A skating we will go

[Neon]

So I binned my bike on the way to work this morning. No serious injuries or damage, but I could use some help understanding what went wrong.

Scene: Albany - Turning right at roundabout from Bush Rd. into William Pickering Dr. 6.30am, dark, road wet from brief shower ten minutes earlier.

I ride this way every day, so after the rain was expecting the road to be slippery as a bastard. I slowed right down and entered the corner at steady speed of maybe 15kph. Halfway through, was looking through to exit (still leaning but mostly upright, starting to accelerate but ever so gently) and felt the front slide to the left. Next thing I was on the ground.

Attached is a photo looking to the exit, halfway through corner - you can see the scratch marks in the middle of the pic.

Other than a few bruises and a sore neck I'm fine. Felt a bit dazed from hitting my head though. Gear did it's job fine. Bike has bent bars, bent brake pedal and a few scratches, all superficial.

I can only deduce that it was one or more of:

a) I took a bad line through either the smooth tar patches, or oil and shit that gets deposited on that roundabout. It's well known for being bad in the wet

b) I was going too slow and the bike was destabilised

c) It was a localised gravitation anomaly (LGA - well documented by Vifferman)

d) I expected to crash and so did.

So, what could I have done differently? I was expecting it to be slippery and so was being ultra careful, but binned anyway.

Feedback appreciated...

[Taz]

Bummer dude.

[Ragingrob]

Damn that sucks al least you're OK. You didn't touch the front brake at all?

[mowgli]

You mention that you were leaning but mostly upright. The roundabout in the picture doesn't look very tight so at 15kph I wouldn't expect much lean at all. Where would you say you body weight was?

Reason I ask is that I had some interesting slow speed cornering incidents (in the dry) when I was leaning the bike but semi-countering by (wrongly) moving my body weight out. Net result was that it felt less stable so I've consciously made a point of not doing that any more.

On a wet road just after rain my experience might have been like yours.

[Neon]

Damn that sucks al least you're OK. You didn't touch the front brake at all?

Nope, I was nowhere near the brakes!

[Ixion]

OK. Firstly, and most importantly , congratulations on a VERY good attitude. Sometimes, shit happens,. But a rider who accepts that a BadThing (tm) happened , and maybe he can figure out what and prevent it happening again, has a long riding career ahead of him. Well done!

Now , as to what happened. Very very hard to say.. But assuming you didn't use the front brake (can't see why you would), then (a) that's a shit of a roundabout , and after light rain it'll will be (as you say) greasy and oily (b) if I remember it correctly, is it not off camber ? (doesn't show in the pic, but it probably wouldn't); (c) at 15kph I doubt you would have exceeded the traction budget, even accelerating gently on a greasy surface.

I suspect you were at the transition point between counter steering (like normal riding) and tiller steering (what you do when going really slowly). maybe you tried (without realising it) to tiller steer around the corner, whilst still a bit leaned over, and on a slippery off camber.

Slow speed steering on a slippery surface has somewhat different rules to oridnary steering . Riding on wet clay is a good way to explore this. Basically you want to do the exact reverse of the sports rider's technique - weight the outside peg, keep the bike upright , and steer with the handlebars. And ENORMOUSLY gentle with the throttle. I always go through that sort of corner completely on the overrun. Totally bad practice by ordinary standards , of course.

I suspect you mixed the techniques. I've seen this more than once , and it's a 'gotcha' for novices.

This is only my opinion , based on what are necessarily very limited facts. others may disagree, will certainly have other ideas. End of the day you may never really know what happened. But don't let it put you off. Odds are , it'll never happen again.

[Neon]

You mention that you were leaning but mostly upright. The roundabout in the picture doesn't look very tight so at 15kph I wouldn't expect much lean at all. Where would you say you body weight was?

It's possible that my weight was slightly off to the right, so yes this could have been a contributing factor. Maybe I should have tried to keep my body more centred?

[aroberts]

If the front wheel slid out at that speed it would have to be oil or crap on the road I would think.

[slick-kev]

could b the paintd lines on the road

[Neon]

OK. Firstly, and most importantly , congratulations on a VERY good attitude. Sometimes, shit happens,. But a rider who accepts that a BadThing (tm) happened , and maybe he can figure out what and prevent it happening again, has a long riding career ahead of him. Well done!

Thanks Ixion, I am certainly not going to let this put me off!

I suspect you were at the transition point between counter steering (like normal riding) and tiller steering (what you do when going really slowly). maybe you tried (without realising it) to tiller steer around the corner, whilst still a bit leaned over, and on a slippery off camber.

This sounds plausible. I have a vague recollecion of direct steering momentarily just before traction was compromised, so you could well be right.

[Neon]

could b the paintd lines on the road

If you look at the photo, there are no lines anywhere near where the front washed out. For obvious reasons I avoid lines like the plague in the wet, and even in the dry I'll take another line if I can.

Thanks for your thoughts.

[Neon]

If the front wheel slid out at that speed it would have to be oil or crap on the road I would think.

Yes, I'm certain that this was a contributing factor. What pisses me off is that I was expecting it to be slippery and was compensating, but lost it anyway!

[Ixion]

An oily surface , beyond any doubt, contributed to the off. But , if it were ONLY a slippery surface, given that you had begun to accelerate, the traction loss would have shown up at the rear wheel, not the front. It was something you did with the steering, for my money.

[FJRider]

I would say you were coasting through the roundabout, letting gravity and momentum do its thing. Little (no) weight/down force on the front wheel (bugger all grip in the wet) said wheel lets go. Slow motion to the deck. Then again ...1001 (other) things, Get a bigger/heavier bike (with insurance)

[Neon]

An oily surface , beyond any doubt, contributed to the off. But , if it were ONLY a slippery surface, given that you had begun to accelerate, the traction loss would have shown up at the rear wheel, not the front. It was something you did with the steering, for my money.

Agreed. My challenge now will be to practice my low speed cornering and try to get it smoother.

I already have a bit of a thing about turning right, and this hasn't helped

Thanks everyone for your comments.