Skip to main content
English French German Italian Spanish

Rogue ball bearing

After I rolled my ES2 off my (new!) bike lift, having removed and refitted the dynamo, I found a rogue ball bearing lying there looking at me. It measures 4.76 mm or 3/16".

I haven't a clue how it got there. Any ideas where it might have dropped from?

The bikes runs fine - so far!

George

Permalink

Never mind the ball bearing, what lift did you buy?!

Forks would have to be very lose for bearings to fall out, thereâs a ball in the crankcase breather but thatâs bigger I think, sounds to big to fit in the mag or dynamo, could it have been attached to the dynamo by magnet and you didnât notice?

Dan

Permalink

Got it on E-Bay from Martyns Bargains. £305 inc delivery.

I think your point about it attaching itself to the dynamo magnet is a good one, Dan. It did sit on my bench for a while.

If that's the case, I've now got to consider why I put it there......

George

Permalink

George......a possible answer to your conundrum may be seen within the attachment. After dismantling my ES2 completely and bagging all the smaller parts, I then discovered a small ball bearing on the garage floor. Thinking that I had dropped one from of the steering head races I counted up all the little blighters.....but all 17 were present and correct for each set. Also the rogue bearing was smaller. Later on, when moving the gearbox to a shelf, I also discoverd a mushroom headed pushrod plus another plain chunk of rod. At which point a light-bulb moment suggested a connection between these two rods and the erroneous bearing.

Please note, in the attachment photo, the distortion caused by the camera lens.

Attachments extra-ball-bearing-jpg
Permalink

That's right, Philip, I recognise the ball bearing that fits between the mushroom and clutch thrust rod. Prob is, I didn't remove the clutch or gearbox.

I suppose I could remove the clutch thrust rod from the timing side and see if the bearing is still in there. Although I've got a feeling that if you try and remove it from the timing side the ball drops out somewhere along the way - although looking at the exploded diagram, I cant see where.

George

Permalink

It would probably drop into the outer cover waiting to get caught somewhere....

You might have success with a magnet on the end of the pushrod although it would probably just stick to the mainshaft.

I would assume the shed fairies put it under your bike as a joke.

Permalink

From memory the clutch rod ball bearing is larger than 3/16" - maybe 1/4".

Oh no. Not the shed fairies again!

Geeorge

Permalink

Previously George Phillips wrote:

From memory the clutch rod ball bearing is larger than 3/16" - maybe 1/4".

Oh no. Not the shed fairies again!

Geeorge

It is at the actuator end of an AMC box. Around 10mm or larger. The ball in the photo I posted measured around 4.5mm and as can be seen is about the same diameter as the rods.

Permalink

Mine is a laydown mid 50's box, Philip, and my size assessment is from memory. If it is from the box, I can't for the life of me see how it got out - perhaps when I wasn't looking?

I prefer the idea of it being a spare bearing picked up when the dynamo was on the bench and going unnoticed. Maybe I prefer that solution as it doesn't entail removed the drive side to see if the bearing is still in place behind the mushroom!

George

Permalink

Is it coated with oil or grease that would suggest it may be from inside something or clean which you would not expect if it had come from a grease packed head bearing say or gearboxes oil filled internals.

Permalink

Hello George, wonder if the ball has fallen out of an extension bar or ratchet you have used . the one that engages with the socket to hold it on to the shaft.

Barry.

Permalink

I fail to see how the ball could have escaped from the clutch push rod, George. You have had the gearbox apart recently, I know, but I am sure you will remember installing the ball on re-assembly, wouldn't you? The ball should be the same diameter as the push rod, so if you can ascertain that measurement, it could save you delving into the gearbox to have a look, if this ball is a different size. Also would not the feel at the clutch lever be different if no ball is present? The absence of the ball would make the push rod assembly too short.

As to where it came from, Barry's idea is not without merit. Also folding kick start levers have a detent ball.....

Permalink

I'll check that Barrie but it seems a little large for my socket set.

I agree Ian. I can't see how it would have got out either.

Of course, I may have forgotten to put it in. In which case the extra 3/16" would be taken up on the spiral thread at the timing end.

My folding k/start is permanently tightened to "operating mode' as it keeps coming loose if I leave it adjustable. And it has no ball.

Back to the drawing board!

G

Permalink

My kickstart footie/kickie bit kept swinging out when I did not want it to. So I added a thin rubber tap washer under the nut which has helped.

Permalink

I'll check that Barrie but it seems a little large for my socket set.

I agree Ian. I can't see how it would have got out either.

Of course, I may have forgotten to put it in. In which case the extra 3/16" would be taken up on the spiral thread at the timing end.

My folding k/start is permanently tightened to "operating mode' as it keeps coming loose if I leave it in "foldable" mode. And it has no ball.

Back to the drawing board!

I think I have no choice - for my peace of mind - but to open the timing side of th g/box, remove the clutch actuator, put a magnet on the end of the thrust rod and slide it out hoping to see a ball on the end of it.

That's tomorrow sorted!

G

Permalink

Previously George Phillips wrote:

I'll check that Barrie but it seems a little large for my socket set.

I agree Ian. I can't see how it would have got out either.

Of course, I may have forgotten to put it in. In which case the extra 3/16" would be taken up on the spiral thread at the timing end.

My folding k/start is permanently tightened to "operating mode' as it keeps coming loose if I leave it in "foldable" mode. And it has no ball.

Back to the drawing board!

I think I have no choice - for my peace of mind - but to open the timing side of th g/box, remove the clutch actuator, put a magnet on the end of the thrust rod and slide it out hoping to see a ball on the end of it.

That's tomorrow sorted!

G

Hi George,

Don't forget to de-magnetise the pushrod before reassembly otherwise all the metallic swarfe in the box will stick to it and make lapping paste.

Dick

Permalink

Hadn't thought of that, Dick. Presumably belt the rod with a hammer?

On the other hand, the rod is enclosed in the mainshaft so it shouldn't be too much of a prob.

George

Permalink

Right. Down there first thing. Bike on lift. Outer g/box cover removed. Clutch disconnected and thrust rod withdrawn with a magnet on the end. No ball. I figured that didn't prove too much as the magnet may not have been strong enough to pull the ball through. I also figured that two balls would do no harm (as they say) so slotted the new one in but then realised that the clutch worm barely bit into its housing so out with the new bearing and put it all back together.

The new bearing is certainly of a lesser diameter than the thrust rod - 3/16" against 1/4".

Prior to lowering the lift I thought I'd check that I'd left nothing under it and whilst rolling round on the floor guess what I found. Another ball bearing!

Are the shed fairies having a laugh?

I'm beginning to wonder if it's off the lift? After all, it was made in China...........

George

 


Norton Owners Club Website by 2Toucans