Topic: Tapered Steering Bearings Thread

[Bodi]

Try cleaning the race with a scotchbrite and see if it looks OK. You can try the new lower race and roller cage and feel if it runs smoothly.
I've had to remove one, same problem (he forgot to pack it with grease) but really rusty and badly pitted after sitting outside all winter.
Drill 2 holes at an angle from above the race down through the outside of the steering tube on the frame - the step makes it pretty easy to start a drill. 3/16 is enough. The drill has to hit the bearing race, it won't go into the race as the steel is hardened - the tip of the drill will probably get buggered. Then use a pin punch to bash the race out through the drilled hole. You need the 2 opposite holes because the race will tilt and jam as you bash from one side. 3 equally spaced holes would be best, but the frame tubes get in the way. You will have to smooth out the mess inside (where the race seats) where the drill came through and the punch finished the hole, I drilled back with a larger drill to de-burr it. Once done you can plug the holes with silicon or epoxy.

[LRSDTIM]

Try cleaning the race with a scotchbrite and see if it looks OK. You can try the new lower race and roller cage and feel if it runs smoothly.
I've had to remove one, same problem (he forgot to pack it with grease) but really rusty and badly pitted after sitting outside all winter.
Drill 2 holes at an angle from above the race down through the outside of the steering tube on the frame - the step makes it pretty easy to start a drill. 3/16 is enough. The drill has to hit the bearing race, it won't go into the race as the steel is hardened - the tip of the drill will probably get buggered. Then use a pin punch to bash the race out through the drilled hole. You need the 2 opposite holes because the race will tilt and jam as you bash from one side. 3 equally spaced holes would be best, but the frame tubes get in the way. You will have to smooth out the mess inside (where the race seats) where the drill came through and the punch finished the hole, I drilled back with a larger drill to de-burr it. Once done you can plug the holes with silicon or epoxy.

Thanks a bunch to everyone who replied, very helpful suggestions. I'm going to try and clean up the race that's in there, it's only been a month and doesn't appear to be pitted. I feel like a dumbass for not packing it with grease, I don't know why I thought it didn't need it

[jonbuoy]

Only other way might be to tack a piece of bar across it and hit it from the top.  Are all the taper bearing sets  this tricky to remove?

[LRSDTIM]

Only other way might be to tack a piece of bar across it and hit it from the top.  Are all the taper bearing sets  this tricky to remove?

It's not the bearings but the races. The original races stick out into the stem far enough to be tapped from above with a punch. If you look at the picture above you can see the race for the tapered bearing is a very tight fit and flush all around to the recessed part of the stem it fits into. If seated properly, you wouldn't be able to get anything slipped in there to hit. It was my first idea but I couldn't get it to work.

[jonbuoy]

I thought you might be able to tack weld a bar across it - or run a bead around the inside face of the bearing cup with a mig or something to shrink it down. 

[LRSDTIM]

I thought you might be able to tack weld a bar across it - or run a bead around the inside face of the bearing cup with a mig or something to shrink it down. 

Oh.. that's a good idea, if I need to get that race out maybe I'll give that a shot. We have a small wire feed welder at work that I've used once in a while. Would I risk welding the race into the frame at all? Any idea if welding to hardened stell is an issue? I ended up scotchbriting the race that was in there and installing new bearings with tons of grease. I'm going to check it all out in a week or so and see if it's still holding up but riding home today it felt great.

[tbone]

Try a Dremel tool with a felt buffing wheel and jeweler's rouge. Load the buff with rouge and buff the piss out of it. Reload the wheel with more rouge every couple minutes and it'll shine it up quite nicely. Wash it out real good with Zylol and let dry. Grease up a new set of bearings and re-assemble. You should be good to go! 

[HondaMan]

Try polishing that race first, see if it cleans up well, to reuse it.
To get it out, use a cutoff wheel(s) in a Dremel tool and cut a diagonal slot across the face until you can break the race with a punch and a sharp blow. Then it falls out, right on your nose...

