drilling lightening holes
- simonineaston
- Posts: 8063
- Joined: 9 May 2007, 1:06pm
- Location: ...at a cricket ground
drilling lightening holes
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?
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
Re: drilling lightening holes
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.
Sherwood CC and Notts CTC.
A cart horse trapped in the body of a man.
http://www.jogler2009.blogspot.com
A cart horse trapped in the body of a man.
http://www.jogler2009.blogspot.com
Re: drilling lightening holes
google drillium theres some wonderful examples.
https://duckduckgo.com/?q=drillium&atb= ... &ia=images
https://duckduckgo.com/?q=drillium&atb= ... &ia=images
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway X2, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840
Re: drilling lightening holes
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.
Re: drilling lightening holes
Very pretty, but in reality, a silly idea.
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- Posts: 2046
- Joined: 27 Aug 2014, 2:40pm
Re: drilling lightening holes
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.
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.
Re: drilling lightening holes
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 ...
Re: drilling lightening holes
I wonder what effect all the holes had on the airflow dynamics.
Re: drilling lightening holes
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.
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.
Have we got time for another cuppa?
Re: drilling lightening holes
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?!
Re: drilling lightening holes
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
- Posts: 8063
- Joined: 9 May 2007, 1:06pm
- Location: ...at a cricket ground
Re: drilling lightening holes
Good article - nice photosCyclist Magazine did an article on it not long ago.
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
Re: drilling lightening holes
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
And one of the real thing
'Give me my bike, a bit of sunshine - and a stop-off for a lunchtime pint - and I'm a happy man.' - Reg Baker
Re: drilling lightening holes
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.
But the second, drilled version was about 15g heavier.
Evidently, they found that all those holes weakened it.
Caveat Drillium, or something.