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How can you tell when the bike is about to lose the front/rear? Or more in general something is wrong with your riding. I know, there are many variables, but I've read that tires and chassis are designed to give riders feedback. So how does this famous feedback manifest?

 

For example, I've learnt to read a Q3 cold tire using these indications:

 

- Accelerate to a speed above 30/40 mph (no feedback in the pit lane or low speed)

- Signal comes mostly from the rear tire, not the front

- Sit forward to avoid loading the rear tire for better feedback

- On a straight, feeling of slight sideways tire movements. It's very subtle, but definetely readable

- At approx 30/40 degrees lean angle the twitching is a bit more obvious

- Rear feels lighter than usual

 

Of course, this won't work for any bike/tire/track but I'll be happy to learn signs for any configuration you might have :)

So what are the specific indications you're about to lose the front and/or rear? I'll attempt one: as you push on the handle bar through the corner, you feel resistance coming back at you (again this can be very subtle but I did notice it a few times).

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Subtle "wagging" of the handlebars tells you that you're pretty close to the limit. In my case, the front tyre was worn out and needed replacement.

Mind you you need to be fairly light on the bars to pick it up.

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How can you tell when the bike is about to lose the front/rear? Or more in general something is wrong with your riding. I know, there are many variables, but I've read that tires and chassis are designed to give riders feedback. So how does this famous feedback manifest?

 

...

 

So what are the specific indications you're about to lose the front and/or rear? I'll attempt one: as you push on the handle bar through the corner, you feel resistance coming back at you (again this can be very subtle but I did notice it a few times).

 

 

The main thing I notice when approaching traction limits is that the BMW S1000rr starts flashing a yellow light at me. :)

 

On slicks, when they are very cold (no warmers), they feel stiff and I notice that the bike wants to "stand up" in the corners - it's a weird feeling, I turn the bike in and into a corner and it wants to stand back up and go wide. I am told that is because the tire carcass is not warmed up and doesn't deform the way it is designed to (normally) in the corners. Usually that stops within a half a lap or so. This may be the same thing you are describing above, when you say you feel resistance when countersteering the bike.

I also notice on cold tires that they don't feel planted in turns - lots of tiny little slides, it feels a little like riding on rain grooves on the freeway; probably the same "subtle wagging" of the handlebars that khp mentions above. The traction is greatly reduced on cold tires so you get to the traction limits at much slower speeds and gentler lean angles.

 

A great article to read about this overall topic (traction limits, not cold tires) is "The Bands of Traction" by Keith Code, it is in the Articles section of the forum, here is a link: http://forums.superbikeschool.com/index.php?showtopic=877

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I find the Q3's to get that feeling also. I call it squirmy and in MotoUSA's tire shootout, they mentioned the same thing. They also used the term flex but not necessarily in a bad way. My Q3 experience is only on the 650 though.

 

On the 636, it comes stock with S20's. I have yet to feel anything from them. Helps and hurts confidence? It has me a bit worried because someone who races mentioned they never feel anything from Bridgestones and they just let go. He is a Pirelli fan because he says he can feel what they are doing. Anyway, I have one more track day on the S20's and then have some rebated Q3's to throw on next so I can't wait to see if they feel like they did on the 650.

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  • 2 weeks later...

What about the chassis? What is chassis feedback, does it even exist?

 

Surely it exists, assome of the championship level riders notice it (e.g. Marc Marquez on the Honda 2015 chassis).

 

Personally, I have yet to notice a feedback that I could refer back to the chassis. But it just might be that I don't know how to identify feedback that comes from the chassis.

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I find much depends on the tire, its make and its condition. I've been low-sided by a worn front Bridgestone with no warning at all (except that I damn well knew it was worn, but decided to give it one last outing. How stupid was that?).

 

But a decent tire, properly warmed up, will squirm and wimper, twitch and wobble. Not much, but normally enuf ... I can't say for chassis respnse/feedback.

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Modern sport bikes are so composed, so technologically advanced, that the chassis does not do as much of the dramatic shaking, flexing, and twisting that older bikes used to do. Get on something old or not designed for the track and it will start talking to you. :)

 

IMO chassis feedback on modern bikes is subtle, I'm not sure I'd count on it for early warning that you are approaching the limit.

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