G15 side stand and tacho ratios

Information relating to the Matchless G15 or AJS Model 33 750cc twin. This also includes the G15 Mk II and the G15/45
StuartN
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G15 side stand and tacho ratios

Post by StuartN »

Does anyone know a way of adapting the side stand so it stays where it is put so I can stop worrying about dropping the bike all the time?

Also can someone please explain tach ratios; specifically what tacho drive box (on the timing cover) do I need and what ratio on the tacho itself? It is most confusing. There are right hand and left hand drive boxes, different rations and reversing and non-reversing types.

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Biscuit
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G15 side stand and tacho ratios

Post by Biscuit »

If you fit some form of hook to the front bottom engine/frame uniting stud on the offside and hook the spring on there, the stand will retract.



ranger
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G15 side stand and tacho ratios

Post by ranger »

Stuart

Im not sure of your problem. Is the side stand on the G15 the clamp on type that locates against the inner engine plate, as on the P11?

The G15 Atlas engine should have a 2-1 tacho drive and a 2-1 tacho which is usually written on the tacho dial. If you take a look at the A Gagg & Sons website, there are some good descs/pics of the tachos and drives.

Tim
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Biscuit
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G15 side stand and tacho ratios

Post by Biscuit »

Made a cock-up there didn'tI!. Missed the fact that it was a G15 and of course I should have said the stand stays down



ranger
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G15 side stand and tacho ratios

Post by ranger »

No probs Alan, Stuart needs to expand his problem description a little as I'm a bit unsure of the exact symptom.

Tim
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Biscuit
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G15 side stand and tacho ratios

Post by Biscuit »

I think what Stuart is after is for his propstand to stay down when the bike is lifted, as with modern bikes. I know of several instances where owners, used to modern bikes have lifted their 'classic' from the offside, moved it a couple of feet and let it drop back on the stand, which of course as 'gone' - loud crash!!



StuartN
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G15 side stand and tacho ratios

Post by StuartN »

Alan is exactly right. Modern bikes and my old A65 (sorry won't mention BSAs again) have stands that stay either up or down but don't spring back when you move the bike or kick start it (won't try that again). I wondered if anyone had a modification for this.

ranger
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G15 side stand and tacho ratios

Post by ranger »

Hi Stuart

The G15 sidestand is designed to stay down or stay up. For this to happen, it needs the correct spring which expands just enough to keep the stand in an 'overcentre' position when pushed down. Also, it needs to be the correct stand and not be worn. Check for wear on both the stand and frame lugs and get the correct spring from the club. Glad you are not going to kickstart the bike on the sidestand again! Kickstarting and letting the bike run on the side stand is an emotive subject but one practise that I would never do. The effort required to get the Atlas engine spinning to start, particularly if wet sumped, puts an enormous strain on the sidestand lugs, stand, and single retaining bolt. With the components being many years old I would advise being very careful as you may find your bike lying on the ground, possibly, with you underneath it. I would certainly recommend putting in a new correct 'high shear strength' bolt for peace of mind.

Tim
Don Madden
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G15 side stand and tacho ratios

Post by Don Madden »

I'm not sure about the G15 but on my bikes from 1956 to 1962 there are two small holes in the R/H lower engine rail, on the inside, lower area & just behind the front engine mount. They are spaced equally to the larger formed hook on the spring. The spring is fastened by feeding the hook into one hole & out the other. If fed into the forward hole first, the stand will stay down, & if the rearmost hole it shifts the spring behind the over-center point of the pivot & the stand pops up when the weight is taken off. These holes are often covered over by filth, paint, etc.
Cheers, Don Madden.

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