We had a break in the Canadian winter (in April) and I finally got a chance to exercise the Concours. This jaunt took me over 250kms from where I live in the tedious industrial farming desert of South Western Ontario, an hour up to the road to the edge of the Niagara Escarpment where I have a small chance of finding a corner to ride around. It usually gets colder by the lake, but contrary to physics, it went from 12°C when I left up to 27° by the lake. It only dropped down into the low 20s again once I found some altitude on Blue Mountain (a hill anywhere but in Ontario).
It is actually nuclear powered! I feel like I really bonded with the Connie on this ride – we sailed for miles and we had many more in us when we stopped for the day. If you’re light on the throttle it gets reasonable mileage, but it’s a wonderful thing when you wake up that motor. Kawasaki has a special touch with engines.
I had the 360 camera along for the ride and put together a montage using an incredibly complicated process that involves batch processing the 360 panaramas into ‘tiny planet’ images and then clipping them all together in video editing. It isn’t for the faint of heart, but it sure looks unique. This is the how-to if you’re feeling brave.
I’m in the process or stripping the last bits of hardware from the frame and bodywork in order to clean up and paint the frame and bodywork on the 51 year old Bonneville project bike. The bolts holding the licence plate holder onto the rear fender were 4 different sizes with the longest ones protruding so far toward the wheel that they’d be a safety hazzard on a big bump (the tire would make contact with them on full suspension compression, especially with me on it).
I was talking to a friend online who made a career out of flying helicopters for the military and he said he’s found wrong sized hardware in controls that have actually jeopardized flight safety. One of the rhings I enjoy about motorcycle mechanics is that it feels closer to aviation than four wheel appliance repair where an error like this might cause you inconvenience as you roll to a stop on the side of the road. If you’re up in the air or out on a bike and you have a catasrophic mechanical failure, it’s a very different consequence.
Another pilot friend (the perils of being an air cadet), when we were going up for a flight in a Cessna, brought it back around and landed when the engine didn’t feel right. Everyone was impatient at the delay, but he said something that is simply true that many people don’t consider when their flight is delayed: “it’s better to be down here wishing you were up there, than being up there wishing you were down here.” It’s a shame more people who work on bikes don’t think the same way. I’ve seen even professional work that was half assed to save time/money. Incompetence like that puts a rider’s life at risk needlessly. It can end up costing you far more than you saved.
Pretty sure that last one isn’t a stock Triumph bolt. These’ll all get replaced with metric bolts because they’re easier to find, but they’ll be the right length, matching and be staineless steel.
The 14-0101 bolts used to fasten the fenders on the ’71 Bonneville are 1/4″ X 1/2″ X 28 UNF, which are a bugger to try and find a match for. The longest bolt on the bike was an inch and a half – way too long for where it was. Working with SAE/imperial sizes on this bike makes it a real pain to match hardware out of what I have on hand, but stuffing a bolt that long onto a bike where it can interfere with the wheel isn’t sensible.
SAE Wrench Size
Bolt Size (SI)
Metric Wrench Size
5/16″
1/8″
8 mm
3/8″
3/16″
10 mm
7/16″
1/4″
11 mm
1/2″
5/16″
13 mm
9/16″
3/8″
14 mm
5/8″
7/16″
16 mm
3/4″
1/2″
19 mm
13/16″
9/16″
21 mm
7/8″
9/16″
22 mm
15/16″
5/8″
24 mm
1/4″ bolts can be replaced with an 11mm metric option and finding stainless steel versions of these are easy. I can also get four matching that are the correct length for the job at hand rather than bunging whatever I have in the toolbox onto the bike. Compared to other costs in this restoration, hardware costs are trivial (for under $40CAD I can get a 900+ piece kit). When I’m dropping $600+ on a new head, spending a bit on properly sized bolts seems like a no-brainer.
Of course, body panel fasteners are a different proposition to what you put into a motor or transimssion – in those cases I’d always use stock pieces to manage the heat and pressures involved as decided by the engineers to designed the thing, but for bodywork there is a bit more latitude, you just don’t want to be a pratt about it.
