Help lurker with air pressures
 

Hey guys an ex lurker needs help, I run Dunlop 208ZR's, 120/70/17 and 180/55/17, I run the standard air pressure in the front, and the standard in the rear which is 42, but when the rear gets up to temp, it feels squiggly and slippery, I tried adjusting the rebound, which helped some but not alot, I think im running to high of an air pressure in the rear, what do you guys run. Oh yeah on a side note I really get the tires pretty hot, in fact my tires are pretty much melted on the side's anyone have an idea what pressures I should try. sorry about length

Re: Help lurker with air pressures
 

I don't run dunlops anymore but IIRC 42 is max. This keeps the tire cooler thus lasting longer. For better traction/feedback, run a lower psi although it sounds like your tires are "cooked" all ready.

Is the ZR a track compound? If so, you don't get many heat cycles out of these kinds of tires before they "go off" and don't feel as good.

Honda Manual calls for 36 front & 42 rear. This is quite a bit more than other bikes call for, but Dunlops website makes the same recommendation. Most sources I've seen recommend 30 - 32 PSI for trackdays, so I think it's unlikely that your tires are overheating. Heat is created by carcass flex & more heat in the tires helps them work (stick) better...up to a point.
Metzeler's website calls for 32 front & 36 rear on the Super Hawk.
I think with your agressive riding style that the standard pressures are too high for you, so you're getting too small a contact patch. Try the Metzeler recommendation & see what you think.
Also, I read somewhere this year (I think it was WEBBIKEWORLD.com) that the optimal pressure for the track could be determined based on the differential between cold & hot tire pressures. The idea was to achieve a 10% differential on the front & a 20% differential on the rear.
See attached chart that I made up. Note: I haven't had time to check this out, so it's not gospel as far as I'm concerned.

Check cold pressure, then run bike under expected operating speed & conditions. Check hot pressures. Hot pressure should vary 10% on front & 20% on the rear for optimum use.

First column is Cold Pressure, second one is Plus 10% (front) and third column is Plus 20% (rear).

Cold
Pressure Plus 10% Plus 20%
28 31 34
30 33 36
31 34 37
32 35 38
33 36 40
34 37 41
35 39 42
36 40 43
37 41 44
38 42 46
39 43 47
40 44 48
41 45 49
42 46 50

Any one else, such as racers, have some knowledge about this?

The dunlop ZR's are a street tire. THe GP's & GP A's are the track tires.
I use the 208's on the street and run the rear at 36psi, the front at 32psi.
If you fill them to 42 they do get a slippery feeling to them, but will extend the mileage you get from them.

I've been running Dunlop 208 GP-As on the street and track. I run them on the street so that I'm not always changing tires for track days and I only have one set of wheels.
I always run 28-29 psi rear and 30 front. Probably too low for the street, since I never really cook the tires street riding. But I like the way it feels on the street, even cold. On the track I roll big gumballs off the edges and it's like riding rails.