Restoring & Modifying 1971 OIF TR120

[NM Bonny]

As so often happens, the discrete threads I've started on a handful of issues with this newly purchased bike have veered off into (entirely welcome) digressions on other items. So, I'm starting this thread as a catch-all for those interested in following what amounts to an 'axles-up' restoration and mild modification of an OIF 650 Bonneville--and offering help as things arise. (I will soon be importing the beginnings of a front brake discussion.)

I'll start off with a 'day of purchase' photo and where she is currently, then list what's been done to date and proceed from there.

The bike was purchased with all the bits there, new seat and tires, and 140 psi in both cylinders dry/cold but with an awful French Taxi Cab Green paint job, applied right over more than a dozen significant dents, including a pair on the creases that form the L/H knee indentation, and the rear fender was rippled below the taillight mounting holes.

Here's where I am thus far:

• stripped sheet metal all the way down, removed dents, prepped pieces and had a friend mix up some 1966 GM Mist Blue Metallic, which has both metallic and pearl in it (see photos in and out of sunlight)
• have begun making hand-formed aluminum side panels with polished-and-painted scheme
• removed signals, ran control wires inside low-rise handlebar (UK spec?), added drop-in LED British Prefocus headlamp bulb, LED Norton-style taillamp (original horn works fine & is loud)
• converted to negative earth 12v system & soon installing 3-phase alternator, rewired loom with Honda rectifier (Boyer Branden ignition was on bike)
• sorted new Amals that came with bike, installed & sorted new cables
• fitted Hagon rear shocks & chrome chainguard

Here is what I'll do and post on in coming weeks:

• install 3-phase alternator & inspect primary, basket, and clutch
• install 20T front sprocket, new chain & rear chain ring
• pull, polish, and reseal primary, kicker, and timing covers (rebuild oil pump)
• install dust boots over what PO told me are new fork oil seals (looks like it)

Then I'll test ride the bike and decide whether to convert to a DIY hybrid front disc setup I've sketched out. The bike will get Borrani aluminum rims regardless, as the OEM 52-year-old steel rims are losing their chrome. I will also decide whether the lower-style bars on the bike (maybe someone can tell me whether they're UK spec) will suit my 6'2" frame and mild forward tilt I'm looking for to duck the forceful high desert winds in New Mexico, or whether I want to fit the flat bar that I got cheap--but which looks quite nice (though that would mean drilling and rerouting the control wires inside, yet again).

Also, per another thread, once I've ridden her, will decide whether she'll get Dunstall replica mufflers. And away we go...

 

[NM Bonny]

So, took some fiddling but made some templates for the side covers, transferred them to a sacrificial (and too thick) piece of aluminum, made the bends, and adjusted things a bit. Made finished templates, cut them out with the saber saw (duct tape on the foot to avoid deep scratches), and looks like they'll fit well.

I then made up a little die with some hard maple I had laying around and a forstner bit, and pressed an indentation with a socket into the extra piece of aluminum I bought for experimentation... and voila. There will be a nice recess for the ignition switch's bezel to nestle into.

I had wanted to make an oblong recess in each cover, into which to put the waterslide decals (over white paint along the bottom of the recess), but the Bonneville script is too long to fit onto the flat, rearward area of the cover before the gentle radius that follows the frame tube and seat profile. So, I may just put a stripe along the covers--white with a pinstripe to match the tank and fender color--and lay the water slide over that, straddling the large, gentle radius. Then, polish up the balance of the covers to a mirror finish and throw some clear coat on top. Should look cool with the K&N filters...

 

[rodsridin]

Nice work. Thanks for sharing.

 

[NM Bonny]

So, grabbed some time today to make up the side cover blanks, using 5052-H32 aluminum sheet @ .050" thickness. First time with this Harbor Freight metal brake (or any metal brake, for that matter).

