Roadster/Interstate/Thruxton R tank (2020)

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Looking good Glen!

Yes, there can be many hours of unseen work between ‘mock up’ and ‘fitted’ !

Great results on that seat. I like my Corbin and think it’s the best overall compromise (for me) on offer currently (without doing your kind of work). But... it’s unfeasibly heavy for something made out of plastic and foam. Probably designed by ex HD designers !?
 
The front mudguard is mounted and polished. I followed Nigel's suggestion of making mounts similar to the new Norton 650. The only difference is I made them out of Al. tubing to save weight.
These are also the type used on postwar Vincents, albeit in steel.
A small bracket was added to strengthen the mounts.
 
I also made up a sprocket mount/ spacer/cush drive similar to the type Ken Canaga detailed.
The rear wheel is a GSXR front so the bolt pattern is for a rotor, a bit smaller than any standard sprocket I could find. That actually worked out ok as it left room to get the cush in. The natural offset was also helpful, this required a 9/16" spacer for alignment. This is a good space for the cush pieces.



 
According to my measurements, some leftover tank material, .063" Al, would be right as a cylinder base spacer to yield 9.5 to 1 Cr.
Sometimes hand tools are best.
 
I decided to paint the crankcases with VHT 900f caliper paint in cast grey.
The crankcases on the right are a 750 Combat set I'm working on for a friend. They have been blasted with walnut shells and look nice.
I think the painted cases are a close match in appearance and might be a bit easier to keep clean. The VHT requires baking at 200f for one hour in order to achieve full hardness and chemical resistance. This can be done anytime after the paint is fully dry.
The baking will happen... eventually.
 
Wow, you have been busy Glen!

Front mudguard looks bang on.

Barrels look nice, are they Dreer barrels ?
 
There seems not much more barrel material between the liners than there is between the DS bearings
in the gearbox!
Is this not fraught with undesirable possibilities?
 
Onder said:
There seems not much more barrel material between the liners than there is between the DS bearings
in the gearbox!
Is this not fraught with undesirable possibilities?
Click to expand...
They’re lipped liners, so it’s not QUITE as bad as it might look.

But yes, material is a tad on the minimal side for sure.

Seems to be ‘enough’ though given how many 920s are happily running around.
 
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Don't tell me that 920s are happy. Now all that does is make me dissatisfied and you know where that
leads to! Alloy jugs AND 920....oh oh.
 
Well mine seems happy enough. Quite honestly, I can’t believe how good it is. Although mine is a bit more than just bigger jugs, and would not suit everyone’s ideals. But I love it!
 
Yeah well, remember my wife’s nickname for the bike...

Wallet Emptier...:rolleyes:

Make you fell better ??
 
Nigel the barrel came from Ken Canaga, LCR.
I believe he had a batch made up in the UK 1980s.
They would be well suited to 850 sized liners.
For the 920 size, I made pre-emptive welds at all the through bolt areas as those were going to daylight out.
The welding warped the barrels so the gasket surfaces required re- machining.
The instructions with the RGM kit recommend shifting the bores 10 thou apart, just to help with that narrow slice in the centre. I did that but it's still a very narrow point, as mentioned above.
I made interference fit on the liners at .005 " rather than the .002" as is generally done.
The reason for that is we set Vincents at 5 thou interference as at lower interference figures such as 2 thou, they don't work. Heat does not transfer out properly, the liners come loose and go out of round, bike burns oil and performs poorly.
Hopefully I can avoid those problems!

Glen
 
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