Two used Hondas: £496,388.80

This is the 1983 factory NS500 triple that Freddie rode at Monza, Aderstorp and Imola. His other bike from that year, the only other example in the World, now resides in Honda’s incredible museum at Motegi. Spencer was the youngest ever 500cc World Champion in 1983 at just 21 years-old

The NSR250 is a 1985 example, the year that Freddie won the double 500 and 250cc World titles. Like the 500, it’s one of only two in existence with the other model now housed in the Honda museum. Says Freddie: ‘This is the actual bike I wrapped up the 250 Championship with a fourth place finish at Silverstone. Four out of my seven wins were on this bike that legendary ’85 season’.

Freddie winning at Monza on the 500. This was round three of the '83 series in what was to be a season long battle with Kenny Roberts

1985, Rothmans 250 action. Judging by the high kerbstones this is Kyalami in South Africa, round one of the '85 campaign and the first win for Spencer on the 250

The scary guard rails of Jarama in Spain. Round two. Carlos Lavado may have won the 250 race but Spencer took the top step in the 500s the same day

Assen 1985. The fourth of six back-to-back 250cc wins for Spencer

Slithering and wheel-spinning to fourth place at a very wet Silverstone. Anton Mang may have won the race but the title was Freddie's still with two rounds to go

Cresting the rise after Eau Rouge at the Belgian GP at Spa. Roberts was enjoying something of a purple patch at Belgium - this was the mid point of his three back-to-back premier class victories. Spencer was always there to pick up the points behind him, though

A specialist dealer in Japan is selling what are probably the rarest and most evocative bikes in existence. They only come as a pair and the price may be an eye watering £496,388.80 ($800,000 US) at today’s exchange rates but there’s no denying the desirability of these historic motorcycles.

They are Freddie Spencer’s title winning 1983 NS500-triple Honda and the legendary NSR250 from the now infamous 1985 season, the year Spencer clinched both the 250 and 500 World Championships – a feat never likely to be replicated as the rules were changed to prevent riders from undertaking this Herculean physical and mental task again.

The 1983 500cc battle between fellow American Kenny Roberts and Spencer was mooted as being one of the most epic Grand Prix seasons since the titanic 1967 scrap between Mike Hailwood and Giacomo Agostini. The '83 500 title would not be decided until the last race of the season. Ironically, Agostini was Kenny Robert's Yamaha team manager for the '83 season.

These two almost priceless bikes currently belong to a man (who wishes to remain anonymous) that Spencer owed money to. The bikes acted as a form of collateral. When the bikes are moved on some of the money will be placed in trust to pay for the education of Freddie’s kids.

We don’t know about you but if our kids were worth half a million we’d be flogging them straight away to park this pair in our garage.