Aluminium frame. The internet tells me I need a kit of bits which I don’t mind buying…

…but out of interest…

…does the lower bearing press directly into the head tube or does the kit contain an adapter?

My guess (hope) is that a 50.8 mm diameter bearing with a 40mm (1.5″) hole through it sits directly in the headtube 😐

Anyone done this?

Isn’t this what all non-lefty cannondales do now that 1.5” straight steerer forks are less common? Doesn’t sound like a longshot, but maybe I’m missing something. I did it with my jekyll and as I recall it was just a spacer to add to the top bearing.

Shame that the 1.5 straight didn’t stick as it looks miles better at the stem than 1 1/8 IMHO.

Converted a Flash alloy to tapered recently, used a cannondale kp205 converter kit for about £30. It’s effectively a complete new headset to fit an SI headtube & yes from memory lower bearing fits straight into frame – I did find I had to file the crown race to get it to fit as it was too tight on the fork steerer but cutting a slot in it would probably have been a better idea. Good luck

yes from memory lower bearing fits straight into frame

many thanks