Surprise gravel, mid corner: what now?

[Viking01]

Hi, I share your concern on this one. Was riding around Shelley Bay as well late Sunday afternoon, and hit loose shingle on approaches to and in several corners. Seems like contractors performing roadworks are sometimes reluctant to get roads surfaces broomed once work has been completed. Comments from Davereid earlier are good advice (re head-up and look at exit; avoid breaking or quick throttle-off; clench tank with knees; try and avoid stiff arms). Easier said than done. Cheers.

[schrodingers cat]

I usually just shit myself. I assume it has some amazing adhesive qualities as thus far its been a winning formula.

[beyond]

With gravel on sealed corners you normally find it's rare for the gravel to cover the entire lane unless it's just been spread over the road. Often you will get clear lines through it where cars have scrubbed it away.

Once spotted, scrub your speed as hard as you can before hitting it. If you haven't been scanning the road and don't see it till you're in it, look for the areas of least gravel to maximise grip.

Unless you are riding at 7/10ths or more you have emergency lean available and should do the following which can be assessed by the brain all at once and quickly enough to make the moves:
Instantly recognise the left or right scrubbed areas of the lane depending on left or right corner, stand the bike up while leaning off and aim for the clearest patch and then turn the bike in again to catch the clearest line.

9 times out of 10 this will save you. In the one time out of ten when the road is totally covered you're going to have to do whatever it takes to stay on board and if it's thick gravel...... it's all about luck.

[98tls]

Had an off on the TL a few years back re gravel,going hard through some uphill twisty bits on a back road i know well,rounded the corner to find the shit everywhere and no way out the end result being i managed to stop with the bike 1/2 over a bank and me carrying on stupidly hanging onto the bars until i thought my bloody arms were going to snap,let go and sailed until coming to a halt flat on my back staring at the sky.Once the dust had settled i gave thanks to the man upstairs for not having me land on the concrete fencepost a foot or to from my landing spot as i am pretty sure if i had landed on it i wouldnt be walking again.Moral of that story is expect the unexpected eh.

[slofox]

Had a similar experience at Easter (see "Two Wheel Drift" if you can be bothered...)

This was a newly resealed piece of road about fifty metres long and covered the entire road. No signs anywhere around to warn. It was on an uphill left-hander - the kind of corner I love to blast through...no clear tyre tracks either. The whole bike moved to the right across the stones but stayed quite stable and didn't really scare me too much. To be honest it was over before I had time to get scared. I didn't really have time to "do" anything. As much luck as anything else I think.

Would like to have seen it signposted though.

[R-Soul]

Hmmm... actually, you're right on this. Lateral force on the tires is a solely a function of speed and radius, so hanging off wouldn't actually benefit, contrary to my earlier assertion. Leaning less as a consequence of slowing down obviously would help, though.

Your suspension should still deal with surface imperfections better if upright though.

The benefit gained from having your suspension working better by being upright will overcime any benefits you might get from having your tyres on a softer compound on the edge of the tyre. by leaning off, you are keeping teh bike more upright- and getting beter traction. So leaning off will help.

An important part of riding is having one eye on the vanishing point, and one eye on any potential road surface problems. Scary but true.

If you see it in time, prolly the best thing you can do is try and scrub off as much speed as you can before you hit it, and try and go through it upright and then turn quickly afterwards to avoid changing lanes. You can't slip out if you aren't leaning. Obviously you dont want to be moving into the oncoming lane since this could mean instant death. But this is why you are riding at legal speeds, that CAN be scrubbed off easily when unforeseeen circumstances occur....

if you dont see it at all, yeah - like sentox said - keep arms relaxed. The bike's suspension is designed to go stably through a corner itslef with little or no rider input. By going rigid, you are actually hindering the suspension. Also keep a samll amout of throttle and hope like hell the back end bites again. By going off throttle, weight will transfer to an already overleaded traction on the front wheel.

