Can I use an MTB? Yes, you can use an MTB with your Bkool trainer without any problem. Thanks to the design of their frames, Bkool trainers are compatible with practically any wheel diameter, including MTB wheels with 26", 27.5" and 29" diameters.
You just have to keep two things in mind. In the case of the Bkool Go and Bkool Pro2 trainers, remember that you have to use the correct rear skewer (See FAQ Correct rear skewer with my Bkool trainer). Second, we recommend always using a slick tire to avoid excessive noise due to contact with the cylinder on the trainer.