They came out reasonably well for a 'first take' and I think they're keepers. Left to do:

• cut the relief for the seat hinge in the R/H cover
• form the recess with the arbor press (per above post) & drill the hole for the ignition switch in the R/H cover
• sand and polish the covers to mirror finish (should match chain guard, or fairly close)
• determine how much paint is left from the tank and fenders in the pint (feels like not very much), and figure out design feasible with that small amount. I'm thinking some sort of white (to match the white in the tank badges) and mist blue metallic stripe that widens slightly to become all white, over which I will put the waterslide 'Bonneville' decal... I dunno, something...
• lay down catalyzed clear over the covers to protect the color and decal scheme, and keep the aluminum from hazing out

It's pretty handy that, with spring-back factored in, a gallon of paint was just about the right radius to match the frame rails' bend paralleling the seat contour.

 

[Rocky]

Well done

 

[solomon]

ay down catalyzed clear over the covers to protect the color and decal scheme, and keep the aluminum from hazing

Just me. I'd rather repolish aluminium, than laquer that might scratch, decolour. Sure it must shine much better without laquer?

 

[solomon]

Just me again. "Oh, no," thinks you.

I think rounded edges easier on eye and fingers?

 

[NM Bonny]

Hi, Solomon.

You're right on the repolishing point--but I'll be applying a paint stripe and a waterslide decal, too. So, a clear coat of lacquer plays a double role: protecting the paint and the decal from degradation due to petrol splashes or drips, etc. That's what Classic Transfers in the UK recommends doing. Also, a good catalyzed lacquer clear coat should have UV protection built in--but I'll take care when choosing one to make sure.

On those two lower corners: I agree, but couldn't visualize how to cut those radii when the pattern was laid out for cutting. Attached is a shot of the bottom/inside view. If I were to cut them now, no biggie on the bottom edge of the cover--but the forward and aft portions of the radii would intrude into the tabs bent into the cover at each end which affix it to the frame...

...huh. Well, indeed, if I shortened the tabs slightly, I could make smaller radii at those points--essentially just enough to eliminate the corners of the shape. Visually, it might make the covers look less folded and more natural, too. Take a look at the second and third photos.

The only downside to that change, is that the bottom edge would be vulnerable to bending inward or outward, as it would lose its fore and aft structural mooring for an inch or so up from the bottom.

Let me see what I come up with. But either way, I'll be sanding the edges to avoid slicing me mitts. Thanks for the comments. Out to the garage!

 

[NM Bonny]

Well, didn't get around to futzing with the radii at the corner(s), as life intervened and I lost the morning. However, after making three iterations of the die for the ignition switch recess to make it tighter than the above experiment re: depth and O.D., at least I got the R/H cover done, too.

If you enlarge the image and zoom in a bit, you can see the more modest depth and O.D. I settled on for the ignition switch recess. I think it looks better with outer edge of the bezel just a few thousandths proud of the cover than below the deck--but purely a matter of taste.

I did learn one lesson, though: cut the hole after pressing the recess. I did it in the reverse order (contrary to my initial experiment--dunno why), and the maple die wasn't hard enough to cause the aluminum to follow the socket around the radius; instead, it just dug into the wood on my experiments... but I'd already drilled the hole. I flipped it over and tapped the sharp edge with the ball peen and it looks fine, but if one were wanting a slightly wider recess, you'd want a flat ring at the bottom for the switch's bezel to grab onto so it wouldn't walk around when you tighten it.

At this altitude (6,000 ft / 1,829 m.) it may get too cold to shoot paint stripes in the garage fairly soon, so these may just get polished and that's it until Spring. But at least now I can move on to getting her running, as the ignition switch isn't dangling at the ends of the leads. Just have to install the new 3-phase alternator and that's it for the wiring/electrical--unless I decide on the flat bar, in which case I'll have to drill it to pass the control leads through as I did for the existing bar...

 

[solomon]

Hey! It not fair! Look at your view from the garage!

 

[Rocky]

Hey! It not fair! Look at your view from the garage!

Nice mountain view

 

[sikatri]

Nice mountain view

Indeed!

 

[NM Bonny]

Hey! It not fair! Look at your view from the garage!

Yeah, I know... whenever I get blue, I try to remind myself to just step outside and walk the dog, lift my head, and look around at my little slice of heaven. We bought it back when land was cheap, but one requirement was a spacious garage for my tinkering--and this fit the bill!

