Abstract: A chair-drive interface assembly is for use with a wheelchair assembly having a first chair-connection member and a second chair-connection member, and also for use with a drive assembly including a wheel assembly, a motor assembly, a drive-connection member and a steering assembly. The chair-drive interface assembly has a first connection member configured to be fixedly attached to the first chair-connection member. The chair-drive interface assembly also has a second connection member configured to be fixedly attached to the second chair-connection member. The second connection member is spaced apart from the first connection member. The chair-drive interface assembly also has a third connection member configured to be fixedly attached to the drive-connection member of the drive assembly.