Is it practical to buy a Mountain Bike, and swap out the wheels

>>1053991
yes

>>1053991

If you use the mtb to ride actual mtb trails then yes. Unless your hubs are the same you might have to adjust your brake calipers and/or rear derailleur slightly when you switch wheels, which isn't too bad.

People will tell you "huurrr it's not geared high enough" but even 36x11 is fine for inner-city usage.

>>1053998
Thanks, i did not think about breaks....I hate dealing with them honestly...but it couldn't hurt to get better.

>>1053991
Yes, I'd specially consider a 29er hardtail (xc or trail oriented) for that.

If you're riding primarily on paved surfaces then don't get a mountain bike. If it's an even mix of on and off road then off road tyres will likely suffice unless you have some really aggressive tread (e.g. Maxxis Wetscream).

>>1053991
buy a 27.5 mtn bike. then you can switch the tires for smooth 650b for city riding.