Restoring & Modifying 1971 OIF TR120

[NM Bonny]

Given all the other work you do yourself, surprised you do not make it yourself? I have made my own braided brake hoses for years, using Goodridge stainless parts, very simple, very foolproof, very long lasting. Happy to suggest Goodridge and standard Triumph parts to use, if you wish?

Sounds like great minds think alike. That's exactly what I did on the '51 FL's DIY front disc brake, and what I have in mind for this one, too. But thank you for the suggestion.

My 17-year-old nephew was in town and wanted to help, so I got the metalastic bushes for the handlebar pressed into the triple clamp (took some fiddling, but in they went), installed headset bearings, the P-clamps and handlebar, headlamp rubbers and nifty LED bulb, and brake master cylinder.

The bars are a bit 'floppy' with the metalastic bushes, but I assume that means the vibration isolation design is working properly...? With the new headset bearings properly adjusted, the steering action is effortless and smooth, so I don't imagine much leverage will be needed to steer this light bike.

I've heard dissatisfied murmurs about that funky headlight bracketry, but with new rubbers and the 'C' shaped washers, it actually holds the OEM headlamp housing adjustment very firmly.

Slipped the tank back in place, so I no longer have to worry about it getting dented. It's starting to look like a motorcycle again...

 

[Rudie]

bars are a bit 'floppy' with the metalastic bushes

Over the years, there have been ... various ... qualities of bushes. As a rough possible guide, handlebars in your photo, ime 'good' would be only barely perceptible movement at the bar ends when pushing the bike around.

heard dissatisfied murmurs about that funky headlight bracketry, but with new rubbers and the 'C' shaped washers, it actually holds the OEM headlamp housing adjustment very firmly.

Aiui, not the headlight mounting as such but that the "wires" are prone to fracture from vibration?

starting to look like a motorcycle again...

 

[NM Bonny]

Over the years, there have been ... various ... qualities of bushes. As a rough possible guide, handlebars in your photo, ime 'good' would be only barely perceptible movement at the bar ends when pushing the bike around.


Aiui, not the headlight mounting as such but that the "wires" are prone to fracture from vibration?

Hmmm... well, by that measure, I'd say the L/H bush is 'good' and the R/H one is not great. These are 'new' bushes, or NOS, whatever is sold these days by the usual suspects.

I can, if need be, pretty easily supplement the OEM setup by placing an appropriately firm rubber or 'prothane' disc under the hemispherical washer. But it's a little disappointing that the 'new' bushes aren't 100% out of the box... I suppose the alternative is to order another, hope it's good, and R&R the R/H one again.

Huh, the steel rods or 'wires' are pretty beefy--and if installed correctly, largely isolated by rubber from vibration coming through the headset and triple clamps. I would think folks suffering from vibration-induced failure didn't renew the rubbers...? But anyway those 'wires' are tough.

The top affair (as you obviously know better than I) requires the 'wires' to be aligned properly--and my R/H piece needed the top bend adjusted to get the threaded end center in its hole. Once that was done, my nephew was able to tuck in the top rubber with a small screwdriver as I pressed upward and manipulated the piece to center it. As I've said, seems like a neat design: firm but totally isolated from serious vibration. But I guess we'll see...

Obviously, I will need to R&R the handlebar to install the fork sliders, but my nephew really wanted to see how the array of fasteners worked with the bushes we had laboriously installed in the triple clamp--and I wanted his help with that fiddly headlamp mount. Wish he lived in NM, as it was neat to see a young kid enthralled with the old bike and problem-solving...

 

[NM Bonny]

I did not want to R&R the triple clamps and forks again, so found a 3/4" hose barb fitting and ground it down... perfect. Drove out the defective bush without removing anything but the handlebars.

The OIF specialist I bought them from, K.M. Jones, was wonderful and sent a replacement immediately, so I'll have the front end all rebuilt by the weekend at the outside.

The other device you see is an assortment of stuff in the 'box O washers' and some all-thread. Draws the bushes in perfectly flush without stressing the rubber or drama. The only thing I found helpful was to sand a little bevel on the end of the bush's outer sleeve--and also around the opening of the hole it goes into.

Finally: the steel from McMaster Carr came in... wow. The fit is so precise it's hard to believe. You don't need to drift it on but neither is it a 'shudder' fit. Just incredibly nice.

Now, to build the first wheel I've ever laced up...

