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The religious wars continue…
The Daily Volk has been whingeing about bicycles a lot recently but their latest moan is about speed bumps to slow down bicyclists on a back alley in Islington. Apparently local pedestrians have complained about the danger posed by “speeding cyclists rampaging” down the street. Apparently.
from The Daily Mail, 25th Sept 2009
Hells teeth…! Just look at them, would you? Pedestrians and cyclists battling for space on a thronging suburban thoroughfare… LOOK! Look at those “rampaging” cyclists!
Can “throng” be used as a verb?
r:B
Entire frame, without any attachment, F, fourth line, F clef; handle-bar Bflat under first ledger line, G clef; a piece of tubing C; brake handle, D; front fork, Eflat; right crank with a portion of attachment to sprocket wheel, Esharp; left crank only, F; handle-bar post, G; saddle post, A; brake-rod with brake, Bflat; sprocket wheel, C; front hub, D; spokes, E on the first line and its octave above; step F; front axle, G.
“The Music of the Bicycle”,
Musical Standard, November 1897
r:B
I remember having a leather hub cleaner on my three-speed bicycle some years ago, before it eventually rotted and fell off along some country lane. I’ve never seen them for sale anywhere – even the ugly, modern, toilet brush alternative is difficult to track down. So I made some…
I was so pleased with the results that I drew up a pattern (PDF) for public dissemination…
Simply find an old leather belt, cut some straps, lube them lightly with machine oil and affix them to your hubs. Job done…
r:B
Whilst perusing some fascinating 19th century material on chainless bicycle solutions, I happened across this drawing of the Hildick Chainless Bicycle Gear.
The Hildick Chainless Bicycle Gear (1898)
Given the main reason for replacing the bicycle chain is to obviate a messy, potentially dangerous and fragile drive system, the decision to opt for a large, open gear and all the greasy, moving parts that entails seems somewhat eccentric. In case you haven’t worked it out, the inner ring of the mechanism is fixed and the outer ring runs on bearings, something like a giant freewheel. In its favour, it looks as though it could have been retro-fitted to any standard, chain-driven bicycle.
It made me reflect on something I’d once read Dean Kamen, inventor of the Segway, say about the South Pointing Chariot invented by the ancient Chinese – a cart which, through an assembly of differentials, pinions and annular gears, would always point an indicator stick South, no matter in which direction it was driven. The odd thing is that the Chinese had already discovered the magnetic properties of lodestones and thus had a ready method of detecting North even when unable to use astronomical navigation. They had essentially reinvented the problem! Now, if only someone had pointed Mr Kamen towards the bicycle he might have saved himself a lot of bother.
To me, the most elegant solution for a chainless bicycle offered in the late 1890s was the bevel-geared shaft-drive system by Sterling and others in the USA, possibly because it looks so much like the hand-operated food mixer I remember mentally disassembling as a child. Unfortunately, it would probably have limited serviceable life due to gear wear – the bevelled teeth providing such a small point of contact that they would be unable to take the full leverage of the crank over a prolonged period – but it does offer some inspiration.
The Sterling bevel-geared Chainless Crank Bracket (1898)
What if the crank axle were a fixed worm gear so that there was more metal in constant contact with the drive shaft and hence a more evenly spread load? This after all is the chief benefit of a chain – the spread load of numerous teeth being driven at once. Would the gear ratio be too low to be practical? It would certainly take up less space in the bottom bracket…
If we revert to a chainwheel and chain, with the appropriate constraining rollers, there is no reason at all we could not have a chaindriven system which was completely enclosed in the chainstay!
Any thoughts?
UPDATE: Appears that UK company Zero Bikes have already resuscitated the shaft-driven chainless bicycle. I really should keep up to date!
UPDATE 2: OK! There’s also Dynamic Bicycles in the USA. Jings! I’m so out of touch!
UPDATE 3: Yes…and also from Beixo in the Netherlands. This post is now closed!
r:B
Given all the videos that are being posted, I felt a special mention was needed for all the viewing pleasure provided by Marc at Amsterdamize.com…
Thanks and I look forward to whatever you’ve got up your sleeve for 2009!
r:B
