When you are in the market for a new mountain bike the first question that pops out is: Which is the right mountain bike size for me? After examining the manufacturer size tables sometimes we find ourselves in between sizes or the right frame size is still not so obvious. After finding the recommended bike size from the manufacturer, many people are still wondering if a smaller mountain bike will be better.
In general, smaller mountain bikes are better on very technical trails where maneuverability is the most important factor. On straighter and faster trails, a smaller mountain bike will be less stable and will be slower than a bigger one.
In this article, we will discuss the main problems of choosing a smaller bike and how to determine if the bike is too small for you, we will see if a smaller or a bigger bike is the right choice and we will determine if the frame size is important. So keep reading!
Is It Okay to Ride a Smaller Mountain Bike?
As a general rule, a mountain bike shod be the correct size that perfectly fits the rider, but if you desire the best maneuverability a mountain bike can offer then it is ok to choose a smaller bike. Be aware that you can only go a number smaller.
If your normal mountain bike size is L, an S mountain bike will be too small and you will have a hard time adjusting to the bike you will find that your center of mass will be in the wrong places regarding the bike and often you will lose grip. This will make the bike to unstable and will result in you losing confidence in your mountain bike and mountain biking skills.
If your goal is to have fun on trails and like playful sessions, a smaller mountain bike is the way to go. Keep in mind that there is no perfect answer here, it comes to rider preferences, and there are pro riders that feel more comfortable on a smaller bike.
So if pro riders can choose a mountain bike with a number smaller than the recommended and still compete at the higher levels, then you have the green light to go a number smaller and get a more playful mountain bike.
Should You Choose a Smaller or a Bigger Mtb?
The best-case scenario is to choose a bike the correct size for your body, but if you are in between sizes a smaller mountain bike will be more playful and will offer more maneuverability but a bigger bike will be more stable, feel better on climbs, and will be overall more comfortable.
Be aware that if you chose a mountain bike that is too small you can not raise the saddle to the correct height and this will make pedaling a nightmare, this will be more pronounced on stiff climbs. The bigger mountain bike will be more stable and will be more fun to ride on faster terrain. The level of comfort on the bigger mountain bike will by far surpass the smaller bike.
If you ride a smaller mountain bike you lose grip on the front wheel when you descend and you feel the need to be out of the saddle, your center of mass will be too far off the back and this will make the front wheel lose grip with the trail. When you ride a bigger mountain bike the opposite happens, your center of mass will be too far in front and the back wheel will lose traction.
In general, it is recommended that if you can’t buy the exact mountain bike size go with a bigger mountain bike for increased stability, comfort, and better climbing capabilities.
What Happens If the Saddle Is Too High?
If you have a mountain bike that is way too small for you and you need to rise the saddle very high, be careful to have the minimum immersion of the seat post in the mountain bike frame. Otherwise, you expose yourself to the risk of breaking the frame of the bike and maybe injuring yourself.
Maney seat post manufacturers draw a line with a max warning on it, insert the seat post at least to this line to be safe, if you need to insert it more don’t worry, it is better but does not insert il less.
If your seat post doesn’t come with this mark, you need to check the minimum insertion specified by the manufacturer of the post and check the manufacturer’s official website. Now measure and mark the minimum insertion yourself and you are good to go.
If the minimum insertion is not specified on the manufacturer’s official website, you are left guessing. At this point, I lose all trust in this manufacturer and I will seriously consider changing my seat post. If you set the saddle too high and do not have the minimum insertion criteria met you risk destroying the frame of your bike and injuring yourself.
If you what a more in-depth comparison on riding a smaller or bigger mountain bike check out the video from GMBN Tech (included below), I find it to be the most informative but be aware that they ride bikes that are two numbers too small or too large, from a medium-size mountain bike to an XL one is a big jump (not a good idea).
Does Bike Frame Size Really Matter?
Mountain bike size is the most important aspect that you need to get right when buying your bike, this will greatly impact the confidence you have when riding with speed on technical trails.
The center of mass from your body needs to be in direct correlation with your mountain bike, if it is too far in front you lose traction on the back wheel and if it is too far behind you lose traction on the front wheel. This effect is felt on high-speed descents, where stability is a big factor.
Do not treat this lightly, at the beginning of your mountain biking journey this is not as important because you don’t have the skills needed to ride downhill or on trails with speed. When you ride slowly and with great care, the bike size will not impact you too much, unless you try to climb a big hill and your bike is way too small (a really undesirable situation ), but as you get better you will ride faster and faster no doubt about it.
So as you get better at mountain biking the bike size matters more and more. If you are just getting your first mountain bike and plan to upgrade in the future, bike size is not a massive thing. But if you plan to hold on to your mountain bike for a long time then you need to get the correct size for your body.
I think that now we can easily say that the best situation is to have a mountain bike that is the right size for your body. If you what a more playful bike you can size down but if you need more stability on descents and faster trails you can go up a size.
I recommend trying to find the exact fit for your body, mountain bike size is an important factor that will have a massive impact on your mountain biking experience and the amount of fun you can have on trails.
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I started mountain biking many years ago to improve my overall health state. After my first ride, I fell in love with the sport. Now I spend dozens of hours a week researching and training to compete in local XC and Enduro events.