Steering Yoke conundrum....

olympus

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Hi There
Started assembly of the steering head bearings spacers yokes etc.
something is clearly wrong. So where we are

  1. New bearings & spacer set ordered & fitted from AN (OE was single ball set up). Bearing are seated right down against registers in the tube, removed and refitted bearings without spacer measured internal & external and there the same, so i know that the spacer isn't holding bearing off the registers.
  2. I always knew there is something odd about my bottom yoke as i cant find this design listed/available anywhere and certainly not two lock stops welded onto the steering head tube
  3. Or indeed a removeable bolt on inverted "T" lock stop
But this is what was in the "package" so i thought OK
This is where it starts to go wrong

  1. There isn't enough thread on the shaft to fit a lock washer & barely enough thread to get a full nut
  2. When you insert OE headlamp support brackets, the distance between yokes is excessive
I'm thinking that changing from single ball the ball bearing sets is causing the problem, but I'm told repeatedly these are a straight swap & the bearings are seated corrected
So is there something wrong with the bottom yoke set up?
But looking at what units are available this would mean the two existing lugs on the tube are wrong, but they look right even with ground chamfers on them??

I'd appreciate the wealth of your knowledge.

Thank you





 
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is there a washer between top of bottom yoke and bearing , it seems I see something ??? first pic the right one ..............
 
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There is something odd going on as the spacer tube should hold the bearings apart so that they do not both touch the bottom of the seats, the top one should as it is the short recess but the bottom one should not as this is the long recess. Is this supposed to be a 72, if so the headstock stops and the yoke stop are not factory for 72, in which case it looks like you have a mix of parts and what ever you have, they are holding the yokes too far apart.

The washer is a dust shield and too thin to keep the yokes that far apart.
 
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how about,.... Those yoke stops are the same as my '70 model's stops, so maybe you have an early frame with a new ID plate on it..

Explaining why the yoke won't seat all the way might be because you removed the upper portion of the old bearings, but the outer race is still seated in the yoke, preventing the new sealed bearings from seating lower. I'm just guessing of course, because I don't know how the later model is set up being that I've never owned one...

So, pull the new bearings and make sure you didn't leave an old part in place that should have been removed.
 

Craig

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B9E00B3D-0987-40F5-843E-C08CD1B871D4.jpeg

5FD8C5AE-D498-4213-905B-8379424E83FD.jpeg

This is my ‘72 setup , matching #’s have replaced bearings years ago , AFAIK all original ..
 
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From Craig's pictures of his '72's steering stops, it seems like you might have an early frame with the same stops as my '70 model. (unless someone welded those stops in place at a later date for some reason) You can differentiate the frames by the cross member placement under the engine and the type of side stand/ center stand the bike has. Certainly you could have an early frame with a later cradle and swingarm, so looking at them doesn't explain the steering stops on the yoke...

Maybe one of the many norton savants here will explain it better... or correct me.
 
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The wrong yokes for that frame.

Tell us a lot more about this bike. Did the yokes fit before you put in the new bearings? Is this a new restoration?
 

olympus

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There is something odd going on as the spacer tube should hold the bearings apart so that they do not both touch the bottom of the seats, the top one should as it is the short recess but the bottom one should not as this is the long recess. Is this supposed to be a 72, if so the headstock stops and the yoke stop are not factory for 72, in which case it looks like you have a mix of parts and what ever you have, they are holding the yokes too far apart.

The washer is a dust shield and too thin to keep the yokes that far apart.
Thank you..
But surely if the bearing are both in contact with their respective registers and the spacer tube is nipped.. which it is, then the lower bearing is sitting deeper in the head stock tube so would ultimately give me the opposite problem to what i have.. or am i missing something??
 

olympus

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The wrong yokes for that frame.

Tell us a lot more about this bike. Did the yokes fit before you put in the new bearings? Is this a new restoration?
The yokes were fitted into the headstock, but i diddnt really take that much notice on the pull down...
I know the frame is early as the lower engine cross tube was rearward with the early side stand mount.... it doe have both upper frame tubes fitted
 

nortriubuell

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Toss the bearings ... AND THAT SPACER; cheap rubbish and a very poor design IMO. Save yourself some grief ...

Even the OIF Triumphs ... AND ALL other modern bikes that handle, use tapered roller bearings. Just my 2 cents ...
 

