Review on 🔧 Profile Design Threadless Size Converter: 1" to 1 1/8" - Simplify Your Stem Compatibility by Aaron Allen

This is a cheap good looking aluminum adapter that will allow you to fit a new 1 1/8" stem to a bike with an old (or cheaper) 1" headset. Two things to look out for: 1. Make sure you're buying the right size (as many shoppers seem surprised). If your bike has a "1" headset, the stem that fits the stem (ie your old stem or this new adapter) will be thinner. , about 7/8"/22.2mm. If your old stem is 7/8"/22.2mm thick, your stem is 1" thick and this adapter will fit. (Your stem is measured from the outside, but you may not (on many bikes you can actually see the tube.) If your old stem stem is thicker than 7/8"/22.2mm then your stem is not 1". Also make sure the thicker stem end (where you mount the new stem) will fit your new stem.This adapter will fit 1 1/8"/28.8mm stems, which is the standard size (although some stems are larger or smaller). Unlike similar adapters, the top cap of this adapter is wider than the stem bore. You cannot mount an adapter on a bike and then mount a stem to the adapter. Instead you have to remove the adapter and new stem from the bike and then insert the combo unit into the steering column. The reward for your efforts is a cap that closes the connection between stem and adapter. This will likely prevent water from entering your building and also make it look more elegant.