My current ride a 2007 Goldwing is the only bike in my life that I have changed brake fluid in. I changed it at 36K and now have 105K on it. Everything works fine and the fluid looks a nice light color. I see no reason to change it again unless the fluid darkens or I have a problem. I have changed the clutch fluid a couple of times. Coolant gets changed about every three years. Like a previous poster stated you do not get all the fluid out anyhow by conventional bleeding. I have been riding 45 years and never had a problem with brake fluid. Just my thoughts guys.