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

Saturday 19 February 2022

650cc Air Cooled Triumph Bonneville Exhaust and Seat Options

More 1971 Triumph Bonneville restoration project research (all prices courtesy of BritCycle):

High pipes:

721-T74X exhaust pipes - $304.51/pair.
711-709669/9670 mufflers - $486.00/pair.
2x 742-158 clamps - $16.61 ea.
70-9673 “H” connector - $72.28.
2x 742-112 clamps - $16.61 ea.
TOTAL:  $930

Plus associated bracketry and hardware, etc if needed. The one item we’ll have difficulty sourcing will be the ‘chip basket’ heatshield; our manufacturer of those long since retired.


Looking like Steve McQueen on a scrambler styled Bonneville costs extra!  Britcycle said they might have some scratched and dented options on sale, but those aren't regular stock (obviously).



Stock(ish) exhaust system:

721-T79 exhaust pipes - $289.02/pair.
712-102 Dunstall decibel replica mufflers - $330.32/pair.
70-9888 balance tube - $29.09.
2x 742-138 clamps - $16.61 ea.
TOTAL:  $683





What I'd really like to do is form my own pipes, but I don't have the space, equipment or time to do that.  For this project I think I'll use it as a learning process and get this particular Bonneville cleaned up and mechanically sorted and leave the radical customizations to a future time when I'm loaded, have lots of free time and a much bigger workshop with a full range of tooling in it.

I think stock is the way I'll go on exhausts...

As far as seats go, BritCycle has just the sort of thing I'm looking for: 


  
The only thing that might knock it out of contention is if, price and fit-wise, Corbin's customizable seat is in the ballpark.  It says they might fit a '71 but they're mainly for '72 Triumph twins and up.






Quality (made in England) newly manufactured seats specific to the oil in frame 650 twins run at about $500US ($612CAD) - I'm not sure what Britcycle's go for.  The customizable (and probably higher quality) Corbin is $618US ($788CAD).  There are cheaper options manufactured in India & China to less exacting standards to consider too.  I'll be keeping that all in mind as I juggle seat options and make a decision.

Monday 17 January 2022

How Bespoke is Too Bespoke?

Owning a Fireblade checked a box, taught me
many things and was a zero cost experience!
I always try to balance out bike projects so that I land in the black on them.  I've gotten pretty good at this.  The Fireblade Project cost me about $2300 all in and then I got to ride it for a season before selling it for $2500, which I then put towards the Concours14.  Even with fancy seats, windshields and other gubbins, the Connie only owes me about $7000.  Older model, double the mileage bikes are going for eight grand, so I'm still ahead there too.

People who throw big money down on customization that they like seem to think other people will pay extra to adopt their choices and tastes, which never made a lot of sense to me.  This goes for houses or in vehicles - just because you're willing to pay a premium to get a certain look, doesn't mean anyone else is, and expecting them to shell out for your choices is a bit naive.


The Concours was a cagey purchase that
still has me well in the black.
What does always sell is functionality.  As much as I'd like to get all romantic and throw money at the old Triumph I'm restoring, I'm more interested in making it work, and then riding it.  To that end, I'm not interested in creating a perfect replica of a 1971 Triumph Bonneville to put in shows, so modern touches (especially when they're more cost effective than stock-at-all-cost options) are something I have no trouble with.  A bike that starts easily and runs sweetly sells itself much more quickly than a cantankerous but period correct trailer queen.  One's a motorcycle, the other is art, and art is notoriously in the eye of the beholder.

One of the reasons I've always gravitated toward cheap and cheerful 80s and 90s Japanese restos was because the parts are usually easy to find, including hard parts from a breaker if needed, and they're as cheap as chips to buy because people tended to use them rather than put them up on a pedestal.

My first brush with 'vintage' (I think a 51 year old air-cooled Triumph from before the collapse of the British bike industry qualifies as vintage) has me wondering if my approach still works.  The cost of parts is much higher than more recent Japanese bikes and this particular Bonneville was half taken apart by a muppet who wanted to be in Easy Rider, so I'm constantly finding parts missing or incorrect.  I'm also struggling with missing non-metric tools after having owned metric bikes my entire life.

When I'm reading Practical Sportbikes I enjoy the articles on DIY and the stories of scratchers who got a machine put together with their own hands.  When they run one of the 'specials' articles where it's a rich guy with clean hands throwing money at a project, I lose interest quickly.  Classic Bike Magazine is similar.  When they're talking about an owner keeping an old machine running on ingenuity and guile, I'm all in, but the minute it's a millionaire adding to his collection with another bespoke machine put together by someone else, I've lost interest.

I just finished Guy Martin's new book, Dead Men Don't Tell Tales, and Guy ends the latest one talking about trying to find what makes him happy.  This requires a fair bit of self awareness - something that most people don't have.  Guy's particularly difficult in that he will often act on an urge that turns out to be incorrect, but, as he says in the book, he's evolving.