[LRSDTIM]

However you make out, you should also consider installing a grease fitting in the neck to prevent further rusting

I saw another thread where someone had installed a grease nipple for just that purpose. More than likely I'll just pull it apart and chuck some more grease on the bearings.

[Vagelis]

Goodmorning everyone,
I finally got around to changing my steering stem bearings to tapered bearings. Three weeks have passed since I put them in and I'm still trying to set them right, or they are too tight or to loose. Is there a "magical" way of getting them right? The bike is a CB400F.
Let me inform you of something that alot of us have thought about, I discovered a shop in Germany https://ssl.kundenserver.de/www.cb-four.com/sess/utn;jsessionid=1546a99c648ce40/shopdata/index.shopscript that has a complete kit with bearings for the rear fork for all our models. Their english is not very good but they are pollite and eager to help. I got one for my bike, it goes on easy and works like a dream!
Ride safely, Vagelis.

[Bodi]

Looking at the site, I see the nedle bearing kits for the 500/750 and bronze bushings for the same models, but nothing for the 400. What did you use?

[Vagelis]

Goodmorning Bodi, I sent them an email that I wanted the kit for a 400 and they sent it to me. On the packaging it doesn't say anything for the 400 but it fit like a dream. No cutting no guessing, just pulled the bronze bushings I had (15 years old!) out and put the kit in. Just a word of caution, when you tighten the fork nut only use 3-4 Kg of torque on the wrench. It says it on the packaging but it's in german. I was lucky a friend was here when I was putting it together and he noticed it, he knows a little german!
If I can help let me know. Vagelis.

[dpen]

Try the standard, well-worn way.

Bike on centrestand, two ways basicalyy

1 - an accomplice moving the forks back & forward slightly whilst you keep a finger on the stem & on the frame yoke. Tighten the nut gently until no movement is felt

2 - tighten nut gradually whilst moving the handlebars from side to side. Adjustment is right if there is no sign of binding  & the bars will swing slowly if tapped on the end when in the straight ahead position (may need to disconnect cables etc for this method)

[kirkn]

OK, so, lots of discussions on converting from stock ball bearings to tapered roller bearings.  So, I thought I'd add my own project to the mix.  Mostly photos, some discussion.

My bike is a '78 CB750K with 10,200 original miles.  Overall, the bike is in very good, original condition.  Steering was definitely notchy, with a very noticible 'detent' in the steering at straight ahead.  I suspected the PO had overtightened 'em at some point.  Or, it may have been just hardened grease.  But, I decided to convert to tapered bearings, partly just as an experiment.

I purchased an All Balls kit straight from the Dennis Kirk catalog.  $40.99.  Shipping was free because I'd ordered enough other stuff too.

Step One:  Disassemble front end of bike.  This took about an hour & a half on Thanksgiving morning to get to this point:




Here's the kit:  upper and lower bearing, upper and lower bearing seat, upper and lower dust seal, two spare "spacers" - one thin, one thick.




I had to remove the lower and upper bearing seats from the steering neck.  I have a length of 1/2" bronze all-thread that I picked up somewhere, and it's my bronze drift.  Here, I pound out the lower race.  It came out very easily, with no damage.




Some folks have questioned about the before- and after- fit of the upper seat, so, here's a shot of the old upper seat before removal.  You can notice at about the 9 o'clock position, a few dimples in the seat.  You could definitely feel them with your fingernail, or a sharp screwdriver.  Looks like I really needed to do something.  I was curious going in if this all was really necessary, or would a cleaning and re-greasing have sufficed.

[kirkn]

Here's a look at the upper bearing seat 'ledge'.




And, a look up at the lower bearing seat 'ledge'.




Here's a look at the upper bearing race.  Again, you can see the dimples from being overtightened.




OK, the next order of business is getting the lower seat off the steering stem.  It's pressed on, so some beating will be in order.



The stock dust seal was still soft enough to stretch over the seat and remove.




