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This may be the stupid question of the week but I can't figure it out.

What are the bolt sizes on this bike? I have come across some that are a perfect SAE such as 7/16" for the bolts on the fender stays. I have also come across some that are a perfect metric size such as 13mm for the spindle cap bolts.

I have come across some that seem to be 13.5mm or some size that is exactly the wrong size for any wrench I own.

Am I missing something basic here?

Mike
 

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Whitworth.

Yes, 7/16, 13mm (1/2") and 14mm for some fasteners will work, but are already damaging your fastener heads.

there are tool sets on e-bay all the time. buy 6-point (instead of 12 point) when possible in spanners & sockets.
 

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This should be another simple question but I cannot find the answer, what year did Triumph stop using Whitworth and go to SAE?

Thanks,

Joe
 

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Actually - I just found this very helpful post by Mecchanica

"Those nuts are 1/4 CEI, or 1/4 X 26. It is a Cycle Engineer's Institute thread and uses a 1/4BS or 3/16W wrench. You can't get it at a hardware store. You won't find any metric threads on fasteners on British bikes of the late sixties. The sparkplug threads are metric and perhaps the drains in the late concentric carbs and the main jet cover on the monoblocs are the same 14mm, or a near British equivalent.
Essentially, you will find that 68 and earlier bikes are mostly CEI threaded nuts and bolts, and mostly BSF bolts into alloy....like case bolts, but the cover screws are CEI (26 tpi from 3/16" [or was it quarter?] through 1/2" shank size. These can be replaced with the "U.S." sizes if you use both nut and bolt. Fine thread is preferred for vibration resistance.
The headbolts remained CEI through the end of the 650s, changing to NF with the short rod 750s in 73. I believe the rocker box nuts and studs changed in 70.
From 69 on, most of the fasteners were UNF (SAE fine)....particularly any nut and bolt combinations.... and the bolts into the case alloy were NC (including the cover screws). These you can find at the hardware or marine supply store (if you require stainless....look for grade 316 instead of standard food grade 308). The heads can be easily domed to remove the lettering and then polished, looking as good as chrome and never rusting.
The stock "U.S." bolts are identifiable by a circular depression in the top of the hex. Fasteners without a hex head sometimes have a groove cut on the side of the hex. The nuts are usually full finished, as compared to the CEI nuts which were half finished (lead-in bevel only on one face). Some components also are marked....such as passenger footpeg abutments, the later ones with NF threads have a groove cut into them at their base.
The carbs and the points systems kept the British threads, generally. The rectifiers switched to NF centerbolt and nut and the zeners kept the british thread, but fitted a nut with a 1/4 CEI threaded bore with a 7/16" hex....a hybrid. The emblem retaining screws remained British Association thread. Other odd electrical fittings remained Brit, for interchangeability.

[ This message was edited by: Mecchanica on 2007-06-15 13:36 ]
 

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I think I saw somewhere where you can buy Allen head "kits" that convert the heads and/of nuts of the complete set of nuts/bolts to metric. Of course, the threads remain British but it allows you to use your regular tool kit when doing maintence. Also, of course, youll need to have British tools to get the exisint British bolts off!

Anyone had expereince with these kits? They seem like a great idea.
 

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NOTE: ORIGINAL QUESTION REGARDED FASTENER HEAD SIZES, NOT THREAD SIZES.

CEI, BSF, UNC, etc, do NOT refer to fastener HEAD sizes, but the type of threads on the actual fastener.

Sure, understood. The kits I saw (wish I had a link) "Convert" 1960s Bonnies to all metric wrench/allen head heads. Of course, the thread sizes are same as original (CEI, BSF or other etc.) They come in stainless/alloy too.
 

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This should be another simple question but I cannot find the answer, what year did Triumph stop using Whitworth and go to SAE?

Thanks,

Joe
As the rest of the world was embracing metrics, Triumph had the 'Go American' initiative in '69 that was supposed to convert the bikes to all SAE fasteners. I can't speak for the 'wet frame bikes, but I know that, as of '70, there were still plenty of hidden Whitworth goodies.
 

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As the rest of the world was embracing metrics, Triumph had the 'Go American' initiative in '69 that was supposed to convert the bikes to all SAE fasteners. I can't speak for the 'wet frame bikes, but I know that, as of '70, there were still plenty of hidden Whitworth goodies.
I have a 69 tiger 650, most of the head sizes are american ,whereas the threads ar almost all british:)
 

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On my '70 TR6R: I need to replace my rear brake light switch. I noticed it's mounted to the chain guard with small bolts, anyone know this bolt size? Also the nut on the other side of the screw for the sliding adjuster for the brake light switch, I've been using needle nose pliers to hold it while turning the screw, which bolt size is this one? I already have a set of whitworth wrenches but the smallest one is way bigger than any of these sizes. Thanks for the sizes if anyone knows for sure.
 

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On my '70 TR6R: I need to replace my rear brake light switch. I noticed it's mounted to the chain guard with small bolts, anyone know this bolt size? Also the nut on the other side of the screw for the sliding adjuster for the brake light switch, I've been using needle nose pliers to hold it while turning the screw, which bolt size is this one? I already have a set of whitworth wrenches but the smallest one is way bigger than any of these sizes. Thanks for the sizes if anyone knows for sure.
I believe it's a 2BA X 3/8" U.H. for the brake light switch. BA stands for British Association for the Advancement of Science. This standard tends to be used for electrical parts. You'll need BA wrenches to fit. Google "2BA wrench" and you should find some information. They run around $15 U.S. dollars each.
 
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