Feeling For Rear Traction

[marcus]

Is there a way one can feel for rear traction, specifically on corner exit?

 

Previoulsy I let the rear squirm around a bit but that was on pilots and was quite easy to do, since changing to a better tyre I can use a lot more throttle out of corners which sort of makes me wonder how I can feel if the rears going to break loose.

 

Surely there is a safer way to notice signs of rear grip!

[2bigalow]

Hey Marcus,

 

That is a good question. And you answered it. "Feeling" the squirm of the rear tire is a good indicator you are close to maxium grip for the tire at hand, however feeling the amount of grip available beyond the squirm is a fine skill possesed by the really, really, really, fast guys. IE AMA WSBK MotoGP guys.

 

Check this out. http://forums.superbikeschool.com/index.php?showtopic=877

 

 

Also, you could try the slide bike available to level 4 and two day camp students. This will get you closer to that fine skill.

[marcus]

I would but the conundrum is they dont have a slide bike in Australia.

 

Ok, I had a bit of a play around and im not sure what to do. The tyre is spinning but there is no real jump in RPM's. I actually thought it was quite mild but I accidentally weighted the inside peg too much and it stepped out more then anticipated.

 

I managed to ride the road the opposite way (slowly) and noticed the marks. There was a faint mark from my riding buddy, then 4 or 5'' over you could see my mark which was a lot darker. I sort of weighted the peg to change my line (to set up better for the next corner) and you can see where the line is in an arc that starts to straightens out, then it steps out 3'' (where I tried to change direction) and then continued on the arc as I realized and adjusted. It was already in a gradual slide and there is a slight crest ahead so I wanted the bike to be set up before that and tip in. Basically I didnt want to push my front end that hard into the next corner if I could help it.... braking more didnt really occour to me at that point.

 

I know its a bit stupid to do on the road but thats changed now.

 

I have been struggling with chassis stability on corner exit and the rear shocks been redone. Its a lot better but its made the grip issues more apparent, but its stable and a lot more controllable with further fine tuning scheduled.

 

But up until this point, I really didnt know the tyre was spinning up so much. I had an idea it was spinning a bit as I could "induce a slide". But for the most of it, my roll on was smooth (but aggressive), my throttle application felt "about right" but looking at the marks I was leaving, its more then what I interpreted- hence it stepping out quicker then what I expected. The bikes a lot smoother and im probably improving as well. I dont usually need to make any adjustments at this part of the corner and im sort of letting it drift a bit but I wanted a little bit of a nicer turn in point. The slide didnt really worry me and I now know I need to be a little more gentile if the bike needs more input or to hold a longer apex/make the adjustment earlier when im not on the gas as hard etc. (other options?)

 

Sorry if im using car terms, I used to club race but the bike things a bit new to me.

 

Reading the article again, am I correct in guessing that I have to chock this up to "experience" and learning that this is a particular stage of learning what the tyres and bike is capable of in its current trim?

 

And relearn these things again if there are any changes made?

 

I was sort of back to the stage of feeling the bike out, but comfortable with it

 

The cars I used to have gave subtle hints that the tyres were going off and you had to back it off a bit, but with a bike, im a little concerned that its going to "let go" without any warning or im going to go for a ride when the tyres are near due for replacements and have an opps.

 

Or do I have to get used to the fact that every time I ride, I have to constantly feel the bike out? I.e knock 5-10% off my last known pace and slowly build up pace again?

 

Sorry if this is a bit cryptic, if there is anything that needs further explanation let me know.

[prand]

Is there a way one can feel for rear traction, specifically on corner exit?

Yes, when the rear starts to come around. Sorry, but I'm not aware of any method that does not involve the rear sliding a little (coaches, please speak up). I think the whole purpose of "standard throttle control" is to SLOWLY apply throttle on the exit so that you can experience a little slide while avoiding a big slide that will cause an SR (Holy sh*t I'm gonna die!) which will make you snap the throttle shut and high-side, pitching you into the weeds.

 

Previoulsy I let the rear squirm around a bit but that was on pilots and was quite easy to do, since changing to a better tyre I can use a lot more throttle out of corners which sort of makes me wonder how I can feel if the rears going to break loose.

 

Surely there is a safer way to notice signs of rear grip!

In my limited experience, the Dunlops tend to hold tighter but break more quickly whereas Pirellis give me small slides that serve as a better warning.

 

Paul

[Cobie Fair]

Hi Marcus,

 

You've covered a bit of ground, I'll start with a few questions and one point: what if any schools have you done---in Oz I assume?

 

You commented that you put pressure on the inside peg and it altered the line. Have you looked at Chapter 19 in Twist of the Wrist 2, on Pivot Steering?

