Headset Parts & Accessories

The 2012 Madone uses an IS41 upper headset, which uses a 41mm bearing.

Unfortunately there are no conversion headset products to allow a one-inch (1") fork to be used in any headtube other than a 30mm inner diameter (ID) head tube.

1" forks and bikes that use them are much less common these days with most bikes made in the last 25 years using 34mm ID head tubes or larger.

Your best option is to find a fork using a 1-1/8" steer tube, or a bike with a 30mm ID head tube. We do offer headsets for both...

It appears your 2008 SuperSix needs a 42mm top bearing, and 52mm lower bearing. It does not indicate whether these need to be 36x45 or 45x45 contact angles but your current bearings may have this laser etched into the side of them. If you are not sure... you can replace the entire headset so all the parts (bearings and components) are the same manufacturer and this will work great. The complete headset needed is IS42 top and IS52/40 lower. We offer this in our 40 Series, Hellbender 70, and 110 Series depending on which level you need...

The best information I could find on your 2011 Stumpy hardtail is that its using...
"HEADSET - 1-1/8"" upper and lower campy style cartridge bearings for integrated alloy HT

This indicates the frame uses an integrated headset, which does not use press fit bearing cups. It appears to be an IS42 straight headsets (upper and lower). You can verify this by seeing if the frame has cups, and if it does not, you should measure approx 41.8mm for the inner diameter of the head tube.

If this is the case, and the frame uses an integrated headset, you cannot use a tapered fork. Conversion headsets require a 44mm ID head tube and your Stumpy has a 42mm ID head tube."

You need an EC34 complete headset... meaning EC34 for both upper and lower headset. This is our part number: BAA0068K - 40 Series EC34/28.6-EC34/30