Fullauto

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Toss the bearings ... AND THAT SPACER; cheap rubbish and a very poor design IMO. Save yourself some grief ...

Even the OIF Triumphs ... AND ALL other modern bikes that handle, use tapered roller bearings. Just my 2 cents ...
Hahaha. There is absolutely nothing wrong with the standard Norton bearing setup. Tapered rollers are, quite simply, not needed in this application.
 

baz

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Toss the bearings ... AND THAT SPACER; cheap rubbish and a very poor design IMO. Save yourself some grief ...

Even the OIF Triumphs ... AND ALL other modern bikes that handle, use tapered roller bearings. Just my 2 cents ...
I don't think taper rollers are used much these days on sports bikes
I think they have gone back to balls and cups for better steering ?
But don't quote me
 
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Thank you..
But surely if the bearing are both in contact with their respective registers and the spacer tube is nipped.. which it is, then the lower bearing is sitting deeper in the head stock tube so would ultimately give me the opposite problem to what i have.. or am i missing something??
If both bearings are fully engaged with their registers and the tube is left out and the yokes are still too far apart then the registers are in the wrong place for the parts you have. So either get the registers closer which needs the frame placed in a milling machine or get parts modified or changed. I will measure a 72 frame tomorrow and get the distance inside the headstock between the registers.
 

Time Warp

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Edit... (Its most likely that wonky triple and rightly so if it was from a taper bearing bike as I see posted now, check the 36.5 mm measurement.
The taper bearing head and ball bearing head would have to be different and the part very well not interchangeable without some machining of the triple.
#
If you have seated both bearings in the frame with the inner tube removed, either the lower triple clamp is thicker (That one does not look OEM ?)
A 1971 lower triple is around 36.5 mm thick, the steering stem is around 193 mm from under the top triple to the shoulder where it drops down to the (top of) thread.

If you have used tapered rollers then there will be a difference and the head light ears remark suggests that or the problem is that lower triple clamp pushes the distance out.

#
Normally when taper roller bearings are used over the ball bearings the head light ears are almost floating between the upper and lower triples, the reason I machined the lower triple bearing contact face to decrease that measurement.

This is my 850 but the picture up the page from the OP (and it might be the picture) makes the triple stick out look excessive.
This is with the superior tapered roller bearings (axial and radial loads) with a acetyl dust shield.
This is without the locking plate and before I machined the top surface but still had good thread stick out.

IMG_5807 - Copy.JPG
 
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Is that dual stops on the steering head normal ?
Yes, the dual steering stops are normal for my '70 frame. In fact, I thought they were all like that until I saw this thread.



It's obvious that Olympus has a mismatched front end because the early yokes didn't have a nut on the bottom, and his pictures show a nut there. He has the early frame steering stops so somebody did some mixing and matching somewhere along the line. It would be interesting to measure his front end and see where his trail numbers are, being that he has greater offset and a steeper rake, his trail should be smaller than a standard commando's. (rumoured to be potentially dangerous)
 

Time Warp

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Yes, the dual steering stops are normal for my '70 frame. In fact, I thought they were all like that until I saw this thread.



It's obvious that Olympus has a mismatched front end because the early yokes didn't have a nut on the bottom, and his pictures show a nut there. He has the early frame steering stops so somebody did some mixing and matching somewhere along the line. It would be interesting to measure his front end and see where his trail numbers are, being that he has greater offset and a steeper rake, his trail should be smaller than a standard commando's. (rumoured to be potentially dangerous)
Sorry I edited that out as I was adding more to my post and was doing so as you were replying.
The early bike had tapered roller bearings as far as I know and had the means to set them unlike the budget move to ball bearings (most likely a cost cutting measure only based on 50000 Commando's in total)
I know nothing of the geometry of the early to later 750's but am all ears.
 
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I saw NO mention of tapered roller bearings on OP bike.
Only mention was of AN kit which MAY have been intended to put regular late 6205 ball bearings in an early frame with early triple trees.
HE DOES NOT HAVE EARLY TRIPLE TREES! so the kit wont fit and...it will be too long when using late triple trees.

Early commando front end set up is the same as atlas and therefore are both cup/cone races with seperate balls.
Never seen tapered roller bearing on any factory (production) commando set up, only after market mods...
LES: beat me to the enter key
 
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