Originally Posted by
fixed1313
I use the correct fender size for the wheel size on all my bikes so far. The only issue I have had is a small amount of lift at the front edge of the front fender on one MTB. I make my own spacers as needed and I like to run my clearance as tight as possible (usually no light visible around the tire). I should note that these are all on-road use for wet weather, no mud. I am starting my first winter of commuting and I expect to increase my clearances some to accommodate snow and slush.
I agree, I don't like to see light between the tire and fender. Also it seems to me the fender will do its job better if it's closer to the tire, all else being equal. Usually the fenderline comes down to some compromise of 1. aesthetics; 2. stay bridge clearance (not so much on mtbs); 3. clearance for wheel removal (not as critical with vertical dropouts). If
#2 isn't an issue then I would space the front of the fender so it looks good and allows for wheel removal, then maintain that fenderline by whatever means you can devise.
An mtb with vertical dropouts should be one of the easiest bikes to fit with fenders. On one with horizontal dropouts, depending on the tire size, I might be inclined to space the fender so that the tire has to be deflated for removal. To do otherwise would, to my eye at least, create too much space when the wheel is mounted.