Question regarding my low side at Turn 7 at Road ATL [Video]

tujabro

tujabro

New Member
Howdy all

I got the video from a rider who was behind me when I went down at Turn 7 during the rain. Before I seen the video I was told I had to much lean angle when I rolled the throttle and the bike got away from me. While looking at this, I think that I had enough contact patch when I rolled on the throttle. Could it be that I hit a slick spot or I just didn't have enough of a contact patch?


Tujabro
 
ninjamansc

ninjamansc

THE Comstock
Control Rider
Rain significantly reduces the coefficient of friction between tire and track. It's simply too much throttle for conditions. Or rather, depending on your engine RPMs, the rate of change in power to the wheel exceeded available traction, regardless of your perceived throttle application. Thus your really slow low-side. Just be glad it didn't turn into a highside.
 
Otto Man

Otto Man

John
Control Rider
ninjamansc said:
Rain significantly reduces the coefficient of friction between tire and track. It's simply too much throttle for conditions. Or rather, depending on your engine RPMs, the rate of change in power to the wheel exceeded available traction, regardless of your perceived throttle application. Thus your really slow low-side. Just be glad it didn't turn into a highside.
Click to expand...


This, all of it. You simply added too much throttle, too fast, given the low traction condition. You tried accelerating before standing the bike up enough to get on the fat part of the tire.
 
Smithereens

Smithereens

Control Rider
N2
You could have taken away a little more lean angle with body position.... you could have entered with a better line and opened up your exit .... etc. etc. etc. ..... but those are all minor compared to main reason which John stated .... too much throttle for the amount of grip you had regardless of the size of your contact patch at that point. Most of us have experienced what you did and we all learn from these incidents. Glad your learning experience came at a low speed.... and that you got video so you could see it clearly:)
 
N

NH_to_MS

New Member
What kind of bike are you on in the video? The lean angle and speed seems very moderate and you just appear to overpower the grip of the rear tire. I'm assuming you have a good amount of power to spin it out that easily. Amazing how pros can still ride at the pace they do on wet tracks, or some of the isle of Mann video I have seen.


Sent from my iPhone using Tapatalk
 
tujabro

tujabro

New Member
All

Thanks for analyzing my mishap. I was ticked when this happen as this is my first crash ever in the 6 years I have been riding. I did tell say when I started riding that, "...if I ever go do, I hope its at a track." well I guess I got it out my system now. The rest of the sessions, I took it easy and I really worked on just trying to get the bike up before rolling on the throttle. I guess the old saying is true, "Experience is the best teacher".

NH_to_MS
Its an '05 CBR600 RR.

Regads
Tuan.
 
tujabro

tujabro

New Member
1stRoundPick said:
As a guy new to this forum, I really feel good about how well we all can share and learn from one another without ridicule and flames as they say on the bike forums.
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1stRoundPick

I can't agree with you more. I take all things as a learning experience and I am very appreciative of the helpful feed back. Crashing does suck but what I have taken away from this is:

In the rain make sure I'm upright before rolling on the throttle

Everyone crashes

Still get out and have fun

Regards,
tujabro

Sent from my SM-G925P using Tapatalk
 
physicistkev

physicistkev

Control Rider
Talking about overall traction isn't very simple. The simplest way to look at it, is to see that your available traction is some value and all changes in force are either contributing to or taking from that value. What generally contributes, is the friction coefficient (there are actually 2 kinds, static and dynamic, but we will treat them as one for this post). This is the sum of the frictional force between two objects and the force pressing the objects together. You can treat this as the "sum" of your traction. When you apply the brakes or apply the gas, you are taking from your traction value. When you turn you are taking from your traction value. When you brake and turn or accelerate and turn, both forces are taking from your traction value. So, its a math problem to see how much acceleration and turning is taking from your traction value. As long as the total of turn (lean angle/change of direction) and acceleration is not >100% of your traction, you should keep the rubber side down.

This discussion usually comes up in regards to trail braking, as for some reason people see it as a better way to demonstrate the "change of direction" + braking force <= "traction" means you don't crash.
 
physicistkev

physicistkev

Control Rider
whitarnold said:
AND that is why I will "NEVER AGAIN" ride in the rain.!
Click to expand...

Riding in the rain is one of the best things you can do for learning the value of smooth. If you can ride in the rain, you can go a lot faster in the dry. It may not be as enjoyable as a sunny day in the 80s, but it is far more valuable for your future skills.
 
Baehlit

Baehlit

New Member
I did the same thing that weekend but it turned into a highside. I was the one who shut down the track before lunch on Saturday during Intermediate (hate that I was that guy). I enjoy riding in the rain because it really teaches me about tire grip. At much lower speeds you can learn when your tires begin to lose grip, which means if you do go down, your not flying at top speed. I came through turn 7 and felt a little lose and much much faster than Tujabro in the video but kept it together. I thinked I slightly chopped my throttle a bit to settle. I then put too much power in my back wheel as I began to bring the bike up and my rear stepped out and started the low side. I made the mistake of chopping the throttle while my rear end was out and when I regained traction sideways it slammed me down on my left side.

All and all a great learning experience and I walked away with a bruise and some scrapes. Bike was wrecked though, oh well.

I do have one question though. In you alls opinion, would I have been better off opening up the throttle? Do you think that would have guaranteed the lowside?
 
imadraver

imadraver

Make Every Moment Matter!
Control Rider
temp.jpg
Here's a pic the moment the tire loses grip for tujabro. The learning points have been noted above, particularly the combination of...
  1. need to be more gentle getting on the throttle
  2. having the bike more upright getting on the throttle
  3. body positioning - hanging off a bit more to help reduce lean angle and a knee out to possibly help save it
I did a similar thing last year in the wet at RA and mine turned out more like Cooper's - high side.

To recover a rear wheel slide from over acceleration, I'm in the camp that says...
  1. DO NOT: chop the throttle, continue to accelerate further, stiffen up or hunker down.
  2. Keep everything very steady and loose.
  3. Ideally ever so slowly decrease throttle, or at least hold throttle.
  4. Ever so gently raise your body up to centerline, above the bike, at least your butt not touching the bike. The idea here is to help straighten the bike and to dampen any kick that ensues.
  5. If all goes well you should feel the bike slowly decelerate, get back in a straight line, upright and recover grip.
All easier said than done; definitely takes practice (but obviously not something easy to setup or that you necessarily want to push practicing).
 
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