Restoring & Modifying 1971 OIF TR120

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No idea, hopefully someone will chime in.

what i do is pull the dowel in the right hand case and then just tap the hole for a grubscrew. the drillway has a plug in the bottom that you can see down there near the oil junction block. pull the plug and you can make sure there are no chips in the oil ways.

if you plug the hole in the crankcase then the pressure cant reach the cylinder base gasket to blow it out.

or you could tap a BB into the tappet block. i never thought of that. or a single 00 lead buckshot pellet, maybe.
 
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what i do is pull the dowel in the right hand case and then just tap the hole for a grubscrew. the drillway has a plug in the bottom that you can see down there near the oil junction block. pull the plug and you can make sure there are no chips in the oil ways.

if you plug the hole in the crankcase then the pressure cant reach the cylinder base gasket to blow it out.

or you could tap in a BB. i never thought of that. or a single 00 lead buckshot pellet, maybe.

Perfect, thank you!
 
the tappet blocks dont actually have a hole, its an annular ring cut out to match the orifice in the jugs

youd have to tap the BB into the crankcase or the cylindrs

s-l1600.jpg
 
the tappet blocks dont actually have a hole, its an annular ring cut out to match the orifice in the jugs

youd have to tap the BB into the crankcase or the cylindrs

Ah... I see. The pictures help--much appreciated. Okay, well, apparently the Morgo kit doesn't have an option to select with or without oil feed provision, like the Aerco kit does. So, guess that I'll see whether the Morgo kit comes with the feed.

BTW - I have settled on the Morgo kit, as I like the 20% larger cooling fins that protrude laterally to match the shape of the fins on my head. Well, plus it's less expensive than the Aerco, even after you add the additional gaskets the latter comes with.

Here are their fitting instructions.

Just waiting for them to have the kit back in stock... Evidently, the only downside to pre-ordering would be that the instructions say to determine whether your studs are Cycle or UNF. It comes with the former, you can opt for the latter.

A little surprised to see that run-in is 1,000 miles < 3,500 rpms. Pretty conservative. I usually do ~500 miles.
 
my morgo is not drilled for an oil feed.

i need to save up and buy another. these things are made for a machine that was last marketed over 50 years ago. theyre going to go awy sooner than later
 
my morgo is not drilled for an oil feed.

i need to save up and buy another. these things are made for a machine that was last marketed over 50 years ago. theyre going to go awy sooner than later

Exactly why I am gonna snap a kit up, even though I'll probably get lots of miles from the existing 650 barrels. I'm on their 'notify me' list.
 
It was 25 years ago, but I think you have to tap a BB or small bearing in place, then the dowel in the cylinder base holds it in (it's bore is narrower than the hole)
I've forgotten, sorry. Way back then, I didn't take 200-400 photos per overhaul...
 
All righty then! Met with my machinist, who I made a little grumpy. He wanted to make a much simpler, overhanging part but I really like the flush outward face of the more complex, underhanging part I've designed. Especially if black anodized, it'd look really cool on the bike (mine will be polished, as anodizing a single part is too expensive).

That just means he's gotta devote more time to the CAD drawing that will inform the machine's routines. Also, as regards others who might want to replicate this conversion, a production part of this design would take ~30% more machining time and is 1.5" longer than the less attractive overhanging part. So, fewer parts from [x] length of material. But I feel that part of a vintage British bike's appeal is its lines, and a part that protrudes 10mm out from the caliper's surface is just too clunky for my taste.

One change he suggested that I do like is removing the OEM caliper studs and using button head stainless 3/8-16 allen screws to affix the adapter to the fork slider, which will visually match those I have holding the caliper to the adapter (though they are 3/8-24 in light of the material they thread into being slightly thinner than the fork slider's ears). It turns out that the studs come out easily, so long as folks have a vise grip and (ideally) a cheap home improvement store plumbing torch. I don't think adding that task to the conversion is too onerous for most people.

