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Installing Chris King headset on Look frame and fork.(7 posts)

Installing Chris King headset on Look frame and fork.Ian
Mar 11, 2001 7:42 AM
It has finally arrived! My Look KG281 frame with HSC-3 fork. Now I get to have the joy of building my own bike from the ground up. But, I am a little intimidated by the headset and crown race installation. I plan to cut the carbon fiber steerer with a toothless hacksaw blade, after measuring twice of course. I will use the Park steerer tube guide tool to make a straight cut. I will press in the headset using the Park tool and King adapters. The part that really scares me though is the setting of the crown race on the carbon steerer. Do I whack it just like I would on an aluminum steerer? I have good bit of mechanical knowledge and feel very comfortable doing everything else to build the bike, but I have only installed a couple of headsets and doing so on a $2,000 frame and fork with a $100 headset makes me want to get it right the first time. If I have anything wrong or if I am missing anything, let me know.

Mar 11, 2001 12:20 PM
Some of these may be redundant but here's the steps I do when installing a new headset and carbon steerer fork.

1. Make sure the headtube is properly faced, i.e., both ends of the head tube are parallel to each other to insure the the fork rotates smoothly. I don't know how the headtube is on the Look frame but I assume there is some sort of metal insert where the cups press into. These surfaces should allow the cups to fit snug and flat.

2. Press the headset cups using the Park cup press and King adapters. Go slowly and make sure the cups are going in straight. Cosmetically I always line up the King logos on the bottom and top cups.

3. Install the King baseplate (crown race) on the fork. Most carbon steerers have some sort of raised band to achieve the correct race diameter. King baseplates have a raised inside collar for the cartridge bearing. Most simple race setters could potentially damage this interface if you aren't careful. King makes a special crown race setting sleeve, and Park makes a tool that is essentially a race setter with attachments that will transmit the force to the outside of the baseplate. Depending on your tools and your particular installation, just make sure the race setter will not damage either the baseplate or the raised collar on the fork. On my last two carbon steerer crown race installations I improvised by using an old Park fixed cup wrench over the baseplate to divert the force to the outside.

3. Install the fork including spacers according to fork manufacturer specifications for stack height. Lightly tighten the stem. Make sure that the fork and headset are correctly installed. Make a mark at the top of the stem. Remove the fork and make a mark 3mm below the mark for the top of the stem. I usually place masking tape to indicate the cutting line. Just to be on the safe side, reinstall the fork and make sure this is where you intend to cut.

4. Cut the carbon steerer with a hacksaw blade. People have successfully cut carbon steerers with a fine tooth blade (32T) but I've had the best luck with a carbide grit blade (I bought mine at Sears) which will cut the steerer very easily and smoothly. If you have never cut a carbon steerer you could make a practice cut near the top so you know what to expect. Put the saw guide on the fork and clamp it in a vise and cut the steerer. Make sure the fork is straight while you are cutting. Use a file and some 100 grit sandpaper to smooth the cut and remove any burrs.

5. Reinstall the fork, make sure the steerer is 3mm below the top of the stem. Preload the bearings, tighten the stem and there you go.
One more question.Ian
Mar 11, 2001 6:17 PM
Is there a tool to face the headtube? How do I measure that they a parallel to each other? And the Look frame uses aluminum lugs, so the whole headtube is aluminum.

Visual inspectionBipedZed
Mar 11, 2001 8:01 PM
Facing and reaming a head tube is an extremely advanced mechanic skill and is best left to experienced bike shop mechanics. The Campy tool is $700 and the Park facer/reamer is $400 or something. In fact, I would only trust shops that did a lot of pro-level frame sales. That being said, these days most quality frames are properly faced from the frame manufacturer. I mentioned checking the head tube just as a precaution. When I worked in bike shops doing custom frame builds, I would mark the faces of the head tube with a Sharpee and then use the facing tool to see that it removes the ink evenly and completely all the way around. For your installation, just visually inspect the ends of the head tube to check they are square and free from burrs and irregularities. If you feel uneven resistance when you are pressing the headset cups, stop and take the frame to a qualified bike shop. Most likely your frame is properly faced and you won't have to worry about it.
Thanks! nmIan
Mar 12, 2001 4:26 AM
re: Installing Chris King headset on Look frame and fork.grz mnky
Mar 12, 2001 7:25 AM
In addition to the tips here it would be worth your while to go to the Chris King website and download their specific instructions. Iusually recommend that people get it done at a LBS, but since you have the proper tools you should be able to do it.

No point in cuttng the fork until _everything_ is all assembled and stacked up - this takes the guesswork out of measuring. It's been my experience that sometimes the steerer is left a little long since not everything gets totally compressed. You end up with the top cap bottoming out and a slightly loose fork. You either need to cut again or add another spacer. Also, the expansion bolt (not the star nut) can slide a bit, so you need to keep an eye on this.

Enjoy your new ride!
Thanks also.Ian
Mar 12, 2001 7:58 AM
I will visit the website. The headset came with a King catalog and a few other pieces of paperwork, but no instructions. I am glad to know they are out there.