Great mini-tutorial Andy...
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.....next time we expect you to make the final pass on one wheel and at 200mph....
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.Great to see the Aeropress endorsed as the ideal solution for camping.
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.Would a change to grippier tyre help too? Not sure if special tread/compound would improve traction on salt?
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.
Nah, not needed, too busy laughing maniacally with a grin in my helmet big enough to make my jaw sore.I would have been wearing brown underpants
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.ComAir wind tunnel
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.
So tyres was the main topic of conversation over a morning coffee with fellow bike competitors??
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.
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.So tyres was the main topic of conversation over a morning coffee with fellow bike competitors??
WOW! That's a fascinating insight and a very cool thing to have been a part of.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.
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.
Great pic. Andy. It took days to clean up our concrete bunker after the failure, just get the brooms out on the drag course I presume. Very different constraints with the dragsters tho', not just top speed but getting there in such a short distance, so massive grip needed. The Grand Prix Sunday was interesting from the tyre point of view.
You're too modest Andy. Just checked DLRA results and see that your 198.238 (the one that you backed up to the third decimal point!) set a 1000 MPS-BG class record (=1000cc Modified Partial Streamline Supercharged Gas). Also, on my counting, your 8 passes was equalled by only one other competitor. Surely that is also testament to your preparation and attention to detail. Wasn't there a motorcycle Rookie award? You must surely have been in the running for that. Congratulations!
It really was a great week away.
I didn't notice that the 8 passes was "that" high, I did know that I would have done 8 a day if the queues moved faster and I would have been happy to run at night if the lake didn't close at 6pm.
Hmmm... night racing on the salt would be wicked. A fair bit cooler and as long as you had a wide enough beam you could still see the track markers.
The biggest gotcha with salt racing is that it's really "in my head" now. I'm seeing aerodynamics everywhere I look and sometimes in really odd places, I can't sit and watch telly without drifting off into thought about how to improve the bike next year and get more of that power it's making down to the ground. I don't have answers yet but I have plenty of ideas.