FT: Frame (Twin) Fitting chain guard

Albervin

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I am trying to align the chain guard on my early C Shadow. It has straight seat stays and the guard is fouling the heads of the nut and bolt. Even if I was to use thin nuts and grinding the head of the bolt there would not be enough clearance. I am contemplating taking the easy way out and fitting a short spacer to fasten the rear of the guard to the lifting handle. The RFM has been check for trueness and may be out by 30-40 thou. The previous owner just pulled it in tight as the dents in the guard attest. Any ideas out there?
 

Albervin

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Re drill the front fitting ?.
Bill, the previous owner has slotted the bracket which is handy. I am loathe to drill another hole in case the guard then fouls the chain. I could try and fit a Series B guard and will into this possibility tomorrow. Thanks for your input.
 

Bill Thomas

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Drill 2 holes in the guard where the Nuts or bolt heads push the guard away ?.

Or a Bit non Standard !.
 

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Simon Dinsdale

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Alyn, have you fitted the rear wheel to check the rear sprocket & chain run down the centre of the chain guard? I bet it’s not in alignment and in my opinion it not a good idea to have the chain running close. I have found with every series B &C Vincent I have worked on that a small spacer approx 3/16” is needed where the chain guard bolts to the lifting handle to get things running true which also helps with your problem. If you paint the spacer black you will never see it.
 

Albervin

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Alyn, have you fitted the rear wheel to check the rear sprocket & chain run down the centre of the chain guard? I bet it’s not in alignment and in my opinion it not a good idea to have the chain running close. I have found with every series B &C Vincent I have worked on that a small spacer approx 3/16” is needed where the chain guard bolts to the lifting handle to get things running true which also helps with your problem. If you paint the spacer black you will never see it.
Yup, I am at the moment guessing 3/16" will do the job. A closer look will tell the story but I think it is less than 1/4". I will fit a chain tomorrow to test. That is a PITA!. So far just a laser check. So what happened at the factory?
 

Bill Thomas

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ClevTrev told us the Twin chain was never in line in the first place,
1950 + or - a Bit, My kind of Mechanics !,
Even Fords had Selective parts !.
 

Simon Dinsdale

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I suspect at the factory they just bent the chainguard over if there was a problem as they were all hand made bikes. I have seen at least one rear chainguard with dents in the seat stay bolt head area and its not unusual to see paint rubbed off in that area. Was that owner done or factory done, who knows?
 

Albervin

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They weren't called "fitters" for nothing. My Series A had a few "shims" spacers" etc. fitted that were not factory numbered parts. The original Series B bikes had a set screw threaded into the stay and a thin headed bolt for clearance on the narrow channelled guard. This then changed to nuts and hex screws for both fasteners. Obviously there were clearance issues from the beginning. Some people fitted the Thackeray washer in the wrong place to try and alleviate the issue but this then made the clearance of the rear stand and the torque clip very close or too close. You cannot fix a problem by just taking a short cut. As long as the chain clears the guard and the rear stand clears the torque clip and the chain runs straight I will be happy. If that takes a non standard spacer then so be it. I guess someone will point it out to me one day. Only last week I had a friendly (?) bloke who pointed out the seat pattern in my Riley car was incorrect. Never met him before and hope to never meet him again. The seats were original from factory and like Vincent, Riley had a history of rolling changes between models. Dickheads are in every club.
 
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