Australian Streamliner Bike Build

[JimL]

That is a consideration, however...wind was from our right, and after the first adjustment to get leaned into it, the steering pressure required was to the LEFT (pushing forward on the right bar).  Other riders with large area streamlining have mentioned the same experience to me.  It's also experienced with some street bikes at higher speed in side wind. 

In 2010 I did experience the front end blowing away, in a giant low frequency wobble effect.  That was my fault.  When my twin-engine coupling gears failed, shortly before the event, I pulled the front engine and ran 750cc class with just the rear engine.  That big empty hole in the front of the frame was not enough to keep the front wheel planted above about 145-150.  Now, I have the engine more forward with a big water tank directly behind the front wheel.  That keeps the front end planted well enough to lean into the wind, but then the there is more steering effort required.  With little or no wind, you dont even have to steer at my speeds on this bike......just sit there wishing for more power.

Regards, JimL

[55chevr]

There is never enough power in the timed mile.

[Jon]

Tony Foale has some interesting info on crosswind stability, from different bikes Naked's, Conventional faired bikes, Feet Forwards, Dustbins, and different suspension types and geometry.
Highly recommended reading.

jon

[wobblywalrus]

Sometimes I think we have attached flow on the windward side of the bike and detached flow on the lee.  The attached flow exerts less pressure on the side than the detached, and it pushes us into the wind.

[Jon]

There is some interesting things happening on a bike in a side wind, especially when looking at the steering input caused by side loading on the headstock and the steering input it creates. I've misplaced my Tony Foale book again....


Anyway, latest from Woody, no CFD runs done yet.


I did say it looks a little different, it's what I wanted and Woody reckons it makes sense, CFD results will tell us if we're heading in the right direction.

I'm interested in other's thoughts as always.
jon

[Peter Jack]

Your thinking got out of the box again! I really like the idea of carrying the rear wheel fairing further on back. Adding the additional area down low, closer to the point of traction, should minimize the effect of side wind.  

Pete

[Koncretekid]

Jon,
What is your convergence angle at the back?  If your width at center of rear wheel is 14", you will need 40" in length from the center of the real axle to the rear end of the body to keep the angle down to 10 degrees, and 57" in length to keep the angle to 7 degrees.

I'll post it as a PDF and maybe someone else can convert it to jpg.
Tom

[SPARKY]

you bike guys have my head spinning-- --   I think you all just proved my point on why I run solid suspension---until it generates enough lift to not steer or fly---I just have to worry about how fast to depress my right foot  much much simplerer

[Stainless1]

you bike guys have my head spinning-- --   I think you all just proved my point on why I run solid suspension---until it generates enough lift to not steer or fly---I just have to worry about how fast to depress my right foot  much much simplerer

Minor Thread Jack...
Sparky, when you are trying to go 200 with 60 ci in an open wheel car you push the throttle to the floor faster than the motor can keep up with in low gear and leave it there until you see the 5 flash by.... YEWV
Back to subject

Wow Jon, this just gets cooler and cooler the more you guys play.  I'm guessing you are not planning to push like Ack does although the right vehicle would be above the extended lower.... stay out of that box... it looks great

[Jon]

Thanks for the kind words guys.

Peter Jack: the idea is length for yaw stability but down low for less roll input, waiting for numbers from Woody's smarts now.

Tom: my bike is a fair bit shorter than that, the flow stays pretty attached though, even in yaw the leeward side is attached so isn't correcting as much as I'd hoped

Sparky: us bike guys can't work out how to do scrub radius and wheel alignments, that's why we run single track

Stainless: if I'm ever lucky enough to be chasing decent numbers I'll be getting a push, I'd love to drive off but don't have the $ to throw at a 7th or 8th gear.

Missed bike transport by 24 hours with the written of Hayabusa, won't get it until mid Jan now , bah humbug.
Not as if I don't have plenty to go in with though.

Cheers
jon

[rgn]

I'd love to drive off but don't have the $ to throw at a 7th or 8th gear.

A high hp-torque electric motor powered by lithium-ion battery with one way clutch tied into the drive system?  Gear it like a conventional 1st gear for rapid acceleration to 60 mph... drop the clutch and call it a starter motor?  

[Stan Back]

And maybe get a Million Bucks from the government for building a hybrid?

[twodear]

Hi Jon, DaveB gave me a link to this build diary and I've been enjoying it heaps.

Your research into attached / detached flow and drag in general brought something back from the dark recess of memory about a drag-reducing experiment on the hull of a competition yacht some decades ago - micro lines laid in parallel below the waterline. I looked for some confirming details on the web but could find nothing about that; If it worked and was subsequently banned there would be something written about it. The lack of information probably means that either the experiment failed or my memory was from a parallel universe.

There were related articles on golf ball dimples and the LZR fabric that Olympic swimmers use. Although the article I read said dimples help keep flow attached longer, I don't think they would help on something needle-like that doesn't spin (at least, not under normal circumstances), but fore-aft parallel lines...or you could be the first to achieve a LSR wearing a Speedo.

[Jon]

Thanks guys
While the motor is out for the transplant a joey box isn't totally off the table, it will be of under house engineering standard if I can make it work.
There is another guy that's a fair bit smarter than me (doesn't narrow it down much ) that's working on something very similar, might see if we can make a pair and a spare if we can come up with something that suits us both.
Just need to work out if I can now get 5kgs in that 2.27kg bag, was going to be fun fitting 4.54kg in there.

RGN: I like the idea of some electric drive happening but not in that manner, need a rule change first. (and get this bit built and settled)

Stan: Wouldn't take the governments money off them, they're obviously broke cos they can't replace my wheely bin.

Hi James: Welcome aboard, lots of very nice projects on here.
Your not going nuts (This time) search Riblets and I think America's Cup, 3M developed it for Boeing and used it on a race yacht but I can't find anyone in 3M that knows about it. Not that I did much looking
Bringing your bike to the Lake?
jon

[DND]

Hi Jon

I think when Dennis Conner was Cup racing down your way, the TV guys were talking about a film that Dennis tried in a water tank and on a boat that had mini lines front to back.

Don't remember the final outcome of the product, sounded good though.

Don