Wobble at speed related to tire pressure?

[coolhandgarreth]

On the interstate today, my handlebars would start to wobble just past 85 going into 90mph. Before my return trip, I let some air out of the front tire. Seemed to help some. I was running just over 40 psi in both tires based on the max tire pressure indicated on the sidewall (42). If I'm running too much pressure, what would be the recommendation? If it isn't a pressure related issue, what else would cause that wobble?

 

[konarider94]

should be running 36 front and 38 rear while cold. some people prefer to run a little less but that is a good starting point. other things that can cause wobbles are bad head bearings or wheel bearings. also if your suspension isnt setup properly. if one fork is adjusted differently than the other. check out the page below for some suspension settings.

http://steveturnbull.co.uk/buell/thexbpages/xbhandling.htm

 

[G Diablo]

you should never put the tire pressure based on what it says on the tire. go by what the manufacturer of the bike says to put in. same goes for cars and trucks. you might need to check your suspension as kona said. believe me, the last thing you want to be doing is tank slapping at 90 mph.

 

[coolhandgarreth]

Great info, thanks a load! I had come across that settings page but then couldn't find it. Perfect. Wouldn't have guessed that suspension could have that effect, at least not in a straight line.

 

[GOduc]

The psi on the sidewall of the tire is the maximum it can hold safely. You never use that as an indicator. Check owners manual or call manufacturer of the tire and they can tell you what's recommended for their tire on your bike on the street, track, etc.

But always 30/32. Can be a good place to start.

 

[apriliaryan]

Also dont check em hot/warm. Youd be amazed how much pressure rises with heat. Id make sure nothing is loose that might be catching air like a sail.