Building a race bike

Hi Julian - Coming along nicely !

Clem,
Yes the lower engine mount and swingarm mount was my idea as I think it will be a lot more rigid than the Egli design which I actually don't like very much, Just "feels wrong" 
Click to expand...


Have to agree there - I was offered an Egli triple to race one season - but turned it down mainly due to the (IMHO)  flimsy looking swinging arm mounting arrangement. - regards - Phil
 
Regarding welding sequence you use whatever works. I've found that finishing with the swing arm pivot spindle tubes works for me, other people like to fit the steering head last. 

LavSF2RRMK5003a1.jpg


It is a good idea to let things move around as they want to do during the build and keep correcting as you add new tubes so you don't lock a lot of residual stress into the frame.  I've cut apart frames that either spring apart an inch or two or clamp down so tight on the saw blade that you can't pull it out.  Assembling all the tubes together and then tacking it all to lock them in place may keep things from moving, but it doesn't prevent them from wanting to move.

I have the recollection of my SF2RR being 340 pounds dry.  I did not modify engine castings to save weight, and the rocker cover was heavier than stock because it was used as a structural member of the frame.

cheers,
Michael
 
Michael Moore said:
I have the recollection of my SF2RR being 340 pounds dry.  I did not modify engine castings to save weight, and the rocker cover was heavier than stock because it was used as a structural member of the frame.

cheers,
Michael
Click to expand...
Was always interested in the idea of beefing up the cam cover and running the steerer tube assembly off it, with no substantial frame between the top and the rear of the gearbox, with hefty plates mounted to the rear of the engine for the swingarm pivot. Have you got any pics or a thread on that, Michael?
 
http://www.eurospares.com/lav750.htm

I started one like that (the Mk3 version) with the stock rocker cover and had second thoughts.  I was probably a bit cold on the temp when brazing:

LavSF2RRMK3002a1.jpg


The new cover was on the Mk5

LavSF2RRMK5011a4.jpg


LavSF2RRMK5015a2.jpg


Tony Foale did a CBX and KZ1000 with the engine being the main structure

http://tonyfoale.com/gallery/StrFrame/home.htm


Thanks Vince.  Julian recently sent me an email and pointed me at this thread so I thought I'd check it out.  I've not had any Laverdas in 10+ years, and I don't expect to have one in the future, but I"m still mildly interested in them.
 
Lost a little weight over the last months,  not much progress but "some"

Rims lost 200g each,  rear drum lost 120g  engine lost "lots" but will post individual weight loss later in a spreadsheet. 
New 63mm stroke crank should weith less than 6.5kg  :D :D

Holes drilled and milled and lots cut off.  I like holes as they look nice and period, I think CNC milling etc looks absolutely awful on classic cars and bikes so will not be done on this bike.  Aiming to be the lightest Laverda 750 SF ever imagined.  Will see.

Julian
 

Attachments

  • IMG_9282s.jpg
    IMG_9282s.jpg
    197.5 KB · Views: 491
  • IMG_0001s.jpg
    IMG_0001s.jpg
    199.6 KB · Views: 650
Hi Greg,

Using the pistons I had made for the 1000cc project, they were a hell of a lot lighter than the std pistons and also allow me to use the 63mm stroke and still get it to 750cc
Going for a 50% BF to start with I think.  Aiming to see max power at about 10500 and get 11500 to 12000 rpm out of it.  Time will tell.  Calculated that at about 11000 rpm we have the same forces on the pistons and rods etc as a std SF at 8500.  Will be an interesting project. Am sure there will be a lot of trial and error along the way though.

Julan
 
Hi Phill,

Says nothing about it in my rule book and I have eaten it and digested it numerous times, I did look very carefully before I went for it.
If they complain then I'll machine the entire flange down, That's not drilling is it,  ;o)

Regards,
J
 
julian said:
Hi Greg,

Using the pistons I had made for the 1000cc project, they were a hell of a lot lighter than the std pistons and also allow me to use the 63mm stroke and still get it to 750cc
Going for a 50% BF to start with I think.  Aiming to see max power at about 10500 and get 11500 to 12000 rpm out of it.  Time will tell.  Calculated that at about 11000 rpm we have the same forces on the pistons and rods etc as a std SF at 8500.  Will be an interesting project. Am sure there will be a lot of trial and error along the way though.

Julan
Click to expand...

Is that 50% for each throw - treat each as a separate single ?  What angular phasing are you going to use ?
I have a feeling that the twisted twins use a higher factor than that - hope there's enough web left to insert some mallory.
 
You must log in or register to reply here.
Back
Top