Lets build a SOHC for less than a grand

[eight0]

Trigger, Take a look at this site if you haven't seen it already. https://blacksquaremotorcycle.com/dual-disc-conversion/

He explains about mounting the second caliper with both the round and cut out hub designs.

[Bryanj]

Thats a very interesting article, might be worth putting in tricks and tips.
I know the "oval" did carry over into the US 550 K series for a while as i bought a few from Dave Silver, 750 hubs also perhaps Trigger knows when they changed.
When i did it it was with 500 front wheels which were deffinately of the "oval" of "flanged" type so the discs were symetrical.

[SteveD CB500K0]

Interesting.

Google Kyril Dambuleff.

I will ask him if we can reference his work.

Steve


Sent from my iPhone using Tapatalk

[Trigger]

Thank you for the link eight0. I had read it but, what I have found is there are so many different fork bottoms on the 550's and 750's that you should never assume yours will be the same.

I used a cut away early hub but, I could not understand the speedo drive for it. The one I have will not sit in the cut away and the drive would not go in to the ID of the disc.

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[Trigger]

And finally the disc centre hole  If you do the maths from the pictures, nothing adds up.


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[Trigger]

When I was trying to line everything up, I was doing one of the biggest mistakes as an engineer. I was reading loads of articles on how to do a double disc conversion and not taking in to account the two different hubs and all the different fork bottoms.
The article in Blacksquare said that you should have a 3mm gap on the top mount of the pivot. I was getting 2.564mm so, got a load of old fork bottoms out to compare and in the end I came up with 3 different gaps over 4 different fork bottoms.

3 hours later after a load of measuring from a datum line, I finally got it right 


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[Bryanj]

When i get home next week Trigger i will measure the nos early drive i have, when i did mine i hotched out the inner hole in the disc carrier to make rectangular holes for the tangs, i could have ground the tangs to an ellipse shape instead.

[Trigger]

As for the speedo drive thing, are you sure that's not an original drive with the prongs folded down? they were flat originally and used the chrome dish to secure them to the hub so it wouldn't fit inside the disc as it was never meant too.

The flat tabbed one is cupped and is in a picture on page 2 of this thread. I don't have another original to compare 

[Trigger]

As for the speedo drive thing, are you sure that's not an original drive with the prongs folded down? they were flat originally and used the chrome dish to secure them to the hub so it wouldn't fit inside the disc as it was never meant too.

At a closer inspection, you are right Oddjob. I can see a few ruff cut marks on the edge.

[Trigger]

Started on the engine today. These cases have already been to the acid strippers. Had to do a alloy repair on the front mount first.
Then it was remove all the corrosion and chase all the threads. Fill all the threads with bolts and test the threads. The last thing you will want to be doing is taking a crank case apart to do a thread repair. It takes a bit of time but, always worth while as it will be the last bolt that you put in the crank case that will strip the thread.

After a good blow out with the air line , running bottle brushes down every oil way and then a wipe over with thinners. Get the oven up to 50c and heat cases for half an hour, heat up the paint in hot water, help the flow. One light coat and back in the oven for 10 minutes, a medium second coat and back in the oven for another 10 minutes. Then the third heavy coat and in the oven for 30 minutes. Leave in a heated room for 24 to 48 hours and then back in the oven at 200c for a hour and a half.


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[mattsz]

Trigger, is that an original period newspaper in the first pic?

[Trigger]

Trigger, is that an original period newspaper in the first pic?

That will only just have been delivered where he lives 

Nice living out in the wild blue yonder  At least I don't get my workshops and garage flooded 

[Laverda Dave]

Great thread Trigger, I'm really enjoying this build.  Will you be taking it to Crich?

[Green1]

Trigger, is that an original period newspaper in the first pic?

That will only just have been delivered where he lives 

Nice living out in the wild blue yonder  At least I don't get my workshops and garage flooded 

If mine got flooded the whole of your location would be under about 300ft of water 

Any sign of a biblical flood I'm heading your way Paul. I won't be taking the Guzzi though got a hernia trying to back it into your drive. 

[Trigger]

Great thread Trigger, I'm really enjoying this build.  Will you be taking it to Crich?

I don't know what I will be having for dinner tomorrow, never mind what bike I will be riding in 6 months time