no motorsport....
....and they was still (and always) rivals...
a good example for this was Craig Breedlove's 1963 record.....there was no category for this racer...not in the FIA nor in the FIM rule book....but the FIM accept this record...the first and last time a FIM racer was the fastest vehicle on earth.....
in 1964...the first jet car record accept by the FIA was Tom Green with the Wingfoot Express....when Craig set more records with the Three wheeler SoA the FIA accept this record, albeit this jet racer had only three wheels....FIA didn't like that FIM had the fastest on earth in his book....
With the jet engines in the record book....and the FIA understand that they can't compare apples with pears - means thrust power and wheel driven - they changed the rule book, not only in wheel driven and thrust power...they also changed the wheel driven....into N/A and Charged engines, also turbine and electric engine....in all the years before their was no
rule what kind of power unit they used....unblown, supercharged...doesn't matter...faster was faster.....combusting engine also got now displacement size, turbine and electric run under weight....they was not thinking that electric could run so quick...and that a turbine can became a very small power unit....
the outright record became the World Speed Record...the wheel driven was for a long time international records....
meanwhile, the 1 percent rule is history, also the wheel driven are again world speed records....
The FIM also done some changes.....the biggest was when they frozen the most of the records....their was so much confusion with the different kind of classes and configuration that they simple done a "cut"....some of the records was still the benchmark....other can't be broken anymore....because the category is now a new one with more or less different rules...so their are now records to the old and the new rules.....
hope this helps to get a better understanding for the "regulators" of the speed records