These are views from the back yard and the entry courtyard, respectively--both looking south toward the Sandias, whose foothills you can reach on foot in ten minutes--but you've got to watch your step out here in the sticks...

I should give credit where credit is due: Baloo, who received rattler training I thought was a scam, alerted to that mature (maybe 3 ft.) while sunning inside the French doors. I very likely would've stepped right on it while checking the laundry, if not for that class.

But I digress. Hope to get back to the T120R this weekend...

 

[sikatri]

Yeah, I know... whenever I get blue, I try to remind myself to just step outside and walk the dog, lift my head, and look around at my little slice of heaven. We bought it back when land was cheap, but one requirement was a spacious garage for my tinkering--and this fit the bill!

These are views from the back yard and the entry courtyard, respectively--both looking south toward the Sandias, whose foothills you can reach on foot in ten minutes--but you've got to watch your step out here in the sticks...

I should give credit where credit is due: Baloo, who received rattler training I thought was a scam, alerted to that mature (maybe 3 ft.) while sunning inside the French doors. I very likely would've stepped right on it while checking the laundry, if not for that class.

But I digress. Hope to get back to the T120R this weekend...

Definitely a place for wildlife! Looking forward to more progress pics!

 

[NM Bonny]

Rode the '51 Pan-shovel down to the PO Box to retrieve one of the last checks I'll ever cash from my 'day job,' as I'm retiring the minute this probate closes... and this photo shows why I did a DIY front disc conversion on that bike--and why I may end up doing the same on this '71 Bonny, per the earlier posts in this thread.

If you open the photo and zoom in a bit, you can see this herd has a couple of new colts, and a very frisky Philly, who was darting this way and that. As I came back by from the post office, they were parading down the middle of the south-bound lane with about a dozen angry, impatient drivers behind them.

It's been a long while since I did any riding--much less any roping--but I pulled a U-turn, throttled past the line of cars, got behind the horses, and revved the engine a few times, then moved up on their L/H flank, herding them off the road, into a pasture and out of danger. Pulled another U-turn and headed back home to feed my pie hole (dog first, of course).

I'm thirteen chapters into my second novel, Los Dolores, which is about a young woman who's returned to Texas Hill Country upon the death of her mother, and which takes place on a sprawling (fictional) horse and feed ranch run by her maternal grandfather, the last of his line who's wondering what will become of his beloved ranch when the narrator returns. So, this was a fitting catalyst for an afternoon of writing, as I've been remiss for a couple of weeks--but also a reaffirmation of why I love living in the West and will never surrender my motorcycle endorsement on my driver's license.

 

[NM Bonny]

I do intend to get the bike running per my opening post and take a test ride through the canyon before making a final decision on this, but after this morning and unless I experience a big revelation on my initial outing(s), I am leaning more and more toward a DIY front disc setup for this bike, too--which after all is not a concourse-correct restoration.

Buchanan Spokes makes prepackaged stainless kits for both the OEM TLS conical front brake, and the aluminum 2000 Sportster hub I've got in the garage (see pic), to lace up to the Borrani drop-center 2.5" aluminum rims I will eventually mount to this bike, to receive a Bridgestone Battlax BT46 100/90-19 up front.

The BT46 100/90-19 will fit the OEM '71 OIF front fender stays and fit between the OEM fork sliders, and it looks like the BT46 110/90-18 I'd pair it with will fit aft. (Someone will get the new K70 Dunlops that came on this inoperative bike for the cost of a cheeseburger and shipping; they'll have just a handful of miles on them, solely for purposes of this assessment and confirming operation of the engine and tranny.)

In peering at the '71 OIF fork sliders, I believe that I can design a kit composed of two mounts to adapt this Wildwood aluminum caliper (see attached diagram) to the OEM R/H slider, which will take the 11.5" rotor pictured earlier. The top mount would attach to the OEM drum's anti-rotation ear on the slider, while the bottom mount would take the place of the existing, four-bolt clamping block. Or, I may make up a one-piece mount to eliminate any possibility of caliper movement--but I can't hold that design in my head so would need to make some sketches to make sure it would look reasonably elegant...

