Showing posts sorted by relevance for query 1971 Bonneville. Sort by date Show all posts
Showing posts sorted by relevance for query 1971 Bonneville. Sort by date Show all posts

Sunday 3 October 2021

Taking My Motorcycle Restorations to the Next Level with the help of the Canadian Vintage Motorcycle Group

Heavy rain all week made Beaver Valley a
muddy mess.  The Tiger waded through it all,
spinning it's wheels in the deep mud but
always getting me down the track.
Sunday was a long ride up north to clear my head after another week of pandemic teaching where they pile on extra work going on two years into a pandemic and then reduce your ability to do it.  The trusty Tiger was on song and we sailed and sailed, up past Horning's Mills and through Creemore before tackling the Grey Highlands.  I was timing the ride because I had a meeting!

Last week I joined the Canadian Vintage Motorcycle Group and then connected with their Facebook page (that part is free - if you're into old bikes I'd urge you to join up!).  By dumb luck the admin who accepted my FB group request happens to live nearby and has a lockup ten minutes from where I live.  He asked if I wanted to see what he had kicking around in terms of project bikes I could buy.  That CVMG membership is already paying off!

Four hours and three hundred kilometres later I rolled up to a farm just south of town and met Brian and his lovely wife Terry.  We drove down to his storage containers out of sight at the back of the farm and he unlocked a hidden magical kingdom!

The bike I think I'm going to do a full ground up restoration on is a 1971 Triumph Bonneville.  This year was the first oil-in-frame model.  There are benefits to this model that suit me, the main one being that this bike has a taller seat than other Bonnies.

The bike in question has been partially 'choppered' with a big sissy bar and king/queen seat.  It also has long front forks - someone was on their way to turning this into some kind of Easy Rider homage, but it won't stay that way.  I'm not stuck on the stock-at-all-costs angle but I like motorcycling for the dynamic feel of it and a chopper isn't about that.  A modernized custom that stays true to the original look but makes use of the bits and pieces that will make this classic a bit more dependable is where I'm at.

Fortunately, Brian has lots of stock spares which he'd include with it so I'll be able to strip it down and begin working out how to put it all back together again without having to start from scratch.  When I pick up the bike I should also be getting some tupperware boxes full of additional parts.

Classic Bike Magazine had a great issue in June about Steve McQueen, On Any Sunday and desert racers.  McQueen himself did a Bonneville desert sled back in the '60s.  I like the stripped down scrambler look of that kind of bike, though I'm not going to go all knobbly tires and brown seat with it, but a simplified, high piped Bonneville for the road?  That's something I could get into!

I'm going to have to wait until after Thanksgiving Weekend to get my hands on it. I 'll also have to figure out how to get it over here, but I'm looking forward to my first deep bike resto after successfully putting a number of early retirements back on the road again.  This one's going to be an engine out, frame up restoration, Henry Cole style!

Brain had some beautiful old bikes - this 1950s BSA bitsa was a wonderful looking mashup.  The only thing that made me hesitate was the 350cc engine trying to move my bear-sized self around.

Back to stock? The '71 was the first of the oil in frame Bonnevilles and an odd duck with
a tall seat height, but it was also a handsome thing!

Here are some other resources and reference images as I bring this old thing back from the edge.

"The new frame raised the seat height to 32” which meant only tall riders could really get both feet down" - yeah, that's not a problem for 6'3" me.

Thursday 30 December 2021

Motorcycle Electrical System Rebuild From Scratch

Researched links on re-wiring the 1971 Triumph Bonneville... 

The old Bonnie has an intact loom and many of the original electrical components, but many of these pieces won't have weathered the decades well and I'd be crazy to try and rebuild a hacked on electrical system in a fifty year old bike, so it's all coming out.  I'm going to take a page from the custom scene and build a loom from scratch and design and build a complete electrical system from scratch.

This ain't no modern digital machine so the electrical system in it is prehistorically simple.  Building a dependable replacement with quality modern upgrades (proper copper wiring, modern connectors, new electronic ignition and coils, etc).  The result should be a 1971 Bonneville that is more spritely and dependable than anything that rolled off the line in Meriden in 1971.

Tutorials on creating a motorcycle wiring harness/loom:

BikeExif Tutorial:

Rewiring tutorial:



Resource (costs 20 pounds):

Another good resource ($40):

I've purchased and read that last one - it's a gentle introduction to electrical work but I found it a bit simple and wished it had picked up speed as it went.  If you've never done any electrical work then it's a good place to start, but that's what I do all day so I was hoping for something with a bit more depth.

Replacement harness:

Prebuilt '71 Bonneville wiring harness:

Original loom wiring colours:
  • RED (seems to be earth but then battery + so this is a positive earthed bike?)
  • WHITE (headlamp loom)
  • GREEN/WHITE STRIPE (LH handlebar switch & main loom)
  • BROWN/GREEN STRIPE (headlamp loom)
  • BROWN/GREEN STRIPE (headlamp loom)
  • WHITE/YELLOW STRIPE (L/H handlebar switch) + ignition coil
  • BROWN (headlamp switch)
  • GREEN/RED STRIPE (L/H handlebar switch)
  • PURPLE (horn press R/H switch)
  • LIGHT GREEN (L/H handlebar switch)
  • PURPLE/RED (earth?) horn
  • BLACK/WHITE STRIPE (condesner pack/ignition coil split)
  • IGNITION COIL: BLACK/YELLOW STRIPE to coil & condenser pack + WHITE to coil
  • RED (earth frame)
  • BROWN/BLUE: Zenor diode
  • RED to battery positive (that doesn't make much sense)
  • BROWN/BLUE: battery negative
  • REAR LIGHTS:  BROWN/GREEN STRIPE (rear lamp)+BROWN (stop lamp)+GREEN/WHITE STRIPE (L/H indicator)+GREEN/RED STRIPE (R/H Indicator)+RED (earth)
  • STATOR (GREEN/YELLOW STRIPE+WHITE/GREEN STRIPE) were advertised in the UK's BIKE Magazine...

The Motogadget is an all-in-one electrical block for all electrical items on a bike - it also provides you with a bluetooth connection so you could start and stop it by your smartphone:

Not really what I'm looking for for the Bonnie project, though I'll keep it in mind for a future ground up custom build.

A new ignition barrel with keys looks to be about $80.  I'll see if Britcycle has them.

The existing wiring looks like it was taken apart and left that way - I'm tempted to take it all out and just rewire it rather than trust the old mess.

Electrical Systems Parts List:

  • Ignition barrel & key set
  • wiring to rebuild loom step by step - I'd need correct gauge wiring & connectors
  • fuse box
  • fuses
  • reg/rectifier
  • upgraded/modernized stator

Motorcycle wiring how to:  A commonly found writeup someone has done to walk any interested DIYer in how to rewire your bike.

Monday 25 October 2021

1971 Triumph Bonneville T120 Online Resources

Searching the internet for parts and technical details for a 1971 T120 Triumph Bonneville 650cc air cooled twin.  Here's what I've found - hope it helps if you're looking for similarly vintage parts and details.

Technical Details
Love me some hand drawn drafting!


British Motorcycle Supply Co.  (with Canadian Contact info!  Thx Brian!)

Wednesday 16 March 2022

1971 Triumph Bonneville Project: Engine Out

The weather's all over the place at the beginning of March this year.  Last weekend I had both road-ready bikes out for a shakedown, this weekend we're skiing in -20°C windchill; that's the road I was riding on last week.

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:

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:

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: