Cannondale aheadset size

[dan28]

I ve got a cannondale with the oversize head tube that I assumed is 1.5 inch
I have the aheadset cups but no bearings the diameter of the cup that sits in the frame is approx 50mm
I bought a nukeproof 1.5 angleset cheap from crc but these cups are 56 mm
Something seems amiss is the cannondale not 1.5
See photos

 

[d00m]

They're 1.56 on the older headshok cannondales :/

 

[dan28]

The modern aheadset that I bought is bigger not smaller
Just been looking at head sets 1.5 inch equals 49mm
I measured the cannondale headset at 50mm so this seems correct
But the angleset headset is 56mm so what does it fit ?

 

[clubby]

Ah, good old head set lottery. Remember it’s the steerer that is 1.5” but depending on the style of bearing cups, the headtube is different sizes.

https://www.hopetech.com/_repository/1/documents/HOPEHEADSETS2011Web.pdf
As for what you need, try here.

https://www.cannondalespares.com/products.php?type=2&subcategory=34&p=1&category=&b=515&s=h

 

[dan28]

Tried my local bike shop all their bearings are not the correct size
Two of the headsets in the cannondale link above look very similar but if don't fit would be an expensive mistake
Can some one explain modern headset codes
I think an ex 49 might work ( external cup with a diameter of 49mm ) I assume the part of the cup that sits in the frame is 49mm

 

[clubby]

What year frame and what forks?
Cannondales are very “Apple”, their stuff is only designed to work together. Headshok forks need their own bearing as the bearings are interference fit and there’s no tensioner on top of the stem. If you choose to use a standard fork you can get converter headsets but it still may need to be Cannondale specific.


It’s usually the reason you can pick up bargain frames as people get so frustrated they just dump their projects.

The Hope link I posted earlier is the best explainer of headset sizes but does depend on knowing what your frame was designed for in the first place.

 

[dan28]

I m unsure of the year
An I have no idea what forks it used originally
Assuming the head tube standard 1.5 diameter I want to run a convertor headset 1.5 to 1 1/8
I ll take some pics an get some measurements

 

[clubby]

If your bike still has the serial number here’s a very good guide totrsvkin* down what you have.

https://vintagecannondale.com/info/serial_numbers/

 

[dan28]

There are 3 sets of numbers
One bar code sticker
An two others stamped on the bb shell
I m struggling to read the stamped numbers at the moment I have silicone oil in my eye due to detached retina
Anyhow the internal diameter of the headtube is 49mm so I think my instinct is right I think I need an ex49 headset
The frame is an f6 will add a photo

 

[clubby]

S bar code is 2007.
Looking on Vintage Cannondale, there is a Catalogue with F4 or F5, but Cannondale were always adding models mid year. Looking at the spec Headset is listed as Headshok SI or FSA converter where a normal fork is used.