Every bowman frame is supplied with our integrated headset, this means the bearings sit directly in the frame rather than a pressed in cup. In an integrated headset the bearings are held in place by their chamfered outer edges mating with the machined chamfers in the frame's headtube and held under compression by the stem. Fitting an integrated headset doesn't require any special tools.
This guide covers the complete installation and adjustment of the headset, expanding bung, spacers, stem and top cap, whether it’s the first time or during a service. If you haven’t already cut your fork to length, take a look at our guide HERE first.
Depending on the year and model of your frame, the fork will have either have an integrated carbon crown race which allows for direct fitting of the bearing to the fork, or it will require the use of the supplied split crown race. If the fork crown is flat you'll need to slide on a split ring crown race.
The (larger) lower bearing slides onto the steerer tube with the external chamfered edge facing upward. Make sure to grease both the chamfered edges and the outer edge of the bearing.
Place the (smaller) upper bearing into the frame with the external chamfered edge facing downwards to match the machined aluminium chamfer in the frame, making sure to grease the chamfered edges and the outer edge of the bearing. Now slide the fork through the bearings and frame.
Slide the compression ring, washer and dust cover onto the steerer tube one at a time and push down until flush with the top of the frame. A small amount of grease on the inside edge of the dust cover will help it slide on easier.
Determining how many headset spacers you need can be done in a number of ways: from bike fit data, replicating an existing bike or from a trial and error method after a few test rides. The important thing to remember is that you can always remove spacers later on, but you cannot add more once you have cut the steerer tube down.
We recommend no more than 40mm of spacers underneath the stem and to add one 5mm spacer above the stem to allow it to clamp properly and prevent damaging clamp forces. Once you have decided on how many spacers you want underneath the stem, add them to the steerer tube, push the fork upward with one hand and slide the stem down onto the steerer tube with the other.
Take the expanding plug and tighten the 6mm centre bolt to partially expand the plug until it is slightly smaller than the inside diameter of the steerer tube. While holding the upper edge of the bung, tighten the bolt to 1.5-2Nm so that it lightly grips the inside of the steerer. If you’re having trouble getting the expander to grip the steerer or it’s not expanding properly don’t overtighten the bung as it can damage the fork, take a look at this video for troubleshooting:
Add your 5mm spacer above the stem, it should sit above the expanding bung. If the bung sits higher or flush with the top spacer you will need to add another spacer or trim the steerer tube down. This part may seem trivial but if not set up in this way the headset assembly as a whole will not work, your headset will regularly loosen and can end up damaging your fork or frame as the top cap will “bottom out” on the bung rather than tensioning the headset.
Screw the top cap and bolt into the expanding bung until you can't spin the headset spacers by hand (this doesn't need to be very tight, typically 1-2Nm. Over-tightening will pull the expanding bung out of the steerer).
Align the stem to the front wheel and using a torque wrench, tighten the stem clamp bolts to your stems printed spec (this will be no more than 5Nm.) Check for play in the fork by rocking the bars back and forward, if you find any loosen the stem bolts and repeat steps 7 and 8.
You're all done! You can move spacers from below to above the stem to trial different positions over time. Once you're happy with a lower position you can always remove the excess spacers and expanding bung, then follow our steerer cutting guide HERE.