Monday, February 1, 2010

K9 Cup Installation by Scott Smith

One of the things that got me stoked on the Rune, was the ability to custom tune the geometry using angled headset reducer cups. This combo has gotten great reviews, and with the headset cups now coming in -1 and -2 degree options, seemed like the way to go. I opted for the -1 degree cups.e="font-family: times new roman;" class="MsoNormal">
One thing I considered was if the head tube needed to be faced or not. The K9 Industries cups are designed for a 4.625" head tube, and the Rune's head tube is 4.75. That's only .125" difference, or 1.58mm off both ends. K9 advised that facing was not required for this amount of difference. I also wanted to avoid facing since it could potentially cut into the welds a tiny amount. So I opted to skip the facing and proceed directly to....

The K9 cups have notches at the front and back, which are meant to align with the front & back centers of your head tube. So the first step for installation is to determine exactly where the centerline of your head tube is. The method suggested by K9 is to lay masking tape down the center of your top tube, then sight along this to the front of your head tube, which also gets some tape to temporarily mark the center. Although not suggested by K9, I found a set of vernier calipers were very helpful in determining the center of the top tube. I was pleasantly surprised to see that the banshee team graphics are perfectly centered!

Installation of the tape down center of top tube and head tube:

Using calipers to make sure the tape is centered:

After checking with the calipers, it occurred to me that a laser pointer would be great for this- and I had one in the form of a cat toy. Playing with lasers in my garage also sounded like a lot of fun!

laser-checking the top tube

And the headtube

After verifying the center lines were correct, it was time to press the cups in! The cups are a tight fit, so K9 calls for anti-seize paste on the head tube. I tapped the cups in just a tiny bit with a block of wood and hammer, checked to make sure they were straight, then pressed both cups in at the same time, using a park headset cup press.

Upper cup

The cups pressed in easily after that, and everything tightened up nicely and spun freely. To be honest, this was a job I was a little apprehensive about- and it certainly requires more patience than a typical headset install- but it's not too complicated and I don't expect any durability issues.

Thanks for this Scott, I'm sure a bunch of our Rune, Wildcard and Scythe customers will find this a very useful and helpful tool if they choose to go for this option.

We make our frames strong here at Banshee, and we have no issue with these cups being used on any of our 1.5" headtube frames, except the Legend (Would you really want a 61.8degree head tube angle when unsaged anyway?). We don't want to limit our customers at all, and we realise that you guys are bike coneseurs anyway, who know what you want, and that sometimes it doesn't always perfectly match up to what we make, as everyone is different. So if you want to alter the head angle using this method, then go for it. However, be sure not to face the head tube to the point where it interferes with a weld, and to take your time and do the job properly just as Scott has done. As long as you do it properly then the frame will still be under warranty.