 

[NM Bonny]

I have two questions about the forks, which I'm about to reassemble:

1) the 97-4004 (H4004) cap screw seals - these settle into recesses inside the fork sliders, correct?

2) I do not see any reference in the parts diagram to the studs that somehow limit the left-right steering travel, to save the tank damage (just repainted mine). Mine just have nuts on them that seem too stiff, so I suspect are the wrong thread pitch.

So, I wonder if there are additional parts that make up the stops and afford adjustment...? BTW, the metal where whatever goes on the studs would contact is chewed up a bit. I'm assuming I might have to weld on some bits to recreate the flange...?

 

[Rudie]

forks, which I'm about to reassemble:
the 97-4004 (H4004) cap screw seals - these settle into recesses inside the fork sliders, correct?

Correct. I also degrease the cap screws, coat each one in Hylomar during assembly, follow the Hylomar instructions when assembling.

do not see any reference in the parts diagram to the studs that somehow limit the left-right steering travel
Mine just have nuts on them

Should not have afaict ... Cannot load photos directly here - "Oops! We ran into some problems. The uploaded file is too large." - but, if you look at:-

. OIF frame steering head https://i.ebayimg.com/images/g/kWAAAOSwixhhTKJ1/s-l960.jpg

. OIF bottom yoke https://isteam.wsimg.com/ip/4018fe96-9ddb-11e5-a267-180373f13e48/ols/4676_original/:/rs=w:600,h:600

... the 'square' bits of the yoke beside the stanchion pinch bolts contact the edges of the turned down part ("flange"?) under the frame steering head.

 

[NM Bonny]

Correct. I also degrease the cap screws, coat each one in Hylomar during assembly, follow the Hylomar instructions when assembling.


Should not have afaict ... Cannot load photos directly here - "Oops! We ran into some problems. The uploaded file is too large." - but, if you look at:-

. OIF frame steering head https://i.ebayimg.com/images/g/kWAAAOSwixhhTKJ1/s-l960.jpg

. OIF bottom yoke https://isteam.wsimg.com/ip/4018fe96-9ddb-11e5-a267-180373f13e48/ols/4676_original/:/rs=w:600,h:600

... the 'square' bits of the yoke beside the stanchion pinch bolts contact the edges of the turned down part ("flange"?) under the frame steering head.

Ah, okay... this is a big help, thanks very much.

On my bike, the L/H side of the steering head has a flange that's intact like the photo you've provided. On the R/H side, it's really chewed up. I'll need to get out the welder, bend up a little piece of steel, and reconstruct that flange.

On the bottom yoke, both of those flat spots that would make contact with the steering head flanges have studs emerging from them. Weird. I'll have to take a closer look in the daylight and see if this was something the PO did to the bike.

Either way, since I went to all that trouble to rehabilitate a badly damaged tank whose lines are now utterly perfect, I want to be 100% sure nothing will swing around and make contact with those beautiful curves.

 

[Rudie]

On my bike, the L/H side of the steering head has a flange that's intact like the photo you've provided. On the R/H side, it's really chewed up. I'll need to get out the welder, bend up a little piece of steel, and reconstruct that flange.

On the bottom yoke, both of those flat spots that would make contact with the steering head flanges have studs emerging from them.
I'll have to take a closer look in the daylight and see if this was something the PO did to the bike.

Online photos suggest it is. 71 and early 72, Triumph fitted the same tank to all OIF versions, including those exported to the US; this was a "large" tank, afaict similar to the pre-71 TR6R tank. Later in 72, Triumph fitted a smaller tank to T120R and TR6C, as they had done pre-71; then, for those versions, the "square" parts of the lower yoke casting were removed during machining, meaning T120R and TR6C steering could be turned further side to side than TR6R (and T150) before the yoke reached the standard stops on a 'dry frame'; however, tank size and lower yokes had to be compatible so the fork legs did not contact the tank on full "lock".

Your bike's frame damage on the right hand side suggests what we would call "a prang" ... possibly the lower yoke on your bike is not original but a later 72 T120R/TR6C one intended for use with a smaller tank, modified by the bike's then repairer to stop the fork legs hitting the correct 71 large tank?

