As always, it's the sound that gets you - the sharp, piercing crackle of the two-strokes, the extraordinarily aggressive bark of the MV Agusta's sensuously curved megaphones and the deeper rumble of the of the big Ducati V-twins.
Historic motorcycles speak to you in a way that modern racebikes simply aren't allowed to.
They're vibrantly, exuberantly, outrageously non-PC; they guzzle precious fossil fuels at a dizzy rate and the 'strokers, in particular, announce every blip of the throttle with a pungent blue contribution to global warming, even before they smite your ears.
These bikes take you back to a golden moment just before the first oil crisis, before motorsport became a business, when the world's best riders, mechanics and designers worked insanely long hours for peanuts to create the finest, fastest, most elegant motorcycles they could.
Today those bikes are revered as works of art, as well they should be; they are remarkably sophisticated mechanically but unbelievably primitive electronically. Not one is fuel-injected and there are no rider aids whatsoever - not even anti-lock braking.
And their riders were just as outrageous; they raced machines that were faster than their brakes, suspension or tyres could handle, riding by the seat of their leathers because they had to. The best of them developed a smooth, flowing riding style as a survival technique, a style that's held up as an example to wannabe motorcycle racers to this day.
They rode hard, played hard and broke a lot of bones - and even champions were often paid no more than beer money. That hasn't changed; most Historic racers pour a fortune of their own money into their sport to keep that spirit - and these iconic machines - alive, and to bring that spirit to the enormous crowds who turn out for Historic meetings all around the world - including South Africa.
But don't kid yourself; this is real racing. These priceless old bikes are pushed beyond breaking point and there are sometimes big crashes. There's less strategy and more racecraft than in today's racing but the competition is no less intense for that.
And so it was at the weekend's International Historical meeting at Killarney, the final round of the SA Tourist Trophy series. Former Grand Prix star Mick Grant put the ex-Barry Sheene 1983 Suzuki RG500 GP machine on pole with Gauteng's Marius Botha (1981 Suzuki GSX1100), and local riders John Kosterman (1981 Honda CB1100RC) and Tony Jones (1981 Cagiva Alazzurra 650) filling out the front row.
Manx GP star Maria Costello qualified her Steve Wheatman Suzuki XR69 1000F 14th, but the big bruiser went sick on the parade laps, so crew chief Paul Boulton promptly put her on Wheatman's RG500 Mk7. Costello, who'd never even sat on a 500cc GP bike before, went out feeling understandably apprehensive.
Local Vintage Superbike champion David Bolding's 1982 Suzuki Katana “Big Bertha” broke its chain before he'd completed a lap in qualifying and he had to start from the back of the 24-bike grid.
As the lights turned Botha got a perfect start to lead the field into Turn 1, but Bolding was taking no prisoners, slicing through the field to slot into third behind Botha and Grant by the end of lap one.
On the next lap he passed both to take the lead and Grant demoted Botha to third. Then it was all over bar the shouting as Bolding walked away to win by 17.127sec from Grant and Botha - who just held off a late charge from Kosterman to take third.
Costello made up two paces after a shaky start and was closing on Alan Westman home-brewed Yamaha SR500 single on lap four when the Suzuki's gear lever came adrift and her race was run.
The start of Race 2 was a ragged affair as Bolding muffed it badly and Neill Wilkie (BMW R100RS) jumped it - and then nearly stalled the big boxer! Botha got another corker, holding on to the lead until lap three, at which point Bolding blitzed through into the lead.
He was unable to press home the advantage, however, as Botha and Grant went with him, giving the large crowd a superb performance on three very different bikes.
Two laps from the end Grant got by Botha to make the final order the same as in Race 1 - just a lot closer.
Costello knocked four seconds off her best time in Race 1, moved up four places on the first lap, disposed of Westman on lap three and Simon Portlock's very neat SR500 two laps later to finish eighth.