ALPENDINGLE: The hour record; how to build a custom, alpine gear cassette for a vintage 8-speed road bike and a 3 gear dingle-speed that does the job.

On September 18 last year, Jens Voight set the the first of the new UCI unified-rule hour records riding 51.115km in an hour, on a standard endurance track bike.

We loved the hour record in the 90s because of Graeme Obree and Chris Boardman, pushing the limits of technique and equipment with extreme riding positions and masochistic training regimens. The whole thing eventually got so out of hand that the UCI took the record back to Eddy Merckx's 1972 mark of 49.431km. They reclassified the Obree, Boardman shenanigans as something called "Best Human Effort" and restricted further attempts to riders using equipment roughly the same as Merckx rode. The boffins migrated to the International Human Powered Vehicle Association, where riders using fully faired recumbents pushed the mark out to over 90km. Boardman set a new mark of 49.441km in 2000, riding a standard drop bar, wire spoked machine, to prove that it wasn't all about the bike and Ondrej Sosenka pushed it out to 49.7km in 2005, to prove that it wasn't all about Chris Boardman.

Since then, the hour record has languished with no one seriously interested in what had really become an artificially restricted record for replica vintage track bikes.

Voight's effort, his final retirement performance as a professional rider, launched new rules for the official UCI hour record. The new record is for distance travelled in an hour using a bike that is legal for track endurance events under the rules in effect at the time of the attempt. In a fair but confusing arrangement, some of Obree and Boardman's records were reinstated, including the 56.375km "superman position" record set in 1996, but Sosenka's mark was set as the one to beat for new attempts because his bike would have been legal under today's rules.

The new hour record allows riders to compete using standard modern equipment and you could say that the new mark was set using a standard, modern, top professional rider.

Wikipedia gives Jen's Voight as it's first example of a  Rouler, a french term for a particular type of rider. Sometimes translated as "all rounder" sometimes as "non-climber". A Rouler doesn't have the short term high power explosiveness of a heavy weight sprinter or more compact puncheur, and is generally not small enough to be a specialist climber. They can be great team riders, and sometimes pull off a win in a heroic breakaway or solo effort. Voight is 190cm tall, he's not the most technically perfect time trial rider, but what he can still do, at 43 years old, is wind up to maximum power and consistently stay there, hovering around the limits of his physiological performance for as long as he needs to, then launch a final drive into the red zone to reach the finish line on the point of exhaustion. And Jen's special talent is the eternal unmeasurable of cycling, the capacity for suffering. His famous saying is "Shut up legs!"

One for the Roulers! Voight's new hour record was a great mark for the end of a professional career and launched a stream of new competitors. So far 7 attempts have pushed the mark out by just under 1.5km, with more challengers lined up to try including Bradley Wiggens who is resting from the grand tours to concentrate on track and olympic riding.

My qualifications as a "non-climber" are more modest, and have less to do with innate physiology and more to do with an unmeasurable capacity for chocolate.

I've got a reasonable level of fitness in my 40s, and I've always had big legs. So with a bit of re-training, even though I hadn't done any regular riding for nearly 20 years, I was able to keep up with the group on weekend rides around the river loop. That's Brisbane's famous, and mercifully flat training ride for everyone. But I'm also 180cm tall, and I like to eat. My leg muscles grew with more riding, but despite my slimmer face I didn't actually get any lighter. That's OK riding on flat land because most of your energy is used overcoming wind resistance not weight, but when Brisbane riders get bored with riding round The River, the obvious next thing to do is ride up The Mountain.

Mt Coot-tha is not a particularly big mountain. The loop over the summit and back is 9.4km and climbs only 217m, but it is steep with sections over 20%. The infamous Tour de France stage on Mt Ventoux climbs 1617m over 21.8km but is seldom over a 10% gradient. Inevitably I started out with a patient friend who knew the way.

I started too fast and boiled over on the first steep section, climbing up to where the road branches to start the loop.  A rest and a drink and we rode on, and again in the last 500m of about 2km of hard climbing, where it suddenly gets even steeper, I had to give up and sit on the side of the road, physically unable to turn the pedals over.

Although my problem could probably be solved by not eating chocolate in front of the TV every night, I decide to see if I could fix it with Gear Theory for Bicyclists.

sheldonbrown.com can tell you all about shifting patterns and the trade off between Range and Gradation. Between having a gear high enough for the fastest and low enough for the steepest terrain you're riding over, and keeping the steps between the gears small enough so that you can always find the gear you want without breaking your rhythm. Modern road bikes go for the obvious, by simply putting more cogs on the rear wheel. This is possible through design improvements like the freehub replacing the freewheel, allowing the rear axel to be made longer without breaking, and trade-offs with durability and maintenance like using thinner more flexible chains so the rear cogs can be put closer together.

Modern bikes have up to 12 cogs on the rear wheel, but my 1994 Trek 5500 only has 8. With the mix of riding I was doing going from fast flat riding, straight to steep climbing with nothing in between, what I really wanted was a cluster of close spaced medium to high gears with one, low survival gear to get me over the hill. I needed old school alpine gearing.



Every part of your bike will eventually wear out if you keep using it. You can build a whole new bike one part at a time replacing them. But the parts that wear out first are the ones that move the most, under the greatest stress, while most exposed to the elements, the chain and the rear gear cassette. It's handy for bicycle cdd maintenance if you know how to check for chain and sprocket wear and how to remove and install a cassette.