While sorting the frame I’ve cleaned up the oil in frame drain system.
The Amazon bolt set arrived in less than 24 hours. It is (of course) snowing today in mid-April in Canada, so moving the other bikes out of the garage to paint things isn’t likely, and I can’t paint outside if it’s snowing. You need 10°-30°C temperatures, no direcf sunlight and good ventilation. If I can get the other bikes out of the garage, open the door a foot and run the fan, I might be able to retain enough heat to do it, but Canada’s ‘spring time’ isn’t helping things along.
If had a wee outdoor shed I’d use it as a paint booth, heating it to the required temperature and then having a fan to move the overspray out. This DIY paintbooth would be a thing if I had a larger workshop, but a shed outside is a real possibility. It could provide storage, freeing up space in the garage, but with some crafty ventilation it’d also be a paintbooth. If I don’t get to painting today, I can at least finish prepping the frame and body panels and hope for warmer temperatures later in the week.
New tires and innertubes are on hand. The frame is being prepped. I’ve still got some other body panels to clean and prep for painting.
Long before I got into riding motorcycles I discovered ice hockey as a new immigrant to Canada. I played whenever I could from backyard rinks to 5am practices to driving miles for games on evenings and weekends. The smell of a hockey rink is a happy one for me, as is the process of getting ready for a game. For many years I played net, which involved putting on over 70lbs of gear each time (this was back in the day when it was made with leather and bricks rather than the fancy space-aged stuff they have now).
I enjoyed getting to a game early and made putting on the gear a pre-game ritual. It gave me meditative time to get into the zone before I had to peak-perform. Perhaps this is why, when I saw this question on Facebook, it took me by surprise:
My ride starts when I go out into the garage and start putting the kit on. This isn’t tedious, it’s a chance to echo all those hours spent in cold arenas getting ready to lay it all out there on the ice; it’s an opportunity to put on my game face. I never end up on the bike out on the road half paying attention or thinking about something else because putting on the kit is a integral part of getting ready to ride for me.
Getting my gear on builds a sense of anticipation, so the idea that this might be tedious feels very foreign. How can you be bored when you’re preparing to do something awesome? Robert Heinlein gives a good description of the feeling in Starship Troopers:
I always get the shakes before a drop. I’ve had the injections, of course, and hypnotic preparation, and it stands to reason that I can’t really be afraid. The ship’s psychiatrist has checked my brain waves and asked me silly questions while I was asleep and he tells me that it isn’t fear, it isn’t anything important—it’s just like the trembling of an eager race horse in the starting gate.
Perhaps riding a bike for you is a flipflops, t-shirt and loud radio half-paying-attention kinda thing, but I take my riding a bit more seriously. Every time I’m able to get out onto a bike it’s worthy of my full attention, every time. Making sure I’ve got the right gear is an integral part of that, but so is the opportunity it provides to cultivate a strong mental riding game.
Back in 2015 we rode down to the Indy MotoGP round. Helmets are optional down that way and we went out once to pick up dinner just up the road without helmets, and it just felt wrong. The right kit means you can ride longer without getting wind or sunburned and can even make you more comfortable than free bagging it. Once you’ve got that approach, trying it the other way just feels wrong.
The gear makes the rider angle also means you don’t buy the cheapest junk you can find to check a box. I’ve spent years honing my gear so that when I put it on it fits, feels right and does what I want it to do. I started off cheap but soon found that if you spend a bit more you get the kind of quality that makes the extra outlay worth it. You can sometimes save money getting quality things second hand or on sale, but it’s false economy to get cheap gear and then expect it to work. If you get quality ventilated kit for the summer, it can keep you cool while keeping the sun and wind off you. If you get properly insulated gear for cold weather riding, you can sail for hours in temperatures approaching freezing. Good gear makes you superhuman.
