Yes, you can use a mountain bike saddle on a road bike and vice versa but deeply each and every saddle for both categories of bikes have its own characteristics depending on comfortability and tiredness. but you have to look for the compatibility between both of these saddles, it includes the diameter and width of the saddle tube and the length of the tube, bike sizes also matter a lot, 26 27.5, and 29 size bikes have a different diameter of dropper post tubes, if the saddle is compatible and is fitting accurately on your bike, never confuse, install it in your bike.
Replacing and interchanging saddles totally depends on the working principle, and then you have to do the experiment you can ride with the replaced saddle for a few miles and feel the comfortability, if it’s more comfortable than the previous one then install it in your bike because mountain bike saddles are tough and hard, mostly riders install road bike saddles in their MTB, the difference is present in the pair of the rails of steel and aluminum which are present on the surface of the MTB saddles, those riders which have lower weight would feel a comfortable ride with MTB saddles but those which have heavier weight can replace and interchange their MTB saddles with the road bike saddle for comfort zone.
You can easily install road bike saddles on mountain bikes and mountain bike saddles on road bikes because there is a diameter and width difference between the sitting region of both saddles. mountain bike saddles have wide sitting diameters and road bikes have a narrow sitting diameter, depending on these differences, both of these saddles have their own characteristics and properties. the major difference is present between the weight of the road and mountain bike saddles and also these are different in their price ranges, so depending on the weight and the price you have to choose an affordable saddle.
wider Mtb saddles have much more advantages than narrower road bike saddles because MTB saddles are manufactured for zig zag and twisted trails and you have to follow corner and turning trails but narrow saddles of road bikes mean the road trails are straight forward and you have to sit on the saddle on the whole road bike tracks without standing and pedaling.
Nose Difference:
The nose of road bike saddles is longer in length as compared to the nose of mountain bike saddles. but we can say as it is not a big noticeable difference and you can easily swap and interchange road and Mtb saddles, so you can easily swap and replace road and Mtb saddles without any difficulty. it’s simply just a name that is different for both categories of bikes, if one brand is road saddle and the other is mountain bike saddle, but both of these brands are interchangeable.
Colour Difference:
When you are interchanging and replacing road and mountain bikes saddles with each other then you will notice the colors of both of these saddles should remain different but these would fit on different bikes without any issue, the difference in the color of bike saddles does not mean that these saddles are non-compatible with each other.
Difference In The Material of The rails:
Rails are the two zig-zag rods within the centerline of the saddle surfaces, these rails are made up of two materials steel and aluminum, this difference is present between the road and MTB saddles, but you can easily swap and interchange different materials of rails on different categories of bikes.
But there are specific road bike saddles that have carbon fiber rails in the center lining of the saddle surfaces, these saddles are different from the normal MTB, gravel, and enduro saddles because the clamps and bolts of the carbon rail saddles are different from the steel and aluminum rail saddles.
Position of the Saddle And The Rider:
It is the main purpose when you are changing and replacing road vs MTB saddles on two different bikes, you have to sit on the saddle and check your body position, if you are comfortable with the new saddle then replace it, and also check the position of the saddle which is road and MTB saddle, if you are comfortable with your body position and the saddle position then you can interchange saddles on your road, MTB and gravel bike.
Height Of The Saddle:
Saddles vary differently in their height from the ground surface, the most comfortable road and MTB saddles are those which have a good and comfortable reach between the pedals and the nose of the saddle, so interchanging and replacing road and MTB saddles can easily be done but comfortability matters a lot regarding saddles.
Flat And Curved Saddles:
Flat saddles are road bike saddles and curved saddles are mountain bike saddles. here is a different road bike trails are different containing bumps and drops and you have to stand on every drop of the trail again your sitting bones would hit on the saddle but road bike saddles are flat because the trails are flat and smooth without any twist, corner, and drops, but ignore all of these differences and 50% of road bikers are using curved MTB saddles and MTB riders are using flat road bike saddles.
Conclusion:
The main purpose of the article is to highlight the differences between the road and MYTB saddles but these differences do not mean that you can never replace or interchange road and MTB saddles on two different bikes, these are simple changings that are not much complicated and you can easily swap or replace road bike saddles with MTB and vice versa.