What's with my crooked Norton?!

Nielsen · Apr 11, 2015

I should have noticed this before, but..... As you can see from the photo, the rear wheel is closer to the left side than the right--which makes it look off-balanced according to the fender and light cluster. I respoked the wheel last winter, exactly as it was before (with the correct spokes from Walridge) and it is true to within 2 thou. I just measured the front of the tire, and it is 1/4 inch closer to the front side of the swing-arm on the left side of the bike than the right, but it is much more so than that on the rear. Is this alignment? I have the Haynes manual and the Commando workshop manual, but neither say how to check the alignment and adjust it--just to do it. Meanwhile, the frame is straight as a die--as far as I can see. I'd be grateful for an assessment and solution. Cheers.

Rohan · Apr 11, 2015

Hard to see anything much with that great big (but pretty) numberplate blocking everything !!

You don't say what year it is, but the rear mudguard can slide about a bit on its mounts (sideways) a bit, unless they are firmly tightened down.
You sure the guard simply hasn't drifted sideways a bit ??

That rear tire does look fairly close to the chainline, in that view.
It might just be the perspective though ?

Have you tried loosening the axle nuts, and adjusting the back wheel so the chainline looks perfectly straight,
and see where the rear tire sits against the swingram both sides ?
It could just be rear wheel location/alignment, like you say.

We can confidently say the rear blinker function on the left side there is not up to much...
hth.

Rohan · Apr 11, 2015

P.S. A photo taken from higher up, so we can sight down the frame backbone and view where the tire is in regard to that may show something too.
Its the tire location to the centreline of the bike that gives you straight steering.
If you haven't noticed anything, it can't be too bad ?

Nielsen · Apr 11, 2015

Dohhhhh.... not a good photo. Here it is without the license plate, and one from underneath showing the chain. It looks straight to me. The fender appears to be about 1/2" off to one side against the rear frame--measured right at the back by the light post, but the wheel is clearly well more than 1/2" off centre. I'll get one taken along the spine of the bike too, and post it, though viewing with my inexperienced eye it looks pretty straight.

As for the comment about my dysfunctional left turn signal. No way. It's my new system. The wire goes up the rider's arse and then he holds the bulb in his left hand. Signal as usual. Saves energy.

Nielsen · Apr 11, 2015

Here's one taken from higher up. I'm not an experienced rider, but I certainly didn't notice anything weird about the handling. Oh yes: it's a (early) '74.

YellaPeril · Apr 11, 2015

Since you say that it was re-spoked, I will guess that the rim was not properly offset from the hub.

Rohan · Apr 11, 2015

YellaPeril said:
Is the rim improperly offset from the hub?

Thats what he is asking.
Looks like it, doesn't it.
Maybe the offset is done the wrong side (?).

Can you take the wheel and shove it side-to-side, while up on the centrestand. (don't push the bike over !).
If your swingarm pivot is worn, the wheel can sag sideways a bit.
Shouldn't affect the clearance to the swingarm each side though....

Have you tried undoing the axle nuts, and playing with the wheel adjustment/chain adjustment ?
The chain alignment doesn't look too bad, but a slight twist to the wheel location doesn't show as much.

May (ultimately) need to see a pic of the bare wheel out, to view wheel offset.
If it doesn't affect the riding, maybe later than sooner ?

Nielsen · Apr 11, 2015

YellaPeril said:
Since you say that it was re-spoked, I will guess that the rim was not properly offset from the hub.

Can you please explain this. I respoked it based upon the way it was when I bought the bike--broken and welded spokes and all--and used the spokes I bought from Walridge (two different spokes for the rear). I didn't notice, unfortunately, whether or not it was off-set before I started to respoke. How do you achieve an off-set? This sounds like it might be the problem.

gjr · Apr 11, 2015

My rear tire looked a lot like that before I straightened the frame. If everything looks lined up except the centerline of the tire and the top frame tube and it rides fine, summer's coming, ride it. Have a look at the frame next time you have the motor out.

Greg

CanukNortonNut · Apr 11, 2015

Your spine looks straight but you have to favor the right side for the offset.
Take the tire off and put the rim/hub back on the swingarm with the spoke nipples showing. These should be closely aligned to the spine centre....that is if you have all the spacers in correct on each side of the axle.
Re check with the parts list for this year bike.
Tom
CNN

jug · Apr 11, 2015

I had a wheel re-spoked years ago and it looked just like that. Guy that did it, didn't give it the offset. I now do all my own wheels. The rim should not be centralised on the hub' it should be offset.
JUG

Hobot · Apr 11, 2015

Most the untouched factory Cdo's have rear wheel offset to LH on spine-loop center along with the whole power unit, commonly between 3/16 to 3/8". So nothing may be wrong with yours except not yet changed rim geometry for a better rear view. On my factory 750 I just fudge the fender over a bit so only picky Nortoneers notice. Its a decorative issue only - unless flying Princess on pees then can sense a tad more effort-delay to fling to RH with rear rim re-centered to symmetric view rather than to center of gravity.