Anyway, I'm eager to get the front end back together, so I can pull the swingarm and R&R the bushes, and lace up the rear wheel. It's warm enough to ride today, so I'm itching to get this old bike on the road.
 
One change he suggested that I do like is removing the OEM caliper studs and using button head stainless 3/8-16 allen screws to affix the adapter to the fork slider
Specifically OEM caliper mounting studs were never 3/8"-16 (UNC) into the slider, they were always 3/8"-20 (BSF). Possibly UNC was too coarse for the length of thread in the slider?

Button head stainless allen screws possibly not available with 3/8"-20 thread ... probably easier is what the Co-op did when they fitted twin discs - so the wheel could be fitted and removed, right hand sliders were helicoiled 3/8"-24, bolts used to mount the right hand caliper. My T160, when I added a second front disc, I had the left hand slider helicoiled 3/8"-24 also - any wheel easier to fit with all calipers unbolted.
 
Specifically OEM caliper mounting studs were never 3/8"-16 (UNC) into the slider, they were always 3/8"-20 (BSF). Possibly UNC was too coarse for the length of thread in the slider?

Button head stainless allen screws possibly not available with 3/8"-20 thread ... probably easier is what the Co-op did when they fitted twin discs - so the wheel could be fitted and removed, right hand sliders were helicoiled 3/8"-24, bolts used to mount the right hand caliper. My T160, when I added a second front disc, I had the left hand slider helicoiled 3/8"-24 also - any wheel easier to fit with all calipers unbolted.

Oh, okay, thanks, Rudie. I had just assumed it was 3/8-16 from looking at it (and perusing stud offerings in various lengths). I don't think 3/8-16 is too coarse for those mounting ears on the slider, as the rule of thumb per my machinist is 1.5x the O.D. of the fastener is enough threads into the material for sufficient holding strength.

Anyhow, if that's the situation we're facing, I may just go with nylock nuts on the OEM studs, or folks could use pretty acorn nuts with loctite. I would rather not require end-users to have to resort to having the slider helicoiled. That said, I willl also check with a local machine shop, as if that job is cheap, people may not mind having to do it. Thanks for the suggestion!
 
I think what we'll do is use these flat-head allen screws. I'll have Zach cut a countersink for the heads, so they'll sit flush with the surface of the adapter. That'd look really cool, be very tough as these are alloy hardened screws, and easier for people than finding a shop to do helicoils. Just grab a vise grip pliers and cheap torch (if even needed), back out the old ones, insert these with loctite.

The place isn't open, so I'll have to wait until Monday to get specs for countersinks. I'll either need 3/4 or 1" length, depending on the length of the fastener under the heads--and I can't see profile of under-head portion in the photo. Could be a taper or enlarged cylindrical shape... I've seen both.
 
Rudie (or anyone who knows), I understand that the dampers were new for '71 and later models, but two questions:

First - was the stanchion O.D. the same going back for '70 and any other earlier models?

Second - was the triple clamp/stanchion spacing the same for pre '71-'72 models, or did it differ over the previous years?

Put another way, are the '73-and-later sliders I'm using compatible with stanchions on bikes earlier than '71-'72 models? If so, for which ones?
 
stanchion O.D. the same going back for '70 and any other earlier models?
Not strictly speaking ... if you look in your bike's workshop manual, page GD9 says the stanchion diameter is 1.3605" to 1.3610"; otoh, if you look in the 63-70 workshop manual, page GD8/pdf page 21 says the stanchion diameter is 1.3025" to 1.3030" ...

Otoh, I happen to know pre 71 97-1500 seals fit in 71 on sliders, work on 71 on stanchions ... :cool:

triple clamp/stanchion spacing the same for pre '71-'72 models
71, 72 and early 73 twins with drum front brakes, the stanchion centres are 6-3/4", same as 69/70 stanchion centres. Pre 69 centres are 6-1/2".

'73-and-later sliders I'm using compatible with stanchions on bikes earlier than '71-'72 models?
Probably not completely impossible to make work but the gain would never be worth the pain ...