I use 10mm (3/8") 6061-T6 aluminum to make my Creative Spridgets rear disc brake adapters, which handle a great deal more rotational stress (which turns into sheer on the attaching bolts analogous to the fork slider's ear) than would the brake on this bike's front end. So, the design I have in mind using the same thickness (at the thinnest portion of the part) should be more than adequate. Should look pretty nice, too--though I have yet to put what's in my noggin down on paper.

Aesthetically, and weight-wise, I like the idea of retaining as much of the stock front end as possible (also, the Sporty front end feels like it weighs more than the OIF front end, even with the aluminum triple clamps--though I have yet to unbolt the OIF front end, which I'll do soon enough and post the numbers when I get around to R&Ring the headset bearings). Those polished or chrome OEM sliders have that neat rib running along the outer edge... I really like that feature. And the Sporty hub simply looks like a slightly larger version of the later model aluminum hub that Solomon's bike has--and it uses inexpensive, pressed-in sealed bearings, too, so maintenance is straightforward (though I already turned a bearing removal tool from the specs in the Triumph manual for the OIF hubs on the lathe--I'd still be able to use it on the rear conical hub).

I should add, though, that in the unlikely event that the 2000 Sporty front end is actually very close to or even less than the '71 OIF front end, I might well just bolt it on and be done with it. But those thin OIF fork tubes and neato sliders... that'd be a tough decision!

 

[Rudie]

peering at the '71 OIF fork sliders, I believe that I can design a kit composed of two mounts to adapt this Wildwood aluminum caliper (see attached diagram) to the OEM R/H slider

Have you considered starting with standard Triumph 73 onwards disc sliders? The stanchion o.d. is the same, the fastening to the bottom of the damper rod is the same. The more common left hand slider if fitted on the right places the caliper mountings ahead of the fork leg or, 82 onwards, Triumph made a right hand fork slider that mounted the caliper behind the fork leg. The later slider also had the caliper mounting holes helicoiled 3/8"-24 (to take bolts as the caliper had to be detached to remove and fit the wheel); the left hand slider has 3/8"-20 BSF threads for caliper mounting as the caliper mounted on studs; however, the threads can obviously be helicoiled to a more common thread.

Using disc sliders would also get rid of the bizarre comical hub front axle. It is the same o.d. through the hub as pre-71, 71-74 T100 and 73 onwards disc axles but, for some bizarre reason, the ends of the conical hub axle through the clamps were reduced to 9/16"(?) o.d.

If using the standard Triumph forks, there are some upgrades worth considering:-

. Leak Proof seals as fitted as standard 78 onwards. The original 97-7010 consists of two seals and two thick steel retaining washers that are an interference fit in the tops of the sliders. Mid 79 onwards, Triumph machined a circlip groove in the tops of sliders (that can be machined in earlier sliders), retained each 97-7079 seal with a 60-7269 circlip and 97-7093 washer in between.

. Better dampers that actually work. There are a number, I know of ones by 3D Motorcycles in the UK, about £140.

. If you retain the standard dampers, replace the standard 97-4003 O ring seals (a source of much stiction) with L.P. Williams's Damper valve seal conversion 1971 on (pair). These replacement seals were originally made by Progressive Suspension in the US; when PS stopped, because they make such a difference to Triumph (and BSA) alloy slider forks, LPW decided to continue having them made. Replacement damper makers might also recommend them.

. Ensure the insides of the stanchions are also polished, not all were/are.

. Progressive Suspension progressive springs.

 

[solomon]

Rode the '51 Pan-shovel down to the PO Box to retrieve one of the last checks I'll ever cash from my 'day job

pulled a U-turn, throttled past the line of cars, got behind the horses, and revved the engine a few times, then moved up on their L/H flank, herding them off the road, into a pasture

You're a cowboy?

I'm thirteen chapters into my second novel, Los Dolores, which is about a young woman who's returned to Texas Hill Country upon the death of her mother, and which takes place on a sprawling (fictional) horse and feed ranch run by her maternal grandfather, the last of his line who's wondering what will become of his beloved ranch when the narrator returns

I'll catch it on Netflix when it's serialised.

