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1976 T140v slow rebuild

6702 Views 48 Replies 8 Participants Last post by  Hooli744
Hi all,

I'm finally getting on with rebuilding the T140v I've had for years, a house restoration & so forth seemed to get in the way for a while.

I'm only at the stage of sending bits off for work I can't do & to that end I need to know the correct OD of the fork stanchions. I've a suspicion they were rechromed undersize before as when I got the bike & they didn't show any wear the fork seals never sealed properly, so I'd like to let the chromer know the correct size to do them.

I've got this info somewhere in the manuals, but I've yet to locate them so this would let me get things started while I search them out.

Thanks.

PS, pic from when it was in one bit & working a few years ago, just for attention.
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Hi,

Firstly, welcome to the Forum. :)

need to know the correct OD of the fork stanchions.
1.3610/1.3605in. (33.04/33.03mm.)

From the online copy of the Triumph '73-'78 Workshop Manual, manual page GD8, .pdf page 20. :)

like to let the chromer know the correct size
You know they should be specifically hard-chromed, not decorative-chromed? Who are using, Philpotts?

Hth.

Regards,
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Hi,
£75 seems a hell of a lot for two braided hoses.
It isn't, and that's probably with cheapo swaged and plated end fittings. Go to 600 hose and fittings in the Goodridge online shop, price up hoses with reusable stainless end fittings. However, do that for what it costs, build it yourself and you'll have something that looks good for a long time.

neater hose setup for the front brakes
two braided hoses
Am I right in thinking that's two single continuous hoses, one to each caliper from a double banjo bolt into the master cylinder? Not my definition of "neater" but beauty-eye-beholder, I've found continuous hoses to be a pita when forks need other work and there's suggestions in some recent threads on various forums that the banjo bolt might be causing bleeding problems.

My preference is for a single hose straight out of the master cylinder - similar to your photo. - to a crossover bolted to lower yoke stanchion pinch bolts, hose to each caliper from each end of the crossover, brake lamp pressure switch also mounted on the crossover; however, my Triumphs have standard yokes.

Interesting handlebar levers, do you know their history? Master cylinder one is Lockheed? Clutch lever is ...?

Hth?

Regards,
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Hi,
agree with you that using a Tee looks tidier,
Another possibility? is, when Triumph fitted twin discs, they used:-



... bracket-mounted between the yokes behind the headlamp shell; one hose in from the master cylinder, two hoses out to the calipers, pressure switch for the stop lamp in the fourth outlet. Or there's a similar Tee if you don't want a switch. However, these aren't peculiar to Triumph, they're widely-available, Triumph used ones with 3/8"UNF threads but they're also available with metric threads (M10 x 1.00?).

I'll see what I could make up to replace the rubber lower hoses so it all matches.
600 hose and reusable end fittings are DIY if you can work a hacksaw or Dremel cut-off wheel and standard spanners. (y), Goodridge used to put the instructions in the back of their catalogues but they've recently taken the last one off their website. :( However, certainly one of their long-time resellers (Merlin Motorsport) still has the instructions available; say if you're going in this direction and I'll find the link?

Btw, I advise using plastic-coated hose - clear's available if you want the bling. Reason I advise against uncoated hose is, if it rubs against anything else between the yokes (say), the braid happily works its way through ally, paint, chrome, etc. :( Plus, if you fancy, say, orange or vile green hoses, that's available ... :)

No idea on the history of the bits sorry, I got sod all history with the bike when I got it except for some invoices off a specialist* for work they'd done so badly the bike blew up on me - full engine rebuild when the sludge trap had never been out & was blocked solid. Some professional job eh?
😡 Pity as it looks like someone started to make something good and interesting. Or are the yokes and calipers your work?

Hth.