If you take a look at, say, the 70 650 parts book forks pages (pdf pages 54/55), you will see the forks are completely different from those fitted 71 on to triples and oif twins. The usual front end change to pre 71 twins (and 71-74 500s that continued to be fitted with the same forks and drum brake) is complete disc brake forks; if a T150 disc brake bottom yoke is used, the forks bolt on.

73 on disc brake sliders can be connected to 71/72/73 drum brake stanchions only because the thread in the bottom of the damper rods is the same and the damper/rod components are similar. Apart from that and seals, no major component is interchangeable between 73 on disc brake forks and 71/72/73 drum brake forks.
 
Not strictly speaking ... if you look in your bike's workshop manual, page GD9 says the stanchion diameter is 1.3605" to 1.3610"; otoh, if you look in the 63-70 workshop manual, page GD8/pdf page 21 says the stanchion diameter is 1.3025" to 1.3030" ...

Otoh, I happen to know pre 71 97-1500 seals fit in 71 on sliders, work on 71 on stanchions ... :cool:


71, 72 and early 73 twins with drum front brakes, the stanchion centres are 6-3/4", same as 69/70 stanchion centres. Pre 69 centres are 6-1/2".


Probably not completely impossible to make work but the gain would never be worth the pain ...

If you take a look at, say, the 70 650 parts book forks pages (pdf pages 54/55), you will see the forks are completely different from those fitted 71 on to triples and oif twins. The usual front end change to pre 71 twins (and 71-74 500s that continued to be fitted with the same forks and drum brake) is complete disc brake forks; if a T150 disc brake bottom yoke is used, the forks bolt on.

73 on disc brake sliders can be connected to 71/72/73 drum brake stanchions only because the thread in the bottom of the damper rods is the same and the damper-rod components are similar. Apart from that and seals, no major component is interchangeable between 73 on disc brake forks and 71/72/73 drum brake forks.

Ah, okay - got it. Sounds to me like this will be a bolt-on fix (saving for lacing up a wheel) for only '71-'72 bikes.
 
So, I got specs from the vendor and it will indeed be the 3/8-20 x 1" flathead hardened alloy allen screws linked earlier that will affix the adapter to the '73-and-later slider. They're on the way. They have a 90-degree (included angle) countersink, which is machine-shop speak for a 45-degree taper under the flat head, which is .168" tall.

The part's outboard structure--the upper level of the 'step', as it were--will be 3/8" thick or just a bit more, which means there'll be ~.625" of threads going into the Triumph slider's ear. That's more than the 1.5X the diameter requirement for full thread engagement, so from an engineering standpoint, we're good to go with 1" fasteners (the head height is included in that figure).

Frustratingly, the vendor's +/- specs described an unusually wide range for the head diameter, so we don't feel safe machining the countersinks for the prototype part until we measure a random sample of screws from the box I bought. I want the screws nestled just a couple of thousandths beneath the level of the part's face or flush--but not proud--and want a close fit around the perimeter. Yet another delay, but I don't want any clunky-looking parts on my bike!

Anyway, the plan is to have the bike at least on its front tire next month--and then I can begin sorting the primary, clutch, installing the 3-phase alternator and final drive chain and sprockets, and rebuilding the swingarm (seems like it'd fall forward off the lift if I removed the back wheel right now, sans front end).

I am committed to getting this bike on the road before summer's end--and then of course I'll have the challenge of dialing in the mixture at my daily cruising altitude of 5,000 ft. (Rio Grande) to 6,000 ft. (home). It snowed today while I was trying to finish sanding the kicker cover, so the dog and I came back in and built a fire.
 
Oh - and there are skinny Amal grips on the bars right now. They look cool but I'm afraid with low bars especially, my hands might go to sleep on the half-hour cruise into town. So, I ordered some nice reproduction GT 'Beston' grips just in case... $15 and free shipping!
 

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