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Posted

I ride the same road (Ortega Hwy) every weekend. The last couple weeks, I've been getting the feeling that my front end is slipping a little bit and have had a couple of wide exits. My tires (Michelin Power Ones) seem to have sufficient tread front and rear and I am disciplined about checking the pressure. I tried letting a pound out of the front but the feeling is still there. I am having new tires installed (same type) because I have lost confidence in these. I discussed the feeling with a faster rider, who told me to wait just a little longer before I get back on the throttle. He explained that I need to keep the front end loaded up to the apex by staying off the throttle and, only upon reaching the apex, get back on the throttle. I've take Levels 1-3 and read TOFW more times than I can remember (honestly, I use it as the "gospel"). I must admit that I've been experimenting with "earlier" (and a little tighter) entry points that allow me to get on the throttle a little bit before the apex, where I used to go "deeper" and quick turn, which caused me to get back on the throttle about at the apex. Could I be unloading the front too soon? I haven't tried the new tires yet (must wait for the weekend). I'd appreciate anyone's thoughts on this. My faster friend's logic makes sense to me but I remember Keith saying "no one ever loses the front end by getting on the throttle" (admittedly an oversimplification of what Keith really means).

Posted

DC,

 

There are a few things here, so just to make sure: tempurature of that day and road. We have had some real differences in temp lately. I'm assuming the road didnt get dirty, but can happen too.

 

Next, with throttle you can adjust the weight/load front to rear, in extreme situations, one can loose the front from TOO much throttle, or could it even just make one go wide. Too little throttle can also cause one to run wide.

 

How about next time you take a run up there, you go a little below max pace, and just watch how you use the throttle, are you rolling it on and off very progressively?

 

CF

Posted

Does this happen at various speeds, or certain corners (particularly slower ones)? Slower corners can do that. As soon as you've made the turn, and you're going to make the apex, it should be perfectly fine to get back on the gas without difficulty unless you crack it too much, brake or sit up while in the corner, or make another steering adjustment after you get on the gas. If your tires are still in good shape, you're going to feel the same thing from the same type of tire. If you haven't done it yet, save your money for now.

Posted
Does this happen at various speeds, or certain corners (particularly slower ones)? Slower corners can do that. As soon as you've made the turn, and you're going to make the apex, it should be perfectly fine to get back on the gas without difficulty unless you crack it too much, brake or sit up while in the corner, or make another steering adjustment after you get on the gas. If your tires are still in good shape, you're going to feel the same thing from the same type of tire. If you haven't done it yet, save your money for now.

 

Just a comment on this - I think the Power Ones are dual-compound tires and two things to watch for - first, the edges may wear out before the middle, the outer compound is soft and I think they do have less grip after a lot of heat cycles, so I DO think changing your tires is a good thing to try. Second, on the Power Ones I kept getting the feeling of mild front tire slips in some places, and I finally came to the conclusion that I was feeling the transition from one compound to the other as I started standing up the bike. I would turn it in, and it felt fine, then I started to roll on the gas and it was OK, but after the apex when I started standing the bike up a little I'd get this weird feeling of little slips in the front. My best guess is that when I started getting the tire on the harder compound, it was either sliding a little or just felt really different. One day at the track I changed to the Dunlop Q2s and the problem instantly disappeared.

Posted
Just a comment on this - I think the Power Ones are dual-compound tires and two things to watch for - first, the edges may wear out before the middle, the outer compound is soft and I think they do have less grip after a lot of heat cycles, so I DO think changing your tires is a good thing to try. Second, on the Power Ones I kept getting the feeling of mild front tire slips in some places, and I finally came to the conclusion that I was feeling the transition from one compound to the other as I started standing up the bike. I would turn it in, and it felt fine, then I started to roll on the gas and it was OK, but after the apex when I started standing the bike up a little I'd get this weird feeling of little slips in the front. My best guess is that when I started getting the tire on the harder compound, it was either sliding a little or just felt really different. One day at the track I changed to the Dunlop Q2s and the problem instantly disappeared.

 

nice description Hottie, wonder if that's what was going on?

 

Would it be too crass to make a tire brand joke at this time?

Posted
I must admit that I've been experimenting with "earlier" (and a little tighter) entry points that allow me to get on the throttle a little bit before the apex, where I used to go "deeper" and quick turn, which caused me to get back on the throttle about at the apex.

 

This seems to be the culprit to me. Does turning in earlier make your exit tighter or wider?

