In this the last part of our mountain bike buyers guide we take a look at the history of mountain bike technology.
The history of mountain bike technology is constantly changing. Mountain bikes started off as steel frames and then moved onto Aluminium. Aluminium is still the most popular today, with various improved grades for strength and lightness. Carbon is popular with most manufacturers offering carbon on middle to high end bikes. The future is in Carbon, but aluminium is still used due to cost efficiency and good strength to weight ratios. Titanium is also used but remains the domain of specific titanium brands.
MTB started out with cable controlled rim brakes, they are simple with low cost, weight and maintenance. However they fall short on performance and reliability. Cable disc brakes were an improvement but still not the best. Hydraulic disc brakes are the answer, found on most mountain bikes these days. Disc brakes became light enough for racers, cost effective and the offer more controlled and effective stopping power. They are also reliable and relatively maintenance free
Mountain bikes started out as normal fat tired bikes known in SA as a ‘Dikwiel’. From there they essentially evolved in two directions, cross country racing and downhill racing. For cross country racing the bike was lighter with shorter travel suspension and more efficient for pedalling. The downhill bikes were robust, long travel, agile and capable on extreme technical trails. So there was the light rigid hard tail versus the heavy long travel full suspension downhill bike. What followed subsequently is a joining of the forces resulting in an infinite range of bikes in between.
Low end cross country bikes remain hard tails from both a cost and fit for purpose point of view. Cross country race bikes are now either hardtails or light and efficient full suspension bikes with travel around 100mm. This gave rise to endurance racing bikes with full suspension 100-120mm front and back, with weight kept to a minimum. These bikes offer improved handling and reduced rider fatigue for longer distance mid field riders. The suspension systems have improved from first attempts where pedaling efficiency was poor. Latest designs include ‘intelligent’ shocks, stable platform valve and lockouts, with all improved pedalling efficiency. A growing segment becoming more and more popular is the full suspension bike with 120-150mm of travel called trailbikes. These are very capable bikes with some downhill characteristics together with some cross country bike features. Trail bikes are becoming the everyday riders bike as they seem to offer a bit of everything for the recreational rider. Downhill bikes remain specialized with super efficient suspension, they are the test arena for new suspension systems on mountain bikes. The trend is towards longer travel bikes, as pedalling efficiency improves and lighter materials keep weight down, but cost increases.
This is where most of the more recent innovation has been happening. For many years not much changed, 3 chain rings in the front and 7,8 or 9 cassette. That was because Shimano had no real competition and in fact blocked SRAM from entering the market. SRAM persisted however and in 2011 mixed things up with their XX 1×11 drivetrain and then came the 1×12 Eagle drivetrain. Shimano eventually responded in 2018 with a 1×12 offering too. All of these improvements have reduced weight while improving reliability and performance. The next frontier is electronic shfting, already available on road bikes, and on very top end MTBs.
Wheel Size 26 vs 29 inch
The main difference between a 29″ and a 26″ is the wheel size with the 29er having a larger wheel diameter. The 29er is now well established as the preferred wheel size over the initial 26″ and the 27.5″. The larger wheel provides larger contact area for the tyre, rolls over obstacles more easily and allows bike designs with a lower centre of gravity. So the bike feels like the big wheels roll faster and easier over the rocks and the bike feels more stable than a similar 26″ bike. The 27.5″ is in between the two and is found on some smaller framed bikes where the frame geometry doesn’t allow for the bigger wheels. The 29″ frame designs are now very refined and the wheels are a lot stiffer and stronger thanks to wider “boost” bubs and thicker through axles. The 26″ bikes are still around and usually found on the very small frame sizes and entry level bikes.