 

[NM Bonny]

Online photos suggest it is. 71 and early 72, Triumph fitted the same tank to all OIF versions, including those exported to the US; this was a "large" tank, afaict similar to the pre-71 TR6R tank. Later in 72, Triumph fitted a smaller tank to T120R and TR6C, as they had done pre-71; then, for those versions, the "square" parts of the lower yoke casting were removed during machining, meaning T120R and TR6C steering could be turned further side to side than TR6R (and T150) before the yoke reached the standard stops on a 'dry frame'; however, tank size and lower yokes had to be compatible so the fork legs did not contact the tank on full "lock".

Your bike's frame damage on the right hand side suggests what we could call a "prang" ... possibly the lower yoke on your bike is not original but a later 72 T120R/TR6C one intended for use with a smaller tank, modified by the bike's then repairer to stop the fork legs hitting the correct 71 large tank?

Maybe so, and in fact if I recall correctly, one of the dents on the tank was where the speedometer mount (or something in that region) would have contacted the tank.

Well, at any rate, I'll need to address that for sure--and the first step I think will be adding some metal to rebuild the flange on the steering head to match the other side. (I misspoke earlier; it's the R/H side that's damaged, and the L/H side that's intact.)

Then, if the triple clamp or whatever is still going to contact the tank, I'll have to add metal to the bottom yoke--or just run with the existing solution and add acorn nuts or make little threaded blocks to screw onto the studs. Perhaps some sort of rubbers? Just something simple, strong, and good-looking.

 

[NM Bonny]

Finally found some time to get back into this project... it's May already?!

Did the rough sanding on the late model sliders (150 grit up to 320, dry). Here is a pic of after the initial go with 150. Nowhere near as bad as the R/H engine covers were, but still a finger workout. Fair number of minor scratches and a few gouges--and same deal re: deciding which of the original casting marks and surface flaws to attack.

Mañana, with luck, I'll be able to finish the wet sanding, hit the buffer wheels, and get these installed.

Then, I can divert to some fun stuff--installing the handlebars (for real this time) and the new GT grips--before sanding and polishing the Sporty hub and caliper adapter. Both of those should only need 320 and up plus the wheel.

And, yes, I know what this means: I'll have to do the rear conical hub and backing plate to match... ugh. Well, anyway, it'll look cool.

Oh, yeah, and I'll need to repair the steering stops per the last post. Upon further reflection and research, the PO (or the broker who sold me the bike) just welded on some little studs and nuts... but never bothered to fix the dents in the tank. Ah, well, it looks great now and I'll fix it right so they don't reoccur.

 

[NM Bonny]

My goodness, how life intervenes in tinkering...

Anyhow, here are shots after taking the sliders up to 3,000 grit this afternoon, followed by the buffer wheels (Tripoli, then White Rouge). Definitely worth doing, as all the gouges, scratches and pits came out and they look decent.

I need to buy more Tripoli to do the primary cover and hubs!

Mañana, I hope to get the new oil seals installed, get the forks back on the bike, and install the handlebars and grips. But then, I've said that before...

 

[NM Bonny]

All rightee then... got the forks rebuilt, installed, and filled with fresh 5W Belray fork oil.

Installed the controls and clocks, new grips and bar-end mirror (it came with two but for now I just installed the L/H... it's looking like a motorcycle again.

Mañana, I hope to get the caliper adapter sanded and polished, and bolt it and the Wilwood caliper to the L/H fork slider. Perhaps by week's end I can get the Sporty hub's bearings out, give it a quick polish (I don't think it even needs sanding), install new bearings... and lace up the front hoop.

This bike will be running this summer--and I can't wait to try out the front discs brake conversion.

 

[NM Bonny]

Okay, got the adapter's machining tool marks removed (only took an hour) and got her installed. Looks very nice.

I didn't know the torque spec to install the hardened countersunk screws into those old castings--with the additional complication of blue loctite acting as a lubricant--so arbitrarily chose 15 ft lbs. The wrench's handle barely moved, but this is a good thing, as my machinist pointed out that with those countersunk heads, there's actually a very large contact face and once the taper mates with the countersink, it's going to stop--hard. So, easy to ruin the threads. I might even recommend 12.5 ft. lbs, I dunno...

The adapter is extremely light, so adds very little unsprung weight. I'm eager to compare the old drum setup to this one when the wheel is built and installed with the rotor and inflated tire...

...which brings me to the third photo. This shows that the Bridgestone Battlax in 3.25-19 fits just fine--though it's a good deal wider than the Dunlop in the same size. It's unmounted and uninflated here, but the beads are farther apart than they will be on the rim. So, I'm guessing we'll have no problem.

