Australian Streamliner Bike Build

[55chevr]

"The rule got up because the car guys thought it was a good idea, and there were more of them at the meeting"



Ah .... now I get it.

[fredvance]

Me too Joe. I find it not a good thing that the car guys haVE a major impact on our, motorcycle, rules!!

[grumm441]

Jon, why are you drawing it in CAD, send photo's

And I should make it clear that it wasn't me talking to Van Butler and Lee Kennedy, it was a good friend of mine
I wasn't at the meeting but was given several detailed reports

I was going to write a longer post but as Chief Motorcycle Tech for the DLRA, a job I share with Shane Gaghan, I have to remember that sometimes my opinions can be considered that of the club I represent.

G

[Jon]

Jon, why are you drawing it in CAD, send photo's

G

A photo doesn't show where the remaining barwork is going to go.
Tempted just to finish the barwork for the cage area and then send photos.

jon

[Dr Goggles]

How much work is it to replace the main members?

I can't believe this.

It has the ultimate fallback for it's proponents though....

" what, are you against safer racing?"

[Jon]

How much work is it to replace the main members?

I can't believe this.

It has the ultimate fallback for it's proponents though....

" what, are you against safer racing?"

Pretty much my whole bike as I read it as not only the hoops but everything out past my feet.
Then I either won't fit in my frame or my frame won't fit in the shell.

Show me how it improves my safety?

This rule gets introduced and then;
"The cars are much heavier than the bikes, the bikes have 1 5/8" cages, the cars should have 2" cages!"

jon

[grumm441]

This rule gets introduced and then;
"The cars are much heavier than the bikes, the bikes have 1 5/8" cages, the cars should have 2" cages!"

jon

Geez Jon
Don't say that. before you know it......
G

[SPARKY]

I have no dog in this hunt---but that hasn't stopped me before: 

I suspect that the thinking is that Liners with 2 or 4 wheels  have much more in common with cars than bikes, structure and shape and are running speeds that are very similar---therefore it makes sense that they should have similar specs and rules. YMMV

Jon as some one who rebuilt my old car 3 times:  My suggestion,  finish this one as a MULE PROTOTYPE run it with out the body to shake out the systems,   Start the other car with the bigger tubing----MENTALLY   My experience is that tons and tons of the stuff caries over---but there will be lots of things you will tweak or change on the second version.

[Jon]

Thanks Sparky

There is a couple fairly major differences between bikes and cars;
If we say the speeds are the same the most relative difference is weight, my bike will will be about 600kg (1300lbs) when it runs, I believe that Ack Attack is the heaviest bike around as well as the fastest at 950kg (2100lbs, confirmed with Mike Akatiff).
I've not researched a lot on cars but believe from what others have told me that 2750 (6000lbs) is a fairly realistic number.
Ack Attack is roughly a 1/3 the weight of a car even if I'm out a bit on the car numbers.

The other is speed, 3 bikes have gone over 350mph I believe.
Just scanning the streamliner/lakester records quickly I saw 15 records over 350mph.
That indicates tha cars have a higher speed potential than bikes.

E=MC^2 is the most well known formula in the world I think.
In this example;
E is the force a rollcage has to withstand.
Made up of;
M the mass of the vehicle
&
C^2 the square of the vehicles acceleration (deceleration in this case)

If the vehicles mass is 1/3rd and speed is same, the energy is 1/3rd.

If the vehicles mass is the same and the speed is 4/5ths the energy 2/3rds.

IMHO if cars and bikes end up with the same size cage the bikes are oversdone or the cars are underdone.

If my bike comes seriously unstuck at a decent pace it's not a deforming cage that I'll be worried about, it'll be the deceleration of my body.
A stronger cage isn't going to make that safer.

Show me it's safer and I'll shut up.


jon

[Milwaukee Midget]

This rule gets introduced and then;
"The cars are much heavier than the bikes, the bikes have 1 5/8" cages, the cars should have 2" cages!"

jon

Geez Jon
Don't say that. before you know it......
G

I've already got an 8 second cage in a 16 second car.  My class calls for 1 1/2, I went 1 5/8.

If that were to happen, I'll be hunting up a 9" and a small block and go drag racing.

[Jon]

I've been advised that 4,000lbs is a more realistic weight to use for a 4 wheel vehicle.

That gives 4000lbs for a 4 wheel streamliner and 2100lbs for a bike.
At those numbers the bike frame has to deal with 52.5% of the energy of the car at the same speed.

jon

[Tman]

I'll say it, I know many of you have wanted to Instead of worrying about the size of the tubing I think tech should be more concerned with the quality of the welds. You have all seen them on the salt, posted here and other types of racing. Crest looking welds, undercut, too cold birsheetesque, you name it. Whether drags, circle track or on the salt, I am always seeing welds that make me go WTF? How did that pass tech!?

[Peter Jack]

I'll back you 100% on that Tman! 

Pete

[wobblywalrus]

Energy is absorbed when a frame flexes or bends during an impact.  Extremely rigid is not always best.

[Stan Back]

I've been told that the gusset rule is partially in place as a sort of fix-it for less than great (and some times incomplete) tube juncture welds.  In fact, I'm absolutely no expert, but I've seen this work in a crashed vehicle.