Adding water into tyres - Blackbourn 456

By: Rob Blackbourn

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breakdown breakdown

The old foe, ‘unintended consequences’, seems to lurk in the wings waiting to leap out and cause you harm

In my parents’ day, Melbournians heading to Bonnie Doon to soak up its summer serenity faced a couple of hundred kays’ drive along the old Maroondah Highway with a climb over the Great Dividing Range thrown in just to make sure they were paying attention. As well it was odds-on that there would be a flat-tyre stop or even a bonnet-up cool-down break when the effort of dragging the old caravan over the Black Spur overpowered the cooling system.

As marvelous a thing as the grey-motor Holden was, early examples were well represented among the bonnet-uppers. Because the General had skimped on the original-equipment radiators they were inclined to boil if you worked them hard on hot days. This was underlined to me one January in Alice Springs years ago after I noticed something odd about an FE or FC Holden ute I borrowed. The group of warning lights on the instrument panel had, of all things, a corn-plaster stuck over the ‘Temp’ light. Having noticed something similar a couple of days earlier in another FE or FC – a bit of insulating tape or whatever in the same spot – I decided to make enquiries. The owner said that the ‘Temp’ light was irritating because it came on so often. He explained that you covered the light and made sure you topped the radiator up regularly. Then if you saw a warning light come on, you took notice of it because it meant you were low on oil or you’d broken a fan-belt.


It wasn’t as though overheating was confined to early Holdens and the likelihood of having to dig the spare tyre out of a fully loaded boot beside the highway applied equally to drivers of all makes until not that long ago. Personally I credit Michelin as the game changer for its pioneering role with steel-belted radials. While the early Pirelli Cinturato radials looked sexier than a Michelin X with the classic ‘Stop’ pattern tread, Michelin’s reassuring steel belts were the deal-maker for me. With ‘Michies’ all round punctures became history for me, whether commuting or trying for a personal best time from Melbourne to Brisbane up the Newell.

Puncture mitigation was actually already on my agenda when I was only about 13 following my experience ‘helping’ a bloke fit a tractor tyre by handing him tools. After he mounted it – it was one of the big rear tyres – he surprised me by partially filling it with water before finishing off by inflating it with air.

It made perfect sense once he explained that the mass of water in the rear tyres boosted the tractor’s stability on slopes by lowering its centre-of-gravity while also counterbalancing loads in the loader bucket up front. The mass of water in the tyres also gave better traction. By way of a little bonus he said it also slowed the rate of air loss through small punctures.

With my junior-peabody lateral-thinking capacity highly stimulated I took my new learnings home to apply them to my trusty bicycle, an old Barb semi-racer with Sturmey-Archer gears. The novelty of patching frequent punctures had worn off, and although I had no front-end loader-bucket issues, who wouldn’t go for the improved traction benefit while also extending the time between repairs?


After a week or two of riding my now fully hydrated bike to school each day, the jury was still out on whether my corner speeds were rising through enhanced grip; two things were obvious though – tyre-pressure was holding up longer despite multiple patches on the tubes but, sadly, the bike was noticeably heavier to ride up hills. I was mulling over these matters as I formed up with my Year 9 mates in full uniform for the Monday morning assembly in the school quadrangle. With the oath recited and the flag saluted we began marching off in house-groups, boys first, girls following, to Colonel Bogey or similar. We were second away, following the girls of the leading house as they rounded the quadrangle corner and began to pass the bike-sheds…


Chaos broke out as the leading ranks of girls scattered, screaming, after copping a soaking spray of rubber-flavoured water. Although investigating teachers established that the attack was clearly launched from behind a bunch of water soaked bikes, they assumed the offender had scarpered during the confusion.


From Unique Cars #456, Aug 2021

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