# Zero Stack headsets vs external cup



## cpfitness (Nov 19, 2012)

HEy guys, bit of a newb to MTB, a lot of road bike experience. One thing I'm weak on in both disciplines is headsets. While I"ve built a bunch of my own bikes up, headsets are something I usually take to the local shop since they have the proper tools to press in cups and install crown races. About to finish up my build of my canfield brothers yelli screamy and I'm building it with a straight 1 1/8" fork steerer so i had to get a conversion as it has a tapered headtube. I went with the Zero Stack cane creek 40 bottom cup as opposed to the external cup. Now looking through pics of everyone elses yelli's they all seem to have external cup headsets. What are the pros and cons to both? Seems that there must be some slight geometry change in the front end with a zero stack. I'm running a Manitou Tower pro 120mm fork. The yelli's claim to fame is it's slack headtube and very short chain stays so I'm thking the only thing I'm doing is slightly steepening the headtube angle? What are the reasons someone would take zero stack over external cup? is it purely aesthetic?


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## GTscoob (Apr 27, 2009)

The folks running the external cup are probably running a tapered fork that requires it. 

If you're running a straight 1 1/8th steerer then the zerostack headset will be correct. You could run a reducer external headset lower cup if you wanted the extra stack height associated with the external cup or are worried about the slightly steeper geometry.


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## fujiblue1 (Aug 9, 2012)

Hey, I have the same bike and fork. I currently have the ZS and got curious when I see everyone else running the EC headset. After some thought I decided to try the EC since the YS geometry was based off with the extra 12-16mm from the EC. I guess I wanted to make the HA wasnt affected and I figure the EC might give better protection from contamination since its sealed?? I might be wrong. Who knows. Either way the EC is on its way.


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## cpfitness (Nov 19, 2012)

fujiblue1 said:


> Hey, I have the same bike and fork. I currently have the ZS and got curious when I see everyone else running the EC headset. After some thought I decided to try the EC since the YS geometry was based off with the extra 12-16mm from the EC. I guess I wanted to make the HA wasnt affected and I figure the EC might give better protection from contamination since its sealed?? I might be wrong. Who knows. Either way the EC is on its way.


well yes the geometry #'s are based off the EC measurment but I guess considering I'm running a 120mm fork it's simply going to be more like running a 100mm fork which I'm sure plenty of people are so I'm confident I will be good to go. Its good to know that the EC is required should I get a tapered fork, that I wasn't aware of.


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