Topic: 74 CB 750 Steering Bearings

[Gary Puckett]

My 750 has a steering bearing issue. When the front is lifted, the steering has stop or groove it falls into at the most straight forward position. I have disassembled it and find no wear spots on the races or bearings. They did have grease. The bottom bearing appeared to be one ball short. I know many people use tapered bearings. I cannot understand how it could have this much of a stop or wear zone if I cannot see it. Can anyone give me any insight? Would a missing ball cause this? Would new balls correct it? Thanks

[1974CB750rider]

I can't say for sure that a missing ball would cause that but in any case I would replace the bearings if one is missing. Thats a safety issue and if you've already got it apart your half way there.

[Bill/BentON Racing]

Gary,check the balls,a flat spot causes this,if you replace races and balls or w/tapered it will be gone. Bill

[mystic_1]

My 750 has a steering bearing issue. When the front is lifted, the steering has stop or groove it falls into at the most straight forward position. I have disassembled it and find no wear spots on the races or bearings. They did have grease. The bottom bearing appeared to be one ball short. I know many people use tapered bearings. I cannot understand how it could have this much of a stop or wear zone if I cannot see it. Can anyone give me any insight? Would a missing ball cause this? Would new balls correct it? Thanks

It only takes a tiny bit of deformation to cause a detent like that.  Keep in mind that half of the deformation is in the top race, and half of it is in the bottom race (discounting the deformation in the ball itself!).  Now extrapolate that across two sets of races and you can see that tiny deformation in the races can add up to large amounts in the total system.  The bike spends most of it's life with the front wheel pointed straight ahead which is why you get the center detent.

Replace everything.  Given the cost that makes the most sense.  Once you're torn down to where you can replace the ball bearings, it's just a couple of extra steps to fit new tapered bearings.  Do it now and be done with it.

mystic_1

[Johnie]

I will be watching this thread with interest.  That K4 I just bought on July 25th has the same thing.  I have not taken the top tree off yet, but mine is bad.  What had me concerned about the tapered is the threads I have seen with guys putting the tapered in and then the top bearing is to high in the stem?  What gives with that?  And just how hard is it to pound out the races and pound in the new.  I saw threads where guys could not get the race to seat on the lower bearing.  Just looking for some thoughts...

[MCRider]

My 750 has a steering bearing issue. When the front is lifted, the steering has stop or groove it falls into at the most straight forward position. I have disassembled it and find no wear spots on the races or bearings. They did have grease. The bottom bearing appeared to be one ball short. I know many people use tapered bearings. I cannot understand how it could have this much of a stop or wear zone if I cannot see it. Can anyone give me any insight? Would a missing ball cause this? Would new balls correct it? Thanks

It only takes a tiny bit of deformation to cause a detent like that.  Keep in mind that half of the deformation is in the top race, and half of it is in the bottom race (discounting the deformation in the ball itself!).  Now extrapolate that across two sets of races and you can see that tiny deformation in the races can add up to large amounts in the total system.  The bike spends most of it's life with the front wheel pointed straight ahead which is why you get the center detent.

Replace everything.  Given the cost that makes the most sense.  Once you're torn down to where you can replace the ball bearings, it's just a couple of extra steps to fit new tapered bearings.  Do it now and be done with it.

mystic_1

Mystic is keerect. If you can feel the "dead ahead detent", then you have it. Period. Even if you can't see it. No point in further diagnosis.

Virtually every bike of that vintage, with bicycle balls and races,  has this problem whether the owner is aware of it or not. Fixing it will make it feel like a new bike, especially in sweeping turns. Your stability and feel will be so nice. With the detent, the bike is always trying to steer into the detent and you are constantly fighting it, even at below a conscious level. Without the detent, steering becomes effortless and oh so smooth.

Replace everything post haste. Preferable with a tapered roller bearing set up. I've never known the tapered bearings to succumb to the "dead ahead detent", while the stock stuff will about every 10K miles.

[mystic_1]

I will be watching this thread with interest.  That K4 I just bought on July 25th has the same thing.  I have not taken the top tree off yet, but mine is bad.  What had me concerned about the tapered is the threads I have seen with guys putting the tapered in and then the top bearing is to high in the stem?  What gives with that?  And just how hard is it to pound out the races and pound in the new.  I saw threads where guys could not get the race to seat on the lower bearing.  Just looking for some thoughts...

Races for tapered bearings are different than races for ball bearings so you end up with some differences from stock, like the fact that tapered races protrude above the steering head's top surface by a small amount, but barring difficulties with the installation tapered bearings meet or exceed stock performance requirements.

If you freeze the outer races overnight, and hit the steering head with a heat gun (ie hair dryer, don't tell wife) just before installation, they go in pretty easy.  If you are pounding the hell out of them then you are doing something wrong.

For the lower bearing on the steering stem, freeze the lower tree and heat the bearing with your heat gun.

Cold causes things to get smaller, heat causes them to get bigger.  This applies to the holes in the things, as well.  Use this to your advantage.


mystic_1

[Johnie]

So All Balls that I hear about here...are those tapered or balls like the OEM ones?

[mystic_1]

Ironically, All Balls does not sell ball bearings   They're the tapered style and All Balls is what I use.

mystic_1

[Johnie]

Ironically, All Balls does not sell ball bearings   They're the tapered style and All Balls is what I use.

mystic_1

mystic - were you able to pound the lower race all the way to the lower race stop? I heard some guys were not able to get it down there creating the elevated problem?  Just use the hot/cold treatment and all should be OK.  Do I use the same bolt secures the top bearing?  The reason I ask is the washer part of that bolt (the bolt and washer are connected) on mine is broke.  I should order a new top bearing bolt if I need it.  Thanks for the info...

[mystic_1]

Yes, as long as your steering stem is free from defects the lower bearing goes on fairly easily.  Most people that run into problems have either some corrosion or nicks on their stem, I suspect.  If you need to you can dress out any nicks with a small whetstone or a fine file.  Clean the steering stem well and hit it with a squirt of WD40 or light machine oil when it comes out of the freezer.

As far as the top retaining collar is concerned, yes you re-use the stock item.  This part not only controls the preload on the steering bearings, it also serves as a dust shield.

Maybe one of the other guys around here has an extra one they could let you have for cheap.

mystic_1

[Bill/BentON Racing]

Gary,what did I tell you?,just kiddin,But get a set of ALLBALLS,tapered set,(just used them in Drew's bike),Don't put stock back in,will happen again.Come see me I'll help N/C,Bill