Mountain Bike Evolution

From shorter chainstays to dropper posts — we’ve come a long way since road components on cruisers.

Like all disciplines of cycling, mountain biking has seen more than its fair share of evolution — the days of riding klunkers on deer trails are long behind us. Today, purpose-built mountain bike trails with differing terrains and degrees of difficulty can be found all over the place. In fact, there are entire cities dedicated to developing themselves in a way that ensures they can get in on the “peak” action (see our Duluth mountain bike article).

As mountain bike trails have evolved, so too have the bikes we ride on them. Wheel diameters have gotten bigger, tires have gotten wider, suspension is now commonplace on both ends of the bike.

These topics have been covered at great length by just about every cycling publication out there (including Call Up!) But what about the subtler developments — such as wider handlebars, shorter stems, longer toptubes — that have impacted ride quality just as much?

We thought we’d bring some of these often overlooked trends in mountain bike geometry and component fit to the forefront. Learning more about the origin and benefits behind these two topics may make your time in the dirt all the more grounded.

Geometry

If you were to swing a leg over an early mountain bike today and hit some trails, you’d notice some fairly substantial differences in how it rides when compared to to a more modern 29er or 27.5" bike. It would feel much twitchier, and you’d likely experience a lack of confidence while descending and riding over rock gardens.

Many of these short comings in the ride quality come down to the type of terrain that early mountain bikes were designed around. Since early mountain bike trails were primarily deer trails and walking paths, longer chainstays, shorter toptubes, and longer stems worked just fine.

But as trail design has continued to evolve, corner radius, berms, grade, and technical features have allowed speeds to increase and suspension to thrive. In response, mountain bike design has also evolved to provide the best riding experience possible on said trails.

Here are a couple of the main differences you’ll notice between the bikes of yesteryear and today’s modern rippers.

Shorter Chainstays

Advancements in front derailleurs — as well as the rise in 1x set-ups — has allowed engineers to shorten chainstays keeping the rear wheel nicely tucked in beneath the rider. This plays a huge role in how the bike handles. It makes for a bike that can carve through tight corners at faster speeds while keeping plenty of weight on the rear tire for increased traction while accelerating and climbing.  

Reach

Overall, cockpit length and reach hasn’t changed that much, but how we get from saddle to handlebar has.

Since many of the components on early mountain bikes were repurposed from road bikes, it was common to see longer stems being used on trails. To achieve the proper reach with a long stem, frames had to be designed with a shorter toptube. While the reach may have been fine, this set up had a negative effect on how the bike steered. Think back to high school math class (and you thought you’d never use that stuff!)

The bike’s stem pivots in an arc around a central point: the headset. The longer the stem, the wider an arc you have to make in order to steer the bike. A shorter stem makes for a smaller arc and much nimbler steering. It’s kind of like the difference between steering a go-kart and a school bus.

To keep the overall fit of frames the same with shorter stems, toptube lengths have grown respectively. The end result is a long front-center — meaning the front wheel is further in front of you — which adds back some of the wheelbase lost by shortened chainstays. Keeping the front axle further forward increases stability and prevents the dreaded “endo”.

Components

Speaking of stems, let’s discuss a few of the evolutions that some other components have seen over the years.

Handlebars

Another benefit to stems getting shorter is the ability to use a wider handlebar, which allows for more comfort without being too stretched out. Wider handlebars offer more balance and leverage as well as slowing steering inputs from the rider. If you’ve ever ridden an earlier mountain bike, you may have noticed how quick and twitchy the turning felt. This was due mostly to the narrow bar.

Seatposts

The biggest change in the seatpost world is the advancement of dropper posts. While the idea of a seatpost that can be adjusted while riding has been in practice for some time, the use of hydraulics in modern dropper posts has proven to be a real game changer. Now, with a simple push of a button, you have complete control of your seatpost height.

Drop it all the way down and shift your weight back while descending, and raise it back up to climb. So simple you’ll be asking yourself how you functioned without one for so long.

Test Ride Set-Up

Now that we’ve covered a little bit about what’s going on in the world of mountain bikes, let’s address test rides as they relate to your customers. Properly setting up a bike for a test ride can be the difference between making a sale and turning someone off from mountain bikes entirely because they had an uncomfortable ride.

The first, and most important, thing you should do is ask questions to get them on the proper style of bike.

  • What kind of riding does the customer want/like to do?
  • What are the trails like where they’ll be riding?
  • Will they be traveling with the bike or just using it locally?
  • Will they be riding alone a lot or with friends?
  • Is it a race bike or just for some casual after work and weekend riding?

Asking these simple questions will make sure that you’re not selling a casual XC rider a down hill bike or vice versa.

After you have that all figured out and you’ve found the right bike for them to try out, grab the right size and get the bike set up. Check the reach and stand over. Adjust the saddle height and fore/aft position. And let them rip around the parking lot so you can double check their position on the bike. If there’s suspension involved, make sure there’s enough pressure in the fork and rear shock. As a general ballpark, shoot for around one quarter of the fork’s travel as well as a quarter of the rear shock units stroke 25% (seated for the rear shock, standing for the fork).

If there’s one thing that’s true about trends in mountain biking, it’s that there will always be something new. As the mountain bike experience continues to grow and change, we look forward seeing what the industry’s engineering pros will come up with next.

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