ra new year and an old subject. regular readers will know of my predilection with the bicycle wheel, something that has been ongoing for a large number of years and fortunately doesn't surface in the post as often as it does in day to day life - otherwise i would have no regular readers at all by now.
however, this time we have a slight variation on the usual wheel trivia - the single speed. now for road bikes this is likely to consist of a fixed wheel, ie a sprocket firmly affixed to the rear hub where pedalling backwards simply makes the bike go backwards, or more likely, stops the bike quite quickly. on a mountain bike we're talking single speed freewheel or freehub. in the good old days of yore, rear hubs used to be threaded on the drive side onto which a multi-speed or single speed freewheel could be fitted. now almost every hub manufacturer worth its salt manufactures freehubs where the freewheel mechanism is built into the hub itself.
i was quite disappointed to discover that hope technology, who manufacture pretty high quality hubs (and disc brake systems) no longer manufacture threaded rear hubs. i found this out while trying to order replacement cartridge bearings for just such a hub. since they no longer manufacture the hubs i was required to dismantle the hub to find the bearing part number to order more.
anyway, i digress somewhat (nothing unusual there) but if you link to the ibis single malt review somewhere on this site, you will see that chris king hubs provided the rear single speed hub for the single malt by placing a single sprocket on a rear freehub with spacers either side and the regular lockring to keep it all in place. this, however, meant that the wheel still required to be built with a substantial dish on the drive side.
for the less well informed, dishing is the nomenclature applied to the fact that the spokes on the drive side of a rear wheel (road or mtb) require to be shorter, tighter and straighter than the spokes on the corresponding side. this is referred to as dishing and is so done to make space for the huge number of sprockets that have to fit between the frame dropout and the hub flange. however, squidge forward a few years and we discover that chris king hubs have redesigned their singlespeed rear hub to incorporate a smaller (shorter) cassette to comfortably hold one sprocket and relieve the wheelsmith of the duty to dish the wheel. incidentally, the splines on the freehub allow the sprocket to be flipped over and used on the other side to maximise wear on the sprocket teeth.
disappointingly, particularly if you live in the uk, the price has gone through the roof, meaning that if you fancy a singlespeed rear wheel built around a chris king hub, you should have very, very deep pockets (but i'll build you one if you want one).
it's not really a practical notion to have a 'fixie' on a mountain bike - offroad riding doesn't lend itself to not being able to back pedal occasionally, while trying to surmount a grassy hillock. road biking does, however, lend itself perfectly to fixed wheel riding - roadies have been doing it for years. in fact in years gone by, almost every roadie worth his/her salt kept a fixed wheel bike in the shed for winter riding. riding fixed is supposed to engender souplesse or, pedalling in circles. on a freewheel or cassette fitted bike, it's easy to take a rest and freewheel downhill for a rest. fixed wheel riding means no such intermission and you'll have to pedal until you stop the bike. in relation to this latter function, the law (in the uk at least) requires only a front brake on a fixed wheel machine, since to stop pedal or sharp back pedalling will also stop the bike, thereby fulfilling the need for two brakes.
anyway, to switch back to the notional subject of this particular column, many options now abound. there are even websites dedicated to this single speed fun and laughter, and particularly for the acquisition of the necessary hubs to build such wheels. (www.hubjub.co.uk) older road frames and even mtb frames were built with what are generally known as 'road dropouts' which refers to an almost horizontal slot for the rear wheel. there are even some that have adjustment screws fitted from the rear to ensure the wheel seats parallel in the frame.
it is just possible to fit a standard single speed hub into such dropouts because there is still a minimal amount of room to adjust the chain tension. on a derailleur setup, the rear mech takes up any chain slack - fit the chain too long and the jockey wheels and associated spring will wind up the extra links (though you might have a few problems when in the very small gears). however, on a singlespeed setup, the chain simply wraps round the front chainring and the rear sprocket. if the chain's too long, it will, as they say, hang loose. moving the wheel backwards in the droputs will apply tension to the chain, and hopefully the dropout is deep enough to take up all the slack, because removing another link may mean that it won't fit into the dropouts at all.
more recent road and mountain bikes are fitted with vertical dropouts, principally to ensure that the rear wheel cannot be fitted squint. however, this setup removes the option of tensioning the chain by moving the wheel backwards, since by the very definition of the word 'vertical' means that the wheel can only be moved up and down. so unless you're very lucky and the front chainring, the rear sprocket and the chainstay length all combine to allow perfect chain tension just by removing or adding a link or two, there is going to be a problem.
