drilling lightening holes

[simonineaston]

When I was a teenager, it was commonplace to fit items that either came ready drilled or else one drilled at home to achieve a sense of lightness. Of course any benefits outside the arena of the race-track were imagined rather than measurable. Do you, dear reader, have any comments to make on the subject?

Holey Mackerel, Batman...

[TrevA]

It was common practice in the 70’s, though I never did it. A mate of mine drilled his brakes. One of them snapped going down a steep hill, sending him through some barbed wire into the undergrowth a la Jonny Hoogerland. He still has the scars to show for it, even though it happened 48 years ago.

[rjb]

google drillium theres some wonderful examples.
https://duckduckgo.com/?q=drillium&atb= ... &ia=images

[ed.lazda]

I'm sure that the old CTC magazine used to have a column filler called the "Drilled out tea-strainer" competition, for absurd attempts to make your bike lighter.

[jimlews]

Very pretty, but in reality, a silly idea.

[rareposter]

Cyclist Magazine did an article on it not long ago.

https://www.cyclist.co.uk/in-depth/drillium-bikes

There are quite a few pictures from the mid-70's of Eddy Merckx racing on drilled-out parts. There was one story that his bike would only last a couple of stages before needing to be replaced.

[danfoto]

I was disabused of the notion as a teenager when I was invited to weigh the swarf I'd produced and then consider by what percentage I'd reduced the weight of the bike ...

[Grandad]

I wonder what effect all the holes had on the airflow dynamics.

[danfoto]

I wonder what effect all the holes had on the airflow dynamics.

Oooooh. All those little eddy currents are bound to add up and cause increased drag. Especially in high humidity ...

[Audax67]

They might whistle and sound faster, though.

My understanding is that just as the rider causes 70-80% of the aerodynamic drag, the bike/rider combo would best be lightened by the loss of a few kilos of fat round the middle and/or taking a laxative in good time before a race.

[mattheus]

I wonder what effect all the holes had on the airflow dynamics.

In hindsight, we know they were mostly terrible for aero drag.

But I think we could learn from golf-ball dimples, which are aero - a dimple is heavier than a hole, but would still save a little weight, right?!

[cyclop]

Not sure dimples in golf balls are aero?Stability more likelysurely.Wouldn,t the drilled out rings be a total nightmare to keep clean?Mind you,if you can be bothered to drill them out in the first place......

[simonineaston]

Cyclist Magazine did an article on it not long ago.

Good article - nice photos

[pete75]

Replica of King Alf's TT Shorter. Note the derailleur cage. https://www.classiclightweights.co.uk/r ... ca-c-1973/



And one of the real thing

[jimlews]

There were two versions of that Huret Jubilee, both very light.
But the second, drilled version was about 15g heavier.
Evidently, they found that all those holes weakened it.

Caveat Drillium, or something.