Steering Head bearings

[Travis398]

 Mark, I had that front end wobble on my bike when I got it, turned out to be the tire.

I doubt that tool is going to work on the lower race.........like Randy said cut a slot for next time.

[movenon]

Mark, I had that front end wobble on my bike when I got it, turned out to be the tire.

I doubt that tool is going to work on the lower race.........like Randy said cut a slot for next time.

I cut 2 shallow divot's right above where I cut the diagonals in the races. That's why I didn't worry about slightly going into the frame with the dremmel up on the top side.  I mean very slightly... Used a small carbide bit in the dremmel. Still not much of an edge but at an angle there is at least something. I made them shallow but about 1/4 - 3/8  inch wide. Rather not go back to do it again.......

Cap'n Ron:   Nice setup !

George

[markmartin]

Capn Ron, Wow, very nice . Love the press.  It makes beating bearings in with a hammer and socket seem barbaric.   There's a house for sale up the street from me with a huge garage that would be great for motorcycle maintenance and such......in case you're interested. :-)  So...strip it down to the top half of the frame but leave the center stand... OK, I can see why Fred said not to plan a trip for the next day!

Travis, George, yes, thanks for that.  It's good knowing that's there's not really an easy trick to getting the bottom race out.  You've saved me half an afternoon and a bunch of stress.

As for the wobble, hell yeah, who doesn't like new tires!?

[ribbert]

I'm curious to know why so many people have changed their head stem bearings.

What condition or symptoms suggested this was a problem?

Noel

[movenon]

I'm curious to know why so many people have changed their head stem bearings.

What condition or symptoms suggested this was a problem?

Noel

Mine was involved with a small mishap and I am just going through it as a safety check.



I noticed some burnishing in the top race (I think it was to tight, not caused by the event) and a "bright" spot on the upper head bearing retaining cage. In a third world country it would be ok to relube, adjust and live with it ??  I just elected inspect the stem / clamp and replace the bearings while its apart. One of my neighbors runs a local bearing supply and that makes it handy  .
George

[Capn Ron]

Capn Ron, Wow, very nice . Love the press.  It makes beating bearings in with a hammer and socket seem barbaric.   There's a house for sale up the street from me with a huge garage that would be great for motorcycle maintenance and such......in case you're interested. :-)  So...strip it down to the top half of the frame but leave the center stand... OK, I can see why Fred said not to plan a trip for the next day!

Thanks...My brother's reaction to that same picture was, "Your garage is too clean."  

I bought that 12 ton press when I bought the house...first time I had a proper work shop and I intended to equip it right!  It's a BendPak unit that ran me just a nick over $200.  I've rebuilt two transmissions with it (about to dig into a third), rebuilt the FJ and a classic Datsun engine with it, pressed bearing races into the FJ frame, done countless axle/bearing repairs on the rock crawler, rebuilt a transfer case and crushed a beer can or two to "wafer thin" with it.  It's definitely paid for itself!!

For the FJ's headset, I basically took it apart, inserted the FJ frame and re-assembled the press around it.

Cap'n Ron. . .

[Capn Ron]

I'm curious to know why so many people have changed their head stem bearings.

What condition or symptoms suggested this was a problem?

Noel

I was a bicycle mechanic in my high school days and saw this over and over...Because a bicycle (and motorcycle) is ridden with the handlebars dead-ahead 95% of the time, the bearings tended to "beat" dents into the races at that position.  To take the play out, you'd adjust the bearings, but then the front end would want to "self center" into that notch in the race.  When turning, the ball would have to climb out of that dent and then the headset would be too tight in anything but the straight-ahead position.

In my case, I was taking the FJ down to it's last nut and bolt and all new bearings were the first thing on my list.  It was a serious case of "Hey, while I'm in there..."

Cap'n Ron. . .

[ribbert]

I'm curious to know why so many people have changed their head stem bearings.

What condition or symptoms suggested this was a problem?

Noel

I was a bicycle mechanic in my high school days and saw this over and over...Because a bicycle (and motorcycle) is ridden with the handlebars dead-ahead 95% of the time, the bearings tended to "beat" dents into the races at that position.  To take the play out, you'd adjust the bearings, but then the front end would want to "self center" into that notch in the race.  When turning, the ball would have to climb out of that dent and then the headset would be too tight in anything but the straight-ahead position.

In my case, I was taking the FJ down to it's last nut and bolt and all new bearings were the first thing on my list.  It was a serious case of "Hey, while I'm in there..."

Cap'n Ron. . .

Cap'n Ron, I know why you replace them, that's why I asked the question. I've had a lot of them out over the years either for inspection after an accident or just for routine cleaning and greasing. Given enough time the grease can go very hard and create a notchy feel favouring the straight ahead position.

On the FJ's this is more common than the rollers seizing up because they are not exposed to the rain and dirt or high pressure washers, they are protected behind the fairing.

Serviced regularly they should last forever. Even ignored they should last a very long time. The tapered bearings modern bikes use have a lot of surface area.

That is why I was curious as to why so many seem to be changing them.

The theory of the race eventually pitting in the straight ahead position is true but in practice I would think you would need a hell of a lot of miles to do so with normal use. It was more common though with roller bearings.

In your case I understand the "while I'm in there......"

You're right about the pushies. A common problem. I don't know how long since you played with a bike but the Chinese shit on the market now has nylon rollers in the head stem and even the pedal cranks. No need to lubricate, just replace them after every hour of riding!

Noel

[RichBaker]

I'm curious to know why so many people have changed their head stem bearings.

What condition or symptoms suggested this was a problem?

Noel

I was a bicycle mechanic in my high school days and saw this over and over...Because a bicycle (and motorcycle) is ridden with the handlebars dead-ahead 95% of the time, the bearings tended to "beat" dents into the races at that position.  To take the play out, you'd adjust the bearings, but then the front end would want to "self center" into that notch in the race.  When turning, the ball would have to climb out of that dent and then the headset would be too tight in anything but the straight-ahead position.

In my case, I was taking the FJ down to it's last nut and bolt and all new bearings were the first thing on my list.  It was a serious case of "Hey, while I'm in there..."

Cap'n Ron. . .

This phenomenon is known as "Brinneling" and is the reason I replaced mine around 55k miles...

http://en.wikipedia.org/wiki/Brinelling

[airheadPete]

NYLON ROLLERS IN THE HEAD!?!? No wonder I hate their stuff!
If anyone needs more background, there are some very big threads on KLR650.net on doing the head hearings. Short version: three dabs of spot-welds and it pretty much falls out. Considered probably the worst job on the bike.
Just lubed my bearings since who knows how long from the last time. Since new? Possibly. Upper race dried out, slight brinnelling, lower grease congealed, but still useable. These things should last indefinitely with minimal maintenance. 

[movenon]

The seal you need is from a '79 Honda GL1000  Part No. 53214-371-010

Arnie

As a note for anyone else. The Yamaha lower head bearing (Part 93332-00008) comes with the lower seal attached.
George