We get this questions a lot – I have an older Bacchetta and the new riser system looks different. Which one is compatible?
The attached table shows the relationship of the different styles that have been used over the years. The 2- and 3- piece systems were/are only available for a 1 1/8″ steerer tube.
The older, 1-piece system was available in 1″ and 1 1/8″. Those parts, however, are no longer available. So if you want to convert to one of the newer systems, you will also need a shim to convert your steerer tube from 1″ to 1 1/8″.
Carbent HPV uses the same riser systems on their bikes, so everything said above applies.