Why Do Mountain Bikes Have Hard Seats?

Mountain bike seats may seem like hard, alien devices meant to torture rather than rest your rear. If you’re wondering why mountain bikes have hard seats, there’s actually a great deal of science behind it. I’m going to share my experiences and the science behind those oh-so seemingly uncomfortable hard MTB seats.

Mountain bike seats are hard to provide adequate firm support to your ischial tuberosities or sit bones as they are referred. The shifting movements of pedaling require freedom of movement and padding in only the correct place to avoid damage to your soft tissues.

As counterintuitive as a hard seat to protect your soft spots may seem, it’s the truth. Let’s take a ride into the world of seats and talk a bit about how these things work in your favor to increase efficiency, even if they may seem uncomfortable at first.

Why Do Mountain Bikes Have Hard Seats? Science Provides A Couple Of Hard Reasons

There are a couple of solid reasons why mountain bike seats are designed the way they are. You may think you want a big sofa cushion of a seat for your lollygagging Sunday morning ride, but in truth, you’re only hurting yourself.

As mentioned earlier, there are a few big reasons to use a specific harder-padded seat when riding a mountain bike.

1. Provide adequate support to your sit bones.
2. Protect your soft tissue from damage.
3. Increase pedaling efficiency.

I’ll explain each of these in greater detail, so stick with me. It’s critical to understand your biology when it comes to mountain bike saddles, and it’s critical to know where you need pressure and where you really don’t. Let’s get into each of the reasons those saddles are hard as most trails.

Provide Adequate Support to Your Sit Bones

When you are riding an MTB, it would be wise to consider the contact points with the bike and the requirements.

• Hands – handlebars – steering and upper body support
• Feet – pedals – piston/crank energy for propulsion, pushes on either pedal and rotates with the pedal’s path of movement
• Butt – seat – torso weight supported, allows for legs to freely move through the motion of pedaling the bike.

In this case, we are concerned with the last item, with the connection of your butt to the saddle. The point of this connection is to support the bulk of your torso weight. The legs support some of the weight and use it for pedaling. However, the legs use more leg weight and often don’t use much or any torso weight in the downstroke cycle of pedaling.

Therefore, the bulk of torso weight must transfer through the butt and into the seat. It must coincide with pedaling, so your thighs need to be free enough of the seat to allow for the legs’ range of motion.

You should already understand this is no sofa in your living room kind of seat situation. The area of your butt that will take the bulk of weight, due to alleviating the thighs of their restraint, will be a much smaller contact area than your butt would connect when sitting on a sofa. However, when on a sofa, you don’t need a full range of motion of your thighs to pedal, do you?

The smaller contact area means that the padding must be somewhat firm to support the weight in such a small area. Otherwise, if it were squishy instead of a hard seat, the soft cushion would merely squish to the sides, spreading out, so more of your butt makes contact. However, this could now squish your soft tissues and cause potential health issues.

The moral here is that we need to have somewhat firm seats to accommodate the small area of connection between your butt and the seat.

Protect Your Soft Tissue from Damage

As I mentioned above, a soft and cushiony bike seat will merely compress and disperse the weight placed upon it. It may seem like a great idea until you consider the range of motion the legs need and the soft tissue that now shares in carrying your weight.

That soft tissue area is called the perineum. It goes between your privates and your tail bone. Or, to be scientifically accurate, the perineum is between the pubic symphysis (pubic arch) and the coccyx (tail bone). (source)

When you ride a bike, you need to support your torso weight on your sit bones, as I mentioned above. And similarly, if the weight pushes and compresses a softer seat to the side, into your perineum, then a portion of your weight will transfer through your soft tissue instead of the hard sit bones where we intend.

Even if you ride a dual-suspension MTB, the vibrations and bumps of a typical mountain bike ride can be pretty abrasive on those soft underparts. Not to put too fine a point on it, but your perineum includes the sphincter for your urethra and various parts of the genitals and reproductive system. Does that sound like something you want to crush because you got the wrong seat? No, I thought not. (source)

Increase Pedaling Efficiency

The last and final real point to having a firm mountain bike seat has to do with power and efficiency. By now, you must understand that you need a firm seat for both support of torso weight and also for proper weight allocation and thus protection of soft tissue. However, the final point has to do with wasting your pedaling energy.

When you pedal, your body weight shifts from side to side. It’s a complex dance of physics as you push down on a pedal, transferring a portion of your weight to aid in the downstroke. Then you do the same with the other leg as you release pressure with the first leg to allow for the pedal’s upstroke cycle.

This shifting of weight from side to side means that your butt and seat must accommodate for the pedaling movement and for that side shift.

The way human physiology works on a bike, we need to have a firm seat to lean partially against during the weight transfer process of the pedaling cycle. (source)

The transfer of weight as you shift on the seat, moving through the pedal cycle, allows all or most of your energy to transfer to the pedals from your legs due to a firm seat that does not absorb any of that energy. Thus, a firm seat allows for maximum pedaling energy efficiency.

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Looking for more “saddle articles? Check out the below:

• Learn how to prevent saddle sores with this article – How to Prevent Chafing when MTBing
• Learn some simple ways to adjust the seat height on an MTB with this article – How to Adjust the Seat Height on a Mountain Bike
• Learn how to make a MTB comfy for street riding in this – 11 Ways to make a MTB More Road Friendly

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More To Consider About Your MTB Seat Comfort

Many mountain bikers new to the sport may use their mountain bike for city riding or long rides on smooth surfaces. When doing these sorts of rides, you might find that you are sitting in one particular position for some time and that your butt starts to hurt. It’s actually normal, given the circumstance.

According to Peter Glassford, a registered kinesiologist and cycling coach, “mountain bikers end up with fewer issues with saddle discomfort…because they are forced to move around on the saddle to get over obstacles and up short hills.” says Peter about mountain bike seat discomfort. (source)

The moral here is that when you are riding, you should try to change up your stance, whether by standing or shifting on your seat. Any repeated position may, over time, cause discomfort.

Seat Measurements and How to Know What’s Right For You

You wouldn’t buy a pair of shoes without knowing either your size or trying them on first. So, why would you do it with a mountain bike seat when there are vital soft tissues to be protective of? In case it’s new to you – you can get appropriately sized for a bike saddle.

Most pro bike shops have special seat sizing apparatus that allows you to find your ideal saddle size. Keep in mind that height, weight, and sex have nothing to do with it. It’s all about the spacing of your seat bones. That’s why it’s essential to get properly fit – to ensure your butt enjoys your ride as much as the rest of you.

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