Road bike 1.5" Integrated tapered Headtube to a 1 1/4 tapered Fork compatibility
If the new fork takes a crown race, you can buy a special crown race to adapt 1 1/4&quot; to 1 1/2&quot;. [these also exist for 1 1/8&quot;]. Search your favorite buy-everything website for some options. It's a cheap, easy way to do it.
HOWEVER if the ENVE fork has an integrated crown race (which you will have to check with the manufacturer or the vendor), the crown-race type of adaptor won't be suitable. It may be possible to buy a shim (or have one machined) for your frame to take the 1 1/4&quot; bearing but this solution is less commonly seen.