Regards,
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Hi,
two different rocker boxes, the rockers are the same part numbers but it seems the adjusters in one are metric (the nut takes a 13mm spanner) and imperial in the other (7/16th spanner). Would I be right in guessing one might be a later Harris part?
Uh-uh, Harris used the same parts as the last Co-op ones (Bloor was quite prescriptive about what Harris could and couldn't change - e.g. couldn't use the late Nikasil-plated cylinder); what you're thinking is "metric" is actually Cycle - 26 tpi rather than 1 mm. pitch, which is 25.4 tpi ... :)

Nevertheless, afaik "the nut takes a 13mm spanner" is wrong, you should check the rocker adjuster threads more closely:-

. iirc, Triumph didn't use UNF-thread adjusters 'til part-way through '73, when they increased the 750 twins' bore from early '73 75 mm. to the more-common 76 mm. - then the rocker adjusters became 5/16"UNF, which is 24 tpi (threads/turns per inch);

. before that, while rocker adjusters are still 5/16" thread OD, they're BSC - British Standard Cycle - which is 26 tpi (M8 Fine is 1 mm. pitch, so 25.4 tpi);

. common 5/16" British Standard hex. is 0.525" AF (that's why a 13 mm. AF spanner fits);

. however, specifically rocker adjuster locknuts are a 'small hex.' - 7/16" AF when they're UNF ... and 0.445" AF when they're Cycle ... which is why some 7/16" AF spanners fit Cycle rocker adjuster locknuts ... :)

Sooo ...

. the adjusters that you think a "7/16th" spanner fits, you should check the adjusters tpi, they might be Cycle and with the correct small-hex. locknuts;

. replace the nuts that "take a 13mm spanner" with the correct 5/16"Cycle small-hex. locknuts.

rocker boxes
as I fitted the first one a thread stripped where the bolt comes up from underneath above the port.
Errrm ... notice the other rocker-box has studs ... if you look in the parts book, studs are standard ... The studs have UNC thread into the ally rocker-box because ally is relatively soft, and wears quickly if fasteners are tightened/loosened regularly. Otoh, the other ends of the studs are UNF, on which steel nuts run, bearing on plain steel washers against the head.

head
skimmed when repaired last.
Mmmm ... this is common practice but can be bad if the head was bent, which turns out to be relatively easy to do if the pushrod tube seals aren't set up correctly. :( The correct practice is to bend the head straight again - skimming might flatten the cylinder gasket face but a) doesn't flatten the rocker-box gasket face; b) causes you more problems setting up the pushrod tube seals ... 😖

front mudguard
shorty.
The brace between the sliders shown in the parts book is pretty good at keeping the sliders moving up and down together, fwiw I advise against missing it out.

Hth.

Regards,
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Hi,
Seager Engineering who did the work saw my post & told me they'd do the thread for free, so it was rude not to accept their offer.
reason the head was skimmed was due to this bike eating a piston years ago & damaging the edge of the combustion chamber, it had to be ground back, welded up, milled & skimmed to fix.
They've been doing this stuff for years & have a great reputation so I trusted them to get it right, which they did.
(y) Put in a link for them? It's always good to know first-hand experience of suppliers, especially positive.

Regards,
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Hi.
front mudguard
what sort of nuts & bolts are correct to hold it to the bracket?
Same bracket as in the image in your first post? If so, originally 1/4"UNF x 5/8"UH Pozidrive Panhead Screws into 1/4"UNF Self-locking Nuts, washer under each screw and nut.

Hth.

Regards,
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Hi,
drill the new guard to suit hopefully getting it straight
Fwiw:-

. I start by drilling the front one very central and smaller than 1/4" - 3/16"? 4 mm.?

. Then I bolt it to the front of the brace and check that the 'guard is central between the fork legs; if it isn't, because I drilled the hole in the 'guard smaller, I can file one side or the other to get the 'guard central before I open up the hole to 1/4" ID.

. Another reason I start by drilling the hole smaller is drilling a hole in sheet metal, it comes out trochoidal. (n) I open up with a conical burr so the hole ends up circular, even if filed the original oval to move the 'guard on the bracket. (y)

. Only when I'm happy the 'guard will appear central do I open up the hole to 1/4". Then I bolt the 'guard firmly to the bracket with the front bolt before drilling the two between the fork legs (again starting smaller and enlarging to size).

