In most cases, yes. However; with the introduction of certain models from Cane Creek, tapered forks can be run in two straight head tubes. The classic 1.5” head tube has an inside diameter (ID) of 49.61mm, with use of our ZS49/28.6 TOP assembly, a tapered fork can be used instead of the straight 1.5” that head tube was intended for. With the EC44/40 Bottom assembly, non tapered 1 1/8” head tubes with a 44mm ID can utilize a tapered fork as well.