Roadster/Interstate/Thruxton R tank (2020)

Started in working on the primary covers today.
Dyno Dave mentioned that he did not understand why people insist on using the wrong part as things are difficult enough already.
I seem to be the inclined to use the wrong part.
This is an older set of primary covers being fitted to a MK3 crankcase and a 750 Transmission. It would have been much easier to use MK3 covers and just slot the inner out for the adjustable transmission.
I had this early set on hand, cost outlay was nil at present, so it's worth a try.

The MK3 inner and outer covers are totally different than the earlier sets.
First off, the hole in the older inner primary is too small. That was fairly easy to fix on the mill.
The MK3 uses four studs to attach the inner primary to the crankcase whereas the earlier bikes use 3 bolts on a smaller bolt circle.
I spent quite awhile carefully measuring and marking the new bolt locations on the inner primary, but something was always a bit off in the process.
Going around one way vs the other gave the fourth bolt locations about 1/4" apart.
It was just accumulated error that I couldn't get away from.
The solution was to make up some aluminium top-hat pins that are a push fit in the threaded crankcase holes and have a top-hat that sits about 20 thou higher than the contact face. I made them with little centre holes in hopes of getting accurate centre locations.

Apply some blueing



That worked well



It appears that everything will just fit
The end of the long MK3 crank is about 1/8" gapped from the outer cover. That was lucky!



There is a lot of work to do to make this permanent, but these cases will do the job.
I've ordered some hydrophobic Teflon coated SS mesh. This mesh allows air through but not water. If it works as advertised, I can drill many large holes in both inner and outer primary cover to reduce weight and gain ventilation.

Interested to see what that mesh turn out like Glen. A waterproof breathable primary cover sounds cool. Almost like it’s made from Gortex !

It does sound like Gortex. I'm hoping that this mesh will have those properties as well as a small amount of rigidity, enough to span the holes.

Glen



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I found a source for hydrophobic fabric mesh and have ordered some.
The hydrophobic ss mesh did not work out. One source is in China and requires a very large minimum order, enough to do about 1,000 primary covers.
The other source is in the US.
They will ship a smaller amount, enough for about ten primary covers, but will not ship to Canada. The US item looks to be the same Chinese product being parsed out in smaller amounts/higher prices, which could have worked if not for the shipping problem. Also, the US supplier notes that the Teflon coating might not cover all of the screening. That's quite useless!
Sounds like a low quality product, still fairly typical of Chinese imports.
The fabric hydrophobic mesh I have on the way might require metal mesh backup.
I'm hopeful that it won't need the metal and can be epoxy glued over the openings.

Made some holes today.
I've ordered a ball end milling cutter to scoop out the inside.

Two baby steps were completed today.
There will be useful storage under the quick access seat, about 4" tall. The rain gear should fit in there.

I decided to use abs instead of the aluminium fender offcut for the wheel well area.
ABS is lighter than aluminium. Also, the flat panel blocks off the area better than the curved fender piece I had planned to use.

If Les happens to read this-please move this thread to rebuilds. I should have located it there from the start, my mistake.

Thanks
Glen

I must have set a new record for tedium here. It seems Les doesn't look at this thread and he looks at nearly everything!

Carrying on with the tedium-
-The Fairing mount -
The Thruxton 1200 fairing main mounting is a very neat curved light alloy cage that attaches to two heavy cast lugs on the Thruxton headstock.
I need to create similar lugs on the Commando headstock. One of the lugs is right at the top, exactly where the top bearing sits. I don't want to weld there as it will distort the tube and bearing mount.
I had an idea for a piece that would be as strong as the Triumph lugs but could be welded away from the Commando headstock bearing locations.

First make the lugs





The lugs will be welded to a curved piece. A short piece of very heavy tubing with the same ID as the headstock OD was found in the steel bin.
It could go on a Harley as is but needs to be pared down for this application.





Notched for the lugs



The holes will remove some weight plus provide a good welding location.





The centre bit is all that's needed.

Everything that goes on gets weighed first.



Welded



Positioned parallel to the forks with the wheels in alignment. I hope its correct. Will tack weld and see how fairing sits.



With the cage bolted up it looks promising.
As much as I enjoy making parts, I'm glad I didn't have to construct this curved alloy cage. It would have taken me ages and the end product wouldn't be on par with this piece. One of the 961 owners suggested that Triumph's come with " sloppy robotic welds" vs hand done welds on Nortons.
Im not sure where that idea came from. These welds are perfection, as is the whole 120 piece fairing kit



It's on and the lug position is good, the fairing centres nicely.


There are two rear mounts or steady points that I will add next. These are needed to keep the lower legs secure at high speed or in strong cross winds.
It's possible that the fairing would work OK without those rear attachments, but it is designed to have those extra connections, so I'll make the attachment points.

Glen

Moving along quite nicely there Glen

Yes it is. Looking forward to more.

We had snow on the ground for a week or so in early January so I tackled the wiring.
The large amount of wiring on a " simple" motorcycle always amazes me. Some of that is my fault, no doubt.
I looked at the M-unit some time ago, but couldn't justify the expense. Also, I needed ten circuits, not sure if there is a ten circuit M-unit?
Anyway, this lighted 12 circuit Marine fuse panel is perfect.
Couldn't resist mounting it in the under seat space. With the quick release seat, it's a dream location for access.
I used a Derek LED headlight, used GSXR switch gear ( high quality, $ 25-30 per side ebay), and a rear light that combines driving light, brake light, turn indicators and license plate light all in one strip.
The GPS speedo/tach face has turn signal and high beam on LEDs, so that was convenient.
Glen

Having all sorts of issues seeing all your pics today. 2nd one in #290, 1st pic in #291 and the second one in this last post (though popping it out works) all dont display.

I thought perhaps I had forgotten to make the photos you've mentioned shareable. On checking, they were shareable.
I tried resetting them. Are they showing now?

Glen

Loud n clear here Glen.

Your work is impeccable. I wish I had a tenth of your talent. I’m afraid I wouldn’t make a pimple on your ass.

Thanks Larry.
Having lots of time to lavish on the project sure helps. It would have been difficult to tackle one of these projects when working full time.

Glen

cjandme said:

Juicy thread Glen!! I for one will be following the build of this beauty for sure.... Surely you have a cNw e-start in mind for this, right? Not exactly fitting the extra lite theme but definitely seems worth its weight.

Click to expand...

Is this Charlie Lipton?