Does bike frame stack number include external headset cups?

[cyan]

For frames that are designed with traditional headsets (e.g. Chris King NoThreadset), does the stack number shown on a BikeCAD sheet take into account the lower and/or upper HS cups?

[ergott]

If it's truly a stack measurement is has to. I work with that program and the output is from the top of headset if you set the specs up properly (choose the correct headset). All the big company geo charts I've looked at have been correctly measured from the top of the bearing cap whether it's internal or external.

[Dave]

Most frames with internal headsets do not include the headset top section in the stack height and neither does the head tube length. There is never any mention of the height of the included headset top section, either.

The included drawings don't have different intersection points for the HT length and stack.

[prototoast]

Bikecad (probably the most commonly used program that custom builders use to design and report geometry) provides the measurement to the top of the head tube, not the top of the headset. Other programs I've worked with do similar.

It wouldn't be unreasonable for someone to provide a stack number to the top of the headset, but unless clearly specified, it's usually safe to assume the stack as reported is to the top of the head tube.

[ergott]

Originally Posted by prototoast

Bikecad (probably the most commonly used program that custom builders use to design and report geometry) provides the measurement to the top of the head tube, not the top of the headset. Other programs I've worked with do similar.

It wouldn't be unreasonable for someone to provide a stack number to the top of the headset, but unless clearly specified, it's usually safe to assume the stack as reported is to the top of the head tube.

Sorry, I'm rusty on BikeCad. You are right. Bottom cup is factored into measurement but stack is reported at top of headtube.

For me, I switched to looking at handlebar X/Y to bottom bracket so I not only have headset factored in, I have how many spacers and which stem to use as well.

[cyan]

Originally Posted by prototoast

Bikecad (probably the most commonly used program that custom builders use to design and report geometry) provides the measurement to the top of the head tube, not the top of the headset. Other programs I've worked with do similar.

It wouldn't be unreasonable for someone to provide a stack number to the top of the headset, but unless clearly specified, it's usually safe to assume the stack as reported is to the top of the head tube.

That seems to be the case. Found a few BikeCAD charts, and the stack measurements all end at the upper end of the HT (at least graphically)

[cyan]

Originally Posted by ergott

For me, I switched to looking at handlebar X/Y to bottom bracket so I not only have headset factored in, I have how many spacers and which stem to use as well.

That's a good point, but the problem is not every BikeCAD chart or builder includes that measurement