Helmets are especially important. I’m partial to Roof Helmets because they’re of high quality and are an advanced, modular design that lets you change from a fully safetied full face helmet (lots of flip ups are only safetied as open-face helmets) to an open face ‘jet’ style helmet with a quick flip. They’re aerodynamic, quiet and ventilate well. I’ve tried many different lids, including a dalliance with that beaked adventure nonsense, but (for me) a helmet that lets me feel wind on my face quickly and easily (I can flip it up when passing through a town then be back to full face comfort again in seconds without stopping) was what worked. Getting into kit that feels this right and is well made is all part of the pre-ride ritual and is no hardship.
I frequently see people out on bikes that are wildly unequipped. They’re usually the cruiser-Captain Jack Sparrow types who are into riding for style rather than, um, riding. The bikes they tend to ride aren’t really into going around corners (or much else) and their riding gear follows suit. If that’s your kind of motorcycling then you’re probably not reading this anyway.
If you’re curious about sports psychology and how it might serve your bikecraft (assuming you see riding as a sport that demands practice and focus to improve your performance), there are a lot of links below on getting in the zone, peak performance and pre-game rituals. Pre-ride rituals work the same way, giving you a chance to clear away the clutter and get your head on straight.
If you watch any motor racing you’ll be aware of pre-race rituals that many riders adopt. Valentino Rossi was famous for his pre-race contortions, and those are only the visible ones! Doing this sort of thing looks eccentric, but you do what works for you in order to get yourself into a peak performance mindset. The amazing things you see athletes do don’t happen without mental preparation. Riding your bike well won’t happen without it either. Don’t get frustrated at putting your gear on, use that time to get yourself into the zone for your ride.
Athletes stand a much better chance for getting in the zone when they make it a point to engage in a pre-game routine that allows them to think about the upcoming game, elevate their mood state, and lower their negative anxiety.
I got the rear tire off the rim today in the ongoing ’71 Bonneville project during a late March snowstorm. It had a Lien Shin tire on it. I’m unfamiliar with that brand and I can’t find a heat pressed time stamp on it. Tires produced before the year 2000 use a 3 digit code that makes it difficult to determine which decade they were made in (first two digits are month of manufacture, last digit is the year). Tires after 2000 use a four digit code (week # of manufacture followed by a the last two digits of the year, ie: 0501 would be the fifth week of 2001). A 511 would be the 51st week (December) of a year ending in 1, ie: 1981, 1991.
While I couldn’t find a stamped date on the Lien Shin tire, there is a three digit date stamp on the Inoue front tire: 511. Based on the bike’s last sticker on the SATAN license plate (’84), this probably dates the front tire to the 51st week (December) of 1981. I was 12 when this tire was manufactured. I’m still amazed that it works at all and the inner tube holds pressure.
Taking a tire this old and stiff off was tricky, but as with the TIger tire change last year, a judicious application of heat really helps soften the rubber and makes removal easier, especially in the winter. It was -17°C outside so I put the shop heater next to the tire and let it warm up, then removing it with the irons was pretty easy.
Once I had the old rubber out of the way, I went at the rim with a wire brush and it cleaned off the surface rust well. Some SOS soap pads and then a bout with the pressure washer out in the snow storm and the rim came up nicely.
Next time I have some time and space I’ll get the front tire removed and prep that too, then it’ll be time to order some wheel hardware (bearings and brake pads). With the wheels rebuild, I’ll clean up the frame and repaint it and then it’s time to start putting the rolling chassis back together.
While I had the wheels off I took the rear brake apart. I keep being surprised by how simple this bike is. The rear brake is a mechanical mechanism, no hydraulics in sight. You press on that big brake lever (it’s big because you need the mechanical advantage for it to work) and that pulls the rod connected to a spinner on the top of the rear brake drum. The drum spins and applies the brake. When you let go, a spring on the drum spinner disengages the brake. You must get pretty good feel out of a direct mechanical system like this, and you’re not carrying any extra weight from a hydraulic system (fluid container, piston, pipes, caliper cylinders, etc), but I bet you’ve gotta have big calves to lock it up.
