Ducati Monster Forum

Moto Board => Riding Techniques => Topic started by: Lord_Bragle on January 12, 2009, 08:43:36 AM



Title: Slides
Post by: Lord_Bragle on January 12, 2009, 08:43:36 AM
What exactly is a ‘slide’ when cornering? Is it the tire breaking traction under acceleration and then biting again causing the snatch that sometimes chucks a racer of his bike, or is it something more controllable.

I must say that I have never felt the tires loose traction except for the back tire hopping a bit when breaking hard, or if I hit a diesel spill and this is scary enough as it is, and if I did get a slide how near would I be to falling off the bike?


Title: Re: Slides
Post by: Spidey on January 12, 2009, 10:00:14 AM
There are all kinds of slides.  Basically, a slide is where a the wheel breaks traction.  But that can occur for many reasons -- spinning the rear, something in the road, too much lean angle, sudden weight change, suspension, etc. 

You won't always feel a slide.  Traction is not binary -- it's not a like an on/off switch.  Your tires can be sliding a bit and you'd never know it.  In fact, it happens all the time.  That said, when people talk about "a slide", they tend to be referring to a quick loss of traction that they actually felt, like when you hit a patch of water or gravel.  Just don't stiffen up, and make sure you try to stand the bike up (push down on outer footpeg, use the handlebars to push the bike to the outside of the curve).

How near would you be to falling off the bike?  There really is no way to answer that because each slide is completely different.  That said, once you get more and more comfortable with the bike, it can move around in a turn, occasionally breaking traction, and you won't care.  In fact, you're more likely to crash if you stiffen up when the wheels slide than if you just let the bike settle itself. 

Just for fun, here are some vids of tires breaking traction.  They're derbys, but if you haven't seen them, it'll give you a sense of how much tires can slide without the rider falling off the bikes.

http://www.youtube.com/watch?v=QQXOsF54x-I (http://www.youtube.com/watch?v=QQXOsF54x-I)

http://www.youtube.com/watch?v=89rDXkMJ5U0 (http://www.youtube.com/watch?v=89rDXkMJ5U0)

http://www.youtube.com/watch?v=DLArUT30F0c (http://www.youtube.com/watch?v=DLArUT30F0c)

http://www.youtube.com/watch?v=6s44KOINBB0 (http://www.youtube.com/watch?v=6s44KOINBB0)

http://www.youtube.com/watch?v=4U24i5cP70U (http://www.youtube.com/watch?v=4U24i5cP70U)

http://www.youtube.com/watch?v=45R9AB_3N5E (http://www.youtube.com/watch?v=45R9AB_3N5E)

http://www.youtube.com/watch?v=KycZk1M7g24 (http://www.youtube.com/watch?v=KycZk1M7g24)


Title: Re: Slides
Post by: ScottRNelson on January 12, 2009, 10:03:45 AM
I consider a slide to be any time a tire loses (not looses, by the way) traction in any way whether or not  it quickly grabs again.  Most of the time the slide feels much worse than it really is.  If it slips half an inch, it often feels like three inches to the rider.  Usually when I feel a tire slip even the slightest amount I try to get the bike more upright but otherwise not make any sudden moves.  I've had it occur under acceleration, braking, or cornering.  Usually it is due to sand, gravel, or dampness on the road surface.

There is no way to determine how close you would be to falling off due to a slide.  The best thing you can do is avoid them as much as possible, but don't give up of one occurs, sometimes it's possible to save even a very nasty slide.


Title: Re: Slides
Post by: Lord_Bragle on January 12, 2009, 10:43:50 AM
Those clips say it all; now I know why I'v never had a slide, its because I'm not racing.  But when people do talk of experiancing slides its got to be accepted then that they would have been cracking on a bit on their bikes, unless it was gravel or damp or diesel or somthing.  I'm going to stop worrying about slides now I think.


