Bicycle Mechanics - removing tight threadless headset bearing cartridges

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I am working on a bike with a rough running headset.
I am stumped on how to extract the bearing cartridges, both the lower from the fork and the upper from the steering tube.
I don't want to force things.
The lower looks as if it just needs to be gently pried off - with a stiff knife blade?
the Upper? is solidly set in the steering tube. Do I knock it out as I would an upper race?
and then even if I did take these to a shop for replacement (assuming they cannot be rebuilt somehow) is it even feasible for an 8/10 skilled mechanic like me (albeit most experienced on old traditional threaded headset systems) to reinstall these cartridges? or is this an LBS job and so I should just hand the while bike over to them?
Thanks
Peter
The heat tube bearings or races are usually a slip fit located by a taper. Sometimes corrosion can bind them, or some mechanics bed them in an adhesive so removing can sometimes be difficult.
Using the lower bearing as a guide, I suspect that you're are of a slightly different design that has a press fit inner an outer, so a bearing puller or pusher may be needed. A bike shop would have these tools, and could remove both for a fairly low price if you went in on a quiet Wednesday morning.
Otherwise you can use a punch to gently work the bearing up your fork until it clears the seat, then slides freely. Walk it up by small degrees working it around the fork so you don't cam it and bite into the seat. If you can get behind the upper race, you can remove it in a similar way, but go very slowly, since camming it could crackthe carbon head tube.
many thanks
This though is an aluminum frame and headtube. Does that fact allow me a little more latitude in extracting the upper cartridge? (apparently this is an Italian headset and the cartridges are model 6806RS.)
many thanks
This though is an aluminum frame and headtube. Does that fact allow me a little more latitude in extracting the upper cartridge? (apparently this is an Italian headset and the cartridges are model 6806RS.)
Only a tiny bit, when the races cam they score the tube and raise a burr. A tiny bit is OK and will fix itself when the replacement is pressed home. Any more, and it needs to be filed and maybe filled, which isn't easy. So best advice is don't cam the bearing, if it does get cammed, tap the high side back, and start anew working in smaller steps.
well, the upper bearing is out (tapped out, fairly gingerly with a wooden dowel.)
the lower race, on the fork remains stubbornly in place.
gently pry it out?
and interesting, they are not tapered (or don't appear so to my eye) but rather seat on a lip in the headtube.
final curiosity. is it normal that a cartridge bearing like this feel rough when installed / seated (if worn) but smooth when out? the upper bearing feels like this.
I've faced this a few years ago and as I recall the was Yes.
my interest is in just abandoning the idea of reusing the upper bearing and instead just replacing the pair.
Peter
Upper headset bearings last forever, but may suffer damage from rust. Normally a bearing should feel relatively smooth in use so I suspect that you have rust on the actual ball track. Try turning it in your hand with a bit of downward pressure, and you'll probably feel the worn track.
As for the crown race, You can try prying, but if it's tight the force at the fulcrum (the top of your fork) may ding it a bit, so I'd save that for the absolute last resort. Since you're scrapping the bearing, use something harder like an old screwdriver, or chisel as your punch, and have a friend hold the fork upside down of the floor, or directly the workbench leg, so it can't move with the blows. I suspect there's some corrosion holding the steel bearing to the aluminum ring (stuck seatpost issue) so it may take some energy to budge it, but then it should walk off nicely.
BTW- if you have any doubts about the upper bearing, you might as well replace it at the same time.
Success! well at least in the removal.
I didn't realize the lower cartridge bearing was just like on old fashioned crown race.
I just walked it off with an old screwdriver.
Thanks for you guidance .
Now I just have to find and install replacements.
Peter
ultraman6970
06-16-12, 02:33 PM
Put plenty of grease next time. LIthuim grease stand water better than others.
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