If you know that, it doesn't take much more to built your own custom bicycle gearing system with a personalised choice of gear ratios.

There are a few different ways to describe bicycle gears including how far the bicycle moves for each turn of the pedals, and the size of the front wheel on an equivalent penny farthing. Sheldonbrown can explain it and even has his own system. If we're just comparing road bikes, so the wheels are all the same size, and we don't want to worry about crank length, it's probably easiest to just count the teeth on the front and back gears. Remember it's the ratio of the tooth counts that matters, the front divided by the rear. A 40T front cog with a 20T rear (40/20T) is the same gear as a 50/25T combination. Small changes in tooth count make a bigger difference when you are using smaller cogs. A 2 tooth change is a sixth of a 12T cog but only a fifteenth of a 30T.

I started with the 53T and 39T front rings already on the bike. A smaller cog at the front is a lower gear, slower but easier to pedal up hill. Theoretically you can get any size you want, but they mostly come in a few standard set ups and they're not all interchangeable. When I swapped the 12-21T rear cassette, that I had been using, for a wide range 11-28T cassette, I had a low enough gear with the 39/28 combination to get up the steep sections on Mt Coot-tha. But racing around on the flats I often couldn't find quite the right gear, or the gears I wanted were in the wrong part of the range so I had to change both front and rear cogs at the same time or run the chain across a big angle from small front cog to small rear cog, which can cause wear and skipping.

I also had a super high gear, 53/11 that was really only useful going down hill at over 60km/h. Although that is easily possible on the Mt Coot-tha descent, it is neither very safe nor legal. So by taking apart a couple of cassettes, I made up one with the gears that I wanted, where I wanted them.

The different sized sprockets on a cassette are usually held together with a long narrow screw which you have to remove. When you make your own cluster you don't have to screw it back together, just stack the sprockets and spacers alternately on to the hub spindle making sure the right side faces out and the splines line up with the grooves on the hub. Pay attention to the spacers because they may not all be the same size.

For me 3 is a magic number. A gearing ratio where the front cog has about 3 times as many teeth as the rear cog is a good, comfortable, flat land cruising gear.

After some trial and error, I ended up with a rear cluster of 13, 14, 15, 16, 17, 18, 21 and 28T. with the 53/39 front rings I can mostly cruise around on the big ring, playing with the closely spaced high gears, then drop the chain onto the small ring for the short hills near the river. When I get to the real climbing I put my head down, shift the chain onto the extra large rear cog, and grind till I get to the top.

There are a couple of reasons why it makes sense to have smaller differences in tooth counts between the smaller cogs in the rear cluster and bigger differences between the larger ones. One is the mathematical effect I mentioned above, a single tooth difference is a bigger proportion of a small tooth count than a larger one. The other is the different physics of climbing versus riding at speed. When you change down because a climb gets steeper, the load you are working against doesn't change because the combined weight of you and your bike doesn't change. But riding at high speed, most of the work is done against air resistance, when you change up to go faster the force you have to generate to go forward increases. If the gap between gears is too big you can find yourself spinning out in the lower gear but unable to keep pushing the higher one.

Sometimes I wish I had an even lower gear for climbing. But there is a physical limit to this game, set by the amount of excess chain your derailleur can take up (see here). Even though it's recommended not to shift into the small-small combination, with my set up I can do it without the chain going slack and falling off, I can just get into the the big-big combo without the chain being too short and seizing up or breaking something. I could take a risk and extend my gear range a bit further, if I could always remember not to shift into these extreme combinations, but I'm too likely to make a bad shift and have to stop and fix my bike, or walk home.

That was fine until I had to put my road bike into the shop to be serviced. I'm a pretty brave home mechanic, but I didn't feel like trying to get a worn headset out of a 20 year old carbon fibre frame. So while it was waiting for professional attention, I was left without a bike for riding the Cootha Loop.

In my previous experiments with 2-speed dingle gearing, I had only built bikes with a fairly small range between the high and low gear. I had been using 2 speed freewheels, with only a limited choice of sprocket sizes. By using a wheel with a multi-speed free hub and the same techniques I've just described, I could build a 2 speed bike with a high speed cruising gear for the flat lands around the river, and a super low climbing gear for the mountain.

Alpendingle Alpine-Gearing

The Alpen Dingle (actually a 3 geared "Tringle") has a 52 tooth large chain ring that pairs with either a 16 or 18 tooth rear sprocket to give a choice of two high gears for flat and rolling terrain. A 40/28T combination gives a low gear for climbing. You have to stop at the bottom of the mountain and change gears with a spanner of course, and again at the top when you are about to come down. The gears are matched so that the chain length is almost the same in the low and high gears. The axle can slide back and forth a little in the horizontal forks to accommodate the small differences.

Just check the brakes, and away you go. A couple of minutes behind, but at much the same a pace as I would be on my multi-speed road bike.

You can't get much simpler than that. Except that the modern track pursuit bikes being used in the new UCI hour record attempts are mechanically simpler than my dingle bike. Only one gear, no freewheel system and no brakes. The new bikes are more aerodynamic than the 1970s style wire spoked ones of the old record. But Graham Obree's rides showed us that even there, the rider is at least as important as the machine.

With all the advances in engineering and materials, training and sports science since Merxxs in 1972, there has been less than  6% improvement in the distance a top sports cyclist can ride in an hour. With new interest from some big name riders, it will be fascinating to see what happens next.