Good thread, a bunch of interesting views. I run my tires to what the book says.

 

In the old days, especially on choppers it was standard to run about 16-18 psi to compensate for no suspension. After shearing off the tube stems twice, I started running a minimum of 26 psi. Handling was still not real good and the wobbles and sliding on higher speed corners made me try 36-40 psi. Handling definetly improves and that is what I pump up on my present hard tail. The ride is not too much harsher and I feel a lot safer when I have entered a decreasing radius turn a little too hot.

 

This argument could go on forever because you are arguing about two different things. One is the ride you want and the other is the tire wear. Basically tire wear is best at higher pressures, but ride quality/comfort is better at lower pressures. Most bike manufacturers try for a compromise and probably ere on the low side for ride comfort. Most tire manufactures will give info on their website or customer service line.

Low pressures in tires leads to cupping and uneven wear and a tire that wears out quicker. The exception to all this might possibly be tires made specifically for a bike like the new dunlaps for the touring family.

So all that said run more pressure for length of wear; run lower pressures for ride comfort or just compromise for where you like it. I tend to run higher cause I can't tell the difference in ride.

Lastly it IS ok to run max sidewall pressure because this is a cold pressure and takes into account the increase in pressure as the tire/air/N2 heats up. If you have to ere always ere on the high side for safety. Low tire pressures cause excessive heat buildup (this is what happened to the failures in the SUV tires). Most people run too low of a pressure because they never check the tires. Air/N2 leaks out so you need to check your pressure.

Dunlap recently went to a bike rally and found the majority of tires were under inflated, again because most people do not regularly check their pressure. If you own a bike you should check the pressure AT LEAST once a week. I run 41 in the rear because that is the max rating on the new dunlap rear(owners manual says 40) and I run 38-40 in the front (owners manual says 36). Call you tire manufacturer they will give you good advice because different tires are designed to run at different pressures. I use to run Avons and I know from discussion with them they like higher pressures like 42/42.

 

Two under max sounds like a good compromise point (that's HD recommended in the rear on my bike.). Comparing HD recommended to max shows a 12% difference for the front tire on my bike (HD:36 Max:41) but only a 5% difference in the rear (HD:40 Max:42).

I'm told that Harley's recommendation in the manual is largely to attain a comfortable ride, perhaps at the expense of some tire wear. But I guess the difference between HD recommended and max is slight enough as to not make a very significant difference. Gotta wonder if Harley's recommended is based on two-up or single rider?

I'll probably settle in at some midpoint for the front such as 38-39 and go with 40 in the rear.

Good discussion.. thanks guys.

 

40'40..easy to remember

 

no matter how much I put in it wont grow to 21"

 

EXACTLY RIGHT, plus I doubt 2lbs +or- really matters

 

By the book on the standard Dunlops on the RKC. Add 2 lbs on the wifes scoot due to an article I read about Metzlers. (her replacements)

 

I run 40 f & r

 

I've always gone a little over the book and less then the MAX. On my Bonnie the pressure was recommended by the owner who is a respected wrench too. Bike manufactures are more worried about the ridding characteristics, too harsh, and not about optimum grip and tire wear.