Yogurt

I'm preparing to re-rim my Miyata's rear hub and instead of purchasing two chain whips to remove the small cog I took it by a LBS (Performance Bike) which I normally don't go to, but it was on the way home. I told the tech that I wanted to get the cassette off of the hub and politely explained what needed to happen.

I must have spaced out or something while the guy was working but the next thing I know he's got a wrench inside the freehub and is turning clockwise on the bearing cone. Bearings everywhere! Yay. Anyways, long story short, he eventually does what I asked to removed the cassette but now I've got a disassembled freehub with the 43 ball bearings he was able to find. On the plus side he didn't charge me. I'm not really upset about it because the hub had some wobble and a little grit but now that I've got it apart I might as well try to learn something and who knows, fix it. I've got a few questions if anyone knows...

How many bearings am I supposed to have?

Was there a seal on the back of the freehub, there seems to be what looks like a groove for an o-ring, but there's nothing now. If I'm missing an o-ring how S-O-L am I on finding a replacement for a 26-year-old freehub?

How tight is the bearing cone supposed to be once it's back together?

PS- I'm correct in thinking that he should have been turning counter-clockwise to remove the freehub, right?

East Hill

Oops, sounds like fun galore at the LBS .

...I know there's someone who can answer this...?

East Hill

Yogurt

Maybe I should sum it up a bit better...

Did the circa 1981 600EX freehubs have seals? Possible to find a replacement/substitute?

How many bearings should I have?

Bill Kapaun

You might post this in the mechanics forum-
OR tell the bike shop to give you a bag of ball bearings and you'll return the rest!

luker

You can replace the seal if you shop and are lucky. The balls are pretty much standard, I think, to every freehub and freewheel on the planet, so you could get replacements from a junker. But you could, pretty easily, get a replacement freehub on eBay, for about $5-$10. You need to be sure that it holds the same number of cogs that your current freehub holds, and you're in business. A mongo (7? 8?) mm allen key is what holds the freehub to the, um, hub.

ga_mueller

Sorry to expose my ignorance. I thought there were only "freewheels" in the early 80's. I mean, you unscrew them with the correct tool, ie "Shimano", "SunTour 2 notch", "SunTour 4notch", etc, whatever. And unscrew the first, second, third, or whatever cogs with a chain whip to redo the gearing. What the heck is a "freehub??". Is it actually a "cassette??" TIA

el twe

Generally it's a 10mm, not sure if it's different for 600EX.

el twe

A freehub is the part of the hub that the cassette slides onto.

Yogurt

In the case of my particular 6-speed, the cassette goes onto the freehub body, which in turn is threaded to the hub. 5 of the 6 cogs are one unit which slides into the grooves of the freehub, and the sixth (smallest) is threaded on (righty tighty) to retain them. You can remove the entire freehub/cassette group at once with the 2-prong Shimano wrench by turning left.

Unfortunately, the tech turned mine right and only merely removed the outer cone, spilling my bearings everywhere.

ga_mueller

Thanks for the info. Wow. Whodathunk. Cassettes in 1981. Were they 10-speed?? Wonder why my 1987 Miyata had a freewheel. Only 6 speed, to boot.

It's a freewheel. 6-speed. Not a cassette. No freehub. You are maybe 10 years too early. I think I have identified the problem... .

el twe

The early Shimano cassettes were 6-speed, then 7, 8, 9, and now 10.

ga_mueller

Thanks for the info.

Although there were no cassettes, from any manufacturer, in 1981.

Whatever.

el twe

Not true. He has a Shimano Uniglide cassette, and early versions of these appeared in the late 70s.

raverson

An '81 Univega Sportour that I sold earlier in the year had Shimano 600 Arabesque with a 6 speed Uniglide cassette. It was a suprise to me too.

Yogurt

Does anyone know if this part at Loose Screws is what I'm looking for?

Charles Wahl

Here's a webpage that I thought useful when I was trying to learn something about freehubs (up 'til now I've been a thread-on freewheel man):
https://www.icebike.org/Equipment/freehub.htm

It says 50 balls.

