Nope.  MTB, gravel, road, etc... are just sub-types under the main "ride" category and all fall under the same leaderboard.  There is no way to separate them.  It is up to the rider to find what "tool" works best for a given segment.  Some segments, a mtb will be faster.  Others, a gravel bike will be faster.  Others maybe a road bike.  There are a few problems with trying to separate them with their own leaderboards.  The biggest one I see is that there is no way to go back over the last decade or longer worth of data in the system to determine what type of bike people were riding when they logged their activities.  That means that any way you split out the leaderboards, you will have a mix of error-filled data making the leaderboard essentially useless.  Another problem is that most people don't bother to input their various types of bikes or bother to indicate which one they are using from day to day.  Really, only a fraction of Strava users bother with those details so, again, the end result would be leaderboards with totally erroneous data.

Hey , 
Thanks for your post. @anchskier is right, this doesn't exist at this time. We appreciate you sharing your feedback with us. There is an existing idea, Separate Leaderboard for EBikes/different types of bikes, posted here that you can check out. Be sure to add your kudos and any additional comments. 

New year new chelleges for strava as well. If thera are so many kind of acctivities it means that there is possibility to add kind if bike. Not for past data but starting from 2024