Using my bronze drift, I was able to remove the lower seat.  Overall, it was not difficult.  A few whacks and it moved, and I was able to work it off.






And, a look at the steering stem with lower bearing seat removed.

[kirkn]

OK, according the the (very meagre) instructions, you need to determine which spacer, if any, needs be installed under the new lower bearing.  This is determined by measuring the 'stack height' of the old set and comparing it to the new set.

Here's the partial reassembly of the old set.  The grease just holds the balls in place, for now.  Note that the bearing balls, once cleaned, were in very good shape - no rust or pitting.  Ah well.




OK, so, once all reassembled, the new lower bearing set is clearly 3 or 4 mm shorter than the old set.  If I installed the new set without any spacers, the steering stem would be positioned 3 or 4 mm higher into the frame neck, and the lower triple clamp would interfere.



The thin spacer put the stack height right where it needed to be.  That's the one I'll use.



Just for grins, here's the thick spacer.  It was 3 or 4 mm too tall.

[kirkn]

So, just for grins, I decided to do this "stack height" check on the upper set too.  Not strictly necessary, because there's nothing you can do about however it comes out.  It is what it is...




Hmmm.... it seems that the new bearing set is 1 to 2 mm taller than the old set.  Weird, given that the lower set was SHORTER.  I wonder if this is going to be a problem down the road.  Hold that thought...



Here's a mock-up of how I'll press the new lower bearing onto the steering stem.  I decided to use the PVC pipe method others have suggested.  Plus, it was all I had on-hand.    We see the thin spacer is in place, along with the new lower dust seal.  I'll use the thick spacer as something to beat against.  The thick spacer presses against the inner diameter of the new bearing, so the bearing won't get damaged during the install.





Oops, sorry guys, gotta go run some errands.  I'll continue this thread later this afternoon.  Stay tuned...

[Jay B]

Keep it coming, I'm about to do this on my '77 550k.

[05c50]

Nice job,great pictures. We'll be holding our breathe to see how this turns out.

.....Paul


   Kinda reminds me of 3rd grade oral book reports....always leave the audience hanging!

[kirkn]

Welcome Back!

OK, next step was to attempt to shrink some of the parts by putting 'em in the freezer.  Hopefully, this makes them fit a little easier.  Hmm.. not so sure it helps, but it doesn't hurt.  Shhh, don't tell the missus...  She was out shopping on 'Black Friday' anyway. 




Here's the initial installation of the upper bearing seat.  The hammer was just to gently get things set.



Then, using the bronze drift, it was pretty easy to tap the seat home, snug against the ledge shown earlier.




Here it is set fully home.  It definitely sticks up higher than before, but the end result may be OK.




The lower bearing seat goes in the same way.  This was a little more fussy, as the seat goes deeper than the pipe it fits it, so my bronze drift is a little clumsy trying to catch that tiny little edge of the new seat.  But, eventually, it got fully seated.  You can see it still sweating from it's time in the freezer.  Altogether, the steering stem and the two bearing seats spent about 3 hours in the deep freezer.

[kirkn]

Next up was the most difficult, least do-it-yourself aspect of the whole project:  getting that lower bearing pressed on the steering neck.  It worked, but it took some creativity, more force that I expected, and perhaps more tools or material that one might have around the house.

First was to warm up the bearing in the oven to expand it in the same way I tried to shrink the stem itself.  Warmed it up to 195 F in the oven.  I was too chicken to go any warmer, but hotter might have made it easier to fit.




Here, I'm just getting started.  Hot bearing and cold steering stem.  We'll see...



This took a lot of wailing.  I eventually turned the 'assembly' upside down, and hammered on the bottom of the lower triple clamp, with the PVC pipe set on the concrete floor.  It was a 10" long piece of PVC pipe, with a length-wise slit sawed in it.  Pretty thick wall, too.  I forget what they call it - schedule 40?  schedule 80?  Good thing, because it took a bit of beating with the small hand sledge.  A regular hammer was pretty light.