Danno · Apr 11, 2015

I remember seeing a diagram that illustrated the wheels being offset 1/4" from the centerline of the frame, but that looks like more than that.

Wheel alignment can be achieved and maintained by using two long straightedges and then counting flats each time the chain is adjusted. If you have a different-sized wheel on the rear, you must measure to both sides, front and back to the front wheel and have the same measurement (50% of the difference between the wheel widths) at all 4 points for alignment to be correct. Once the wheels are in line, you can assess any offset.

dero · Apr 11, 2015

The long straight edges will be a fairly simple way to find out what is going on .
It won't tell you what the problem is , but it will tell you if you have a problem .
You will need a friend and a good straight edge , or very carefull use of a stringline .

pete.v · Apr 11, 2015

I believe the rear offset is 3/16" It appears they have gone in the wrong direction.

This means you need to bring it back 3/8", rim to the right or hub to the left. Your choice. 3/8" may not seem like.

Before you do anything, check your dimensions.

And don't forget to check the front.

Hobot · Apr 11, 2015

Might want to study the NOC-UK lore on asymmetries and the confusing terminology to get straight.

http://www.nortonownersclub.org/support ... el-offsets

pierodn · Apr 11, 2015

Hi.
I respoke the rim with early hub 3mm off on the right, and 4 mm with cush drive hub.
Is the rim that goes offset not the hub.
So the tire is in the centre and in line with the front.
Ciao
Piero

Dean · Apr 12, 2015

Just doing my back wheel now so have an interest in this thread. Should the rim be entered with the swingarm? That's what I'm using to line it all up as I had a 16" rim on it when I got it ( choppered ) it seems right when I get the offset measurement from oldbrit tech notes. Just want to check. BTW 68 commando bolt up rear hud (no Cush drive)

Thanks and sorry for the small hijack

Deets55 · Apr 12, 2015

Nielsen,

It is my understanding that both wheels should be centered in the frame and in line with each other. Assuming your frame and rear hoop are straight, you need to get your rear wheel centered between your hoop by adjusting your spokes. I did this by dropping a weighted string line over the frame hoops directly in line with the rear axle. Then measured in to either the rim edge or center. These measurements should be the same on both sides.
Two things to be careful with. The wheel should be as straight in the frame as you can get it. You will probably need to remove the tire because when you adjust the spokes you will have to be certain none are protruding into the tube/tire area. Once trued in the frame take it off and compare to the numbers that are available from Buchanans. They should be very close.
Using a string line or straight edge on wheels that are not centered can lead to both front and rear wheels cocked in the frame.
After that you can loosen your fender taillight assembly and try to get it to look right.
All this is from trial and error on my part and seemed to work OK.
Good luck
Pete

gortnipper · Apr 12, 2015

I was working on my '74 yesterday, and noticed that my rear wheel lines up off-center as well (and I am sure the fender is a bit cockeyed to boot - this is why I haven't paid much attention, since the bike handles nicely and doesnt snake).

hobot said:
Might want to study the NOC-UK lore on asymmetries and the confusing terminology to get straight.

http://www.nortonownersclub.org/support ... el-offsets

At the end of this thread I saw this post:

Vernon Fueston said:
Commando wheel offset - the definitive answer
I have the definitive answer as to what is offset, how much, and which way!

I set up a 1973 850 on the frame table and verified it was straight. I then put together a dummy engine and installed it with new isolastics, new washers, Hemmings adjusters, and a Norvil head steady. I put both adjusters on the left side, checked the swinging arm in my fixture and then installed it in the frame. I took all the play out of the adjusters and started measuring:-

The frame is symmetrical
The engine/gearbox cradle is offset 1/8" to the left.
The swinging arm is offset 1/8" to the right so the axle pads end up centred in the frame
I then installed the rear wheel:-

The spoke flanges are offset 1/8" to the left as mounted in the arm, so the rim is laced off 1/8" to the right to put the tyre in the centre
The centre of the rim is 3.3/8" from a straight edge laid across the brake drum (not the backing plate
With the stock Dunlop rim, if you sight across the rim on the brake drum side you will see about 1/16" of hub when it's in the right place. In my opinion, front and rear adjusters should be on the same side. Otherwise as things wear and you take up the slop you angle the engine and gearbox in the frame. Since the swinging arm mounts to the cradle, a little one way in the front and a bit the other way in the back and the rear wheel is out of line considerably. The chain will still line up but the wheels will not.

Vernon Fueston (fueston@snowcrest.net) on NOC-L 22nd. Nov 1997

As my rim is centered towards the right tube (at front of rim, wheel true) when the chain is nice and straight (didnt measure it but with my finger thickness @ first knuckle

, is this "normal"? I have seen somewhat conflicting feedback on this, and am wondering if I need to dig deeper to see if there are other alignment issues?

What's with my crooked Norton?!

Nielsen

Rohan

Rohan

Nielsen

Nielsen

YellaPeril

Rohan

Nielsen

gjr

CanukNortonNut

jug

Hobot

Danno

dero

pete.v

Hobot

pierodn

Dean

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Deets55

gortnipper

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