I’m back at work this week so it might be a few days before I take another swing at it, but it’s exciting to get to the point where the bike is enough pieces that I can see how it’ll go back together again.
It was a long winter this year, made particularly difficult by grinding through a second year of COVID19. I find a great deal of satisfaction in spannering my own bikes, but that isn’t an end in itself for me, riding is. With a few days off work and the weather finally breaking, I got over 300kms while I could. Both the nineteen year old Triumph Tiger and the twelve year old Kawasaki GTR1400 worked like a charm.
I’d initially planned to do a rolling restoration of the 1971 Triumph Bonneville project, but the state of the engine and my desire to get it back to a place where I can enjoy an updated, dependable but mechanically sympathetic restoration (I want the bike to retain its patina, but I also want it to be dependable) made a rolling restoration impractical. The engine is lined up for a new 750cc head and electronic ignition system, but before all of that I have to get the frame and wheels sorted out so that I can put the upgraded engine back into a sorted rolling chassis.
To that end, it was finally time to take it to pieces, which also gave me a lot of space back in the one car garage once the bike stand was stacked to the side:
The frame out means I don’t need to fill half the garage with the bike stand.
Black rubber bands cover the frame to swingarm joints (to prevent water getting in?).
Way more space in the garage with the Bonnie in pieces.
With the bike in pieces, I’m restoring all parts that I can reuse. This usually involves some WD40, a toothbrush or wire brush depending on how filthy it is, and then a dip in a hot ultrasonic bath for small pieces to get them back to fresh.
The front wheel Smiths speedometer.
Into the rear brakes. Like everything else on this old bike they are much simpler than modern hydraulic brakes.
Bringing old parts back from the brink is very satisfying.
The entire rear brake system – the brake lever is so long because it is the only mechanical advantage you have when applying the rear brakes. Instead of using hydraulics to amplify your push on the pedal, the old Bonnie is a simple mechanical system. You press the brake lever which pulls that long metal bar which rotates the top of the drums, pressing them into outside of the drum. No hydraulics, and I bet you have to press that lever like you mean it to lock the rear wheel.
I was reading Classic Bike Magazine last month and one of the auctioneers in the back of the mag suggested getting my hands on a copy of The Rudge Book Of The Road if you are looking for an historical read that’ll get you through a long winter and prime you for the coming springtime.
I had a look around and finally found a 1926 version of the book on Amazon for about thirty five bucks.
If you have a thing for art deco drawings, the Rudge Book of the Road will scratch that itch!
My copy was once owned by.. a W. Chapman?
Reading a book that’s almost 100 years old gives you a perspective on motorcycling that you might not have considered before. At one point the author talks about how much Rudge has learned from building motor-bikes over the past 17 years. I found myself becoming conscious decades of development that since went into my current 1971 Triumph Bonneville project and then continued on for decades more as found in my modern Triumph Tiger and Kawasaki Concours. A bit of historical perspective is a powerful thing when you’re hands on with the engineering found in modern motorbikes. With nearly a century of continuous development, reading about motorcycling from the dawn of the sport is good mental exercise.
The Rudge Book of the Road takes me back to a time when my grandparents were children and, as a modern reader, I’m left struggling to find a frame of reference in our overcrowded and mechanized world. There were a quarter as many people on the planet when this book was written and internal combustion engines were in an early phase of rapid development as they revolutionized and democratized travel for more than just the wealthy. This book makes a point of recognizing this exciting period in history:
Traffic jams and the expectation that everyone be commuting in motor vehicles in an increasingly crowded and polluted world makes this perspective feel particularly alien in 2022. Can you imagine thinking about motorbike travel like this? If anyone could do it, it’s motorcyclists – we may be one of the last vehicular subcultures that clings this kind of romance, even as the vast majority drive their appliances without a second thought for how they work or experiencing any inherent joy in the activity.