But, all in all, it worked.  Everything set tight against the triple clamp, seal in position, and bearing still very free to spin!

[kirkn]

Next step - grease the bearings.  Standard tapered roller bearing greasing procedure, although it's a bit more difficult when the bearing is installed!



upper bearing




Then, go ahead and insert the steering stem back in the frame.  Have the upper bearing handy and the upper dust seal and the nut handy and put it all back together.  Here's a closeup of the bottom end, where we can see that the 'elevation' looks correct.

[kirkn]

At this point, I'm in a bit of a dilemma - how to set the tightness.  The problem is, that new lower seal fits so snugly in the bottom of the frame neck, that the steering is snug just because of the drag of the new seal.   

So, I just went ahead and snugged it down by hand, until I could feel the bearings tighten, then backed it off  "a bit".  Very vague, I know, but I'm not sure what else to do.  The steering is slightly firm (because of the drag) but very smooth and of a uniform effort from lock to lock.

So, I installed the upper triple clamp and prepared to install the headlight 'ears'.  Here, I'm a little nervous, because of other reports of gaps being left, and because of my own earlier measurements showing the new upper bearing being taller than the old upper bearing.

Sure enough, here's what I have:




!@#$%^&*()(*&^%$#@!       

Well, just to be sure, I double-checked the bottom triple clamp fit.  Sure enough, it's positioned exactly at the same 'elevation' as it was in the "before" checks.  The chips in the paint on the steering stops line up exactly.

[kirkn]

So, where does this leave me?

This all means that the upper triple clamp has been moved upward by 2 - 3 mm compared to how it was stock.

However, the new upper bearing is fully seated in the steering neck, as we saw earlier.  Then, the upper dust seal sits on top of the upper bearing, and the adjuster nut fits on top of that and is set properly.  Since the triple clamp "sits" on top of that adjuster nut, I conclude that it is sitting up a mm or two too high.

And that's where I am this afternoon.    Sorry to disappoint.


My plan is to remove the upper dust seal, since it doesn't really seal against anything anyway.  The upper adjusting nut has that built-in curved dust shield, so I think I'll be OK.  That'll gain me a mm or so, as it was pretty thick.

Then, the underside of the adjuster nut has a raised castellated surface that used to fit around the upper bearing race.  Now, however, it just acts as a raised surface.  I think I'll grind those raised surfaces off, lowering the adjusting nut and thus, the upper triple clamp. 

Between the two, I should gain my couple of mm back, and the ears will fit snugly once again.  Otherwise, I'm going to have to come up with my own spacers or shims to make them snug.  I could also just leave it the way it is, and fabricate 'thicker' spacers and be done with it, as I have seen others have done.  But, that doesn't appeal to me either, having some home-made spacer showing.  I dunno.....

Right now, I have a total of about 1 man-day in the project.  This extra work shouldn't take THAT long, and I'll photograph it as I go.  My bike won't go back together the rest of the way right away, because I also have to rebuild the front brake caliper, replace the front wheel bearings, change the fork fluid and lube all the cables.


Any comments?  Can anyone see where I went wrong?  Otherwise, this should be a pretty universal description of the project - of it's steps, pitfalls, and possibilities.

Other than this snafu with the height of the upper triple clamp, it's a completely straightforward project.  Perhaps a few specialty tools (bronze drift, small sledge, slit PVC) but otherwise, straightforward.  Still, if it weren't for the dents in my old bearing races, I'm not sure this would've been worth it.  Although, my riding style is very tame and undemanding, as are the flat, straight Central Fla. roads where I live.  In other words, I'm not sure I'm good enough to even notice the difference between properly functioning ball bearings, and properly functioning tapered roller bearings.

Kirk

[754]

Take a few mm off your top lock/dust shield piece.. best done in lathe to get parrallel or by some other means.

 Or You could mill  3 or 4 mmoff the underside of your top tree and leave the locknut alone. Will require washer under top nut.

 Another way but 2 late for you, would be to turn 2.5 or 3mm off the bottom tree if there is clearance