I'm hoping someone here might have some suggestions. While riding hard Sunday, I noticed that as the day wore on, the back tire seemed to hook up less and less. When I would get on it hard in lower gears the back tire felt like it was spinning, and when downshifting to come to a stop it was slipping as well.
I checked the tire pressure, it is about 30. The tire itself is a pretty new Michelin Pilot Power. The temperature was about 70 outside so I don't think it was because of cold roads.
With the vast amount of knowledge on this board I know someone here will have an answer.

 

Bit odd. Before starting of the cold tyre presures should be 36PSI in the front and 42PSI, without pilion, in the rear for the CBR1000F models. Haven't got a slow leak damaged rim or faulty valve? Picked up a nail maybe, perish the thought.

 

If there is nothing physically wrong with the tire itself then stiffen up the front preload a bit more. As you get more comfortable with a set-up your suspension needs to be spot on to keep you from sliding around. You could soften up the rear a smidge just be careful -- don't want to wallow around the corners.

 

Oh almost forgot -- the title of this thread damn near kept me from opening it If I wasn't paid the big bucks to read all this stuff I'd have left you to your own devices. Slippery rear end just sounds like a personal problem [8D]

 

Twice I've gotten flats and both times a nail in the rear. Mine rides best with 40 psi in the rear.

 

Sounds a bit like a swing arm or wheel bearing; put the bike up on the center stand and check for side to side movement

 

30 PSI is way to low for pilot powers. 42 psi is the best.

Use a proper guage. Don't use the guage that is at the servo and don't use one of those cheap $10 guages.

Make sure your tyres are COLD when checking. I do a lot of high speed country riding and I can feel the difference with little amounts of pressure. At low pressure your tyre will be going through this grip-flex-let go-flex-grip cycle that at high speed will tend to feel like its sliding.

The tread pattern on the Pilot Powers is great for normal roads, but it can become quickly overwhelmed when encountering a lot of loose crap on the surface, or very uneven surface or wet surface. But they stick like **** to a blanket on the good blacktop.

 

Is it possible something was leaking from the overflow tubes under the bike and putting some fluid on the road where your tire contacts that road? antifreeze, water from battery, etc..

 

For constant high speed I'll agree with the 42psi in the rear but not for handling in the twisties. Maybe 35psi max (cold) for street twisties and 28-32 for the track. Reason is the tire will hold more heat and grip better. Too much extended high speed stuff can cause it to over heat but the occasional blast up throught the gears is o.k.

 

Paul-right on the money. My last ride left me feeling like the tail end of the bike was really loose. I stopped to check for fluid leaks and air pressure twice-both were OK. No evidence of coolant/oil and pressure was OK. When I got home, the bike was puking coolant out of the overflow ever so slightly. I suspect it was getting on the rear tire and causing the loose feeling, but being burned/dried off by the time I could check for it. It was also at night so I could easily have missed something. Another possible problem could be in the steering head bearings. It might be worth it to double check that they are snug, but not tight enough to bind. While it's up there, make sure that there is no pitting/indexing when you rotate the bars.

Then put some Metzelers on and have a great ride! (shameless plug for my favorite tires)