BMX - Threadless headset adjustment
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I've never adjusted one, I'm trying to, the guy I bought the bike from used the wrong allen wrench trying to over tighten the bolt in the center of the stem. I just bought a new bolt, and I'm going to be doing the adjustment tomarrow. I have been told that unlike the "old" stems, the bole in the center is notused for tighening. Loosen the side crimp bolts, push down on the stem till it's tight, then tighten the crimp bolt things, then snug the center stem allen bolt thing. How close am I and haow much aggrivation does this sometimes turn into. I'm also going to take a closer look at the bearings just to be sure they are not the culprit. Even though th rest of the bike is sealed the headset is not. I'm starting to apprecieat my threaded headset, so much easier to deal with.
threaded headsets suck.
your correct, loosen the two bolts on the side of the stem, tighten the one bolt on the top just enough so the headset is tight but no over tight. what I do is tighten a tad, lift the front end off the ground and spin the bars a bit to see it it's too tight, then adjust from there.
once that's done, tighten the side bolts again. so simple.
Does this ever happen, you tighten the top bolt nice and thight, but the headset is still not tight? What could cause this? Like I said, I think I need to take a close look at the bearings.
Is this threaded or threadless?
I'll say threadless. The top of the fork tube has no threads. But even with the "neck" pushed down as tight as I can by hand, there is still movement.
Loosen the stem clamp bolts so the stem moves free. You should have a top cap and a star nut in the fork. The bolt that goes through the top cap into the star nut sets your preload. If your steerer tube isn't a few mil below the top of your stem, it won't work, and you'll need a small headset spacer. Preferably carbon fibre. Got it?
Got it. Might need them carbon spacers. :)
Threadless headsets work on the same principal as threaded headsets. The bearing races need to press against the bearings. The bolt in the top cap will put pressure on the stem, which presses on washers below the stem, which press on the bearing races, which press against the bearings.
NOTE: The cap and bolt at the top of the stem do not secure the stem onto the steering column. The bolt or bolts on the side of the stem keep the stem from moving once the adjustment is made. The cap is used for bearing adjustment only.
Begin by removing the adjusting bolt in the center of the steering column. Next, remove the top cap. There may be a star-shaped nut or other fittings inside the steering column. The bolt threads into this fitting and pulls on the fork against the headset bearing surfaces, which acts to tighten the adjustment. Note the height of the steering column relative to the stem. It should be about 3mm (1/8") below the level of the stem. The stem needs to press down on the spacers in order to adjust the bearings. If the steering column is level with the top of the stem, another carbon fibre spacer is needed below the stem.
I got it fixed. I cjecked it over good, and everythng looked ok. But what I didn't know until I figured it was best left to the experts at the shop, was that some piece was missing. I had them replace the whole headset. Now it's all good. They have the tools, and the time, and the know how. It was worth the $10 for me not to even get dirty.
I found 4 spares when cleaning my garage. And the cup remover and press. Woo hoo! I just saved $10. :D
I'm glad it's behind me. I was starting to think something was wrong with me. I can remodel a house, build room additions, fix tons of stuff on cars, install anything that goes on a floor. But was having trouble with that stupid headset. Turnsout it wasn't my fault after all. But since I'd never seen one before, I didn't know that some plastic thing was missing.
12-18-05, 10:26 AM
threaded headsets suck.
Don't let the roadies see that.
I'm pretty sure once a threadless headset is set up porperly, it won't have the same coming loose problem the old head set will. Am I wrong here? No threads, no bolt to come loose. 2 pinch bolts seem to hold pretty well.
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