There's a scene in Guy's Garage where Cammy, his professional race mechanic mate, knows how to fix the car they're working on but Guy has his own ideas and keeps bashing away at it wrong.  Rather than push the point, Cammy backs off and waits for Guy to realize he's using the wrong tool for the job.

Guy is critical of Cammy for being slack in his approach to work in the book, but I'm left wondering if the truth isn't somewhere in between:  what looks like a lack of effort from Guy's point of view is actually a better use of his energy from the professional race mechanic's point of view.  There's more to all this than just jumping in to the physical labour, you need to be exercising the grey matter too.

What I'm taking from this latest round of Guy Martin media is that you're more likely to stay engaged with and finish big projects if they make sense to you.  To that end, I spent yesterday working out why the kickstarter on the Bonneville wasn't working (the muppet had put it in backwards).

The goal is still to have gone through the whole bike and have it back in working order without breaking the bank.  The amount spent on it matters less than whether or not the project is in the black.  If a functional '71 Bonneville is worth about five grand, then that's what I'll work to on the budget, while keeping an eye on what engages me most about all this:  putting a sidelined bike back into service again... and then riding it!

This morning I'm looking at Motogadget's mo.Unit Blue and considering how to best tackle a 51 year old wiring loom that looks to be in good shape but should probably get rebuilt if dependability is the goal.  An ignition powered by bluetooth on a smartphone is just the kind of steampunk anachronism that a riding focused buyer would dig.  That it's also invisible means it won't hurt the look of the bike (the only change is the ignition key isn't there).

Got into rebuilding the Amal carbs only to discover the muppet who took them apart before didn't install any of the air slider hardware for the choke, so now I'm hunting for hard parts for 51 year old carbs... in a pandemic.  Note my anemic imperial socket wrench set.

Ready to go and then stopped - neither carb has the air slider or hardware in it.  I'd normally call around to the local breakers, find a donor set of carbs and then keep them handy for situations like this.  That isn't an option with a 51 year old British bike.

It's coming along - slower than I'd like, but it's coming along.  When it seems too much I remind myself why I'm doing it: one day soon that engine will turn over for the first time in decades and shortly after that I'll be out riding the thing!

Sunday 17 October 2021

1971 Triumph Bonneville Motorcycle Restoration: the baseline

 Baseline photography for this 1971 Triumph Bonneville restoration project:


















According to Low Brow Customs, this means I've got an A (January) E (October 1970 - July 1971) and was the 9125th 650 twin made that year (00100 is the starting number for each grouping so this was the 9225-100th motor made in the 1970-71 batch).
The frame was tricky to pick out - one of those sites mentions that the stampings are sometime very thin and this one's barely there - our best guess is AE07050, which would put it in the same month/year as the motor, which seems promising.









The chopper stuff has started to come off and the bike is up on a wooden base on the stand in the back of the shop.  


Next up will be taking the tank off and beginning the GREAT DISMANTLE OF 2021!

Sunday 4 September 2022

Baffling 1970s British Wheel Engineering

I had a go at mounting new tires on the 1971 Bonneville project rims today, and what a pain in that ass that has turned into.  The rear tire is a mess of strange engineering decisions, including 3 holes for the inner tube valve, two of which are filled with rubber/metal pads with valve stem sized bolts sticking out of them.  Why they would do this is beyond me.  It creates a needlessly heavy wheel just where you don't want it (where centrifugal force amplifies it at the rim when it spins).  Perhaps it has something to do with the spokes and creating a true (round) wheel by adding weight?  The rear tire went on easily enough, but the inner tube was a pain to get the valve in place and it doesn't seem to be taking air.  I'll have to take that apart again and figure out what the hell is going on.

Also in bizarro British '70s engineering world, the front wheel has the valve stem hole drilled in the worst possible location, right near two spokes, which makes putting the compressor's tire inflation nozzle on it impossible.  There are spaces all around the rim where the hole could have been drilled to allow for easier access, but the Meriden Triumph 'technician' threw it in there.  If there is an engineering reason for it, it's beyond me.  Putting the hole in the space between more distant spokes shouldn't hurt the durability, but they didn't do that.

I've done inner tubes and tires for my modern Triumph Tiger recently, and just did a tubeless tire on the Kawasaki (complete with tire sensor hack), so this shouldn't have been the faff that it has turned into.  I ended up leaving both rims sitting in the garage.  I'll come back to it another day when I'm less frustrated by it.

Period tires from Revco look good on the rims, but the rear won't take air and I can't get any into the front.  Damn it.

Here's some old Triumph 'character' and a bit of moto philosophy to remind me why I'm doing this...

Wednesday 16 March 2022

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.


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 Charts                               Motorcycle 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:





Sunday 10 April 2022

1971 Triumph Bonneville T120 Sensible Bodywork Bolt Replacements

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 SizeBolt 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.