Could someone explain this headtube to me.

[Grant]

What is the purpose of making it so fat?

 

[Wildcat]

Looks like they used a leftover bottom bracket.

 

[horsefarmer]

Customer kept breaking the neck wanting replacement frames.
Problem Solved!

 

[SSG]

It's a short head tube with what appears to be internal headset bearings on the bottom at least.

 

[MattiThundrrr]

Is it a small frame? It looks like a 91 or 92, and I'm only seeing that head tube on small bikes, the large version is longer. Maybe they made it fat so they could go internal, shortening it for smaller geo. Gary thought about bike fit.

Looks like they moved the brakes under the stays on the small too, looks good in there.

 

[Grant]

Is it a small frame? It looks like a 91 or 92, and I'm only seeing that head tube on small bikes, the large version is longer. Maybe they made it fat so they could go internal, shortening it for smaller geo. Gary thought about bike fit.
View attachment 120139View attachment 120140
Looks like they moved the brakes under the stays on the small too, looks good in there.

The bike is a small frame.

 

[Grant]

I was told it was to give more structural support with a smaller frame.

 

[Starnger]

As a designer i guess it is simple. The bigger bearing you can put in - the more contact surface you get, and as a result the tougher the connection would be. Maybe this mtb frame was designed for rigid forks and extreme riding. Similar to the way they use oversized bearings on the bottom of newer MTB frames.