Warning to newbies and others.

[slofox]

Here's an Ultra High Pressure (UHP) water cutter that Fulton Hogan developed to remove "Bitumen Flushing" which seems to be the official term for tar bleed. Looks really well thought out, and sounds like it works relatively quickly too. Not much use to us, but to the Regional Councils and other Roading Authorities.

NZ could use a gazillion of those then......

[gijoe1313]

Ayup ditto for all that good advice, I just got back from SH22 not too long ago, at the end, coming around a 35kph corner, whole lane is melted and I end up scooting across into the other lane!

Felt the tyres sliding across and sticky clenchy bum moment as I managed to steer the lil'ol'hornet back into the right lane and keep it all upright! I dunno what I did right, but everything I did kept it upright!

So, ayup, gotta watch out for those dreaded pools of dinosaur goop!

[Ixion]

Upper end of 22 yesterday was a patchwork of melt. I steered a meandering course through some of it, and for the bad parts took to the verge or the narrow strip by the white line. How come the verge, the tarseal bit between the left hand white line and the grass never melts ?

Whoever was responsible for having all the back roads sealed has a LOT to answer for. And, I reckon , a good deal of blood on their hands. Those roads were much safer when they were gravel. I reckon they should be put back to gravel.

[martybabe]

Just come back from visiting friends along Surf highway Taranaki, melted tar in the wheel tracks all the way and some of the bends were completely devoid of any chip at all. It was reminiscent of of a few days I spent on a purpose built skid pan.

Bloody lethal and a bloody disgrace, some lovely bends out that way normally, just blinking deathtraps now. I saw three bikers take to the verge as Ixion described.

[racerhead]

Just come back from visiting friends along Surf highway Taranaki, melted tar in the wheel tracks all the way and some of the bends were completely devoid of any chip at all. It was reminiscent of of a few days I spent on a purpose built skid pan.

Bloody lethal and a bloody disgrace, some lovely bends out that way normally, just blinking deathtraps now. I saw three bikers take to the verge as Ixion described.

Travelled that road myself today and it was pretty bad in some places alright.
At one point I was riding in the concrete gully beside the road because I was sick of pickin chips out of my fairing and anywhere else they stuck. Was even on the grass at one point but got pretty sideways so kept to the solid stuff after that

[slofox]

How come the verge, the tarseal bit between the left hand white line and the grass never melts ?

This suggests that wheels driving over certain parts of the road encourage the melt to come to the surface. It is always the wheel tracks that are worst. Low traffic areas like you mention, Ixion, don't seem to have the same degree of problem.
Which makes me wonder just how much the NZ penchant for Urban Tractors (SUV's) adds to the problem. If traffic does increase the surfacing of melt then it would follow that heavier vehicles would cause more trouble than lighter vehicles. SUV's have great fat sodding tyres on them and weigh tonnes so they are probably one of the more blameworthy vehicles. Ban the buggers I say...(just one of my fav hates....)

[Ixion]

I suspect there is something in the weight thing. Though great big tyres on SUVs should make it better not worse, less weight per square inch. I don't understand though how weight can make the tar melt? Is it some sort of "squeeze" effect, the tar is melted by the sun's heat, but the weight of traffic squeezes the fluid to the surface?

[slofox]

I suspect there is something in the weight thing. Though great big tyres on SUVs should make it better not worse, less weight per square inch. I don't understand though how weight can make the tar melt? Is it some sort of "squeeze" effect, the tar is melted by the sun's heat, but the weight of traffic squeezes the fluid to the surface?

That's what I was thinking. There is no doubt that the wheel tracks are worst, so wheels passing over have some obvious effect...whatever it is...personally I blame SUV's for everything...

[twistemotion]

I suspect there is something in the weight thing. Though great big tyres on SUVs should make it better not worse, less weight per square inch.

Exactly. The average SUV weighs around 1800kg. That makes it 450kg per tyre, assuming weight is evenly distributed front and rear. Now, I would guess the contact patch of a bike is about 1/3 that of an SUV's. 1/3 of 450KG is 150kg. If a bike weighs 300kg including rider (conservative), then it means that each tyre puts 150kg of pressure on the contact patch, equal to that of the SUV. A heavier bike will pronounce the effect dramatically.

In saying that, I think trucks have a much bigger impact than any other vehicles. Say the trailer weighs in at 20 tonnes, which is 20000kg, divided by 20 tyres (12 on the trailer, 8 on the back of the tractor unit), it is 1000kg per tyre, and the contact patch isn't much bigger than that of an SUV.