Title: Re: Slides
Post by: ScottRNelson on January 12, 2009, 10:50:54 AM
I had a rear tire slide the last time I rode my 888, strictly due to cold tires.  I was making a left turn at the first intersection I come to when leaving my house and just gently pulling away from a stop was enough to cause the rear tire to slip.  I blame it on cold Dunlop D208ZR tires.  I'll be putting some Metzler M3 tires on there in a few months.

Sometimes tires slip even when you're not trying to go fast, and there are many different possible causes.  All you can do is not panic and do what you can to reduce traction demands until the tires hook back up again.


Title: Re: Slides
Post by: Cider on January 12, 2009, 07:01:05 PM
Cool videos!  Here's another:

http://www.youtube.com/watch?v=zpHC8HQyKgE (http://www.youtube.com/watch?v=zpHC8HQyKgE)

http://www.youtube.com/watch?v=8jANEUDN4Ts (http://www.youtube.com/watch?v=8jANEUDN4Ts)

Here an article on backing it in: http://www.supermotoracer.com/SMR%20Tech%20stories/iss2_backitin.pdf


Title: Re: Slides
Post by: Slide Panda on January 13, 2009, 08:48:14 AM
I had a rear tire slide the last time I rode my 888, strictly due to cold tires.  I was making a left turn at the first intersection I come to when leaving my house and just gently pulling away from a stop was enough to cause the rear tire to slip.  I blame it on cold Dunlop D208ZR tires.  I'll be putting some Metzler M3 tires on there in a few months.

Yep, cold tires and tarmac can cause sliding even at normally restrained speeds.  I know I've felt a touch of drift like slide on highway ramps on a chilly night.  Like Spidey said, it's not binary.  1st time I didn't realize that I was sliding a little - I just thought I was being a bit sloppy because my line drifted wider than I thought it aught to be.  But after pondering it a bit, and it happening again, but a bit more so on a colder evening, I thought 'a ha.. little less traction than I might have hoped for there..."

But slides like you see in those videos are not the norm on the streets


Title: Re: Slides
Post by: Raux on January 13, 2009, 10:26:37 PM
Those clips say it all; now I know why I'v never had a slide, its because I'm not racing.  But when people do talk of experiancing slides its got to be accepted then that they would have been cracking on a bit on their bikes, unless it was gravel or damp or diesel or somthing.  I'm going to stop worrying about slides now I think.

slides are more possible on the street than on the track due to conditions and not the riding. ie cold tires, gravel, oil, etc.

i spun a rear tire yesterday with temperatures in the 30s because i hadn't given it time to warm up. coming out of the gas station and just throttled enough not to get run over by a bus. rear spun a bit and slid right on the left turn. i corrected and backed off the throttle a bit.

braking in cold/wet can also cause rear slides. had one the other day with an old FJ. but in the end knowing how to handle rear wheel spins/slides is crucial to street riding as well as track.


Title: Re: Slides
Post by: mbalmer on January 14, 2009, 10:35:51 AM
My scariest experience, so far, was last summer when I was riding through Yosemite. Coming west on 120 from Tuolumne Meadows, the road was covered with those snake-like tar patches. My bike was sliding all over the place. It scared the crap out of me. I'm still pretty new to MCs. I just slowed down until I reached the tunnel. I was with a Harley and a Honda trike. The trike didn't care. The Harley stopped because he thought there was something wrong with his front wheel. I haven't experienced the sliding on any other road like that day on HWY 120, but now I'm a bit paranoid when I see a lot of those snake-like repairs (which are everywhere) on twisty roads.


Title: Re: Slides
Post by: Lord_Bragle on January 15, 2009, 06:13:33 PM
People talk of slides in such a matter of fact way that I was beginning to wonder if one was going to sneak up on me someday, and especially if I was maybe getting a bit brave and pushing a bit.  I doubt I will ever push the bike anywhere even near the extent needed to get slides like the ones in the vids.  Of course bad road conditions could get me sliding I suppose and also if I made a mistake in judgment and got myself in to difficulty’s or just shear bad luck with another road user forcing me to break to hard or turn to hard.  It would be nice to be able to try and induce one though, and practice trying to control it, but I only have one S2R to experiment with.