Having lived with rough ‘colonials’ for most of my life, some of the language in this very British book made me smile. It was written for Rudge Whitworth as a sales tool but it leans toward the romance of riding as a theme throughout. Rudge themselves lasted until 1946 before they stopped production, so you’re reading a book by a company that hasn’t existed in over seventy years, which further makes reading this feel like an echo from a distant and unknown past:
The state of the art in terms of motorcycle engineering was making major steps in the 1920s. Earlier bikes had you oiling the motor as you rode it. Too much and it would clog the spark plugs and leave you on the side of the road having to clean your plugs, a job most modern vehicle operators would have no idea how to do. Too little oil and the engine would seize, possibly tossing you down the road. This degree of involvement in motor vehicle operation was being phased out in the mid-nineteen-twenties bringing more people into the moto-fold.
The idea of sitting down with your new machine and understanding what it needs and how it works is a foreign one in 2022, but Rudge makes this process seem almost meditative. The idea of lighting your pipe and comprehending your new machine in your shed still appeals to a few of us. Perhaps this is another of those colonial distinctions. I have no trouble finding programs on industrial history and engineering when I watch British television, but Canadians seem more focused on resource extraction and office work than they are with understanding how things work and then manufacturing them. This sort of mechanical sympathy will sound particularly foreign to Canadian ears:
Sit on a can of gasoline and light your pipe! Those were the days…
This old book doesn’t limit itself to motorcycling mechanics. If you’ve never camped before they offer advice for those new to sleeping on the ground. Rudge made sidecar outfits and even a trailer/caravan for people interested in taking everything with them.
When your trusty leather bound Rudge Book of the Road isn’t teaching you how to moto-camp, it’s explaining how the roads you’re riding on might be built on top of old Roman roads or how to identify the architecture of the historical buildings you’re touring past. This makes me wonder whether Rudge’s target audience was perhaps a bit more educated than your typical rider, but it also makes me wonder if maybe people were just a bit smarter back then without a phone to immerse them in social media in all the time.
The book doesn’t stop at camping or architecture and goes on to teach you how to forecast the weather, tell direction and even tells you where the biggest hills on the island are so you know what gear to tackle them with. It then provides charts on when the sun rises and sets so you know when to turn on your new-fangled electrical light. Rudges were one of the first to go electric. A few years earlier you were lighting a gas powered lamp on your motor-bike before proceeding into the dusk on mostly unfinished roads (while remembering to give the top and some oil). There are (many?) riders now who have never turned a wrench or put a wheel off pavement.
You’ll learn more from doing things than you will from “all the books or professors in the world”. Something we’ve forgotten in our screen-fueled information revolution?
There is another chapter written by F.A. Longman, Rudge’s rider in the 1927 Isle of Man TT road race. He writes with a racer’s urgency and puts you in the rider’s seat as he talks you around the T.T. mountain course while it was still young and relatively new. It’s amazing how little has changed in the racer’s mindset even while they’re using machines that have only just recently become mechanically self contained. They were seeing huge leaps in speed as technology improved and riders came to terms with what this new technology was capable of.
After teasing you with the Isle of Man TT, the RBotR then gives you some 1920s style advice on how to get ready to compete in trials and perhaps even go road racing with your motorbike:
Civilisation continues to makes fools of us all in 2022…
Give up the cigarettes and alcohol entirely, but do keep the pipe smoking! Can you imagine modern, liability-driven manufacturers encouraging riders to do this sort of thing on their new motorbike? It’s difficult not to get swept up in the enthusiasm and possibility of riding at a time when it was still new to so many people, including the people who built the things! The lack of caution is exhilarating.
The book ends with a complete set of colour maps of the United Kingdom, but not before it talks you through buying your Rudge (this is a marketing piece, remember?). Your fifty pounds (about $1350CAD in today’s dollars) gets you the base model of the Rudge Four – for ten pounds more you can get the sport model. New bikes were much more accessible back in the day!
The final gift this old book gives you is a list of future readings if you’re interested in motorcycles and travelling on them:
Unknown Norfolk is on my shortlist. I wonder how many places I’ll recognize from growing up there fifty years later.
