Building a race bike

Ill probably go for magnesium tripple clamps, probably a little safer  :D
And a titanium spindle.

Nice periode modus though,
Although modern power and grip may not mix with it well

Jules
 
Wether in the rules or not i would not use it for wheel spindels as it has a very poot Shear strength.
I woul use it for the triple clamp but it would need to be designed well and maybe it would not be worth it.
Will see.

J
 
Think I'd rather take a quick dump before the race than take weight off that way (the pics of the forks that is). Not even unsprung weight, so hardly worth the risk.

As you say, Piet, fun finding where the limit in metal dieting is!
 
Agreed Tippie, the upper clamp resists twist, the bottom one takes road load.

BTW (as I'm sure you know) those older BMWs had a very thick mudguard mount acting as a fork brace. Without that, it's a great big loose mess and twists like buggery as the upper yoke doesn't clamp on to the fork.  I rode a bobber custom job a while ago without that lower brace - utterly lethal. Looked great though 😱
 
Hi guys,

A quick update,

Made one of the bell mouths on Saturday to test fit,
40mm Dellorto carbs with VERY big bells specially made by me.
Fits in perfectly, Even with the raised port its only a little close to the frame brace in one small area, the rest is well clear,  Very happy,  even the tank is well clear.

Julian

 

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Made one of the bell mouths on Saturday to test fit,
40mm Dellorto carbs with VERY big bells specially made by me.
Fits in perfectly, Even with the raised port its only a little close to the frame brace in one small area, the rest is well clear,  Very happy,  even the tank is well clear.

Hey Julian
waow.. lovely job !
Bike is coming along nicely :) .. cool
Cheers
St?phane
 
Bewdy Julian! You're lucky with the Egli frame, plenty of carb clearance. Can I ask if you encountered breakthrough into the valve spring area and if so, how tricky it was to seal up?

I've encountered a few clearance issues with the FCRs, long inlet tracts and my reangled inlet ports, which I've resolved. In retrospect I would have been better off retaining the original port angle and raising the port, as you've done. I can't raise mine without major drama now, so I'm going to have to live with what I have - or I will quite simply never finish the bloody thing! Comparing my std big valve head (ported) it lends itself a lot more to raising the port than the reangled small-valve-head. I can open the roof no prob and get a more direct charge into the chamber, but would have to 'unangle' to raise the floor any further. It's not a race bike, so I can live with it.
 
Piranha Brother 2 said:
Bewdy Julian! You're lucky with the Egli frame, plenty of carb clearance. Can I ask if you encountered breakthrough into the valve spring area and if so, how tricky it was to seal up?

Hi,
Yes broke into the spring seat a lot,  My ally tube is heavily pressed in and it will also be welded so no sealing issues expected.
I will use completely different springs than usual with titanium inlet valves so do not expect problems here.

Thanks for the nice comments guys, will take more pics this weekend after doing a bit more.
Jules
 
julian said:
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

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Definitely stuff for the next calendar poll - would you mind to post it there ..?

Cheers
Jo
 
Hi jo
You are welcome to use my pics with pleasure
Ask for more if you like, I have loads of stuff in the computer,

Jules
 
Update from today,

Little package turned up in the post,
Magnesium Triple Clamps to go with my delicious new forks.
Light weight stork included!!  Half the weight of the Ceriani Ally clamps.


Been working on the head also,  really getting very good results from it but massive amount of work,  Changing valve angles, valve positioning, port angle and shape, Mammoth job but it should be worth it.  Flow testing regularly (Ill post figures when it's finished) and it really does seem to be worth the effort.
I also have a lovely (but expensive) engine modeling software package from the states, really nice to be able to input the figures and get some idea of the direction you are heading as you are moving.  (used it before and it was impressively accurate)

In a few weeks I will hopefully have some shots of the head for you.  Mocked up in filler and plastic of course  :LOL: :D

Best regards,
Jules

 

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Hi all,

Quick update, lots to tell but not too many pics as yet.

Fitted the forks and new Magnesium triple clamps, Nice 7075 ally centre pin also for more weight loss.
Making up a new fork brace now which will have a special anti dive link Incorporated into it for a bit of fun.
Started to make the fairing / Oil cooler / steering damper / rev-counter mount,  the oil cooler will be mounted behind the headlight aperture so it resembles a headlight with the air intake bell adding to this quality. the fairing is mounted to the intake bell and the ally oil cooler duct mounted to the oil cooler,  the bracket for this doubles as the steering damper bracket and the oil cooler top steady also houses the rev-counter.  All good fun.

Engine mods.
To date I have been using the flow bench from a friend, now just bought one for myself, should have it later this week.  Superflow SF600. 
I then want to do the final port finishing on the head before scanning and doing all the production work to make it "Real"

Engine,  the dyno software that I am using tells me 11500 - 12000 rpm is possible but now the big one,  I need to keep the engine together at these RPMs,
Doing some research and talking to people who have been there, tells me that roller bearings on the big ends will be very problematic. 
Therefore due to several reasons,  the main ones being crank rigidity, crank weight, bearing reliability, ease of operation.  I have decided to go with a one piece crank with pressure feed into the centre two main bearings that will be shell bearings and will in turn feed their relevant big ends. The outer bearings will be a std ball on the dynamo end, and a std roller on the clutch end. The crank in theory can then loose another 500g taking it down to a total of 6.5kg and the Titanium rods should weigh the almost the same as the previous calculations due to the added weight of clamp bolts but reduction of the roller races and hard insert ring. 
New HP oil pump being designed as we speak.

Will update more frequently now if possible and if I have something interesting to say,  (hopefully interesting anyway)

Regards,
Jules



 

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