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:

You're Doing It Wrong: the pain of dealing with dealers who don't like what they do

My local dealer is one of the biggest 'power sports' dealers in the province and they're only ten minutes down the road from me, but they aren't who I think of when I think about motorcycles.  When I was all Kawasaki I found dealing with them challenging at best.  Now that I'm Triumph and Honda (two brands they don't represent) I'm glad I've had an excuse to experience more positive customer service elsewhere (Inglis Cycle and KW Honda have both been positive, engaging and enjoyable to work with).

Pack 'em in tight and no one can sit on 'em...

This local dealer is the only one I've ever used for servicing, but again and again I've found them dismissive and quite arrogant, as though my paying for service was a favour they were doing me.  I've been in the showroom of all three dealers.  The best I can hope for at my local is benign neglect.  The bikes are parked close together on purpose so you can't sit on them and the sales people in there are so focused on the sale that they don't even particularly seem to like bikes, let alone want to talk about them.  Even when I see other people sitting down to sign deals everyone looks like they're sitting in a bank getting a second mortgage rather than purchasing joy.

When I first went to Inglis Cycle the year I got the Tiger the owner of the place stopped and had a chat and then encouraged me to sit on the latest model of my bike.  Even though I wasn't there to purchase one that day (the only thing that seems to matter at the local dealer), he had time to provide a positive impression on his customers.  Inglis isn't some big, fancy, new bike-mall, but the people there seem to genuinely enjoy motorbikes and take the time to treat you like a fellow enthusiast rather than a wallet with legs.  I hadn't intended on buying anything but that positivity prompted me to buy a t-shirt with the Inglis logo on it; something I couldn't imagine doing from my local.  Since then I've bought thousands of dollars of parts and gear from them.

It ain't fancy but they love their Hondas
and encourage you to sit on 'em.

When I went over to KW Honda the first time I didn't own a Honda and just popped in to see what they were about.  The senior salesman on the floor was amiable and chatty and encouraged me to throw a leg over a beautiful new VFR800.  We then had a good chat about the CBX 1970s six-cylinder they had on display.  I made a point of going back there for parts when I finally became a Honda owner and there too the parts guy was chatty, curious about what I was doing and came out to see the old Fireblade.

Last time I was at my local looking for Kawasaki parts, I put my Roof Helmet on the counter and the woman who was new there displayed curiosity about it, so I showed her how it works.  She was enthusiastic about both the style and functionality of my strange, French lid and it left her wondering out loud why they didn't carry such a thing.  The old guy next to her said they were no good and wouldn't sell - in front of the guy who owned it.  That kind of caustic culture must be what takes the shine off everyone there so quickly.

Being a bygones kinda guy I contacted them by email the other day as they have a nice looking C14 Concours and I'm casting about for just such a thing.  We're in the middle of the winter of COVID and it's -20s with six foot of snow outside, so I don't imagine they're very busy, but getting the salesman to have a conversation over email was like pulling teeth... again to the point of rudeness.  I understand that dealers have to mark things up to pay for the premises and I wasn't expecting to pay what private sellers are, so I (foolishly) assumed that starting with offers at over 90% of the value of the bike would prompt a haggle, but emailing this guy was like playing a joyless game of 'no' tennis against a brick wall.

When I asked if there was a possibility of a trade he said he'd consider it, so I made an offer and got a no.  Then a I made a better offer and got a no.  Perhaps I've been watching too much Henry Cole doing Shed And Buried, or perhaps this is a cultural thing (Canadians don't barter), but I'd think a customer offering close to the value of the bike as advertised would be worthy of a conversation and a counter bid rather than series of terse 'noes'.

I was going to reply to the last email and ask why this business would want to turn such an enjoyable thing as the possibility of getting a new motorcycle into such a dreary experience, but I think I'll just cut my losses and finally learn my lesson, bygones be damned.  This latest experience, in line with all my previous ones, will have me looking elsewhere for parts, service and bikes... which is a shame.  I'd love to support a local business and talk them up positively (I do this whenever I can), but these guys can sit in their mega-edifice in misery.  I'll take my enthusiasm for my hobby/sport and my purchasing power elsewhere.

Some awesome local motorcycling businesses in Southern Ontario (from first hand experience):

Mostly Ironheads (my real local motorcycle service provider): in Elora, Ontario - if you want passion and customer service (along with quick turnaround times on work done), this is where you go

Inglis Cycle in London, Ontario

Kitchener Waterloo Honda in Waterloo, Ontario

NCK Cycle Salvage in Woodstock, Ontario

Perth County Moto in Stratford, Ontario

Revco - located in Ontario but found online

Zen and the Art of Motorcycle Mechanics

After another fraught week remote working in a pandemic working twice as hard to do half as much, I was at it again all Saturday morning before finally springing free for the afternoon, but I had a lot to do and I was already off-kilter from a two hour meeting.  I walked into my happy place (the garage) after once again spending too much time trying to work with people badly through screens (one of the joys of a pandemic is WAY too much screen-time) and went about reassembling the Tiger, which was causing anxiety by occasionally not holding an idle and stalling.  