The Rudge Book of the Road was such an interesting read that I’m going to keep digging for some of these other historical moto-reading options. The RbotR suggests slipping one of these in your (tweed?) jacket pocket to read when you get to your destination and finally put your feet up – with your pipe, of course – after another exhilarating day of riding in the dawn of motorcycling.
A more modern motorcyclist philosopher, Matt Crawford, described riding as “a beautiful war“, the Rudge Book of the Road shows that it has always been thus. If you ride, you’ll find this a familiar and enjoyable refrain.
No rear suspension other than springs on the seat and a tank that hangs under the frame: state of the art motorcycle engineering in 1927 seems archaic but these machines were a huge step forward in dependability and hint at the evolution motorcycles would take.
As GP from Hammy Hamster would say, ‘the elephants are against us.’ With the outside trying to kill us again, I’m focusing on doing a complete tear down of the 1971 Triumph Bonneville project. I was originally going to see if I could get the bike in motion as it is, but a combination of factors including 1971 Triumph build quality and the early 80s muppet who tried and failed to turn the bike into a chopper’s spannering skills have me now approaching this as a frame up restoration.
I’ve been working around the edges which has been good for reconnaissance in determining what state the bike is in, but now that I’m committed to doing the bike from the frame up the first job was to remove the bottom end of the motor and clear the way for a frame restoration:
The bottom end was surprisingly light and easy to lift out of the frame and none of the frame to engine bolts caused any problems. Some were quite loose, so a frame up resto is making more and more sense as I don’t trust anything the chopper muppet did to the bike circa 1983.
It was my first time into the rear drums and, like the fronts, they were age seized but otherwise not in terrible shape, though whenever I get into the dark places on this bike it looks like a scene out of Indiana Jones.
I’ve left the frame on the bench as I continue to strip it of accessories. The last time I did some coating work on a project bike it was with Fireball Coatings in Elora but seven years on they seem to have evaporated. I’ve been looking for alternate (and hopefully better) options and KC Coatings in Guelph looks promising. I intend to get in touch with them and see if we can shot blast and powder coat the Bonneville frame, I just have to make sure they can do it on a complicated oil-in-frame design like this one. Powder coating adds thickness and can cause problems with fasteners and fitting things back together so I need to find out if KC understands that and can can work with this one so that its mechanical pieces will still fit back together.
Following the frame I’ll sort out both wheels (bearings, tires and inner tubes) before getting the rolling chassis back together and then rebuilding the motor with my swish new 750cc head.
Motor out and on a pop up workbench by the window. It’s lighter than it looks.
I set up the Black & Decker WorkMate by the back door to the garage to give me somewhere to work on the bottom end of the motor. With the engine split and out of the frame, I can lift the parts off the bike around easily. I might put the bench away and make some space while the project is in pieces.
Revco is fantastic at shipping (even during a pandemic) and very transparent and communicative with delivery times. Everything I’ve gotten from them has been expertly packed, is new stock (no old/new tires). They know what they’re doing with motorsport tires.
The ’71 Triumph Bonneville came with 3.25 X 19″ front & 4.00 X 18″ rears and used Dunlop K70 tires as standard equipment.
It looks like there are modern Dunlop options for vintage SAE (non-metric) wheels at Revco where I’ve gotten my last two sets of tires. The handy chart below shows metric and imperial conversions but after some digging I was able to find SAE/pre-metric modern Dunlop K70s that are the exact fit for the bike. Using recent versions of original equipment that give me the benefit of modern rubber durability and grip while still keeping close to the originally engineering intent in Triumph’s tire choice is fantastic. I’m not trying to recreate riding in 1971, I’m trying to start with that technology and update where prudent for 21st Century use.