 

best,

Cobie

[marcus]

Hi Marcus,

 

You've covered a bit of ground, I'll start with a few questions and one point: what if any schools have you done---in Oz I assume?

 

You commented that you put pressure on the inside peg and it altered the line. Have you looked at Chapter 19 in Twist of the Wrist 2, on Pivot Steering?

 

best,

Cobie

 

I have done Lvl 1 at eastern creek.

 

I use my outside leg/arm/chest as an anchor point. I havent gotten up to that part of the 2nd book yet.

 

I weighted the inside peg to try and change/tighten my line- as I have found that trying to steer the bike with the bars hard out of corner exit doesnt do much except for inducing a head shake.

 

I have found with a bit more time I can better pick up what the rear end is doing.

 

I have also found out there is a slide bike (and no BS bike) but they are based in Phillip Island.

[Cobie Fair]

Hi Marcus,

 

You've covered a bit of ground, I'll start with a few questions and one point: what if any schools have you done---in Oz I assume?

 

You commented that you put pressure on the inside peg and it altered the line. Have you looked at Chapter 19 in Twist of the Wrist 2, on Pivot Steering?

 

best,

Cobie

 

I have done Lvl 1 at eastern creek.

 

I use my outside leg/arm/chest as an anchor point. I havent gotten up to that part of the 2nd book yet.

 

I weighted the inside peg to try and change/tighten my line- as I have found that trying to steer the bike with the bars hard out of corner exit doesnt do much except for inducing a head shake.

 

I have found with a bit more time I can better pick up what the rear end is doing.

 

I have also found out there is a slide bike (and no BS bike) but they are based in Phillip Isl and.

 

OK, so check out what is really bringing the bike up. To re-iterate what one of my coaches went over (2bigalow) if you had a rocking chair, and you're sitting in it and put your legs on the curved part and pushed, would it effect the chair? Nope. Same for steering. If you aren't using the bars, it's not effecting the line or steering of the bike by weighting inside or outside peg. As for the head shake, wonder if you are a little stiff on the bars, rather than a nice smooth easy input to bring the bike up. If the front is very light from hard acceleration, takes a light touch or it will shake as it's just skimming the surface. Don't take my word on this, do some experiments (less than max pace) and check if anything will bring the bike up, but using the bars (many think adding throttle will bring the bike up, but it doesn't).

 

Best,

C

[marcussoori]

"...check if anything will bring the bike up, but using the bars (many think adding throttle will bring the bike up, but it doesn't)."

 

 

So this means when I am cornering to the right and slowly rolling on the throttle, I need to turn the bars right more to stand the bike up again?

 

And does this mean that NOT rolling on the throttle while exiting a corner is okay too AS LONG AS I just turn the bars right more?

 

 

Thanks...

[racer]

And does this mean that NOT rolling on the throttle while exiting a corner is okay too AS LONG AS I just turn the bars right more?

No. Rolling on the throttle to keep a 60/40 weight balance front to rear stabilizes the bike, establishes and maintains your line (turn radius), and provides maximum traction. And the added advantage of lifting the bike to exit the turn is being able to add MORE throttle to go faster.

 

Not rolling on the throttle will see the bike run wide, reduce traction and destabilize the entire machine.

[Leftlaner]

Not rolling on the throttle will see the bike run wide, reduce traction and destabilize the entire machine.

 

What I've previously learned (read and heard) is this:

 

Once you're in a turn, leaning over:

- "Maintenance throttle" will keep the bike perfectly balanced. IE, you don't have to "fight" the handlebars to hold the current lean angle/turn radius.

- Rolling on the throttle will tend to stand the bike up.

- Rolling off the throttle will tend to "tip in" the bike.

- Applying rear brake will tend to "tip in" the bike even more.

- Applying front brake will tend to stand the bike up.

 

...

 

But from what I'm reading on the CSS forum and in TWIST2, this isn't entirely correct. I believe CSS and Keith Code teaches that:

 

- A slight acceleration, giving about a 60/40 (rear/front) weight distribution will keep the bike perfectly balanced and maintain the lean angle.

- Any FURTHER acceleration, will not affect the lean angle (but it might cause the rear wheel to slide --> risk of highsider)

- Any LESS acceleration OR braking (front or rear), will stand the bike up (and it might push the front wheel --> risk of lowsider)

 

..which leads to the conclusion that if you're worried about going wide, the LAST thing you want to do is to chop the throttle or get on the brakes.

If you still have some lean angle left, what you want to do is to keep that throttle steady and push the inner handlebar ever so gently and smoothly.

 

 

Can someone please verify this?