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Discussion Starter · #1 ·
How much of a combination of sizes were used on the 70 model 650's. I have case nuts that are not 1/2" or 9/16".
 

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i apparently have british standard sizes on the case nuts of at least one of two 1970 motors, and in other places, such as the stock valve adjuster nuts.

i don't even look any more. when i work on something, i grab all the wrenches and sockets that are close-- SAE, BS, and metric-- and just pick up whichever one fits the closest for that particular fastener.
 

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Discussion Starter · #3 ·
How much of a combination of sizes were used on the 70 model 650's. I have case nuts that are not 1/2" or 9/16".
i apparently have british standard sizes on the case nuts of at least one of two 1970 motors, and in other places, such as the stock valve adjuster nuts.

i don't even look any more. when i work on something, i grab all the wrenches and sockets that are close-- SAE, BS, and metric-- and just pick up whichever one fits the closest for that particular fastener.
I was hoping to not have to invest in new Whitworth wrenches. Looking at my bench right now I do the same as you, all the wrenches and sockets are there, SAE and Metric.
 

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Hi Marc,

How much of a combination of sizes were used on the 70 model 650's. I have case nuts that are not 1/2" or 9/16".
Not "Whitworth" - a coarse Imperial threadform Meriden didn't use on unit-engined bikes.

The AF is likely to be 0.525", which is the standard hex. for 5/16"BS - British Standard, either Cycle (BSC) or Fine (BSF) - and 'small hex.' for 3/8"BS. With British Standard, the measurement applies to the thread major diameter, not the hex. AF.

Hth.

Regards,
 

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Discussion Starter · #5 ·
Hi Marc,


Not "Whitworth" - a coarse Imperial threadform Meriden didn't use on unit-engined bikes.

The AF is likely to be 0.525", which is the standard hex. for 5/16"BS - British Standard, either Cycle (BSC) or Fine (BSF) - and 'small hex.' for 3/8"BS. With British Standard, the measurement applies to the thread major diameter, not the hex. AF.

Hth.

Regards,
Now you've confused me. Whitworth is not a thread pitch is it? It is the hex sizes, correct? I'm not concerned with the thread pitch on the bolts, but the wrenches to tighten them. Case nuts are too large for 1/2" wrench and too small for a 9/16".
 

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Hi,

Whitworth is not a thread pitch is it?
It is.

It is the hex sizes, correct?
No.

1841, Englishman called Joseph Whitworth published his thread standard and related hex. sizes for the-then rapidly-expanding British manufacturing industry.

"Whitworth" is a coarse (not many threads per inch) threadform and, by the early years of the 20th century, steel technology had advanced sufficiently for a finer threadform that also resisted vibration better - British Standard Fine. It could also have smaller hexs. for each thread diameter; to help adoption of the new threadform by industry, the Whitworth hex. sizes were used so the same tools would work on fasteners irrespective of threadform.

I'm not concerned with the thread pitch on the bolts,
Whether you want to be "concerned" or not, 'fraid what you have is a British bike that has British Standard threads and corresponding hex. AF; as I posted earlier, the 'case nuts that are not 1/2" or 9/16"' are 0.525"AF, which is the standard AF for any 5/16"BS fastener, irrespective of actual threadform.

but the wrenches to tighten them.
The socket or wrench to tighten the 'case nuts that are not 1/2" or 9/16"' will be marked '5/16"BS' - the major diameter of the fastener thread, irrespective of actual threadform.

If you're really desperate to confuse yourself further, you can look for a socket or wrench also marked '1/4"W' but the dimension won't bear any relationship to any part of the fastener you're looking at ...

As I say, you have a bike with British Standard fasteners, for which there are "BS"-marked tools that fit, to tighten and loosen those fasteners. It really isn't that difficult to deal with. :)

Hth.

Regards,
 

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Yes, it's the thread pitch....I stumbled across a bunch of the sockets in an antique store a few years ago and snapped them up just because...well, because they were old tools and they were $5 or something......tools just have a history to them which appeals to me, and for the price of a pack of smokes you can't go wrong. I'll find a use for them one day....I can buy smokes anytime.
 

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What you should be seeing that the three bolts that hold the cases together are UNF aka American sizes on this side of the pond. All of nuts for the studs holding the cases together are British (aka Withworth on this side of the pond and around the World like Koken, Japan). I know that Stuart hates the bastardization of the word, but I am afraid it is too late to change people now. The nuts are 5/16 BSC, and yes you will need at least three BSC wrenches to work on the engine: 1/4 (rocker adjuster nuts), 5/16 (case stud nuts) and 3/8 (cylinder head bolts). Don't be surprised if the guy selling you the tools won't know what you are talking about when you ask for BSC wrenches...
 

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Hi John,

it is too late to change people now.
you will need at least three BSC wrenches to work on the engine: 1/4 (rocker adjuster nuts), 5/16 (case stud nuts) and 3/8 (cylinder head bolts).
"A journey of a thousand miles begins with a single step" (Laozi).

Regards,
 

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Discussion Starter · #10 · (Edited)
Hi,


As I say, you have a bike with British Standard fasteners, for which there are "BS"-marked tools that fit, to tighten and loosen those fasteners. It really isn't that difficult to deal with. :)

Hth.

Regards,
A little less difficult now, Thank you.

Now another question. On page 26 of the parts manual they show parts 11, 12, and 14 as thrust washers and needle bearings. It looks like in the picture they go together, but they are actually spread apart by about 5 inches and a bunch of gears. the issue is when I pulled that bag of parts I only have one thrust washer that was installed inside the gearbox. Not having one for the outside of the gears concerns me as I can't find it on the bench with all the other parts, don't remember removing one from there and can't believe it was run without one there before.

