They are aero - they create a boundary layer of still air around the ball and extend its range massively.
drilling lightening holes
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Re: drilling lightening holes
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- Posts: 111
- Joined: 9 Jun 2022, 7:19pm
Re: drilling lightening holes
The nice boys and girls at GCN bought a tidy Triumph steel bike to see if they could ‘ride a 100 miles on a £100 bike’. Then their ‘tech’ chap proceeded to massacre it by drilling parts and, iirc, adding disc brakes . . .
Sacrilege.
Sacrilege.
Re: drilling lightening holes
As yoofs, me and John discussed drilling our frames to make them lighter.
We dismissed the idea as our frames would collapse!
It was me and John who fitted two sprockets to our SA3sp.
Remove the sprocket and the spacer and the cover, after buying two new sprockets, and a Huret Svelto rear mech, then with the spacer hard under you shoe heel, grinding it thinner using the pavement flagstones. Trial and error produced it thin enough.
Fit the two sprockets - big one dished inwards - then the spacer - the the small one dished outwards - then fit the outer clip.
6sp bikes!
https://velobase.com/ViewComponent.aspx ... c&Enum=108
We dismissed the idea as our frames would collapse!
It was me and John who fitted two sprockets to our SA3sp.
Remove the sprocket and the spacer and the cover, after buying two new sprockets, and a Huret Svelto rear mech, then with the spacer hard under you shoe heel, grinding it thinner using the pavement flagstones. Trial and error produced it thin enough.
Fit the two sprockets - big one dished inwards - then the spacer - the the small one dished outwards - then fit the outer clip.
6sp bikes!
https://velobase.com/ViewComponent.aspx ... c&Enum=108
Mick F. Cornwall
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- Joined: 10 Jul 2014, 1:12pm
- Location: Norfolk
Re: drilling lightening holes
That doesn't look like the bike Engers rode when he broke the 25ml record - I think I have a Cycling mag article tucked away somewhere.
IIRC it had the front brake caliper behind the fork crown (for aero reasons). Maybe the mag feature is online?
IIRC it had the front brake caliper behind the fork crown (for aero reasons). Maybe the mag feature is online?
Re: drilling lightening holes
On a safer note, I used to carry a spanner around on tours to deal with the struggle to get off a freewheel if a driveside spoke went. I did a lot of weight reducing on the spanner and took about a third of its weight away. It just wasn't designed with weight saving in mind, so it was overbuilt. On the bike itself, I have never liked having my hands on the last two inches of the drops, so I have always sawed that excess off. On a straight barred tandem I took a bit off the width of the bars because I hate having my hands so far apart. But that is just getting rid of unused metal, not a weight loss exercise.
Re: drilling lightening holes
Alf had many bikes during his career and broke the 25 mile record several times. Which are you talking about?fastpedaller wrote: ↑1 Apr 2023, 9:45am That doesn't look like the bike Engers rode when he broke the 25ml record - I think I have a Cycling mag article tucked away somewhere.
IIRC it had the front brake caliper behind the fork crown (for aero reasons). Maybe the mag feature is online?
'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
"Adding lightness" used to be a much used phrase, but drillium doesn't add anything, it just takes metal away. That's why true weight-weenies and gram-counters add real lightness by filling the holes with helium, or even better, hydrogen.
Re: drilling lightening holes
There's a bloke on Twitter that goes by the name @TheCampagKid who does some very nice restoration jobs but does like his drillium (I'm not a fan myself). I thought I had a non-Twitter link for him but I can't find one now. Anyhoo, here's an example of his work (picture linked from Twitter):
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute.
Re: drilling lightening holes
Great photo.
One safety point that I don't think has come up: the weakness caused by drilling holes in solid metal roughly follows what it looks like, but the same isn't true of composites such as carbon-fibre-reinforced plastic...
Jonathan
One safety point that I don't think has come up: the weakness caused by drilling holes in solid metal roughly follows what it looks like, but the same isn't true of composites such as carbon-fibre-reinforced plastic...
Jonathan
Re: drilling lightening holes
Imagine cleaning that stuff! You'd be faffing about with cotton buds for ages. Maybe its an alternative to going indoors and talking to the wife.
Re: drilling lightening holes
Gear cable needs an end crimp!
Re: drilling lightening holes
Think of the weight saving though!
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute.
Re: drilling lightening holes
Surprised at the weight penalty from those tied and soldered spokes.
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