Tire ChartsMotorcycle Street Tire Size Conversion Charts
Metric
80/90
90/90
100/90
110/90
120/90
130/90
140/90
Alphanumeric
– NA-
MH 90
MJ 90
ML 90
MN90/MP90/MR 90
MT 90
MU 90
Inch-(Series90)
2.75
3.00/3.25
3.25
3.50
4.00/4.25
5.0
– NA-
Inch-(Series82)
– NA-
– NA-
3.60
4.10
4.25/82/4.40
5.10
– NA-
Front Tires:
Metric
80/90
90/90
100/90
110/90
120/80
120/90
130/90
Alpha
MH90
MJ90
MM90
MN90
– NA-
MR90
MT90
Inch
2.50/2.75
2.75/3.00
3.25/3.50
3.75/4.00
4.25/4.50
4.25/4.50
5.00/5.10
Rear Tires:
Metric
110/90
120/90
130/80
130/90
140/80
140/90
150/80
150/90
160/80
180/55
200/60
230/50
Alpha
MP85
MR90
– NA-
MT90
– NA-
MU90
MV85
MV85
– NA-
– NA-
– NA-
– NA-
Inch
4.50/4.75
4.50/4.75
5.00/5.10
5.00/5.10
5.50/6.00
5.50/6.00
6.00/6.25
6.00/6.25
6.80/7.00
7.00/7.25
7.90/8.00
9.50
Size
120/80V16
130/90H16
130/90V16
500S16
MT90H16 3.00
130/90H16 3.00
140/90H16
140/80VB16
140/90H16
150/80V16
160/80H16
160/80H16
200/60VB16
120/80V18
120/90V18
120/90H16
130/80V18
130/70VB18
150/70VB18
140/70V18
170/60VB18
180/55VB18
230/50 X 15
Rim
2.75
3.00
3.00
3.00
3.00
3.00
3.50
3.50
3.50
3.50
4.00
4.00
5.50
2.75
2.75
2.75
3.00
3.50
4.00
4.00
4.50
5.50
7.00 to 8.00
Overall Width
4.7
5.00
5.2
5.2
5.3
5.4
5.8
5.9
6.0
6.2
6.4
6.8
7.9
4.8
4.8
4.9
5.2
5.4
5.9
6.1
6.9
7.0
9.5
Overall Diameter
23.8
25.4
25.0
26.4
25.3
25.6
25.6
24.8
25.8
25.4
26.1
26.1
25.9
25.9
26.4
26.3
26.3
25.4
26.2
25.7
26.0
26.3
25.3
Note: Measurements are based on the given rim widths. A rough rule of thumb: Each additional 1/2-inch of rim width will be approximately 1/4-inch more in each tire width.
The K70s at Revco are just over a hundred bucks a pop and Counteract Balance Beaded inner tubes are actually cheaper than name brand plain old rubber inner tubes. I’ve been using the Counteract beads for years to great effect so they’d be my first choice even if they weren’t cheaper. All in I’m looking at about $320CAN ($250USD) for new rubber for this vintage restoration project, which considering the price of some of the other parts is pretty reasonable.
In order to rebuild the wheels I’ll need to replace the bearings and clean up the brakes before putting new pads and hydraulic brake cylinders back in them. All that and getting the frame sorted out will get me back to a correct rolling chassis ready for the upgraded engine.
Somewhere at the end of all of this will be a road worthy ’71 Triumph Bonneville, but it’s a lot of parts to find and get in and then a lot time in the garage to get there. I’m hoping it’ll be on the road for next year’s riding season. As we thaw out here in Canada I’ll be out on the Tiger and GTR and not spannering so much.
Meanwhile, here are some more motorcycle tire sizing reference charts found on the interwebs:
Gudgeon: one who will bite at any bait or swallow anything, credulous or gullible person Mer. V. I. i. 102. (that might apply to this project)
Definition of gudgeon
1: PIVOT sense 1, JOURNAL (we’re getting closer)
2: a socket for a rudder pintle (a rudder pintle?)
Definition of gudgeon pin: WRIST PIN
Definition of wrist pin: a stud or pin that forms a journal (as in a crosshead) for a connecting rod (that’s it!)
They can make up anything! Nobody knows! Well, you need a new Johnson Rod in here!
