Steering Yoke conundrum....

L.A.B. said:

Early Commandos had cup and cone bearings.

https://andover-norton.co.uk/en/sho...t-incl-balls-dommi-early-commando-2-per-bike-

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Thanks for the reply, I thought I had read it here but maybe it was a change to tapered rollers related post but the means to adjust clearance on the early bike having cup and ball makes sense though. (It would make going to a taper bearing easy over the later bikes)

That being the reason I (mistakenly) regarded going from a tapered roller as a step backward (but is not the case as there was no taper as standard so clear on that now)

baz said:

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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Baz.
A lot of newer bikes do have a cup and ball (Toyo) type steering head bearing but the balls have a plastic cage so are a little more upmarket. I do know Suzuki use those on many models but those that might see a higher load (DR650SE for one) have tapered rollers as stock.
Before installing tapered rollers in the 850 I had looked at the Toyo caged cup and ball but the size availability did not suit the Norton needed dimensions (either way to big or way to small) but would have gone that route if something had been available as the first option.
The outer makes them almost angular contacts.

Time Warp said:

Thanks for the reply, I thought I had read it here but maybe it was a change to tapered rollers related post but the means to adjust clearance on the early bike having cup and ball makes sense though. (It would make going to a taper bearing easy over the later bikes)

That being the reason I (mistakenly) regarded going from a tapered roller as a step backward (but is not the case as there was no taper as standard so clear on that now)



Baz.
A lot of newer bikes do have a cup and ball (Toyo) type steering head bearing but the balls have a plastic cage so are a little more upmarket. I do know Suzuki use those on many models but those that might see a higher load (DR650SE for one) have tapered rollers as stock.
Before installing tapered rollers in the 850 I had looked at the Toyo caged cup and ball but the size availability did not suit the Norton needed dimensions (either way to big or way to small) but would have gone that route if something had been available as the first option.
The outer makes them almost angular contacts.

View attachment 11606

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Yes the only ones I seen have a cage

Time Warp said:

I know nothing of the geometry of the early to later 750's but am all ears.

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There's definitely more than one variation to the way the yokes and steering head were fabricated, so there's no simple either "A" or "B" situation.

This thread was packed with info... Page 3 was a good one if you want to start there.

https://www.accessnorton.com/NortonCommando/rake-and-trail-specs.10734/page-3

dynodave said:

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...

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Some '69-'70 owners have reported finding apparently original angular contact bearings and felt washers.
https://www.accessnorton.com/NortonCommando/69-steering-dissasembly-stuck.13322/page-2#post-188336

There appears to have been a change of headrace bearings for '69 as the parts supplement lists:

"18263...Head races ... 2
15691...Head race felt... 2
"
If 18263 is searched at AN it comes up equivalent to the later '71-on 06.7604 sealed ball bearing!
No result for 15691.
https://andover-norton.co.uk/en/shop-details/17179

Dimensions from 72 frame.

Headstock overall length 161.6mm

Top bearing register depth 14.7mm

Bottom bearing register depth 20.6mm

Calculated distance between registers 126.3mm which is less than the 129mm of the spacer ref Dynodave so makes sense.

Dimensions from S1 frame (68-70)
headstock LOA 161mm (scaled)
top bearing register 14.7mm
bottom bearing register 14.7mm

Time Warp said:

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.

View attachment 11605

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Hi Time warp,
Can i ask where you obtained

L.A.B. said:

Early Commandos had cup and cone bearings.

https://andover-norton.co.uk/en/sho...t-incl-balls-dommi-early-commando-2-per-bike-

Click to expand...

Hi Les looking at my options, if i convert back to cone bearings, will this give me the extra shaft protrusion through the bottom yoke i need... don't really want to go this way, but may have to
Or is it that my set up is so way left field its anyone's guess??

Thank you

Or just get the correct yokes, and whatever kit converts them to modern sealed bearings. That would increase your trail distance slightly, which you probably wouldn't notice. My '70 model yokes are the original 2 1/4" offset and are still on the original bearings with no issues. The steering stops on the headstock work with the original yokes too...

olympus said:

Hi Time warp,
Can i ask where you obtained

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I got off the shelf tapered roller bearings, but they need some added work to get them to a set up I am happy with.

https://www.accessnorton.com/Norton...head-bearings-removal-2016.20710/#post-423296

Olympus, I will stick my neck out for the chopping block but...
I had seen another thread and noted I had posted at the end of (regarding steering head bearings, might have been taper related) and not noticed it was some 6 pages long.... so ended up reading it from the beginning, some of the replies were a shock as far as mechanical aptitude.
Just because you can do something and get away with it does not mean it is right and that thread proved it.

