Sunday 28 November 2021

1971 Triumph Bonneville Restoration: Front Fork Rebuild

It's all snow and wind outside so I spent a good six hours in the garage this weekend rebuilding the front forks and the triple tree on the '71 Bonneville winter project.



The forks on the bike had been 'choppered' with massive fork tubes and spacers in them.  The bike came with new stock fork tubes so after a cleanup both front forks got rebuilt with stock fork tubes.  I'll put the chopper ones up for sale and see if it'll make a dent in the new parts order I got in.

The internals on the forks were in good shape (it has always been stored inside).  After a cleanup they went back together again nicely.  The picture on the right gives you an idea of just how long those fork tubes were (almost as long as the whole shock!).

The right side front fork went right back in no problem, but  the left side one won't fit in the lower triple tree mount (it has a bolt that squeezes it on but the circular clamp is too tight.  I've tried heating it up and wedging a screwdriver in the gap to respread it enough to accept a fork.  I shouldn't complain, this is the only thing that's being difficult on this fifty year old machine so far.

The lower fork unit as it came out of the giant chopper tubes.

The same piece cleaned up.

Parts diagram from the '71 Triumph's parts manual.

Meanwhile, the first parts order came in from British Cycle Parts.  They were great helping me clarify what I needed to get started.  The order was about $450 including shipping and got here quickly (within a week), one box from their Canadian warehouse and the other from their U.S. one.  I haven't started installing anything yet, but I now have what I need to rebuild the Amal carbs, sort out the electrical system and take apart the motor to prep it to run for the first time.

Motor gasket set!

Electronic ignition system and coils!

Amal carburetor rebuild kits!

Rubber bits!  This time 'round I got a new kickstart rubber & the gear shift rubber.

That's a stock style new rubber to replace whatever the f*** was on it.

The monkey who was choppering the bike put massive footpegs on the rear peg position,
but that doesn't make any sense on a chopper (they're usually feet up and forward).
These are the stock footrests.

Stock foot rests (and hardware)!

The plan is to rebuild the carbs, get the motor sorted, install the upgraded ignition system (which I suspect will also involve creating a new electrical loom) and then see if I can get it all to run.  Once I've got it a step closer to running I'll be back in touch with BritCycle to get the other bits and pieces I need to get it rideable.  The plan is still to get it to a place of getting a safety and putting it on the road next season.

I'm not a big fan of lost causes and I wrench to ride, so the point is to get the Bonneville back into service. After watching a lot of Henry Cole on TV, I like the idea of a 'rat bike', which also means I can focus on the mechanics rather than how it looks.  If I can get the mechanics sorted to the point where I can ride it, I'll do a season with it rough but rideable and then consider my options.  I got the bike and spares for $1500 and I've just put another $450 into it.  I think I can get it roadworthy for under $4000 and a non-running barn find bike of similar era was going for a grand more than that a few weeks ago online, so no matter what the Bonnie project won't ever drip red.

In a perfect world I'll get it sorted and some one will offer me more than I've put into it (cost, not time, I'm happy to put time in keeping bikes on the road).  Whether that's once it's roadworthy or once it's been cleaned up too, I'm easy.  Meanwhile the Bonneville is doing what I wanted it to:  giving me an opportunity to go deep on a motorcycle restoration and learn a lot in the process.

The motor's getting cleaned up and recommissioned.

Once the (now stock) forks are back in I'll wheel it out for a deep clean on the motor
and then start with the electrics before rebuilding the carbs.  With any luck the old Bonnie
will be to the point of starting by the new year.

Somewhere in between all this deep surgery, the Concours needs new brake pads and the Tiger has some new sprockets and a chain to install.  To be honest, these minor maintenance jobs are something to look forward to after the deep diving into the restoration project.

Last winter was a deep maintenance round on the Tiger, but even that pales in comparison to the scale and scope of the Bonneville restoration.  Practical Sportsbikes and Classic Bike are both magazines focused on hands-on motorcycle mechanics and both have talked about the dreaded project stallout that can happen when it all gets too much.  I'm taking the advice of both mags and breaking this up into chunks and then solving things subsystem by subsystem.  The small wins help me feel like like the project is progressing and prevent the dreaded project-stallout from being overwhelmed by the whole thing.

On the upside, the fact that we got 15cm of snow over the weekend isn't really on my mind as I'm keeping track of many things-to-do in the garage.

Sunday 14 November 2021

The Curtain Closes on the 2021 Riding Season

Squeezed in one after work ride last week before the curtain fell on this year's riding season (I hang 'em up when it takes me longer to clean the salt off the bike than the ride was).  We're looking at a weather warning tonight and snow all week.  Yay...









Over the weekend I got the end of year maintenance done.  Both bikes got a deep clean and an oil and filter change and can now hibernate with clean oil, ready for snows to recede in 2022.  Over the winter the Tiger's getting new chain and sprockets and the Concours is pretty much just ready to go, which is good because that's why I got it.




