Speed Week 2017 - Lake Gairdner

[Andy]

So tyres was the main topic of conversation over a morning coffee with fellow bike competitors??

Not really, most tyre discussions I had with others ended with a shrug and "it hasn't self-destructed yet" type answers. It would be great to have someone in the tyre industry have a look at motorcycle tyres but with numbers of competitors worldwide so low I can't see that happening anytime soon.

Great news. Many years ago I was a very junior engineer on the Donald Campbell world speed attempt wheel and tyre development team. The tyres we finished up with had some 16 layers of Egyptian Cotton casing, and only a very thin waterproofing layer of rubber to keep any moisture out. Inflated to very high pressure with this rigid casing, the main worry was the development of a standing wave when the distortion at the contact patch could not recover before hitting the ground again. We ran one test well over speed and watched as this wave developed to destruction.

WOW! That's a fascinating insight and a very cool thing to have been a part of.
In our modern times of high speed film everywhere the best example I can think of the wave is the top fuel dragsters that twist their tyre walls into a knot (loaded spring) and if they get it wrong they get a wave that they then drive over causing either no traction or worse, failure.

[tempeman]

Speed Week Lake 2017-Lake Gairdner

Great news. Many years ago I was a very junior engineer on the Donald Campbell world speed attempt wheel and tyre development team. The tyres we finished up with had some 16 layers of Egyptian Cotton casing, and only a very thin waterproofing layer of rubber to keep any moisture out. Inflated to very high pressure with this rigid casing, the main worry was the development of a standing wave when the distortion at the contact patch could not recover before hitting the ground again. We ran one test well over speed and watched as this wave developed to destruction.

[Dazzler]

So tyres was the main topic of conversation over a morning coffee with fellow bike competitors??

[Dimal]

Great mini-tutorial Andy...

Mal.

[Andy]

....next time we expect you to make the final pass on one wheel and at 200mph....

I'm more than happy to do that as it would mean I was getting traction! I know when the GPS was showing 319 my bike speedo was showing 386... even allowing for some error on the speedo it was still 60kmh odd of wheel spin, near 20% and if that got traction all of a sudden then it would certainly be on one wheel at least for a moment before the backflip and a whole lot of salt/sky/salt/sky/salt/sky action.

Great to see the Aeropress endorsed as the ideal solution for camping.

Not just camping, it's the device I travel with all over the planet. Airport friendly, light, small, simple and all you need is a kettle. No reason to ever drink little packets of instant in the hotel room! However, it doesn't produce espresso (even if it says so on the packaging) but it does produce a bolder, better bodied plunger coffee. It's the first thing in my travel bag when I head anywhere.

Would a change to grippier tyre help too? Not sure if special tread/compound would improve traction on salt?

That's a long discussion, the shorter version is... Before going I contacted multiple tyre manufacturers who as soon as they heard I was going to the salt suddenly went deaf and the line dropped-out. Seriously! The tyre guys have no idea what will survive 300+ with wheel spin heating the tyre for an extended period of time. While a couple of companies make 300+ LSR (land speed racing) tyres for cars no one will put their name on one for a motorbike.

I ended up using RS10R which are medium sticky race tyres with a vague tread. I had soft racing slicks on the bike at Phillip Island which were awesome on the black stuff but I was warned that they might "chunk" (start throwing chunks off) on the salt at speed. I have even seen delaminating at those speeds which would be entertaining to say the least.

I did take a tyre groover with me and was keen to try the RS10R with some additional tread cut into the centre-line of the tyre but didn't get the time to try that with our two fastests passes the last runs for the week. The gotcha with adding more tread apart from vibration and increased chance of chunking is that salt quickly packs into the tread and you run the risk of running on less tyre, not more traction.

The bike runs on centre two inches of the tyre (obvious in the pic below) and that will become more like one inch at speed with centrifugal force. The tyres held-up well to the abuse with just a bit of feathering on the leading tread on the rear and the front tyre looks brand new. Tyre selection was based on compound and importantly shape, you need a pointy tyre for a small contact patch so it cuts into the crust, a wider contact point causes even more slippage as it will run on the loose top surface.

