CCs are often detailed as 20" on bike sites. I believe this is because the front wheel is 20". Because the front tyre isnt used much in trials biking and doesnt need to be as high volume so to make both wheels have the same/similar OD they run 20" rims on the front with lower profile tyres and on the back they run a 19" rim with the higher volume tyre. Obviously because we want the high volume tyre in trials and street we use the back tyre which is 19" so as it has been said it wont fit because it is a tyre for a bmx which run with 20" rims front and back.