Frame Earth or not.

Previously Andrew Wibmer wrote:

Hello,

I understand the point of supplying a separate earth from the headlamp as earthing through the headset ball race cannot be good for either the earth, nor the bearings. However is it worth going the whole hog and running a separate earth for all the components back to a common earth say in the battery box? removing all those poor connections from painted and oily pinch bolts etc. Also would that reduce any electrolysis. Of course the frame would still be positive due to the engine connections etc.

Andrew

Hi Andrew,

Yes, the only reason NOT to do it would be the extra wiring and additional weight. If you have the space then the former is not an issue. And weight should not be either.

Go for it.

Regards

Tony

Hello Andrew,

Apparently all petrol tankers were wired this way; i.e the chassis/frame was not used as the earth. It had something to do with safety; i.e potential sparks and petrol should be kept well apart

This bit of useless/useful information may be completely out of date as it comes from years back when petrol tankers were 8-wheel Atkinsons,/ Leylands,/AECs, etc. But I do use a heavy duty earth cable from the battery to the engine on both Jubilees and Navigators to ensure good engine earthing.

Patrick

If you are not obcessed with orriginality you can put in an earth ring and bring all the earths to a point near the battery and then have a nice tidy single decent gauge wire to the battery.

Robert:

Earth ring???

Can you post a photo of what it looks like?

Andwhere would it be located?

Thanks

Mike

Is this what you mean with earth ring?

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That will do, My bike is enclosed so all manner of non std stuff is hidden, I use a large chock block cable tied to the frame to collect all the earths !. Also no soldering, or silIy flimsy modern wires!!.

As a motor cycle electrical person for over 50 years I would use neither of the above. (hopefully that now means the cat is sitting comfortably with the pigeons!) The gubbins you show as an earth ring might be useful on a model railway, the vibration on a motorcycle will tend to loosen the Lucas. Choc blocks-mightbe at home in a domestic electrical environment but they have no use on a classic motorcycle! They are a bodgers answer to a problem, and the British weather will soon rust up the screws.

A decent crimped bullet or soldered bullet and the job is done. As for earth rings the usual answer is brass (several sizes available) rings that crimp/solder on to the wire which is then bolted to the frame. Robert Tuck above has part of the right idea one decent size wire to the battery. If you have mullty earths to the battery and one wire falls of-trouble especially as some use different colours and then you can't remember which terminal it went on!! Sounds like 'smoke' is about to happen.

Have to dissagree Alan,( is that even allowed?), My 99 has a 1960 version of a chock block in place that has given no trouble for 58 years and still uses the orriginal wires, its called a PSR8 switch!!. One of the screws is a bit chewed up ,may have to splash out on a new screw. The ring earth system has been used on cars for many years (with better connectors granted) and is usually put somewhere totally inacessible. I prefer a super size chock block.Each to his own.

Right, the picture I showed, was only meant to clarify what I thought Andrew meant. Used these in a sealed box on a truck. I,ve had problems with the bullet connectors coming loose on Nortons some 50 years ago, don't know if modern ones has better quality. I've also found that there is a lot of spade crimp connectors of inferior quality nowadays. One thing that I have had no problem with so far is a bolt and ring crimp connectors plus star washers. But as Alan said, if exposed to harsh weather you can get problems.

As Robert said, a decent gauge cable from battery to earth point is needed. I'd like to add that the earth wire to the headlamp shall not be too thin. Bad light is often due to a substantial loss of voltage in the wiring. If checking voltage on the lamp you can be surpriced. Sadly this applies even on brand new vehicles.

I have a confession to make

I have a new wiring loom for my 1965 Jubilee and I installed it without any idea what went where as the bike had no loom previously.

The earth lead on the loom is very short where it leaves the loom just beyond the battery box and has a ring connector. I assume this is the frame earth and the only convenient place it seem to reach was the frame spacer under the seat. I duly cleaned the surface on two of the frame spacers, slid the ring connector between them and passed the bolt through and tightened everything up. Job done.

Having read this thread I thought I would check the earthing on the frame using a multi-meter. To my horror, there was no continuity at the frame earth. It the dawned on me that this particular frame spacer is rubber mounted as it also holds the battery box and oil tank. Needles to say I will find a better place to mount the frame earth and I will include a new earth wire to the engine.

Just goes to show that posts on this site can be informative and thought provoking.

Dennis

I always put in an earth lead on the engine . Ignition systems often rely on the earth through the engine which is often mounted on rusted /greasy/ painted/powdercoated plates.

Aha Mr Tuck, Seems I am part wrong/right re the 'choc block' as you say the PRS8 can well be considered as a 'choc block, but it has decent size Brass screws. And the plastic is bakelite I think superior to the nylon we have in some 'choc blocks'.

On the Navi there is more earths-the battery charging-earth, might be a reg/rect or rectifier, then there is the battery. Just to aggrovate (rubbish spelling) some more, I have often done talks on bike electrics to the club members, and the first thing I point out we do NOT use is sticky tape, time and again I have seen it used to cover up some bad bodge, it usually come loose in the rain. The manufacturer never used it, do the job properly.

Previously Alan Osborn wrote:

Aha Mr Tuck, Seems I am part wrong/right re the 'choc block' as you say the PRS8 can well be considered as a 'choc block, but it has decent size Brass screws. And the plastic is bakelite I think superior to the nylon we have in some 'choc blocks'.

On the Navi there is more earths-the battery charging-earth, might be a reg/rect or rectifier, then there is the battery. Just to aggrovate (rubbish spelling) some more, I have often done talks on bike electrics to the club members, and the first thing I point out we do NOT use is sticky tape, time and again I have seen it used to cover up some bad bodge, it usually come loose in the rain. The manufacturer never used it, do the job properly.

Just to be obtuse ,I always have some "sticky tape" wound round some part as a back up if I have to do some "twist wire " repair on the road. I use Silver DUCT tape which does not come off!!. Has to be cut off . Wiring problems are very rare ,component failure from old age or sub standard parts has been the issue. A rectifier, Two alternators ,both 50 years old and an 80 year old dynamo , all in the last year. Mind you the wiring to my pacemaker gave up ,only 10 years old and fitted by experts!.