I would have been wearing brown underpants

Nah, not needed, too busy laughing maniacally with a grin in my helmet big enough to make my jaw sore.

ComAir wind tunnel

Monash and others have wind tunnels but I don't know anyone that can push more than 240kmh through it and as I found, EVERYTHING aero changes quickly in small speed changes at that end. Lockheed Martin in the states have a great one... but I don't think I'll wait by the phone for the call.

I better understand the real challenge of salt racing now, hostile and changing environment, small number of runs to try something different and 12 months wait between races so you can't troubleshoot with track-time like you can in most other forms of motorsport.

[TampIt]

Had a laugh - great way to start a tradition with SWMBO. "Hey Honey, if I go next year and get just a few Kph faster I can go over 200mph and 300Kph on the same run...

Damn shame Howard closed ComAir wind tunnel isn't it?

All the best for next year - and 319 is damn fast anyway - congrats.

Tampit

[artman]

Awesome video, must have been a hoot!

Would a change to grippier tyre help too? Not sure if special tread/compound would improve traction on salt? Absolute nuts you were breaking traction at that speed! I would have been wearing brown underpants just in case...

Cheers

[Otago]

Oops, missed adding a comment! Great to see the Aeropress endorsed as the ideal solution for camping. After a lot of trial and error I have settled on the Aeropress for mainly the same reasons. For remote area travel, when water conservation is a priority, the quick, easy, clean-up of the Aeropress is a real winner.

[Otago]

For the rest of the trip I fell-back to double dose stainless filtered Aeropress in my travel mug made with a kettle on the gas camp stove with Zed's Espresso beans. Simple, fast, clean for great long blacks and easy to bang-out a few in a row for others at the same time.

[Smee]

Amazing, thanks for sharing......next time we expect you to make the final pass on one wheel and at 200mph......stop slacking at 198.

[Andy]

Holy smokes...that is truly amazing. The most terrifying thing of all was from the sound of your motor there was plenty of power still left...just how fast could you go? (especially now that you have your 'up to 400km/h' licence??)Sniff

With two passes of exactly the same speed I have to change weight and aero to go any faster. I still had half a handful on the right-hand volume control but it just lit-up the tyre when I tried to use it. It's all about traction at the moment and I'm nowhere near the horsepower limits.

30,40,50kg of lead ballast in the swing-arm is pretty "normal" for high powered bikes so that would help get some more to the ground. I could also start to play with the aero and add a belly-pan and more enclosed style bodywork.

Not sure which direction I'm going with it but I know I'll be there again next year to go faster.

...camping coffee solution...

Oh yeah, this is a coffee forum. Umm... took the Bellman stove top and used it once, it works well but a bit fiddly in the dark before sun-up and harder to clean. Made great microfoam and the best bush-latte I've ever had. For the rest of the trip I fell-back to double dose stainless filtered Aeropress in my travel mug made with a kettle on the gas camp stove with Zed's Espresso beans. Simple, fast, clean for great long blacks and easy to bang-out a few in a row for others at the same time.

[Otago]

All very interesting, but more importantly what was your camping coffee solution?

[SniffCoffee]

I do have some Race Chrono footage from the last pass on my phone and have just uploaded it to Youtube. Sound is bad (wind noise) but you can see the GPS speed, G-meter and see the tacho needle (14,000 is straight-up).


https://youtu.be/ALpJbMEBUz8

I'll upload more stuff when we sort through it.

Holy smokes...that is truly amazing. The most terrifying thing of all was from the sound of your motor there was plenty of power still left...just how fast could you go? (especially now that you have your 'up to 400km/h' licence??)

Sniff

[Andy]

(thread was locked unintentionally, I was just told by someone who wanted to comment... sorry for the oops)

Still getting back on top of the day to day at the Snobbery and haven't looked through the other videos or camera card yet as catch-up work gets in the way.

