T120 Fork slider dilemma.

[Grunt]

I'm currently rebuilding my '72 T120v  Bonneville. I've just rebuilt the fork legs, the left hand slider has an oversize wheel spindle groove in the bottom, approximately 19mm diameter as opposed to 17mm which is what the spindle measures and the studs are on wider spacing. The right hand slider has the correct size groove.

Both sliders were replaced as a pair in the past though I can't remember quite when. I still have the original ones, the spindle grooves are the correct size on these. The three sliders with the correct groove have a letter 'J' stamped whereas the incorrect one doesn't have any markings.

I haven't a clue how I managed to fit the end cap all those years ago or why I didn't notice it then!

Does anyone have any idea what the offending slider may be off. I've rang a few suppliers to try and get another one but so far I haven't been able to get hold of one and no one seems to know why its got a bigger spindle groove in it. Apparently all concical hubs were the same and even the disc braked models had the same size spindle.

[L.A.B.]

even the disc braked models had the same size spindle.

No, they didn't/don't. 

The disc spindle is about 0.775" diameter at the fork clamps or, about 19.7mm.

Make/use two semi-circular shims or one nearly circular shim 1.0+mm thick so it takes the smaller spindle?

[Grunt]

Thanks once again for your reply L.A.B.

So do you reckon I was sold a disc braked r/h slider to fit the drum braked l/h fork?

Making up shims was my thought but I've managed to source a new one from A.P. Williams. It goes by the correct part number 97-4342. But the guy on the phone said conical hub and disc models had the same size spindle. As did several other suppliers. So I do have my suspicions and will only believe it's the correct on when it gets here.

[L.A.B.]

So do you reckon I was sold a disc braked r/h slider to fit the drum braked l/h fork?

Yes, that's possible.

Making up shims was my thought but I've managed to source a new one from A.P. Williams. It goes by the correct part number 97-4342. But the guy on the phone said conical hub and disc models had the same size spindle. As did several other suppliers. So I do have my suspicions and will only believe it's the correct on when it gets here.

(I guess you mean L P Williams?)
Phil (if that's who you spoke to) is fairly knowledgeable but if the spindles are supposed to be the same diameter (I don't have a conical brake model or spare spindle to measure) then they must be 0.775"/19.7mm, not 17mm because, as far as I'm aware, the front disc wheel spindle part number 37-4132 (for twins and triples) remained the same from the beginning ('73) until the end of production ('83) except for the T140D that had Lester wheels.   

[Grunt]

Sorry my mistake it is L.P. Williams. To be fair to all the suppliers I spoke to they were knowledgeable, courteous and all seemed busy, I also may not have explained myself very well.

The more accurate dimensions of my conical hub wheel spindle are. Fork cap location area 17.17mm diameter. Bearing area 20.00mm diameter.

[Grunt]

All's well that ends well. New slider arrived today with the correct size spindle groove and for the record it has the letter 'J' stamped on the lower end. Once again thanks to L.A.B for your help.