Riding over gravel roads and tire pressure.

[chrisz]

Hi,

 

On my commute to work, there are sections of road that are bordered by gravel shoulders. Many times at intersections, the trucks turning left run over the gravel sections and carry some sand and gravel onto the road.

 

On several occasions I've had the rear tire side-step at the intersection when making a left or right turn. Then I wandered if reducing my tire pressure would help the tire bite. My RT is typically set up for two up riding, as it's used that way (on the weekends for example), but during the work commute I don't adjust the pressure down. Two up pressures I use is 43 PSI rear and 36 PSI front.

 

Thanks,

 

 

[Mick Glass]

What pressure do you use riding alone?

[chrisz]

I don't adjust the pressure, just keep it at F36/R42. TIres are Dunlops.

[dirtrider]

Hi Chrisz

 

No doubt that lowering your tire pressures can help a bit on loose gravel. But I think you will find that to get any meaningful improvement you will have to get down in the 12-14 pound range. I don’t think you really want to do that on a street bike on street tires.

 

On my GS running 60/40 tires I can’t see much difference in the gravel between 36 psi and 25 pounds. When I get them down under 18 pounds I can start really feeling the improvement.

 

Remember you are riding on marbles that are on a hard surface so unless you lower the pressure enough to allow the stones to deform the tire and allow more rubber to flow around the stones and touch the pavement you are still on the same marbles on the same hard surface.

 

If you want to play with it just find a deserted hard surface road with similar stones on it then start lowering the tire pressures until you quit getting that popping and snapping you hear as the stones pop and shoot out from under the tires as the tire rolls over the stones. At that time you should start seeing an improvement on gravel. But keep in mind you are still riding on marbles that are on a hard surface.

 

On thing that has helped me immensely on gravel when turning or changing direction or acting stupid is to counter weigh the bike so my main body weight stays directly over the center of the tire contact patch. Sometimes I stand but most times I just go real loose on the seat and controls then roll the bike under me while weighting the outside foot peg. Kind of the opposite of correct cornering posture used while cornering at high speed on good smooth pavement.

 

[LDHack]

You're talking about gravel on blacktop. That's a blacktop road hazard. It obviously reduces traction when cornering. Items that reduce tire traction include gravel on blacktop, braking, acceleration, and cornering. Try to avoid doing more than one of those four things simultaneously, or do only two very gently – namely, turn slow using constant throttle while navigating a path through the least graveled section. More often than not, the condition you describe, you can ride straight through the hazard and initiate your turn late.

 

Reducing tire pressure is for significant travel on loose gravel at slower speeds, and it’s not always necessary on solid, higher speed gravel roads. Reduced tire pressure at highway speed on blacktop will increase tire temperature and probably will affect tire and cord wear.

 

[chrisz]

Thanks Guys, I thought as much, that any meaningful pressure reduction will not be possible on street tires/street bike. I tried practicing on nearby dirt roads and found that gravel (dirt) roads, weren't that bad to ride on, but blacktop with gravel is another matter.

 

Thanks again.

[Polo]

Learn to dance the

then apply the same principles to riding. Voila!