Cannondale Prophet Headset

Hi. I have just got my hands on a 2nd hand Prophet and believe that the headtube takes a 1.5 headset. At the momment the frame has the deeper bottom headset cup which is recommended by Cannondale to prevent the forks fowling on the frame downtube. It has a FSA Orbit, 1 1/8 headset fitted but requires replaced. As I am building the bike up with some new parts I was hoping to take advantage of some of the discounted deals for 1.5 forks on the market, but can’t seem to get info on what headset I could use. Does some 1.5 headsets work with the deeper recommended Cannondale headset cup or can I remove it and replace with another headset lower cup (Standard) without new forks fowling the frame. Not sure if 1.5 forks are not suitable for my intentions and should plump for a 1,1/8.

Any advice would be greatly received. Thanks. Whistler

The steerer ‘tube’ is what the 1.5 refers to I believe. So you cannot use a standard 1.5 headset with a Cannondale?

From the internet…

Cannondale headshox STEERER TUBES are not 1.5 inch. The steerer tube is what 1.5 refers to as opposed to the inner headtube diameter. So you cannot use a standard 1.5 headset with a Cannondale FORK. However, the inner diameter of the headtube on Cannondale bikes in 49.6mm, the same as the 1.5inch standard. So any 1.5 inch headset reducer, tapered or otherwise will work fine with the relevant fork steerer. However some models have limited press depth meaning you need a shorter headset that doesn’t go in as far, not sure exactly which ones but some companies offer machined down options for these. Hope this clears things up.

This interests me too as I’ve got a Prophet and wondered what my headset options were if I got some 1.5 or tapered steerer forks to replace my 1 1/8 Pikes.

I’ve just built up a Prophet, running this headset, and tapered forks. All went together nicely. Obviously I’ve no idea of the longevity of the bearings yet.

Looks good apart from the price.

I’m sure it was cheaper when I bought it… 😯 Then again, new bike excitement might just mean I glossed over the price.

I recently built one up with these forks and the bottom part of this headset.

Unfortunately, that headset has gone back up in price now – was 50% off from CRC when I bought it a couple of weeks ago. But those forks are still a good price.

I’d make sure whatever one you choose has some stack height on the bottom. The original (1 1/8) had about 20mm and the replacement was ~14mm. I wouldn’t go any less.

With respect to the insertion depth, the googling I did at the time seemed to suggest you only need a headset with a shallow insertion depth on older cannondale prophet frames. The headset I took off (and the one I replaced it with) both had a ~20mm insertion depth.