An unanticipated issue is that these mid-'79 and later sliders (with the circlip groove machined into the oil seal recess) have fender mounting bosses that do not protrude inward as much. That means the OEM '71 mounting system won't work without stand-offs. I do not think this will be an issue because the tire's sidewall sits above the rounded portion of the mounts--but we'll see...

Now, to rebuild and polish the hub and build the wheel...

 

[NM Bonny]

Thanks, guys!

I figured out I didn't need standoffs after all. Just needed to modify the outer fender mount, so that it would hug the slider's profile. As you can see in these photos, it's actually a good thing that these late-model sliders have fender mounts that don't protrude as far--and that I didn't make standoffs--or the Battlax might not have fit... it's gonna be close indeed, but should just make it.

I like the look of the stock fender with the disc caliper setup, and as you can see in the 4th photo, I chose low-luster black for the stays rather than the original same-color scheme.

Last two images show the Sporty hub bearings pulled out with a wonderful OTC tool that's 1/6 the cost of the other makers' offerings (forget about Harley's tool). Worked great with near zero effort.

I've thought about it and will not sand the OEM tool marks out of the tapered inner profile of the hub, but just hit them with the buffer wheel and call it good. However, the outer faces of the hub are buggered up and will need 150 or 220 all the way up before buffing... ugh. But it'll look smashing with the cleaned up sliders, new Boranni front rim, and stainless spokes...

 

[NM Bonny]

Whoa... wait a minute! Don't those mounts go downward on the sliders rather than sticking up as I have them?

Yeah, look at this picture of the bike right after I painted the metalwork and was test-fitting things...

Shoot, then I've got tons of room!

 

[NM Bonny]

Yeah, this is more like it... duh!

And the modified mounts are now invisible...

 

[CarlS]

Great work!

 

[NM Bonny]

This is my first-ever wheel building experience. So, thanks to whoever it was (Kevin?) who recommended taping spokes together to establish the pattern, especially because lacing a Sporty hub is difficult compared to a regular Harley 'star' hub, as you must insert all the spokes at once: you can't do them one at a time.

I couldn't find a video showing how to lace my style of hub--with non-offset holes--but as the first image shows, examining the inside of the holes showed distortions in the direction the outers went on each flange. From there, it's just remembering the Harley pattern of each outer spoke crossing over 4 inner spokes--and of course things are reversed on the other flange vis-a-vis which direction they go as you face each side. But with a used hub showing the distortions, it's hard to screw it up.

Once I had the spokes inserted with lots of anti-seize goop (which Buchanan's gives you in ample amounts) to prevent galling of the stainless spokes into the stainless nipples, I shimmed the rim up to within 1/32" or so on the hub (the countertop has tiles so isn't very flat) to get it roughly aligned left to right @ center. Then, just went around tightening the nipples a little at a time finger-tight until the thing held together.

It's amazing how with light finger pressure on the nipples going round and round, all of a sudden it becomes a rigid assembly. I'm curious to see how far out it is in a radial dimension once I get it on the stand. It should be pretty good left to right, but we'll see...

After lunch, I'll install the bearings (easy on a built wheel with the draw-type tool) and start the truing process. That may take me a while, so perhaps I won't finish today...

 

[Rocky]

Good for you for having a go at wheel building.
I did that too on both of my vintage bikes. It sure is an exercise in frustration, but so satisfying when it's all done and correct.

 

[NM Bonny]

Thanks, Rocky. Not too bad, really.

I just have to check the runout with the dial indicator tomorrow and then torque the spokes, but I've got it so close using the pointer on the stand that I can't discern any runout. It's likely within spec as is.

I was going to upload a little MP4 of the wheel merrily spinning away on the truing stand, but the 'video' button only takes still image file extensions. Hmmm...

Anyway, here's a still shot. Also, I didn't have to use the steel spacer between the bearings in the Sporty hub, as the Triumph does not use an end-loaded axle like the Harley, with a big nut putting tension on the bearings' inner races. The axle's just clamped with those slider caps and nuts. The bearings' outer races bottom out in their recesses in the hub, ain't goin' anywhere.

So, saved me 4.6 oz of unsprung weight over the stock Sporty setup. But with that ultra high-density steel axle I'm using, probably got it right back...

Looks like I'll have the tire fitted this week, and will set her down long enough to see what it looks like with the front disc conversion all done.