Monday 28 March 2022
1971 Triumph Bonneville: More Bike Archeology from Tires, Wheel Restoration & Rear Brakes
Sunday 27 March 2022
1971 Triumph Bonneville Restoration Project: Frame Breakdown & Rear Brakes
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. |
Sunday 20 March 2022
Motorcycle Book Review: The Rudge Book Of The Road
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? |
Sit on a can of gasoline and light your pipe! Those were the days... |
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? |
Civilisation continues to makes fools of us all in 2022... |
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!
Unknown Norfolk is on my shortlist. I wonder how many places I'll recognize from growing up there fifty years later. |
Art deco inside cover wallpaper! |
Riding in the dawn of motorcycling... |
Wednesday 16 March 2022
1971 Triumph Bonneville Project: Engine Out
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. |
Resources & Links
Power-coating Specialist in Guelph for the frame:
https://www.kccoatingsltd.com/contact
Where to find tires:
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.
How to DIY your own fender:
https://purposebuiltmoto.com/how-to-make-a-diy-motorcycle-fender/
If I had more space I'd have welding kit and an English Wheel set up in the workshop and get into a lot more fabrication. I'd go digital too. A industrial sized 3d printer would make me dangerous: https://tkmotorcyclediaries.blogspot.com/2015/11/iihtm-digital-workshop.html
1971 Oil In Frame Triumph Bonneville Restoration: Tire Choices
The old Bonneville needs new tires and inner tubes so I'm wrapping my head around olde fashioned, pre-metric motor-bike tyre sizes.
Those would be the Dunlop K70s that came with the Bonnieville back in the day. Fortunately Dunlop is still looking after the bike they designed the tire for. |
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.
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- |
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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.
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.