Headsets & Stack Heights - Colnago Master
 

Trying to figure out which headset to get for my late 80's (I believe) Colnago Master:

http://bikeforums.net/attachment.php...hmentid=481325

I've been doing some searches and found an old post - see response #7 :

http://www.bikeforums.net/classic-vi...dset-type.html

Now I'm worried about stack height. Here's what I was originally considering:

wiggle.com | Campagnolo Record HeadSet 1 Threaded | Headsets

I'm assuming this will be fine, but was hoping someone on here could give me a little reassurance.

Slebo,
Stack heights are very specific to whatever the owner before you cut the steerer tube to. From the pic there isn't a lot of excess tube and you won't likely have much room to play with. What you can do to assess prior to installation is measure how much steerer tube you have, then look up the stack height for the given model headset and see if you have enough tube for it. Your part lists a stack height of 36.5mm, so you just need that much free steerer tube above the frame. Hard to tell without measuring, but it looks like you've got enough, and may even need a spacer or two.

Thank you. And to measure, I would essentially just set the bike and fork back up into the same position that is pictured and measure the excess poking out of the top? Would that be accurate with the bottom cup missing?

Yes, stack height includes the entire height of the headset, including the bottom race and cup. Just make sure the crown race (top of fork at base of tube) surface is against the bottom of the frame's tube and not inside (if you let it go inside this will give you a greater measurement that is not true). There's your stack height, you want the number you measure to be equal or a bit longer than 36.5 mm.

Ignore the google images that show a diagram of "stack height" including the entire steerer tube, those are clearly not correct.

Awesome. Thank you.

Happy to assist, and can't wait to see build pics of this gorgeous frame. Please take the time during the build process to document this with pictures, it's a great way to share your bike with the forum.

A little tip is that low stack height headsets will work with taller stacks...

Campy made some low stack Chorus? in the early 90's...