I'll have to get some
Before you buy the bolts, both my T160's came with soft vibe-isolating washers between the bracket and the 'guard, although they aren't shown in the parts book. I was able to buy more many years ago, 'fraid no idea - apart from possibly a long-time dealer - whether they're still available under whatever the part number was. Or you could possibly add off-the-shelf plastic or rubber washers?

Also, the spec'd washers in the parts book were the Imperial equivalent of modern 2 mm. thick - this is unusual as common 1/4" washers are/were only 1 mm. thick/equivalent.

Personally, not a fan of mudguard mounting bolts protruding towards tyres, I replaced with ordinary stainless hex. bolts fitted from under the brace/'guard, topped with stainless domed nuts outside the 'guard.

Hth.

Regards,
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Hi,
went to put the mushroom headed adjusters in, but they don't fit.
Hmmm ... both (Feb. and Aug.) '76 parts books show the earlier British Standard Cycle thread - 26 tpi (threads/turns per inch), which are also shown in the '78 parts book. Not 'til the '79 parts book are UNF (24 tpi) shown.

Do you have a screwpitch gauge? If not, enter the term into the Ebay Search. Inexpensive and very useful tool to have, despite most (all?) come with very coarse and very fine 'leaves' you'll never use (unless you're also into traction engines and similar). Pick one with both tpi (usually marked "Whitworth") and metric pitch 'leaves' and, if you can find one with a 27 tpi 'leaf' (for checking oil pressure switch threads), so much the better.

When/if you have a screwpitch gauge, you can check whether the supplier screwed up and sent you the wrong thread, or you ordered from the parts book and, in fact, your bike has later UNF rockers/adjusters/locknuts. :oops:

Risking telling you something you know already, also worth having (if you don't already) is a way of measuring diameters more-accurately than a plain old ruler. Sadly, these days, threaded component with the correct tpi according to the screwpitch gauge leaves, that still doesn't fit, could be oversize - only takes a couple of thou., which you won't see with a ruler. Aldi and Lidl frequently sell digital calipers for around £8, amazing value considering how long they last. Or an engineering tools supplier,

Hth.

Regards,
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Hi,
Brakes
hoses
might see if I can get a pair made up
Don't forget the info. in posts #11 and #14 ... :whistle:

Regards,
Hi,
need to find out if I could get longer banjo bolts to fit two hoses to the master cylinder
Wonderful thing, the Goodridge online shop ... Jic Double Banjo Bolt | Goodridge ...

not sure I'd trust myself to make them.
If you can work a hacksaw or Dremel cut-off wheel and spanners, you can make 'em; Goodridge 600 hose, "reusable" end fittings and those (originally Goodridge) destructions are the closest thing to foolproof I know.

Or Goodridge Buildaline.

Hth.

Regards,
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Hi,
If you only want one hose from the master cylinder, you could feed only one brake caliper, then substitute the bleed nipple for a hose fitting, a crossover hose/pipe could then be made to feed the second caliper from the first.
quite neat.
Hmmm ... beauty, eye, beholder ... :cool:

However, if you really think this is "neat", no need to lose one caliper's bleed nipple; if you look at Goodridge's Buildaline, there's at least one type of "banjo adapter" that can be 'stacked' and secured to the caliper's standard inlet with a double banjo bolt.

I drilled and tapped the bottom slab yoke, the two bottom hoses join underneath the yoke, similar to what is in your photo, the brake fluid then flows through drilled passage in the yoke to the to the top side, where the hose going to the master cylinder is connected.
My T160's with twin discs have something not wholly dissimilar.

For his T160-based "Legend", Les Williams made a 'crossover pipe' that fitted under the lower yoke, attached to the two stanchion pinch bolts; one braided hose runs from each end of the 'crossover pipe' to the caliper beneath; a third braided hose runs from one end of the 'crossover pipe' to the master cylinder. Les sold this to owners of ordinary triples, only the 'crossover pipe'-to-master cylinder hose length depended on individual handlebars.

Les modified the 'crossover pipes' he sold to me with a fourth outlet, that I use to mount a standard '79-on pressure switch to work the brake lamp.

L.P. Williams still sell either the whole kit or just the crossover pipe, the current version secures the hoses to the ends with banjos and bolts.

Hth.

Regards,
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