Saturday, 3 September 2011

Bambi Bike

Aero wheels, 1890s style. Note the back-to-front saddle for better aerodynamics
Historically, I’ve only ever been fit when commuting under my own steam.  Running-wise, I feel pretty ropey at the moment  but at least I’m managing to ward off total decay by  settling into a regular 3 days / 100 miles per week cycling commute.  On the way in, it’s a net-downhill blast, aided by a generally favourable tailwind and a generous 75 mph speed limit on the Forth Road Bridge cycle track (or is that 7 a continental 1? – I can’t tell, it’s just a blur as I pass).  Things are tougher on the way back but it’s all “character-building”.  No real hills to speak of, unless I view my GPS output in potrait rather than landscape, but gradients seem to affect speed more on a bike than on foot.  Anyway, Sara’s unbounded  joy in welcoming daddy’s return soon makes up for those enleadened thighs.
I’ve been looking seriously into bike design over the last few weeks and it amazes me how little things have changed in more than a century, ever since Lawson's "Safety bicycle" (as in the standard design of today, where the rider sits at a low-ish height between the two wheels rather than balancing precariously 5 feet up on top of a "Penny") was popularlised by John Starley in the 1880s.  That’s maybe partly due to the UCI’s luddite stance in banning anything innovative from bike racing (when a punter turned up at a race on a laid-back recumbent in the 1930s and thrashed the World champion, that style of bike was banned forever to prevent further embarrassment) but it must also be due to the fact that the basic “safety” bicycle is just a brilliant design.  There are hardly any decent books on bike engineering nowadays - maybe there’s just nothing worthwhile left to invent?  One of the earliest books on the subject and possibly the best, is “Bicycles and Tricycles” by Archibald Sharp from 1896, a masterpiece which I’ve been delving into a lot recently for inspiration.  And in case you thought that those poncy time-trialists’ aero wheels were a recent innovation, think again – they were thought of 120 years ago and are featured in Sharp’s book.
Pannier rack goes Hi-tec with tights and superglue
I’ve got the DIY bug at the moment and have decided to build my own bike.  This won’t be anything too radical (for the first one at least!) and I’ll be going for a tried and tested “safety” road bike .  My frame will be bamboo – a superb natural structural material  that I became much impressed with on a visit to Hong Kong two years ago – there it is used to scaffold 100+ storey buildings.  I’m convinced that a bamboo bike lighter than any carbon one under £3k is possible.  And yes, bamboo bikes are covered by Sharp too.  To my mind, the key production problem to be resolved will be the frame joints.  Looking around the ‘Net, quite a few folk seem to be into bamboo bikes (including some high-end commercial outfits) and the majority successfully use carbon fibre/epoxy or hemp/epoxy joints.  I may do that too but I also want to try out my own innovation – the nylon tights/superglue joint.  I was a bit worried these might end up too brittle but they worked great on my garden cane pannier rack (well, one step at a time!), providing tough and (so far) durable joints.

Poundland bounty - bike materials and a book on what to do with the finished product
My first rule of DIY is to see what’s in Poundland, so off I trotted.  I picked up a few bamboo torches – ideal for my bike frame tubes, lots of superglue ( 1/20th  the price of branded stuff but every bit as good) and, as an added bonus, Chris Hoy’s autobiography.  I missed this one first-time round and presumably it’s now doing its final death-rattle round the bargain shops before being pulped.  Still, all in all, not a bad read for a pound
My next steps will be to work out dimensions and build some form of jig to ensure that I can construct the frame accurately.  And of course, the bike will need  will need some’ metal bits’ too, so I’ll see what I’ve got in the garage and then off to the Bike Station and Fleabay for anything else.
My work has now rolled out its Cycle to Work scheme, which has to be signed up to in September.  You save the tax and NI, and pay by deductions from your salary over 12 months.  The down-side is that you have to buy via Halfords.  Still, £50 a month would get me a £1k Boardman Team Carbon which I could use as my daily hack to work, saving my bambi bike for weekend posing.

1 comment:

Ali said...

Love it - I now have the image in my head of you pedalling furiously over the Forth Road Bridge, pursued by a gang of giant pandas.