May I offer some advice..? Having built a Egli frame, I have been around this matter about rear swing arm spacing and chain-line, and I can have a go at "remembering" how i went about it. First.. the Egli usually has the same swing arm main bearing house dimensions as original, i think to remember the length measure of 168mm. And YES, the arms are NOT symetrical on the main bearing house. That meaning that the LH SWING ARM, IS FURTHER TO THE LEFT. (from the centre line of the bearing housing) BUT this is of less importance, as Trevor said, you are working to get the chain line right. The EGLI spacing should be as the original frame/RFM, from the fact ( i think) that it used the original Vincent rear hub... Here we go: 1, The inside spacing of the RFM, should bee around 225mm. (The same as the rear hub spacing) 2, If you measure from the centre of the rear sprocket, to the inside of the RH "swing arm " this should be 28mm.. 3, If these measures are correct you should measure from inside the RH engine plate, to the centre of the "outgoing engine sprocket" (add a few mill) 4, If you then mark, a point on the swing arm bearing house, that is from the RH side, and the number of millimeter found in point 3, inwards, you have the chain centre line across the bearing house. 5, project a line backwards, and this should end up aprox 28mm inwards from the LH s.arm inside! (remember the measure taken in point 2...) If this ads up everything is OK!! Understand?
Early/later RFM
- Thread starter Chris Launders
- Start date
Hello Dag, So what do you think of my photo, Should I take a Hammer to it?, Cheers Bill.
Bill, I don't think there's anything wrong with yours, it just looks strange as does mine, on mine the outside of the right axle casting(where the big hole is) is approx 1.875" out from the right bearing housing, which looks about where yours is in the picture.
Chris.
Chris.
I would say... Measure first. ! If you play the numbers... Ok i can look at a scetch.....Hmmm And then you should have a sideways difference from the ... RH rfm, bearing housing, side, to the inside of the RH Swing arm, of about .. 12mm/1/2"... ok... So that means that from your picture it looks rather correct?
All this makes you think !!, For 50 years I have been swaping Frames from bike to bike, Not giving much thought, If it looked OK and the wheels lined up, No problem !!, It was only when I bought that badley bent rear frame, And Oldhaven had his bad top frame, I started to look harder at what I have, My first Twin had a Chair on it, So that had a hard life, I had 2 big crashes on the L/ning, So that should be Suspect ! Plus the fact that this stuff is 65 years old !!. I think we expect too much some times. Cheers Bill.
Paul Richardson's book VINCENT MOTORCYCLES, Chapter 11, section Crash Damage, (current edition page 40), gives dimemtions of the RFM.
Ian
Thanks Ian, Never thought to look in the Book !! That is the book that I have always thought was the best, Looks like I am 1/4" ish out In places acording to my old ! book, But I make the hollow axle 1/4" shorter, than my book and even more than Dag' said, Can you give us the numbers in the latest book ? Or do I have to buy a new one !! Many thanks Bill.
Morning All, Thanks John, Stay warm up there, I found it in my Old book but I was worried about misprints, I have been caught out befor !, Thanks to a Friend !!, I now know the only differance the New book says 8.375", The Old book says 8.3/8" For Inner fork ends where the Hollow axle touch. If anybody is interested, Looking at my photo, The left gap Should be 1.1/4" and the right gap should be 9/16", I said 1.3/16" and 3/4", I only did it by eye and it's not easy ! I also thought the axle gap was 8.1/2", But now find it on mine 8.7/16", Should be 8.375", So I think mine will do, Cheers Bill.