Ask your wife how many pairs of shoes she has... she can only wear one pair at a time. Same with purses, pants, blouses, sweaters, etc. She has more than she 'needs' of many things.. your expenditures for personal items are not all that much different than her expenditures on personal items

Plus tell your wife it is like a gym membership fee... it keeps you motivated for riding, that it is money well spent for your health and well being, that SHE would want you to be happy and healthy....