Here are some random pics from my phone.



The inland submarine at Mt Ive station. I'm sure it's the most photographed thing on this long red dust road. A true work of bush art.




Camp kitchen/dining room and Zed the "Prepper Master Chef" creation, beans and spag with spicy spam.
It tasted better than it looks and sounds.



Sunset view. Contrast of red dirt and prickly bushes, ice white salt, distant hills and a pretty glow. If you look closely on the salt you will see cars and trucks leaving for the day.



Clean alien looking bike on a suitable landscape.
It didn't stay that clean for long!

[Andy]

Wow, what a week. Heat, sunburn, rain.... we got it all.

The salt is an amazing thing to see, every morning we drove to the lake from the camp-ground at sunrise to see the light change. It was jaw dropping awe every single day... surreal, alien-planet esk and also nice and cool before the blistering sun beat down.

The first couple of days we did our licence passes, you need to prove you can handle the speed before you can go flat out.

Day 1:
First pass on the salt. Not nervous but seriously excited and a tad anxious to see what it was like to ride on this stuff. Speed limited to 200kmh. It was like running on velvet, beautiful, smooth and better than any road I have driven on.

Second pass: Now I'm allowed to go to a 240kmh limit. Ahh, that feels faster, still smooth and nice.


Day 2:
With the first two licences out of the way I'm allowed to do 280kmh. Woah, that feel fast. Front wheel moving around on the salt, back wheel spin and little fish-tails and a huge lump of salt hitting me in the helmet from under the speedo. Now it feels like I'm riding and I can see how much everything changes with a small speed increase.

280kmh licence out of the way and I'm allowed to go 320kmh. First pass, flat out through the 2mile, 3mile, 4mile... tacho up to 12,000rpm then a flash to 14,000... lighting-up the back wheel. Tons of power, can't get it down. 300kmh top speed.

Day 3:
After talking to Ben (Yamaha R1) and Sam (ZX14) they said "stiffen it up!". So I changed the geometry, stiffer front, stiffer rear, pre-load, dampening and rebound. Ran again... 295kmh, still getting wheel spin in the top end. Arrgghhh.
Check the bike over and can see a slight discolouration in the oil... hmm... this is clutch slip, not wheel spin this time. So pulled the clutch out and inspected all the plates. None burnt, just slipping. Spent the rest of the day scrounging heavier springs or washers to pad the existing springs.

Day 4:
Greg (Suzuki's and regular 200mph runner) found some spacer washers in the back of his clutch on a bike that smoked a piston earlier in the day. Legend! I installed the washers and went out again. 295kmh! Wheel spin this time, not clutch slip. Then the heavens opened and we got soaked... racing called off for the day.


Day 5:
After sitting around the camp site pondering most the night, I decided to try removing the top wings. Less down force on the front means more weight transfer to the rear. We were on the lake at sunrise but there was a lot of water on the start line from the night before. It was a late start, they moved the startline to the 2 mile mark and could run "short track" for the morning. First pass... 319kmh top speed with wheel spin and fish-tails but WOW, that was fun.

Got back, grabbed the time slip and rode down to the start for another pass. 319kmh (198.238mph - exactly the same to the 1000th as the previous run).

Being only one and a half miles off the 200mph mark I rode down to the start line for a third pass but Peter the starter said "sorry, all done". Arrgghh. So close yet 12 months away from the next pass.

Punchline: a couple of 319kmh passes and I now have a 320kmh-400kmh "A Grade Licence" so I can drive/ride anything at stupid speeds without qualifying again.

We have lots of photos and video that we haven't had a chance to look through yet (got back and have been on the roaster ever since... including now as I type)

I do have some Race Chrono footage from the last pass on my phone and have just uploaded it to Youtube. Sound is bad (wind noise) but you can see the GPS speed, G-meter and see the tacho needle (14,000 is straight-up).


https://youtu.be/ALpJbMEBUz8

I'll upload more stuff when we sort through it.