There is a deduction for business use of your motorcycle, but it is less than the car allowance. You have to use the actual cost method. Reference: https://www.everlance.com/blog/motorcycle-mileage-rate-deduction
EDITED 2/14/25 1:45PM PST
But, what you describe would not qualify for a mileage deduction ("commute to a job I was working as a outside contractor").
To get the mileage deduction, your home office would have to be your "Principal Place of Business"(POB).
https://www.irs.gov/pub/irs-pdf/p587.pdf (page 3) POB defined