if we refer back to the ibis single malt review you should note that their method of chain tensioning was to fit an eccentric bottom bracket (similar in function to those fitted to the non-drive side of tandems) allowing movement fore and aft of the chainset to tension the chain. sadly, unless the bike frame has been built to accept just such an oversized bottom bracket, this is not a viable option for retro-fitting.
all is not lost, however, thanks to those clever people at white industries who have moved the latter option from the bottom bracket to the hub itself. their 'eno' hub (spell it backwards for a clue) has an eccentric built into the axle. once the chain is fitted and the hub is in the dropouts, loosening a couple of allen bolts allows the pivoting of the hub around the axle, thereby tensioing the chain and bringing singlespeed cycling to the masses in possession of frames with vertical droputs.
and just to provide even more variation, many of the hubs available (but excluding the frighteningly expensive chris king hubs) are of the 'flip flop' variety. since there is no dishing on the wheel, it is by definition, symmetrical, so it is possible to have two different toothed sprockets, one on each side, or to have a fixed on one side and a freewheel on the other, flipping the wheel when necessary.
but why pedal with one gear or with a fixed wheel at all? surely having up to thirty gears which display an incredible degree of efficiency and reliability is something that we should all aspire to? or even the internal hub gears provided by shimano and rohloff which maintain a parallel chainline with no messing and almost unfailing practicality (though the latter two build into rather heavy wheels which may not increase the overall weight of the bike, but do add considerably to the rotating weight).
well, in the short time i had to play on the ibis single malt, it was flipping brilliant. no gears to worry about, sheer simplicity and enough of a reduction in weight to get past the lack of gears. in short, it was great fun and much the same can be applied to road riding. condor cycles, surly, on-one and others provide singlespeed road and mountain bikes on the open market. fixed wheels are beloved of cycle couriers since it enables the elusive 'trackstand' when stopped at traffic lights.
singlespeeds are unlikely to replace the multi gear setups required in day to day and cross country mountain bike racing or in the tour de france and they're not really suited to very hilly terrain, but in the early part of last century, my wife's grandfather used to cycle from the oa round to the dairy at gruinart on islay, a distance of around twenty five miles - and the same distance home at night - all on a heavy single speed roadster, when there was realistically no option. cars were for the rich and farmhands were not in that category. if they could manage it then, there's no reason why the same can't be achieved today.
so building single speed wheels is likey to be something i will launch into just shortly. if you find yourself in need of a pair of wheels or even just the rear, feel free to get in touch.
rss stands for really simple syndication. what it means is that, when i update the post, i set up a brief description of what i've written, and using a newsfeed reader (on the mac, newsfan is a good one) you can be alerted when a new post is on the server complete with a link to take you there. if you're on the darkside (windows) try using newsgator
set your newsreaders to check http://www.ileach.co.uk/post/rss/index.xml and every time you scan the rss feeds, it'll tell you if there's anything new.
if you missed the ardbeg cycle jerseys, click here for a look see.
i had an e-mail from john houston of falkirk bicycle club whom i met a few years back cycling (he was) on a whisky/cycle trip to the island. since john has been gracious enough to link to the post, i am reciprocating. www.Falkirkbc.co.uk
this website got its name because scotland's graeme obree built his championship winning 'old faithful' using bits from a defunct washing machine.
on a slightly different note, my regular reader will have noted the addition of a 'colnago c40' rollover to the left. this contains a reprint of a recent article featured in cycle sport magazine, which they were very kind to let me present here (because i'm a colnago geek) there are also links to cycling weekly reviews of the colnago c50 and colnago dream b-stay. i have also found an excellent review of the colnago c40hp here
i have been asked to add the following link to the post by wheelygoodcause. they're a cycling club dedicated to arranging epic rides for charity and do not charge charities for the pleasure. They ride because they want to. here's the link.
Remember, you can still read the review of 'the dancing chain' the utterly excellent book on the history of the derailleur bicycle by clicking here
any of the books reviewed on the washing machine post can probably be purchased from amazon.co.uk or amazon.com
as always, if you have any comments on this nonsense, please feel free to e-mail and thanks for reading.
this column almost never appears in the dead tree version of the ileach but appears, regular as clockwork on this website every two weeks. (ok so i lied) sometimes there are bits added in between times, but it all adds to the excitement.
on a completely unrelated topic, ie nothing to do with bicycles, every aspect of the washing machine post was created on apple macintosh powerbook g4, and imac computers, using adobe golive cs and adobe photoshop cs. needless to say it is also best viewed on an apple macintosh computer.