Mac Ride is great for cruising. If you cycle on a "cruiser" style bike, or perhaps an an older bike, you'll need an adapter for your stem, so that the Mac Ride front mount spacer fits properly. That's the "quill stem adapter".
There are two sizes of Quill Stem Adapter and it is very important to know what you need. They are not interchangeable.
- 7/8" or 22.2mm.
- 1" or 25.4mm.
Sometimes the size is marked on the shaft of the stem, inside the steerer tube, but not always. If you have calipers, you can determine the size you need (the measurement is the diameter).
If you are not sure what size adapter your bike needs, please check with your bike shop.