Wheel Offset - AJS Mod 18s

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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rhunter
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Wheel Offset - AJS Mod 18s

Post by rhunter »

Both wheels are well off line when reassembling front and rear sections of 1952 AJS Model 18s.....does anybody know what the offset measurement should be for this bikes wheels............the front wheel is well off......the rim is 1 1/2inch from left fork and 5/8ths inch from right fork....should the rim be dead centre?..................Robbi
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saltbox alf
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Re: Wheel Offset - AJS Mod 18s

Post by saltbox alf »

As far as I know the rim should be central to the forks, the offset if any is from hub to rim depending on what bike you have.
The full width heavyweights are no offset.
Allons-y, amis de Matchless et AJS
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clive
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Re: Wheel Offset - AJS Mod 18s

Post by clive »

Have you pulled then spindle fully over to the left hand side using the nut on the threaded part of the spindle on the front wheel? The spindle does not sit equally in the forks but projects to the left hand side.
Similarly with the rear wheel have you included all the correct spacers, including the speedo drive?
clive
if it ain't broke don't fix
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Rob Harknett
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Re: Wheel Offset - AJS Mod 18s

Post by Rob Harknett »

As Clive suggests, Slacken off the fork clamp nuts and fully undo the spindle nut.
Line the spindle up flush with the forks. Tighten up the fork clamp nuts both sides.
Now tighten the spindle nut.
Marty
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Re: Wheel Offset - AJS Mod 18s

Post by Marty »

AMC rims are laced central to the hub. From memory , with a straight edge across the brake drum, there is 1/2" gap from the straight edge to the side of the WM2 rim
Marty
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Duncan
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Re: Wheel Offset - AJS Mod 18s

Post by Duncan »

Resurrecting this post to see if there is any update/confirmed measurements as I have a similar 1952 18s, the wheel looks original the rim is visibly nearer the drive side boss on the forks than the timing side (mislaid the actual measurements :roll: and the spindle is out now so I cant recheck but think the difference is around 5/16"), it has a single sided hub and the distance from the outer face of the brake to the rim is 15/32" to 1/2". Does 1/2" still stand for the single sided hub or is there more recent experience out there?
Mick D
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Re: Wheel Offset - AJS Mod 18s

Post by Mick D »

Hi

I've just stripped an original front from a 53 G9 - it's offset was 17mm from the brake drum face. The rear had a replacement rim installed and it's offset was 58mm from the drum face.

Regards Mick
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Duncan
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Re: Wheel Offset - AJS Mod 18s

Post by Duncan »

That's excellent information, thanks Mick.
Invicta
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Re: Wheel Offset - AJS Mod 18s

Post by Invicta »

Hi, Having just had my 1949 Model 18 wheels rebuilt I can confirm that the front wheel, if you have the 7" single sided front brake, is definitely offset. The distance from the edge of the brake drum to the edge of the rim should be 5/8" . I have just measured mine and it is not quite central in the forks being about 1/8" over to one side. When I checked the off set as best as I could with the wheel in. Mine measured 9/16" , which would account for the 1/8" difference. So the wheel builder didn't get it quite right, but I can live with that.
sno335
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Re: Wheel Offset - AJS Mod 18s

Post by sno335 »

I had a 52 single side front wheel and had the same offset discrepancy.Never really got to the bottom of it.I tried to minimise it by using a thin spacer but then had problems with the torque arm alignment. I visited the National Motorcycle Museum in Brum and checked the various front ends of the Year by year AMC machines.Bizzarely the 52 was offset,the 53 wasn't? Go figure! In the end I relented and fitted a later full width hub which is central in the forks.
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