Yogurt

Thanks Charles. After staring at thing for a while, I don't see where there would have been room for any kind of seal, unless it was a hair-thin o-ring.

luker

I am thinking that this looks much like a fork race for a headset...

unworthy1

no it IS a replacement seal for a Shimano freehub/cassette as supplied by Morningstar for when you use their lube injector and destroy the old dustcap/seal prying it out. This one is supposed to work with any 7 or 8-speed, but I'd check with Loosescrews to be certain...especially since you describe what sounds like an early 6-speed Uniglide with the threaded small cog, and my guess is this seal is for the Hyperglides (that use a lockring).

Yogurt

Thank you for the info, I'm actually going to go straight to the source and see if I get an answer from Morningstar.

ampalabike

This thread is a little confusing. I conclude that you have an early Cassette-hub where the freewheel mechanism (the freewheel body) stays on the hub when you remove the sprockets. The sprockets are secured with the last sprocket which is screwed to the freewheel body whereas the first five sprockets just slide on the body fitting the notches around the body. I further suppose the mechanic has not yet removed the freewheel body which can be done either using a 8mm or 10mm allen key. There is a hollow bolt inside at the center of the body which can be loosened counterclockwise. On some early versions you need a special tool from shimano for this. The mechanic just has reomoved the cones and the balls to pull out the axle. I have done this on a large number of hubs as it is standard procedure for overhauling hubs an repacking them with fresh grease after cleaning everything. The amount of balls (43) seems to be high. Usually there should be 9 or 10 balls on each side. Just clean everything pack the bearing surfaces where the balls will go in with fresh grease and "glue" in (grease = glue) as much balls as there will fit in. Do this on the left wheel side first assuming that the cones where loosened on the left side (where the freewheel is). Then you can insert the axle and do the same procedure on the other side. Then you can screw back the cone, spacers and the counter nut. You should thighten only as much as there is no more play in the bearing axially. If the axle runs rough it is to tight if it can be wiggled around axially it is to loose. Some wrenches recommend keeping it on the loose side since the additional pressure of the skewer will thighten it further.
If there was a bearing it should go between the spacer an the tigtening nut and could be connected to a separate washer. You description about 43 balls an a groove for a o-ring sounds a littel bit like the wrench has opened the freewheel body itself. In this case you should get a new freewheel body.
Pictures of the hub would help a lot in narrowing down the problem and the bearing you might use.

miamijim

OK...a few things here.

1. IIRC early freehubs did not use a large allen key to remove the body from the hub.

2. Yogurt, Do you still have part of the freehub attached to the hub?

3. Miyata, as well as most other manufactureres, used both freehwheels and freehubs in 1987.

4. Just put it all back together. Fill it uo with as many bearings as you can. A light grease will hold them in place.

5. Freehubs were available in the 70's.

Yogurt

Oh dear, I've gone and confused everyone. It is a freehub. Yes to #2, the inside of the freehub (with the pawls) is still attached to the hub. (Threaded onto the outside of the axle, no use for an allen key.) I have the body and the outer cone off of the freehub currently. I think the only real mystery left is if I'm missing a seal or not.

miamijim

We need pictures. The rest of it does come off the hub body in one way or another. Seal? I doubt it considering the vintage.

ampalabike

Yes indeed...first we should stet the terminology straight: Both common systems for mounting sprockets to a hub in a way that allows you to stop pedaling without ths systems still turning ist considered a freehub or freewheel. Shimano has a casette system where the freewheel-mechanism stays on the hub. This is commonly (but slightly unprecise) referred to as freehub.There also is the older traditional system where a cluster of sprockets consisting of up to 8 sprockets is attached to a freewheel body and then this whole cluster is bolted to the hub using those big threads. (Tread-on freewheel)
So do you have a casette system or a threaded cluster?
I am really puzzled when you state you have the body off the hub. The pawls are in the body. If this is so what exactly do you have off the hub? What do you consider the body?
I suspect your mechanic has removed the sprockets and some bearings from a traditional thread-on freewheel cluster leaving the bolt-on freewheel body on the hub.....
Here is a pic off Sheldon Browns site showing the differences: Tell us what you have and post some pics to enlighten us all....