This was on the bench, don't recognize it, didn't have a corresponding bolt near by. It's a small diameter split washer. Anyone know where it goes?


Also have a thin flat washer with a bent tab on the ID, about 1-1/4 OD and about 3/4" ID. Anyone know where it goes?
 

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Hi Marc,

small diameter split washer.
The i.d. appears to be a little over 1/4"? If so, ime it's a bog-standard 1/4" spring washer, nothing special; could go on almost any bolt or screw of that thread major diameter.

thin flat washer with a bent tab on the ID, about 1-1/4 OD and about 3/4" ID.
Improperly fitted alternator rotor nut tab washer? Improperly fitted because it appears to have dents from actually being fitted and the nut tightened against it, but its outer edge doesn't appear to have been bent up against a flat on the rotor nut? :Darn

Hth.

Regards,
 

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Discussion Starter · #12 · (Edited)
Hi Marc,



Improperly fitted alternator rotor nut tab washer? Improperly fitted because it appears to have dents from actually being fitted and the nut tightened against it, but its outer edge doesn't appear to have been bent up against a flat on the rotor nut? :Darn

Hth.

Regards,
I believe I hammered it flat after removing it and it was a bent outer flat.
Is it #24 on page 13 of the parts manual?

The small split washer looks like the only one there, maybe it isn't and I'll know when I see another where it goes.


Edit:
I think the bigger washer is the "clamping washer" that goes under the crank nut on the timing side. I seemed to have not put one there.
 

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Hi Marc, I don't know about the washers. But you need to buy at least a 5 piece 3/8 drive socket set & the corresponding combination wrench set (open/box end). Call them BS or Witworth your choice, mine are marked both BS & W. I'll just use BS for the sizes 3/16, 1/4, 5/16, 3/8, 7/16.

To be clear these are not inch sizes but BS. Witworth is the same head but they call it a different size, still a fraction but way different than BS, again the actual size of the wrench is same.

If you own a Triumph you need these if you want to make your life simple & not damage bolt heads.

On my '73 the fasteners that come to mind are valve adjuster nuts, carb banjo bolt, speedo & tach cables, clutch cable lower end, frame sump oil drain, carb jet holder. A few others as well, but these came to mind.

They are quite easy to find on ebay.

Some inch size wrenchs & some metrics will fit, but not really properly. Just get the tools & you'll be better off.

Mine are Britool which seem quite high quality. I've had them since 1970. I don't think the brand matters.


Here's an eBay # of a Koken set. Koken is good quality. Anyway you get the idea from this. eBay # 321906447657
Don
 

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one solution to the different fasteners on your bike that take weird tools is to reverently place them in a box for your slower days and just use stuff for which you already have tools in the meantime.

case bolts, for example. the motor doesn't care what wrench you use, and you can replace the fasteners with anything that fits and still allows the correct torque to be applied. the case bolts on my 1970 motor are now all ordinary SAE sizes, as is anything else i can easily change. the steering damper and bar end mirrors are metric, as are the carburetor fasteners and front brake hardware. the metric fasteners from the exhaust have been tossed into my metric coffee can along with other obscure stuff, and replaced with SAE.

having said that, my old stuff is all BS, and i'll likely keep it that way, for no better reason than the one that keeps me with ignition points on my 65 BSA.

look on eBay for BS/whitworth tools-- they're cheap, even old snap-on.
 

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Discussion Starter · #15 ·
I'd like to have a set of 6 point sockets and 12 point spanners, but funds don't allow right now. I will certainly have a Triumphs only tool box.
Thanks for the links.
 

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Are whitworth so exotic in the USA that they command an extreme premium?
Even in the uk, a standard DIY store won't sell them but a decent tool shop will

http://www.baconsdozen.co.uk/tools/whitworth sockets.html

Postage of tools is possibly expensive and long but worth it in the end.

I still pick up spanners and sockets at autojumbles for almost nothing

I like to have 2 spanners in every size plus 2 socket sets for each size
 

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Some people tend to overlook a fact of life on old (and not-so-old) British bikes:

Over the years, previous owners, (and many shops), can, will, and do replace fasteners with others they have on hand. They may not always be the original spec bits. I do it all the time on my bikes, NEVER on client restorations.

So, while some people get all rivet-headed about the subject, I stay open to a prime fact of classic bike life:

GET A SET OF WHITWORTH WRENCHES AND SOCKETS.

There, I said "Whitworth" instead of "British Standard". Get over it.

Before you go all ballistic, OF COURSE I do not force incorrect threaded fasteners into or onto original threads that are not a correct match. I'm talking about a new or good condition bolt & nut combination to replace a rusty and/or stripped combination.
 

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Hi Marc,

I have case nuts that are not 1/2" or 9/16".
Slacking while listening to a local 1970's music radio programme, I nosed around the '70 650 parts book; are these "case nuts" the ones on the three studs at the front of the crankcase? If so, I agree, you have to wonder what whoever at Meriden approved this was smoking at the time; wth would you change every other crankcases junction thread/fastener to SAE and leave these three? Bizarre ... :Darn

Nevertheless:-

. The standard 0.525"AF hex. of 5/16"BS is just 6 thou. smaller than 17/32" so a SAE AF socket of the latter size is going to be a good fit on those nuts.

. When Triumph and BSA fitted BS fasteners generally, they fitted 'small hex.' nuts in several places; in the case of 5/16"BS, the nut AF is 0.445" ... which is less than 10 thou. bigger than 7/16"AF, so the socket(s) you have already would fit on those nuts. Gk knows whether a Triumph spares dealer will have 'em but British Tools & Fasteners does.

. Finally, something I've done in a similar situation is have the studs remade in stainless with the BS thread on just one end - to go into the motorcycle part - and UNF on the other end for the nut.

Hth.

Regards,
 
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