Aaanyway...

Here's a pic. T120V conical hub slider, left in pic.
Replacement T140V onwards disc slider, right in pic.
They have a different shaped lower end, different cap.

 

[NM Bonny]

You're a cowboy?


I'll catch it on Netflix when it's serialised.

Aaanyway...

Here's a pic. T120V conical hub slider, left in pic.
Replacement T140V onwards disc slider, right in pic.
They have a different shaped lower end, different cap.

Well, not really. Did some cowboying many moons ago, the summer I got discharged from the service--in addition to other stuff, like 'back-grinding' in an oil field--to earn enough money to make it back from Lawton, Oklahoma to San Diego, where back then one could rent an apartment a reasonable distance from the beach (I designed and paddled ocean-going outrigger canoes for fun) for less than king's ransom...

Well, actually, as surreal as it sounds, "Los Dolores" has already interested a B-movie producer in Hollyweird. But it'll be many months until it's done in novel form, to say nothing of working up a screenplay... if interested, you can use the 'look inside' feature on Scamazon to sample my fiction writing by searching for "Lion at the Door," Joel Young. Though, that said, Lion is a very different genre from Los Dolores.

But I digress...

Thanks for the photos. So, I can't quite tell from the photo, but does the T140V disc slider have the external rib running its full length that matches the T120V sliders I have? The end cap and lower casting differences are minor, aesthetically, to my eye, and wouldn't prevent me from doing what sounds like a much simpler conversion.

 

[NM Bonny]

Have you considered starting with standard Triumph 73 onwards disc sliders? The stanchion o.d. is the same, the fastening to the bottom of the damper rod is the same. The more common left hand slider if fitted on the right places the caliper mountings ahead of the fork leg or, 82 onwards, Triumph made a right hand fork slider that mounted the caliper behind the fork leg. The later slider also had the caliper mounting holes helicoiled 3/8"-24 (to take bolts as the caliper had to be detached to remove and fit the wheel); the left hand slider has 3/8"-20 BSF threads for caliper mounting as the caliper mounted on studs; however, the threads can obviously be helicoiled to a more common thread.

Using disc sliders would also get rid of the bizarre comical hub front axle. It is the same o.d. through the hub as pre-71, 71-74 T100 and 73 onwards disc axles but, for some bizarre reason, the ends of the conical hub axle through the clamps were reduced to 9/16"(?) o.d.

If using the standard Triumph forks, there are some upgrades worth considering:-

. Leak Proof seals as fitted as standard 78 onwards. The original 97-7010 consists of two seals and two thick steel retaining washers that are an interference fit in the tops of the sliders. Mid 79 onwards, Triumph machined a circlip groove in the tops of sliders (that can be machined in earlier sliders), retained each 97-7079 seal with a 60-7269 circlip and 97-7093 washer in between.

. Better dampers that actually work. There are a number, I know of ones by 3D Motorcycles in the UK, about £140.

. If you retain the standard dampers, replace the standard 97-4003 O ring seals (a source of much stiction) with L.P. Williams's Damper valve seal conversion 1971 on (pair). These replacement seals were originally made by Progressive Suspension in the US; when PS stopped, because they make such a difference to Triumph (and BSA) alloy slider forks, LPW decided to continue having them made. Replacement damper makers might also recommend them.

. Ensure the insides of the stanchions are also polished, not all were/are.

. Progressive Suspension progressive springs.

Wow, this is really helpful information--thanks very much.

So, do I understand correctly that all I'd have to obtain would be one L/H slider, an OEM hub and disc, and caliper (I'd prefer aluminum) to convert the suspension/wheel portion of the conversion? If so, that sort of a pure bolt-on conversion (save for lacing up a wheel, which I have to do anyway as my OEM steel rims are pitted) is very appealing. Especially if the slider (as I asked Solomon above) has the external rib running its full length, to match my OEM '71 R/H slider.

The only downside would be being limited to what looks like a fairly small rotor. But I seem to recall Dave of the Lemon Drizzle Gang describing his--which was only updated with a floating disc an aluminum caliper--as 'very good'...?