If you swap a later bike out to tapered roller steering head bearings only an idiot or someone who knows no better will leave the inner spacer tube out.
There is no form of vernier adjustment so the inner tube is used to set the bearings.
The end result is flawless rotation and a breeze to set up once done, simply torque the bottom nut which you can not do with the inner spacer removed, the lower triple pinch bolts would become part of that equation if that Micky Mouse method was used.

kommando said:

Dimensions from 72 frame.

Headstock overall length 161.6mm

Top bearing register depth 14.7mm

Bottom bearing register depth 20.6mm

Calculated distance between registers 126.3mm which is less than the 129mm of the spacer ref Dynodave so makes sense.

Click to expand...

Speaking with a machine shop today, and looking at the above calculations from both yourself and dyno Dave i checked my headstock and indeed the lower bearing aperture is 14.7mm deep
So if i have machined off the lower yoke centre shaft boss 6mm i should be back to the correct spacing between yokes.

olympus said:

So could i ask what is the exact distance between yoke faces (not measuring the recesses for "O" rings)

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7 1/4".

Time Warp said:

I got off the shelf tapered roller bearings, but they need some added work to get them to a set up I am happy with.

https://www.accessnorton.com/Norton...head-bearings-removal-2016.20710/#post-423296

Olympus, I will stick my neck out for the chopping block but...
I had seen another thread and noted I had posted at the end of (regarding steering head bearings, might have been taper related) and not noticed it was some 6 pages long.... so ended up reading it from the beginning, some of the replies were a shock as far as mechanical aptitude.
Just because you can do something and get away with it does not mean it is right and that thread proved it.

If you swap a later bike out to tapered roller steering head bearings only an idiot or someone who knows no better will leave the inner spacer tube out.
There is no form of vernier adjustment so the inner tube is used to set the bearings.
The end result is flawless rotation and a breeze to set up once done, simply torque the bottom nut which you can not do with the inner spacer removed, the lower triple pinch bolts would become part of that equation if that Micky Mouse method was used.

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What was your reason for changing to taper rollers?

baz said:

What was your reason for changing to taper rollers?

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The short answer is because I can.
A taper roller bearing has no problem with axial or radial load and both of those forces are applied in the steering head one way or another.
I bought new 6205 bearings and then thought about using angular contacts but setting the preload would be time consuming, I then thought about a taper bearing in the lower for load with a 6205 in the upper for alignment but then just used the two taper bearings.
Of course the later bike has no means to adjust tapers so to me it is not a simple swap (unless you take the time to set the inner spacer tube length)

Does it matter, probably not, no doubt someone would post they had had the same 6205's in their Commando for 60 years and ran the bike on chip fat for the same time with no problem.

Its not that there is anything wrong with the stock bearing set up (The 6205 bearings are large enough to compensate for being in axial load) but to me based on what was used before and even that seems to be vague (cup and ball or angular contacts) suggests the 6205 was a budget measure based on a simplified triple clamp at a time when the company was under financial pressure.
My Moto Guzzi and three Ducati's of the same time period came stock with tapered roller steering head bearings but of course all have twin bearing adjusting rings which the Commando does not have hence the retained inner spacer tube in my case, done and dusted now and no doubt will never need touching again by me.
It can go in the same line of thought as the Continental radial tyres, not a necessity but can do no harm and might be an improvement.

TW
I'm pretty much along the same lines as you. I had thought of trying to do a tapered bearing set up and was going to do it by definitely using a spacer tube. The next step was to finish the job by measuring the slop using a long spacer (with shims) then removing some of the stack of shims to give me the "preload" I wanted. The inner column could then be tightened to far exceed the expected load, even if doing wheelies or stoppies. It is still a project to be finished among the other 999 to go...but my path and vision is clear.

The devil's in the detail DD.
There is nothing in this picture that did not need some form of attention before use and all name parts.
I need to knock a little shine off those lowers mind you.

What did the Pedge do to you?

kommando said:

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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Since the weight on the bottom yoke comes from above, it would make sense that the outer ring of the bottom bearing is driven home fully in the bottom recess of the headstock. The top bearing is only for radial fixation. You tap it in just so far that the inner ring just touches the spacer tube. Not sure about this particular model, but that is how it is for the Mk3, see Section G6 of the manual.

The bearing depth is 15mm, so on the ball bearing headstock the top bearing recess being 14.7mms the top bearing gets driven in to full depth and stops 0.3mms proud, the bottom bearing hits the spacer tube before it can meet its housing register.

The 68 frame i have is the pits and until i can replace it, this will have to suffice... so I'm having 5mm machined off the centre shaft boss to give me at the very least a full nut