Posted
He explained that I need to keep the front end loaded up to the apex by staying off the throttle and, only upon reaching the apex, get back on the throttle.

 

For public road riding, as you seem to be talking about... in my opinion based on 170,000+ miles of street riding experience, this is not a very good idea. I can't tell you the number of times I had big slips due to something slippery on the road that wasn't even visible. Gravel the same color and texture as the pavement is easy to miss at speed. Trucks spill their diesel fuel on roads all the time. If you are off throttle the front will step out big time in that circumstance. Slightly on throttle and both tires will slip less and equally and everything stays more stable and you are more likely to survive long enough to get back to better pavement, and it's less scary so less likely to induce that dangerous panic feeling.

 

It's just all around safer to get back to gently on throttle as soon as possible after turning in, and set up your entry speed and line through the turns to facilitate this. I realize that there are an infinite number of scenarios and turns out there and none of us can stick to this rule 100%, but to adopt the general habit of being off-throttle half way through the turn is generally a significant risk increase.

 

There are lots of turns on the track where I might go to the apex off-throttle but I try to avoid it on the street as much as possible.

 

Something else about any front tire, with some wear they will get flat spots in the profile at your common lean angle. When you are riding at the lean angle that is on the flat spot, the contact patch is wider, and the bike may have a tendency to want to stand up in the corners, then you lean a bit lower, off the flat spot, the contact patch gets narrower, and suddenly it wants to fall in. This feels very much like the front end is sliding. I experienced this many times with all kinds of different bikes and tires, always fixed with a new front tire. ALSO, you mentioned decreasing front tire pressure, also try increasing it a few pounds, as I've found this alleviates some of this flat spot issue if that is what's going on. Usually going up to 36 on front tires is acceptable.

Posted

I would like to hear from some of the instructors or the chief himself if this is an absolute or if there are several ways to Rome.

 

As mentioned, I prefer to sit on the front brake - naturally easing off as I lean more - because I'm very comfortable with this. I also find it easier to catch a sliding front that a sliding rear. Perhaps this is from years of riding through winters, through deep snow and on black ice, any winter condition you can think off. Always used regular "summer" tyres, always kept me feet on the footpegs and have always relied on the front brake.

 

I still regularly lock up the front on purpose (in a straight line) in both dry and wet conditions just to retain the feel for it. The only bike on which that was a bit interesting, was the Intruder 1400 I once had, where locking the front at 60 mph had the handlebars/front wheel turning instantly and the bike was quickly going over on its side, requiring a quick release of the brake to prevent a crash. But most street bikes will allow a momentarily locked front tyre without any drama whatsoever.

 

I have also many times had the front end slide out around hairpins after dragging hard parts (old style bikes, not speaking race reps here by any definition of the word) and a quick stab with the inner leg will instantly kick the bike back on track. I wouldn't recommend this at high speeds, but I think my foot would still slip off the peg by instinct - only to break on impact, most likely.

 

Again, it would be interesting to learn if this is by definition the wrong way (to rely on the front) of if it's just a different way.

Posted

If one end is going to slide, I'd prefer the rear. The reasons Harnois gves above are all solid, and go with what Keith has written in Twist 2, and match the machine requirements. Typically the front slides from too much load, and the only way to change that effectively is with the throttle.

 

Check out the chapters in Twist 2 on Throttle Control, he'll explain it better than we can (with drawings too), or the new DVD is great too.

 

Rear tire is bigger than the front is another issue--if it doesn't get it's proper share of the load, the best tracion possible is not being attained.

 

Make sense?

 

One last point on tire pressure: when we went up to 33 on the Dunlop Qualifiers, they slid earlier/easier than when we got them in their more ideal range, 30 front, 28 rear. I think the Q2 might be a little lower than that in the rear.

 

Best,

CF

Posted
One day at the track I changed to the Dunlop Q2s and the problem instantly disappeared.

 

They're a multi-compound also. I never thought of the multi-compound being an issue with traction. I'm dying to get some Q2's on my bike though.

Posted

Thanks everyone for the technical wisdom. The new front tire cured the problem. I usually change the front with the second rear. This is the first time I've gone through the complete cycle with the Power Ones (2 rears + 1 front). I suspect the heat cycles on the softer rubber may be the root cause. I stretched the front out to almost 6 months (4 track days + weekends) and I think they started to get a little slippery. Not as bad as Pierreli, so I've given the Power Ones another shot. I've been waiting for someone to weigh in on the new Q2. Glad to hear some positive words. May go with Q2s next cycle.

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