Meanwhile, the '71 Bonneville continues to be dismantled in an archeological manner and I'm waiting on my first order from British Cycle Supply Co..  They should get me to a point where I can actually start the motor for the first time!

1971 Triumph Bonneville Parts Research

Air Filter Pods for 1971 Triumph Bonneville:

https://www.classicbritishspares.com/products/amal-replacement-air-filters







Electronic Ignition Options







Seat:

Sunday 31 October 2021

50 Year Old Triumph Bonneville Restoration: Amal Carbs and the Fuel Tank

A place where logic, precision and cause and
effect still matter in a world gone mad.
 After the random weirdness of work, time in the garage with the old Bonneville is remarkably
straightforward and logical.  I suspect the bike was in the middle of a Captain America Easy Rider customization in the early/mid eighties when it got parked and time left it behind.  I got it from Brian's storage shipping container where it was out of the weather and raised off the ground.  I don't know where Brian got it from but I suspect it was always stored inside.  I battled with a mid-nineties Kawasaki that had been left outside back in 2014 and this much older machine is nothing like as seized, rusted and difficult to get into.

Anything that doesn't immediately loosen gets a bit of heat and then comes free without any headaches.  Not being in a rush and leaning on the spannering skills I've refreshed over the past decade is making this an enjoyable and meditative process.


The surface rust came off the tank with a bit of sanding.  I'm going to see if I can knock out the dent and then strip it all back.  I used Metal Rescue on the Honda Fireblade tank in my last project and it did a fantastic job of cleaning that unused and rust tank out.  I'll let it sit overnight and then do the power wash tomorrow and hopefully the tank'll come back to me.

The Amal carburetors on the bike are remarkably simple compared to what I've been up against before.  Last time around it was a bank of four last-generation-before-fuel-injection carbs on a '97 Honda Fireblade.  Before that it was a bank-of-four on a '94 Kawasaki GTR1000 and then another complex bank of four on an '81 Yamaha XS1100.  The old Bonnie's single Amal carb per cylinder is a simpler design from a simpler time compared to those complex Japanese four-pot carbs.

Airbox sleeves off.

Carb clean up with a fine wire brush and wd40.

Some aluminum corrosion in the bottom of the carb bowls but it cleaned out nicely.

They've been sitting for a long while, but all the hard parts look to be in good shape.




After an initial cleanup I'm going to break down each carb and clean the hard parts in a ultrasonic cleaning bath before reassembling with new gasketry from British Cycle Supply Co..

Ultrasonic bath bringing the carbs back to clean and ready to breathe for the Bonnie again.

My plan is to get the bike operational mechanically and have it going next spring having cleaned up and rust painted the frame and body.  Once it's operational I'll ride it for a season rough and get to know it before looking to a complete engine rebuild and deeper restoration of frame and body panels at a later date.

In order to get it back to rideable, these are the parts I think I'll need:

  • carb gasket rebuild kit x 2
  • exhaust pipes x2
  • mufflers x2
  • ignition cables (and possibly some other electrics)
  • headlight
  • indicators
  • battery
  • head and sump gaskets for the motor (I intend to go in and clean things out/have a look around before I run it)


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

https://cdn.shopify.com/s/files/1/0717/0717/files/1971_Oil_In_Frame_650_Unit_Twins_All_Models_EXPORT.pdf?2276925620862086622

https://www.tomcc.org/Triumph/FrameNumbers

https://www.fagengine.com/blogs/tech/triumph-engine-and-frame-numbers

https://triumph-tiger-90.com/dating-your-triumph/

https://www.baxtercyclebooks.com/FB/Triumph_1971_650cc_models/index.html

https://wiringdiagram.2bitboer.com/1971-triumph-bonneville-wiring-diagram/


https://drive.google.com/file/d/1sbSds50ChTpY_7q8SkhFVOQ5QoRAgc6y/view?usp=sharing
Love me some hand drawn drafting!

Parts

https://vintagetriumphparts.com/?model_filter_id=7

https://www.lowbrowcustoms.com/collections/vintage-triumph-parts

https://www.trojanclassics.com/header-pipes-triumph-tr6-t120-1971-balanced-pair-g

https://burtonbikebits.net/triumph-parts/

https://www.baxtercycle.com/product-category/vintage-triumph/

https://www.thebonnevilleshop.com/

https://kmjonesmotorsports.com/about

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

http://www.britcycle.com/Catalogues/2014pdfCat.pdf

http://www.britcycle.com/default.htm

http://www.britcycle.com/help.htm

Sunday 24 October 2021

Triumph Tiger 955i on the edge of winter

 Single digit temperatures make for a brisk ride.  This one was down to Guelph Line before coming back home and warming up again.  All photos taken with a Ricoh Theta 360 camera set to fire automatically every 6 seconds, attached to the rear view mirror using a flexible tripod.  Here's a walkthrough if you want to try it yourself.