[grumbern]

Not much has happened with the frog. Too much other stuff to do. But I could at least prepare the timing cover for the tachometer drive:




Of course the bolt won't stay there and is only meant to check for allignment. The tap fits the Magneto pinion nut and was a perfect "dummy." Later it's going to look a bit like this:




Ok, that's not exactly right. I will probably not mount a tachometer. And why should I, on a trials machine? The reason really is a different one: The flange makes timing the ignition a lot easier, because you can simply set up a timing disc. I made an attachment to use on the twins and I want this for the Bullet, too. It's a little hint to the genuine works trials as well

The script was already done by the previous owner and is one reason why I wanted to use this damaged and beat up cover to begin with.

Last week, after fixing my welding helmet I was finally able to weld up some material for the tach-drive and repair the broken tap. The face and side is already filed, but the inside, drilling and tapping still needs to be done:




The welded and roughly shaped tach drive flange:




And yes, I did it!




So it's definitely not low budget anymore, but finding a fitting used 21" rim for the bullet isn't easy! The Yamaha wheel wasn't bad either, but just not as authentic
So long,
Andreas

[Adrian II]

Glad you're still with us Andreas, that wretched Covid 19 isn't finished yet.

A.

[grumbern]

No worries, I'm fine. Just lots of different stuff to do

[heloego]

I'm stunned! Love what you did with the tank!!!!!!!!
 

[Adrian II]

I just dug out the picture of an original rev-counter type timing cover, I almost bought this for Not A Fury but Hitchcock's wanted a lot of money for it. Note the area where the rev-counter drive screws on is flatter, i.e. no bulge for the SR1 magneto's auto-advance unit, as the Fury/Westerner had manual advance magnetos. Photo taken from Hitchcocks' site.

A.

[grumbern]

@heloego: Thanks, left still is in work

@Adrian: Yes, I first thought I might cut down the "bulb" and make it flat like the original, but then it's a homebuilt solution and no exact replika, so it wouldn't really make a difference
But that's a great view of the original cover without an agle drive attached, or covered up, quite rare! I immagined it would be like this but now I know for sure, thanks!

P.S.: I haven't forgotten about the fork ears...

[Adrian II]

They're still available! 

A.

[Adrian II]

It's also interesting to see your reclamation work on the oil pump housing. I still have the timing cover off my old Electra-X, the scavenge side is badly scored where little pieces of big end still manged to get through the sump plug strainer. I was wondering if machining out for some sort of oval insert could be done, though welding and a good milling job would do just as well.

A.

[grumbern]

@Adrian: Probably it's even the better way.


Finally I started work on the gear change mechanism!
I was thinking about several options, but none of them was really good or would have worked without having bad side effects. After all I found one that pleases me.

The main problem was the rear set foot rests and a resulting position of the gear change lever.
The lever just turned backwards would result in a very short lever, high forces and a switched shift pattern - not accepable!
One could just fit a lever and some sort of linkage. But still you'd have to find a good way of mountig it on the bike and you'd have a lot auf links and joints on the outside. Not an issue on a racing bike, but on a "dirt bike" that's crap.

So I chose a different approach.
Here's the basic layout of the Albion gearbox everybody knows and loves




Now here's my idea. As standard you'd have a "negative" ratio with the lever on the shaft beeing longer than the one on the ratchet, which leaves you with quite a long foot lever. So if you changed this ratio, you could mount a shorter lever. And the ratchet and lever go different ways. If you were to mount the lever backwards, you'd have to have both going the same direktion, to stay with your known gear shift pattern.
So I changed  the levers to a linkage. To achieve that, I first shortened the parts and turned the rachet 90°:




The linkage looks adventurous, but there are quite some obstacles to look out for!




First tests were promissing. Next I have to make the top and bottom plate to cope with the turned assembly.
But this gives me some advantages:

-Same shifting force as usual
-Keeping the shift pattern
-Keeping the neutral finder
-No outside linkage

One problem is the spring that pulls back the lever. This way I can't use it as it was before and I have to figure out a different way of doing it, but I'm on that!
So long,
Andreas

[AzCal Retred]

What an amazing mind & skill set...it's like watching Michelangelo build a motorcycle.
Thanks for sharing this project, can't wait to see what's next.
Best regards - ACR -

[Adrian II]

Have you seen Grumbern's (RE) Indian Chief restoration? 

A.

[AzCal Retred]

Yes, I found it the other day - very impressive. You don't see artistry like this often. I'm happy when I can bolt on a new part that works! Way back in the 70's in Tucson I knew a retired machinist/fabricator that had built his own running Scotch-Yoke motor from scratch. The small consolation is that without the army of us feckless parts-changers for comparison, the truly talented wouldn't obviously appear to be as amazing as they are. The breadth of skills is what I marvel at, let alone the quality of workmanship. I learned a lot from just following the decision tree dialog, which brings up another separate well developed skill set- an ability to impart what you know in a comprehensible manner to others. This a great website, what a resource rich environment.

[grumbern]

Thank you guys, I'm always happy if my work finds appreciation

So here's some more.
The base plate didn't need much alteration. Only the stop was pressed out and relocated by 90°:






Much more difficult was (or still is?!) the centering spring for the ratchet claw. As I didn't find any good alternative I ground two notches into both parts and clamped them together with a spring band:






Due to the off center axis both parts will cross during operation and tension up the spring, which brings them back into position. Works, but still needs to be secured and protected from slipping and falling off...
As expected it got really close for the kick starter spring, but luckily somehow everything doesn't foul just like that




Maybe tomorrow I can make the top plate and then it's only details.
So long,
Andreas

[grumbern]

The top plate is finished.
But first the original part:




From this the important holes where transfered to the sheet metal and drilled. The one segment is already filed in shape:




Cut and the second one done, it's ready for a quick try on:




And the final shaping done. The somewhat strange shape results from maximum guidance for the ratchet parts and clearance to the gearbox cover:




The linkage just clears the clutch lever and to the bottom the kickstart return spring is the limiting factor:




Clutch lever also is free at the top:




Gearbox cover and neutral finder mounted:




And a quick demonstration:

https://www.youtube.com/watch?v=y68Tk3vONoY



So long,
Andreas

[Boxerman]

Andreas never ceases to amaze me with his skills and ingenuity.

Frank