A few people know, George. Consumer ignorance is expensive, but who has time
to understand the machines they depend on?
Gudgeon pins? After the massive fight that was removing the seized cylinder head, I was bracing for misery, but I was able to pop the circlips (!) out and tap the gudgeon pins (!) through with no sweating and swearing. Pink Floyd was playing on the computer and I think music from its era calms the old Bonneville down when I’m working on it.
The circlips popped out easily and a 3/8 inch socket extension was the perfect size to tap out the ‘wrist’ pins. I thought the one on the seized side might cause more problems because it had been stuck in place with moisture but it didn’t and both came out easily leaving a motor bereft of its pistons.
British Cycle Supply Co. delivered my 750cc kit quickly and without any headaches (and also for about $200 less than comparable kits out of the USA), so I got the shiny new bits out and had a look:
You’d think a 750cc head would look significantly different to the stock 650cc unit, but you have to look closely to see a difference in size.
I had a close look at the connecting rods and they appear to be in good shape and the bottom end of the motor moves freely. I think next steps are to remove the rest of the engine from the frame, give the oil-in-frame a deep clean and then recoat it with some quality paint. With the frame cleaned up and sorted I’ll strip the rest of the motor and clean everything out to ensure nothing’s whacky before I begin the great rebuild.
I could just chuck it all back together now and hope for the best, but if it ends up having other niggles rushing things at this point is just false economy. I’m not worried about making the bike look mint, but I do want it to be dependable and that wouldn’t be the case if I haven’t checked it over completely after such a long (30 year?) layoff. An engine out deep restoration was always the intention here and I’m not in any kind of rush since the other two bikes are both five by five and felt fantastic on their first rides of the year this past weekend.
The gudgeon pin itself looks to be in good shape, which is good because the head kit didn’t come with new ones. The circlips came out nicely too but the kit did come with those. It amazes me that even specialized material like that in these cylinders can withstand the extreme forces they operate in. This Bonnie had done at least twenty thousand miles on these cylinders and they’re still in remarkable shape considering they were face to face with more than 17 controlled explosions every second (a spark plug typically fires about 17 times per second at 2000rpm!). You’d think all that heat and violence would cause more wear than I’m seeing in the beating heart of this motor.
This is the 3/8 inch socket extension I used to tap the gudgeon pins out. Nothing grabbed or slowed the process down and I barely had to apply any pressure. I might have even been able to push them out had I been so inclined. I caught the pin as it came loose and the cylinder lifted off the connecting rods easily. Again, considering the extreme conditions the heart of every engine operates under, I’m impressed by the engineering and metallurgy that makes all this possible.
The new cylinders don’t have the carbon build up from all those combustion cycles and look pretty spectacular in their pristine newness:
Here’s the whole kit from British Cycle Supply. It includes the cylinder head, cylinders, piston rings, circlips for the gudgeon pins and a head gasket. I swiped the last one they had in stock for $688.75CAD ($535USD – told you I got a good deal). Unfortunately I might be the last person on the planet to get a 750cc kit that cheap. Prices will be going up on the new stock and probably even higher than that as we’re in an inflationary spiral thanks to Putin overreaching and years of pandemic fueled broken supply chains; we live in interesting times.
Another tool came in that’s interesting. I was reading Practical Sportsbikes last week (highly recommended if you love bikes and getting your hands dirty on them), and editor Chris mentioned an endoscope smartphone camera he was using on a project bike to inspect the internal parts of an engine. I found one on Amazon for under $40CAD and it came in on the weekend. It lets you see parts of the engine that haven’t seen light before. It’s an exciting thing that offers you a look into the secret life of engines. I’m looking forward to using it as i continue to work on the Bonnie.
Through an inspection hole inside the engine – it’s disco in there!
That look on my face after the first ride in a long, long time.
The 12 year old Kawasaki (left) and the 19 year old (!) Tiger (right) were keen to turn a wheel after a long hibernation.
Bison were out bisoning at Black Power Bison Co. when I was out for a ride in balmy 6°C March Sunday.
