16 Feb, 2017

If 2x is good, 1x must be better


I’m sure you’ve noticed the raft of changes in mountain bike gearing of late. While road bikes have maintained the tried-and-trusted, two chainrings up front and ten or eleven cogs in the back casette, their off-road brethren have been playing shenanigans with combinations.

For much of the mountain bike’s life, a triple-chainring setup in front has been de rigeur. These three provide a wide range, with the big chainring capable of riding on flat district roads; the middle for, well, the middle; and the ‘granny’ chainring for when one feels like climbing up walls. This was perfectly fine for a very long time. Then it all changed.

Like a tree whose growth spurts out new limbs, Mountain biking (MTB) has many offshoots, each with their own requirements, and nowadays there are so many genres and sub-genres that oftentimes all a downhill rig and a cross-country whippet have in common is the fact that they’re called mountain bikes.

As XCO (Cross-country Olympic, as seen in the UCI World Cup and the Olympics) very quickly became more defined, the closed-courses grew shorter and gradually more technical. Riders stopped using the granny gear, as the belief was that if you’re going that slowly then it would be better to shoulder the bike and run!

SRAM jumped on the bandwagon and the 2x10 MTB drivetrain became a production reality. The trusty old triple carried on, relegated to the role of more mundane ‘sport’ and trekking bikes, but Shimano carried the 3x10 throughout, finding that sales figures were maintained, especially in Europe. And that’s how the 2x10 and 3x10 systems stayed, unchanged, for a good while.

The next jump was to an 11-speed cassette. Surely we didn’t need more gears, so why the extra cog? Actually, it had nothing to do with increasing the gear range – that just came as a welcome by-product. The thinking behind it was to reduce the gap between the cogs, resulting in a more efficient transition through the range. This reduced fatigue levels for the rider and raised average power outputs. All good for us then!

However, just as we all got used to the concept of a 2x11 and 3x11 bike, the goalposts shifted yet again. The big guns looked at downhill and freeride bikes and pondered the inherent simplicity, lighter weight and the freedom that not having to worry about a front derailleur could afford frame designers. SRAM therefore took a downhill rear derailleur, increased the length of the pully wheel cage and revolutionised the cross-country mountain bike market. They used the cassette to provide the gearing range, increasing the easiest gear up to 42-teeth and introducing a 10-tooth bottom cog to the mix.

What this gave, depending on the choice of front chainring size, was a gearing range very similar to a 2x10 traditional system, but not quite like that of a triple. The rationale was that even though the range fell short in both extremes – not a low enough granny and too soft a big gear – the 1x11 system would give the rider what they needed for most of the riding they do.

This instantly found favour with both XC racers and trail riders. Shimano followed suit with their own iterations and the dawn of the 1X era began in earnest. But just as frame designers rejoiced about the freedom that a lack of front derailleur provides, the biggest plus being the chance to shorten the chainstay length and still provide space for modern width tyres, it became obvious that not all mountain bikers were able to get the most out of a single-ring setup.

As with a singlespeed bike, somewhere along the line a 1x bike falls short. I’ve had many Epic riders heading off to the event with a selection of front chainrings, from 30 to 34-teeth, chopping and changing the front-end to suit the course. Just like a singlespeed rider! And so the twin-chainring front end started to claw its way back, allowing people to have their granny climbing gear and not suffer being blown out the back on a fast, flat district road.

That saw attention once again being paid to the cassette. SRAM has now launched Eagle, a 1x12 groupset, boasting a 50-tooth top gear. This is now the closest a 1x can get to the range of a double or triple drivetrain, and insider gossip states that they have ceased development of non-1x systems completely. Shimano now offers a 11-46T cassette in their 1x groupsets as well.

So is this the end of the front derailleur? Will road bikes follow suit? Not the same animal, but an enticing prospect nonetheless…