Direction.

A few posts up i was waffling on about a new bike. Those who know me well might be a bit surprised by the direction i've been heading this last year. At least in terms of bicycle drive chains that is!



First came a 27 geared road bike, rapidly replaced by a better fitting, 20 geared one. Then the Vertigo arrived with 6 speeds. As a result of this i did a bit of metal work and slotted 5 Dura ace gears onto the Jones - to tame the longer fire roads of the Kielder 100 mile race.



Since then, i have decided that a 9 speed race bike is a must.

Why the surprise? until last year, i hadnt ridden let alone owned a geared bike for around 10 years. That is a long time to be singlespeed or fixed only, but my riding style (lumpy pedal stroke and all) and the scottish riding environment (gritty, wet and abusive as it is) meant that it made perfect sense.

So why all the gears? for a similar amount of effort you can go faster or further in an allotted time. Thats all. I have been fortunate enough to avoid any injuries or problems that meant a singlespeed drive chain limited me, i just might be slower or i might need to get off and walk on the steepest pitches. Or, i might get fed up doing the ridiculous spin on the flats. Other than that, no major issues. It was the road bike that reignited the desire to have gears again. Then barrelling down hill on the Vertigo opened up a new way of viewing terrain and what i could do on that terrain.

So here we are.

I am pretty convinced that 10x1 drive chains will become prevalent over the next 2 or 3 years. The broadening of the rear gear spread has already meant riders are often dropping at least 1 chainring, if not 2. The big players - SRAM and Shimano _ are even offering 2 ring specific cranksets, often with narrower chainline. This is a good thing, not just for reducing the amount of redundancy in the drive chain, but also it makes for a better chainline with 135mm spaced rear ends, and thus more efficient shifting and less wear and drag. Shorter, tighter chains provide snappier shifting. What is not to like here?

If you move to having one chainring, and dont mind dropping the super low gears mountain bikes now have (back in the day, my lowest gear was a 28:28 !) you can run a 34, 35 or maybe a 36 tooth chainring, have an 11-34 or 36 spread at the rear, use a mid length derailleur and have an extremely useable range of gears which is both efficient and light.



But things are continuing to change. Specialized are far from my favourite bicycle company, but working with DT swiss and SRAM they initially produced a 6 speed wide-ish range 9 speed compatible 'powerdome' rear gear cluster. The hub probably utilises a stepped freehub body.



Now, they have worked on a 10 speed version, that has a 9-36 spread. With a single chainring up front, say a 32 tooth, that gives a fantastic gear range. Downsides? well, a 9 tooth cog isnt going to wear well, and the smaller diameter is going to force the chain into a tighter curve that will be less mechanically efficient. But with mud in the picture it is difficult to know whether this will be real-world noticeable. As Davechopsoptions points out, it seems there are more snapped chains with the 9 tooth/small chainrings on BMX bikes...a problem a pro-mechanic supported DH team are unlikely to face.

UK based Hope have also been working on a 9-34 spread freehub unit that fits directly onto the hub, with the pawls inside a machined cluster. No doubt, this will be prohibitively expensive to make, but it shows that designers and engineers are thinking along the same lines.



I suspect it is something we are going to see a lot more of.

{Some of the pictures were lifted from 3 threads on Pinkbike.com, which is a great source of mtb race and tech info. I downloaded and modified the pictures to better fit my blog. The three articles are as follows:
http://www.pinkbike.com/news/9-36-cassette-prototype-2011.html
http://www.pinkbike.com/news/1x6-specialized-gearing-2010.html
http://www.pinkbike.com/news/eurobike-2010-random-2.html
Well worth a read.}