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Smooth shiny road surface

Discussion in 'New Riders and Riding Tips' at netrider.net.au started by iGolf, Mar 2, 2016.

  1. Just interested in people's thoughts on smooth shiny road surfaces. Particularly where the road has been worn down in the wheel ruts.
    Do you take extra care on corners in the wet and dry? Or is it just an issue in the wet?

  2. I take more care on roads like that all the time, as I reckon they don't have the same grip levels, and it is also harder to notice other variations on them, eg, water/oil patches. Also, if they are worn down smooth I tend to find that they are more uneven, more rutted
  3. Couple of things I've noticed.
    Shiny ruts are very common on the roads approaching snow skiing resorts, which I'm guessing is related to the use of chains in winter (?)
    The mix used on roads above the snow line can be different to other places, and the grip level can be dramatically less.
    So if I see shiny strips, I'm more cautious about grip. I treat it as a warning flag and not necessarily the cause.
    • Like Like x 1
  4. So on a corner like this, it's best to stick to the 'rough' section down the middle?

  5. As a general rule of thumb, I treat anything smooth and shiny as slippery. Road paint, steel plates, manhole covers, you name it. I can't help you with that specific surface because here in NSW, we rarely see anything that good :)

    Plus we have lots of older tar with basalt aggregate that gets polished, when that stuff is wet it's not far off glass even though it looks comparatively rough.
    • Agree Agree x 1
  6. Last November we were heading from Bathurst Past Cowra and further south to Tumit in the rain,a constant spray up and down from the passing trucks, it was very wet, I had a couple of slides just going straight. That road was smooth and shinny like glass, gets heaps of heavy truck use. And that was just cruising along making ks till the good stuff. Did The Eliot Way also in the rain, that was pretty good grip wise.
  7. Truck routes have diesel contamination. Completely dry is fine. Avoid obvious stains (oil or coolant), fine stripes (leaking hydraulic oil) on curves. Really smooth shiny surfaces are fine when they are dry.

    In much of Oz, where rain may not fall for many months, roads will become diabolically slick if they get just enough rain to wet the dust and accumulated oily contaminants. The roads are OK if there is enough rain and traffic to scrub it off, but it's the "just wet" condition before that happens, that isn't good.

    How slick? I was once on my regular commute on the old XT550. Riding on the level it felt a bit vague as I was getting away from the town and going through the gears. I thought I was developing a clutch problem, maybe a deflating tyre. I touched the rear brake - nothing, so slowed right down and went back a few gears. I found I could spin the rear tyre in second, also in third and 4th without using the clutch. I probably could have in 5th too if I had been going fast enough to have a few revs up. It wasn't wet enough to see any rainbow shades like those associated with diesel spills on water, but it sure felt like it.

    Be particularly careful during "sun showers" in the drier parts of the country. A longer rain will wet up the contamination and actually produce suds on the sides of the wheel tracks. The slipperiest parts will contract to the space between the wheel tracks and will persist long after it has become a "real rain" due to tyres not travelling there much. If a shower is only brief and the road dries quickly, without the stuff getting washed off, this will concentrate the contamination in the area between the wheel tracks. The next time it rains, you will have the same effect again and that rough spot between the wheel tracks might not be so friendly.

    Really smooth, shiny roads will also promote aquaplaning more easily - can happen at lower speeds than a road with a rough surface, and require less water for this to be a problem - possibly the origin of Zims straight line slides
  8. There was I think 8 of us and all said the same that night
  9. Avoid the centre of lanes, it may be better asphalt however your more likely to washout on gravel (or whatever debris is on their) and possibly put you on a less than ideal line through the corner regardless of the weather.

    When its shiny it often means the gravel (grip) has worn away or compacted leaving only the slippery tar glue base. Its fine for most people in the dry with road legal and properly inflated tyres who are doing a reasonable speed however in the wet its another story. In that case you follow the tyre track, keep upright and be silky smooth on your inputs.

    If your a sporty rider who gets knees down then it means you should find a better road or at-least take it easy for that corner .
  10. This was really my point here.
    Avoiding the shiny surfaces on corners can make a mess of your line through them.

    I must admit, ive been of the view that a smooth surface provided more contact with the tyre and therefore more grip in the dry.
    Sounds like I was wrong... maybe
  11. I think you were pretty much on the money, Zim.

    Rougher bitumen gives the water somewhere to go under the pressure of a tyre. If the surface is really smooth, there are only the sipes in the tyre as an "escape route" for the water under the very quickly increasing pressure of a rotating tyre . It is unreasonable to expect that sipes in an otherwise smooth road tyre will clear all the water from beneath the tyre.
  12. I typically stay in the right hand wheel track and will vary the position depending. It's not so much of a hassle in the dry but if it's damp I would still prefer to stay in the wheel track because the centre line, while not as worn down, is not covered in as much oil and debris that has dripped from cars. Constant movement of tyres over the wheel tracks means there's less gunk there, generally.
    The only time I've ever ridden in the rain was for my QRide test, so I can't say for certain what I would and would not avoid.