The Tiger rebuild began poorly.  I couldn't find one of the two retaining bolts for the spark plug top I'd taken off the week before.  In the days between taking it apart and waiting for Amazon to get its finger out and deliver new spark plugs, the bike must have been jostled in my too-small garage and the bolts rolled off the head where I'd evidently left them.  I know better than that.  If I remove fasteners I usually put them in a container in groups or loosely reattach them to where they came from so they'll be there when I come back.

While that was going on I got Lloyd's message from Mostly Ironheads saying that I could bring the Fireblade in for a safety, so I cleaned up and got it over there for that.  He has some fantastic projects going on, I've got to see if he'll let me do another round of photos - that shop is half working garage, half motorcycle museum.  (He did let me do another round, they're here).

Back in the garage I was now frazzled with things going on in multiple places and the Tiger rebuild frozen by a lost bolt.  I found a replacement, but doing things half-assed means doing them for way longer than you need to.  It makes me feel like I'm my own make-work project.  I was angry at myself and swearing as I put it back together.  I took it out for a ride in the clearing afternoon weather (it had been threatening rain all morning), but the intermittent stall still happened, even after all the pain in the ass parts ordering waiting during a social distancing slow down.

I put the Tiger up on its stand and figured I'd take a run at it again the next day.  Then Lloyd called saying the 'Blade was all good except tires - so now I have to try and find some tires, in a pandemic (I did, Revco is fantastic).  I brought the Honda home got into a ridiculously complicated plan for suspending it so I could remove both wheels at once.  The end product looked more like a roof mounting for a sex swing when I finally gave up on it and locked up the garage for the night.

***

The next day I spent the morning brain storming ideas for a work project and then finally got to the garage mid-afternoon.  My mind-set was completely different this time.  Instead of being weighed down by worries from a meeting, I was buoyant from just having thought my way out of them.  In a good mood and with the importance of keeping my shit organized clearly at front of mind, I went about fabricating chocks for the front wheel of the Honda and attached them to Jeff's motorcycle stand.

They worked a treat and before I knew it the CBR was suspended and the wheels were off.  The brakes were pretty grotty, so taking it all apart, even if the pads and rotors do all meet MoT safety standards, wasn't a bad thing.  The music was playing, it was a cool, sunny afternoon and I was getting shit done.

As I disassembled the Fireblade, I was Sharpy marking parts, taking photos and batching fasteners together so I can find everything when I reassemble.  I've been mechanicking for too long not to do this, but a callous disregard for shop etiquette gave me the result I knew I deserved the day before, but not this time.  The jigs we create make the jobs we do possible, and vice versa.

What had taken me twice as long to do badly the day before, took me a fraction of the time to do better the next day.  Instead of spiralling into anger and frustration, I was in the zone.  Problems still occurred, of course.  This is mechanics where I'm dealing with immutable reality, I have to bend because reality won't, but rather than succumb to those problems I was agile and adaptive.  I can hear the sound of one hand clapping when I'm in the zone like that.  It feels effortless and completely engaging.

The Honda was sorted so quickly I turned to the Tiger and began the astonishingly fussy job of taking the fuel tank off (again).  What was tedious the day before became a matter of minutes the next day.  With the tank and air-box off (again), I looked over the idle control valve under the air-box and discovered one of the tubes going into the back of it was loose.  I cleaned up all the connecting and ensured they were tight and put some gasket compound on the rubber gasket to help it seal where it was squashed.

The whole thing went back together again equally quickly and the bike started and ran, so I shut it all down and cleaned up (some more good shop etiquette I'd been ignoring).

I'd gotten two days of work done in one, but it didn't feel like it.  Disappearing into the garage is one of my favourite things to do, but doing it when you're frazzled and fraught can mean you're bringing a lot of negative energy in with you.  That negativity can make you ignore best practices you'd otherwise follow and might result in simple jobs becoming much more frustrating than they need to be.

Just like when you're riding, you need to find your inner zen when wrenching.  Not only will it make you a better mechanic, but it'll also make the work itself a joy.


Followup:  

A couple of days later I was working through week six of the Science of Well Being course I've been taking and it went over the state of flow and how it induces a sense of happiness.  There is a lot of research into flow states, especially in terms of peak performance in sports, but any complex task, from painting to mechanics, will offer that moment when you're balancing your skills with your situation in a way that's so engaging you forget yourself.  That's actually what you're doing in a state of flow, you're so immersed in what you're doing that you don't have any mental acuity left to self realize.

Sony's mission statement:  what a place to work that would be!

If that doesn't clear it up for you, maybe the TEDtalk by the guy who invented the concept of flow will: