Mountain bikes have changed a great deal in the last decade, wheels have got bigger, then smaller, then
bigger again; tyres have got wider, a lot wider, then slightly thinner again. Plus, there’s suspension design, improvements in carbon layups, boost hubs and of course 1x drivetrains. Seamus Allardice takes a roll down memory lane.
The 29er may not have been born in the twenty-tens, but it may well have been perfected in the last decade. Gary Fisher and Surly had made big wheeled off-road, or true mountain bikes in the case of Fisher, bikes in the Noughties already. But it wasn’t until 2010 that the real driver of mountain biking evolution for the era started to gain traction.
In our ultra-distance obsessed South African sporting culture, the Absa Cape Epic serves as a handy yardstick. They first started keeping records of wheel sizes in 2011, after noticing bigger wheels popping up in 2010. In 2011 78% of the field rode 26ers. Though 80% were already on full suspension bikes. In 2020 I would have expected somewhere in the high 90% range to be on 29er, full suspension, bikes. Only the hard-core hard tail die-hards, like Bart Brentjens, choose to shun rear suspension. While only the shortest riders in the field will be on anything other than 29ers.
But the bigger hoops weren’t initially as easy to handle as they are now. It took a while for mountain bike designers to get to grips with 29ers, as PYGA’s design guru Patrick Morewood explained: “[it took a while for designers to] understand that it’s not a 26er”. And then they had to realise the need to “work with feeling and not computed numbers to get an answer. In the early stages of 29er design it was commonly
thought by many that one needed to mimic a scaled up 26er by compensating trail and offset of the fork angle.”
Getting increasingly technical Morewood reflected on the latest incarnation of the bike style that dominates the South African market. “There are still many different types of layout or suspension configuration on bikes today, some which have been used consistently over the last 10 years or so” Morewood said. “What we have found is that back then, most XC/Marathon type bikes had rear seat-stay/chain-stay pivots; but in order to save weight, many have now gone to a ‘flex stay’. (A seat-stay that relies upon carbon’s ability to flex in order to negate the need for a pivot within the rear triangle. As one would have found on
the previous generation Specialized Epics). We, at PYGA, have stayed with bearings because it’s the only way to perfectly define placement, on brands like SCOTT. This, if they are doing it for the same reason we do so, is to allow for better control of the shock rate or progression curve. Another factor which has aided bike designers is 1x gearing. 1x has made it a slightly easier job to achieve consistency in the suspension feel throughout gears; so, it makes it easier for most designers to have a reasonably good feeling bike now.”
“Aside from all of the above, the trend now is to go with more travel,” Morewood pointed out, using bikes like the Trek Top Fuel as an example. “This has been made possible with the improvements in the shocks, including the switch to metric shock sizes. The main area of improvement, I believe, is the reduction of friction, combined with higher negative air volumes. These two factors ensure that modern suspensions require less initial force to activate the shocks and forks. Metric shocks have made things easier as a brand too. We are now able to adjust suspension travel on a bike without affecting the shock length. In the past we had to use a shock extender on a shorter stroke shock, which lengthened the overall length to the same as the longer stroke shock. This allowed us to have two different genre bikes from one frame design; like our Stage [which has 110mm of rear travel] and the Stage Max [which has 130mm]. Now with metric it’s just
so much simpler as metric shocks can simply be adjusted internally to achieve different amounts of travel.” the braking characteristics and anti-squat of a bike. This we feel is important as part of the whole bike’s package.
“Our bikes have always had high amounts of anti-squat and suspension progression,” Morewood continued. “These work handin- hand to provide a supple bottomless feel while limiting pedal induced bob, the added benefit to this is better grip all-round and superior traction while climbing and at the same time removing the need for rear shock lockouts. Many of these properties have been implemented across the board on other bike brands models. An example of this is Santa Cruz updating their VPP design to fulfil
many of these criteria.”
“What we have noticed is that most of the evolution has been happening in the Trail/ Enduro segment,” Morewood further clarified. “We’re seeing sub-categories forming, with new names for these categories, such as ‘down country’. Which is essentially a STAGE MAX configuration. Or in layman’s terms a bike that is comfortable, efficient and handles well.”
Turning to the question of shock orientation, Morewood said: “There was also a trend towards horizontal shock placement which then moved to vertical.
The changes in mountain bike design, of the last 10 years, weren’t just limited to wheel size and improvements in suspension. There was of course the mid-decade fling with 27.5-inch wheels. The in-between wheel size by and large fell away, as Boost axels and designers getting to grips with 29er geometry negated the need for them. For most riders, that is. Even downhill bikes are now rolling on big hoops, an idea which seemed completely implausible when big wheeled mountain bikes first emerged. Wheels were simply not stiff enough.
Boost hubs changed that. By providing a wider base from which spokes are laced to the wheels Boost hubs ensured that wheels could be built with increased torsional stiffness.
Another trend mountain bikers lived through in the twenty-tens was the move to wider tyres. Way back in 2010 tyre widths on crosscountry or marathon bikes seldom exceeded 2 inches. Now 2.25, or even 2.35, is common. There was of course also a flurry of plus sized tyre bikes. Seated on 27.5 rims the 2.8- to 3-inch tyres provided exceptional traction at the cost of rolling resistance. They have now found their place on eBikes however where rolling resistance is off-set by electric power and the weight penalty of more rubber is hardly a concern. Having a monstrous amount of grip on a full sus eBike is simply fantastic. Speaking of eBikes … The future appears to be electric. Though there will always be a place for a superbly balanced short-travel bike. So, watch this space towards the end of the year. Cannondale Factory Racing have already been spotted aboard a new Scalpel and they are unlikely to be the only riders aboard redesigned bikes in 2020.