Tire pressure

[Bohn Frazer]

Tire Pressure

I actually run 41 psi in the rear and 39 psi in the front. That is what the guy who has a motorcycle tire shop here in KC told me he recommended. He is about my age and has a store here in KC called Cyclops. He has seen it all when it comes to motorcycle tires and he told me that the tires that came on our old 11's are about as close to modern tires as a model T is to a modern car. That is what I run and have had no problems. Bob Jones used to tell me he ran 40 front and rear. Of course he had and I have fully dressed bikes and with a passenger are at probably 1100 lbs total weight and I run 75 - 80 mph across the great basin each year in 100 degree temperatures. I agree with Tod, it has to be based on your own experience and what works for you. I put 12 - 15,000 miles on my bike per year and go through a couple of tires in some years. Bob always preached that the best tire you could afford is your best and cheapest insurance. One thing to remember is that under normal circumstances, a tire will lose 1/2 psi per month so you should check your tire pressures frequently. I set my pressures before every trip.

[Bigfoot]

I run 40 psi front and rear as well. Never had an issue and have a great handling ride in the twisties. I have 14 psi in the front forks and 23 psi in my rear shocks, both set on the third setting. Comfortable enough on the freeway, great in the twisties.

[Elevener]

Yes, the 80G should have air caps. If you have the 3 position screwdriver adjustable caps, then someone put the 78-79 Standard forks on there.

I have been wondering about this. Mine has hex heads with about a 5/16 round base on them. No adjustment or air.

And Im going to try the 40 psi in tires.

[trbig]

I also run the 40 psi in my tires. At this last rally, I was talking with Bohn Frazer, and he talks with guys that go hundreds of thousands of miles on bikes. He was saying that most of them have told him that they get the longest wear and best gas mileage when the tires are run at their max. Actually they recommend to him to run 41 psi.. just OVER max. I sure can't argue with that much experience talking. Not only do I get a better firmer feel in the twisties, but I get really good longevity out of the tires.. when I stay away from those Arkansas roads for a while. I run @ 20psi in the front shocks, 40 in the back (XJ has air shocks) and dampeners on both set at #4. Anyone seeing my bike in the twisties can't argue too much with my setup.

You can read me all the manufacturers "recommendations" you want or numbers out of a manual. That doesn't mean s*it in my book compared to what my azz tells me and what I can see with my eyes in the real world. I also run my vehicle tires at the max. For some reason, they last a long time and wear out evenly across the tread?? It bumps the gas mileage up there also. But.. I also drive pretty aggressively and want a firmer tire.

The point is... try different things and learn from personal experiences.. not what a manual or Joe Blow says. If you like the way your bike handles with the recommended pressures.. by all means use that. If you prefer a nice squishy smooth Cadilac setup.. run less. If you like a firm reactive bike.. try more. It's a personal choice. If there was a perfect setup.. then why does everyone at Nascar not have the same settings on the car and use the same tire pressure? Surely someone is recommending a proper tire pressure to them. Or.. could they be going by what FEELS best to them?


Tod

[bikerphil]

That brings up another question. Shouldnt my 80 have air up front? It doesnt.

Yes, the 80G should have air caps. If you have the 3 position screwdriver adjustable caps, then someone put the 78-79 Standard forks on there.

[Montreux_Blue]

I have come to find that the 40 psi front and rear tire plus about 15 psi in the forks and hard rear shocks make for a great bike for the twisties. Not the greatest setup for long distance traveling but I do it.

Not a misconception but a trial and error evaluation over the time I have had the bike that works for me, obviously it may not work for everyone. And out of all my 5 vehicles I have, not including my wifes 2 cars, this is the only one that I run like that. It just handles the best for me at that setup.

[cywelchjr]

Proper pressure for a tire on a vehicle is NOT based on the max pressure for the tire, but rather on the proper pressure for the load. Yes, a tire with a higher max pressure may want a bit higher pressure, but it has be be calculated based on the max load @ max pressure and then you figure out your load and lower the pressure by the same percentage of max pressure vs max load. The idea is to maintain proper profile of the tire when under load, and that is seldom achieved at max pressure (if you need max pressure for the tire to handle your load you need a tire with a higher load rating).

This is one of the most common misconceptions about tires, to think that you should run max pressure in them, this just is not and never has been true. Having actually had a NEW car or two, the recommended pressure is never the max pressure for the tire.

[Montreux_Blue]

All I know C-bug is I can smoke just about any XS11 in the straight and keep up with the craziest in the twisties. Besides, the tire gives you the max pressure on the side of it....... if you read it....... instead of a 30+ year old manual basing pressures off of 30+ year old tires.......... we are in 2009 now.

[CatatonicBug]

40 psi??? Isn't that a bit much??

The manual says 26-28psi in the front and 28-36psi in the rear, depending on load. For a rider, alone, under 198lbs, 26 psi in the front and 28 in the rear is the suggested pressure, with 12-14psi in the forks.

This is all on page 19-21 in the OEM manual, BTW.

[Elevener]

That brings up another question. Shouldnt my 80 have air up front? It doesnt.

And what are dampners set at? For performance and handling. Oops that was two questions.

[Montreux_Blue]

Well............. I have come to find that the 40 psi front and rear tire plus about 15 psi in the forks and hard rear shocks make for a great bike for the twisties. Not the greatest setup for long distance traveling but I do it.

[Elevener]

What is everyone running in their non dressed bikes? Im more interested in handling than long life. And maybe Im oblivious but what is the 'feel' of under-over inflated tires?

Of course I know the feel of a grossly underinflation.