i just had some custom numbers made for my new to me R6. They arrived today and the numbers are 5 inches tall. The rule book says 6 inches but I was told by the company that made them that 5 inches is fine for WERA. Will I pass tech?
You'll be fine - main thing is no goofy fonts that make one number look like another and spacing between them so we can see them at speed.
Sorry to bring up an old post, but I had my bike painted last year and had the number plate put on my lower for rear numbers. From all the pictures I had seen it looked like most were using 4" number since bikes today don't have much space. I was curious if 4" are allowed on the lower as long as we still have 6" on the front number plate. Otherwise I have figure out a way make a number plate in middle of the lower, only place I may get a 6" number fit (even 4" numbers will be tight)
I have found this chart to be useful for the purpose of number and letter sizing (track days and/or racing). Thought it might be worth posting - keeping in mind, of course, that these are obviously not calculating high speeds and movement, but still a decent reference point nonetheless. Source: http://sweets.construction.com/swts_content_files/1343/512482.pdf
Or you can paint your bike a specific color scheme in fluorescent yellows and oranges.. That way Mongo doesn't even have to know the number when someone on the radio says "dumbass took another baja again". (True story)