Title: Re: Slides
Post by: BastrdHK on January 15, 2009, 10:09:33 PM
Cool videos!  Here's another:

http://www.youtube.com/watch?v=zpHC8HQyKgE (http://www.youtube.com/watch?v=zpHC8HQyKgE)


Nice find Cider.....I laughed when I saw Biaggi on the motard.   He almost reenacted the famous near loop of his marlboro motogp yamaha on the yamaha motard. 

Stay away from the yamis Max until after you retire 8)


Title: Re: Slides
Post by: w7ck7d on January 16, 2009, 08:46:13 PM
This was some cool video..


Title: Re: Slides
Post by: derby on January 20, 2009, 08:09:40 AM
People talk of slides in such a matter of fact way that I was beginning to wonder if one was going to sneak up on me someday, and especially if I was maybe getting a bit brave and pushing a bit. 

at my last track day i was concerned about some "looseness" i was feeling. my shock had just been serviced and i thought that it'd come out of adjustment in the process. i finally decided i was going to walk over and talk to dave moss (catalyst reaction) about it when one of my riding buddies let me know that i'd been leaving big, sliding darkies on all the corner exits.

yes, they can sneak up on you.  ;D


Title: Re: Slides
Post by: Moronic on January 23, 2009, 08:10:41 AM
It would be nice to be able to try and induce one though, and practice trying to control it, but I only have one S2R to experiment with.

Probably not such a smart idea on a road bike anyway. Obvious way to induce one is lots of throttle coming out of a turn, but then when the tyre does let go it is likely to spin up pretty fast and get you into big trouble. As in over the high side and out.

Dirt bikes much the best way to learn. Almost no grip, so on anything with some grunt you're spinning up the tyre every time you open the throttle.

Road racers such as McCoy or Melandri doing long controlled power slides in Nos 5 and 6 of the above vids (thanks for posting those, Spidey) are pretty close to the rear tyre grip limit from cornering forces alone when they start to spin it up, so it doesn't take a lot of extra throttle to break the tyre loose just a little, and they control it from there.










Title: Re: Slides
Post by: bschur13 on January 27, 2009, 07:09:14 AM

Man I actually had a dream about this topic last night!  I was out riding early in the season when it was a little cold, I was on a turn that was wet and when I hit the stripe on the side of the road my tire slid across the line but it happened quick and the bike and myself were fine.  I dont know if it happens like this in real life but this was an article I read that is good for this topic.   

http://www.mistihurst.com/files/J_F_07.pdf (http://www.mistihurst.com/files/J_F_07.pdf)


Title: Re: Slides
Post by: w7ck7d on January 29, 2009, 12:43:28 AM
Good info here man..


Title: Re: Slides
Post by: Jarvicious on February 04, 2009, 05:19:56 PM
Unless you are riding your bike like my grandma drives her Taurus, always assume that you can or will lose your rear tire at some point.  I don't remember where the quote came from but it's saved my ass a hand full of times

- When in doubt, throttle

I was on a moderately paced group ride once when I hit a good sized "puddle" of gravel midway through a loose sweeper.  I remember losing my front for a second (most terrifying thing ever) but my back swung out a substantial amount more.  I'm sure I over estimate how far I really slid, but I just keep the throttle where it was (or maybe backed off the tiniest bit) and rode it out.  Whatever you do, don't just chop the throttle off like this guy

http://www.youtube.com/v/pDVFL_RlPLw&hl=en&fs=1 (http://www.youtube.com/v/pDVFL_RlPLw&hl=en&fs=1)

If you keep your throttle running and the wheel spinning, you can control the ass end.  If the wheel is spinning or otherwise loosing traction and suddenly there is no power there (throttle) to keep it moving, it will grip hard and very suddenly. 


Title: Re: Slides
Post by: the_Journeyman on February 05, 2009, 09:32:27 AM
Slamming the throttle closed in a slide often results in a highside ~

JM


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