Athletes getting into mountain bike racing often ask whether they need a road bike, or if they have one, whether they need to spend a fair amount of time on it. 

I would say you do, but that answer needs explaining a little.

There are pros and cons to riding the road bike as an XC mountain biker, and too much or too little time on one will alter the effectiveness of this type of training.

Benefits?

The first “pro” is consistency in terms of terrain. Riding on the road is far less “stochastic” or stop-start that on a rocky trail. This becomes important when you’re trying do perform certain workouts. 

For instance, long rides upwards of 3 hours are often best done on the road bike because the primary goal is to be exercising for a long period of time, rather than building technical skills or working on force production. 

Riding for 3 hours off-road can needlessly tire out your arms, back etc, as well as make it very hard to pedal consistently for the duration of the workout.

On the road bike, you should be able to pedal for 90% or more of the time, therefore accumulating the most time in your appropriate training zone.

The 2nd pro for road bikes, especially in the winter, is that riding on the road makes the clean-up job post-ride a lot quicker and easier.

If you’re training to a high volume, having to clean a lot of mud off of the mountain bike every day does little to help you recover or promote day-to-day training consistency.

Downsides?

Riding on the road does little to help your technical ability off-road. That’s why even professional road cyclists don’t often rock up and win MTB races. 

In 2016, courses are technical and punchy, and even though fitness is the biggest component, being able to transfer that fitness into speed on the trail is the key to performance.

Road riding is also much lower force than mountain biking in general, never mind racing. XC racing requires a lot of stop/start surging, which places a huge requirement for torque on the muscles.

This is one reason why those that don’t train as much as they should off-road experience cramping in their races. It’s simply that their muscles aren’t conditioned for the amount of strength needed to keep accelerating out of corners or up short, steep climbs. 

It’s also arguable that more time on the road bike can negatively impact your pedalling dynamics unless you work on them specifically. One of the keys to climbing technical sections on the mountain bike is a smooth, even pedal stroke that is circular and free from jerky movements. 

Spending more time on the mountain bike is beneficial to developing this pedalling style, whereas excessive road riding can allow these good habits to slip somewhat.

The right balance

From my point of view, it all comes down to using the right bike to achieve the specific goal of your session. For some workouts, like long endurance rides or long intervals, the road bike will be the best tool for the job.

Working on short, sharp efforts, technical skills, force production etc will always lend itself to being done off-road on a mountain bike if that’s your primary sport. You’ll also get used to your position on the mountain bike and the way in which the muscles activate slightly differently.

Final thought

You can of course ride your mountain bike on the road, and get almost all of the same benefits. 

The only issue is that if you have one mountain bike for training and racing, you’ll likely have a gear setup that doesn’t lend itself to the speeds on the road (i.e. a 1×11 configuration, where your chainring will likely only be a 38t at its largest).

Please let me know your thoughts in the comments below!