Ideal for carrier bikes, but I use these on other non carrier bikes, as they are bigger, so in theory giving better braking power. I have use nos brske blocks in the past, but I prefer these, as they seem a little bit softer & therefore gentler on the rim... Considering some of my rims are old original, over 70 years old. Yet still hard wearing, once they're bedded in, you'll be good to go/stop. I usually mask off the rubber bit & paint the metal bit black.