Center line of tires vs crankcase split

litnman

Well Known and Active Forum User
VOC Member
What is the dimension from center line of the tires to the center line of the crankcase split. It appears to be about 1/4". Possibly a factory drawing would have this dimension.
 

davidd

Well Known and Active Forum User
VOC Member
I copied this out a an earlier post by Trevor:

The centreline of the rear axle castings are offset to the pivot casting. By 9/16" to the left, as viewed from above, from the rear of the machine. 8 5/8" between those rear castings.

David
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Hello John, I don't have a twin in bits now, But if it's any help !, If we can agree the mudguard front lug would be in the wheel centre line, I make C/C joint 3/8" to the left, Looking from above from the rear, Good Luck, Bill.
 

vibrac

Well Known and Active Forum User
VOC Member
So long as the centre of the rear wheel is in line with the headstock , and the drive sprockets are also aligned , the position of the crankcase is not an issue. Think about it! Roy.
Absolutely Roy you might as well worry about how it lines up with the petrol cap I dont think E J Potter worried :) ej-smokey-start.jpg
 

greg brillus

Well Known and Active Forum User
VOC Member
He's running the same front tires as us...!!! What a legend.....the Michigan Mad Man. Didn't he use to spin it up and then just push it off the back stand....?
 

litnman

Well Known and Active Forum User
VOC Member
Searching centre line, centerline and center line, I found Trevor's posting, which is the answer I was looking for.
I'm building a wide tire / tyre bike frame.
"Given that the dimensions on page 6 are correct. Using the dims at the position B, the case split line is 1/4" to the left of the given machine centreline. You can work that out by knowing that the case is at that point 6" wide, equal either side of the split line.
The rear is NOT the same."
 

vibrac

Well Known and Active Forum User
VOC Member
Searching centre line, centerline and center line, I found Trevor's posting, which is the answer I was looking for.
I'm building a wide tire / tyre bike frame.
"Given that the dimensions on page 6 are correct. Using the dims at the position B, the case split line is 1/4" to the left of the given machine centreline. You can work that out by knowing that the case is at that point 6" wide, equal either side of the split line.
The rear is NOT the same."
You wont get that wide without a lot of work. On our Egli racer we almost had the chain kissing the rear tyre side wall and the tyre width was not exceptional so thats the real point to keep an eye on. Big tyres are for big power outputs and nowadays Vincent twins are not regarded as a big power plant, Never forget the further round the tyre you have to go for a given corner the further over you lean and the longer before you are upright. Anyone who has ridden a Comet in a modern track session will know how you can beat big tyre guys on sharp corners (Of course you are soon gobbled up on the straights;))
 
Top