Bicycle Mechanics - headset... um.. problems

let's just say that someone decided to take their mountain bike fork off and didn't look to see how the headset was put together. we won't name any names *ahem*.

info: 1 1/8" threadless fork. external headset.

i looked on park tool's site and it did a fair job of explaining how to put it back together except for two things

the part near the bottom explaining headset installation (http://www.parktool.com/repair_help/howfix_headthreadless.shtml)

which race is the cone side, which side is the cup side? I'm assuming the cup side is the headtube side. [for purposed of knowing which orentation to put the bearings back in... since one side of the bearing is more open than the other]

there are three spacers that go on top of the fork, one that's about 10mm and two that are about 5mm each. what's the point in this? why would there not just be one big one or two 10mm ones? does it matter how they are stacked together?

ok I think that covers all my questions.

thanks in advance guys! :-D I'll just be drinking a beer until I can ride again :beer:

oh wait, that's assuming that I was the one that took their fork off ;)

You're right. The cups go into the headtube. It doesnt matter how you stack the spacers. They are various sizes so you can maybe go 15mm instead of 10 or 20mm.

ok, the cups are pressed into the headtube, of course i didn't... er i mean my friend didn't take those out because I Didn't have the tools. but the bearings can go in two ways.

they are more exposed on one side than the other (they're in a retainer). which way does the exposed side go?

If I'm understanding you, then UP. The more exposed side should be resting on the cup that is in the headset.
The retainer for the bearings is kind of "cupped" and the "scooped out" side faces down, the "outside of the cup" faces up

Maybe this will help
http://www.cyclingnews.com/tech/fix/?id=howfix_threadless

http://www.cyclingnews.com/tech/fix/?id=howfix_headtypes

Originally posted by Ritalin


they are more exposed on one side than the other (they're in a retainer). which way does the exposed side go? Try lookin at how they fit into the cup and also how they interface with the crownrace and top adjusting nut.

I don't want to cause contraversy here, but.... You'd be better off losing the bearing retainer alltogether and fitting loose balls into the headset. This way, more balls can be added, spreading out the load on the bearing races. I have done this on both my bikes (recommended by more than one LBS). The only downside is that it is more fiddly to reassemble, but a good stiff grease helps to stick the balls in place in the cups (have a few spare anyway!). General rule is to fit as many balls into the cup as possible, then remove one because there needs to be some clearence between them. Also, check to make sure if the top and bottom bearings use the same size balls, as some are different.

Cheers,

Ed

The frame pieces can be either cup or cone shaped. The image below is a cone race that is pressed into the frame. A frame race in a cone design usually goes at the top of the headtube.

There is another test for retainer orientation. Without grease, place the retainer in the top cup. Place the top race over it, press down by hand, and rotate. Now reverse the retainer and try it again. One way will feel smoother, as you are turning on the ball bearings. The wrong way you will rub on the retainer itself, not the balls.

Generally, the open face of the retainer faces the cone.

Using loose bearings is often a good idea. Use care not to allow the bearing to become jumbled upon assembly. Do not pack the cup full of bearings, leave a good size gap of say 3 bearings. This allows the bearings to move and so helps to prevent fretting (pitting).

http://www.parktool.com/images/repair_help/fork24.jpg

Originally posted by Calvin Jones
The frame pieces can be either cup or cone shaped. The image below is a cone race that is pressed into the frame.
http://www.parktool.com/images/repair_help/fork24.jpg



ok thanks for the info guys, i think I have it all cleared up now except for one thing.

except, bear with me.... how can you tell a cone race from a cup race by simply looking at one?

I was thinking that the cup race was the one pressed into the frame... since the cups are pressed into the frame but from the above now I'm confused. damn bearing retainers.

Originally posted by Ritalin

except, bear with me.... how can you tell a cone race from a cup race by simply looking at one?


A cup is concave. A cone is convex. The bearings sit on the cone inside the cup. So, the cone is smaller than the cup.

Does that help? Give us a smooch, ya big hunk!

:love: :love: :love:

Originally posted by Ritalin
ok

except, bear with me.... how can you tell a cone race from a cup race by simply looking at one?

If they are the same,it makes no difference.if they are different go by best fit.

you guys rock! back together and works like a charm.

and smooches to A.Troll

Originally posted by Ritalin
you guys rock! back together and works like a charm.

and smooches to A.Troll Hint...next time you take something apart,draw a picture of how the parts go back togerther.