[R-Soul]

Or you could adopt MX style position, stick inside leg out, lean outwards, lie bike down in corner as much as possible to break back traction and give it a big handful of throttle, so that the back wheel acts as lateral traction in the corner, instead of the friction of the tires.

Good luck on that though, unless you are practised in the technique....

[bogan]

Or you could adopt MX style position, stick inside leg out, lean outwards, lie bike down in corner as much as possible to break back traction and give it a big handful of throttle, so that the back wheel acts as lateral traction in the corner, instead of the friction of the tires.

you really need to get out on a MX bike, cos thats not how it works at all

[one fast tl1ooo]

Put ya head between you'r legs and kiss you'r ass good

[george formby]

Poor light conditions & a bad road surface really stack the odds against you. Sounds like your reaction was good. The only thing you can do to react well instinctively, IMHO is to spend some time on a dirt bike which gets you used to sliding whilst counter balancing & steering where you want to go. Ultimately no grip is no grip.

[R-Soul]

you really need to get out on a MX bike, cos thats not how it works at all

thats how I have always done it myself...
so how does it work for you? and are you offering?

[bogan]

so how does it work?

basically, to go fast on dirt, you have to dig in and/or use ruts to generate high cornering forces, in doing this the tyres slide around a lot. When the bikes slide its simply far easier to stay on it if you have leaned the bike beneath you, and its bloody hard to stick a leg out when leaning off the bike too! Lying the bike down is not to break traction or to provide lateral acceleration (though I'm not 100% sure what you mean there) it's to deal with broken traction when it happens.

Even simplier put, go for a good cane on a MX bike (preferably on track) and it'll all become clear, and you'll have great fun doing it too

[R-Soul]

basically, to go fast on dirt, you have to dig in and/or use ruts to generate high cornering forces, in doing this the tyres slide around a lot. When the bikes slide its simply far easier to stay on it if you have leaned the bike beneath you, and its bloody hard to stick a leg out when leaning off the bike too! Lying the bike down is not to break traction or to provide lateral acceleration (though I'm not 100% sure what you mean there) it's to deal with broken traction when it happens.

Even simplier put, go for a good cane on a MX bike (preferably on track) and it'll all become clear, and you'll have great fun doing it too

I was not talking about ruts- with ruts you have limitless traction, so you could actually lean in or out if you wanted to.

I accept that you would not intentiallly break traction by leaning the bike over ( I had assumed that you would do this -like for dirt speed way racing)

As for what I was talking about:
The bike has a force outward on it in a corner. This force is normally (on the road) countered by the sideways friction forces of the tyre on the road surface. These friction forces are non existent on the gravel (not talking about ruts). So a different force must replace the sideways friction forces. The force that replaces it, is a component of the forward traction of teh rotating tyre that is acting radially inwardly in the corner. This is why the bike is not aligned tangentially in a corner on dirt, but slightly more inwardly.

Do you understnd what I mean about lateral forces?

[Elysium]

Not sure you can do much if it happens too quick. Just hope the bike holds!

[bogan]

I was not talking about ruts- with ruts you have limitless traction, so you could actually lean in or out if you wanted to.

I accept that you would not intentiallly break traction by leaning the bike over ( I had assumed that you would do this -like for dirt speed way racing)

As for what I was talking about:
The bike has a force outward on it in a corner. This force is normally (on the road) countered by the sideways friction forces of the tyre on the road surface. These friction forces are non existent on the gravel (not talking about ruts). So a different force must replace the sideways friction forces. The force that replaces it, is a component of the forward traction of teh rotating tyre that is acting radially inwardly in the corner. This is why the bike is not aligned tangentially in a corner on dirt, but slightly more inwardly.

Do you understnd what I mean about lateral forces?

I see what you are trying to say, but its wrong, firstly there is friction on gravel dirt etc, its obtained by driving the knoblies down into the soil. Secondly, the rear of the tyre would counteract such effects (front knoblies go down, rear ones go up), and for those effects there must be friction in the first place. Though I suppose on very high lean angles the slip generated would help the knobblies dig into the ground a bit more, but then so does sideways slide under normal conditions.