Fix a flat is for tubeless, high volume low pressure tired like you find on a car. You don't want that in a bicycle inner tube!
To have dependable tires on your motorbike, use heavy duty flat resistant tubes. A tire liner as an extra layer of protection should give you a very high level of dependability at low cost.
Well actually they sell miniature cans that are designed for use with bicycle tires.. Yep, say right there tubed and tubeless bicycle tires.
OK so I used it all of about 3 or 4 times...
Bicycle front wheel used one can and inflated during a slow leak that formed, I wasn't on rim when I stopped. Filled it as according to the instructions.. Failed 2 blocks later and I walked half a mile (thank god..) with my heavy backpack of assorted groceries and a front tire that was starting to look more like a kidney bean that was coated in weird green slime (that never washes off if it has a chance to dry) and being pulled into the wheel by the popped tube, also covered in slime, so that my pocket knife and hands and handle bars are also slimy.
This happened twice except one time was leaving home, on a different tube, and only a block from home..
Never again thanks...
Did try it on the lawnmower 12 inchers. That didn't work either.
Perhaps the product sucks.
To be fair, my tires are also 3 inch wide and 27.5di.. Perhaps the simple design doesn't work in the instance because of the lack of quick pressure buildup... The can is only so big. Either way I had terrible experiences, I have a spare tube I can replace it in a bit of time with my multitool and tire irons that I keep in the box.
Good luck, flats are the worst..