Tire pressure

scott s

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What's everyone's thoughts on tire pressure with modern tires?

My manual list 23 psi front and 28 psi rear, but that seems awful low to me. I've had a few shops tell me that those pressures were for old, bias ply tires. I've been told to run the Max PSI listed on the sidewall, but isn't that the MAX?

My Avons list a load at Max 42 PSI. I've been running about 32 psi front and a couple pounds more at the rear. Someone took a picture of the bike in motion recently and the rear seemed a little underinflated.
I'm about to head out for a ride and I just set both tires closer to 40 PSI.

With modern tires, what works for you? Maybe not the max PSI on the sidewall but more than the low PSI listed in the 30+ year old manuals?
 
You don't want to run the maximum number that's on the sidewall. That is just a safety rating, not for everyday riding. I use 31 psi, front and rear. If you have a passenger on the back , then maybe up the rear to 34 or 35 psi.
 
I intend to start at 32 and 35, which is where I run my SV. With the typical 16 inch rear, (67H rating) you should run a minimum of 32, or the side wall will flex excessively and generate lots of heat. If you are running a heavy duty 16 inch rear with a load rating index at 71H or above, run 36 as a minimum.
 
There are some good threads on tire pressure, do a search and check them out.
The tire manufactures web site has info on tire pressure for there tires and make of bikes, I know Dunlop does anyway.
Ive been running mine 29 rear and 24 front and have been happy with my Dunlop elite3's
http://www.dunlopmotorcycle.com/info-center/care-and-maintenance/
They say: rear 32psi, front 30psi at max load
I try and check mine every 2 weeks
 
I like about 32 front, 36 rear in today's modern tires. If you'd rather follow the 30+ year old specs in your owner's manual (that pertained to the 30+ year old tires of that time), be my guest, lol.
 
I'd rather not...that's why I asked and that's why I said I was running similar pressures as to what you recommend.
I tried 40-ish today and the bike seemed skittish and a little greasy on the road. I think I'll go back to mid 30's.
 
I'm no tire expert, but personally I feel that around 31 psi, my tires have more grip on the road. As you go up to mid 30's you're running more on the very centre of the tire, and perhaps a little less rubber actually meets the road.

Just my seat of the pants logic:shrug:
 
I'm no tire expert, but personally I feel that around 31 psi, my tires have more grip on the road. As you go up to mid 30's you're running more on the very centre of the tire, and perhaps a little less rubber actually meets the road.

Just my seat of the pants logic:shrug:

Some of us squish the tires down more than others too!:laugh:

Think about your combined weight as well. There's no magic formula that works with every bike, rider, tire, and pressure, so some experimentation is generally the best route, but understand that no tire is constructed to run properly at less than 85% or so of max inflation pressure. It's simply impossible to develop optimum characteristics acoross that broad of a range of pressures and loadings. ALWAYS proceed with caution when trying different pressures.:thumbsup:
 
Yes there is a magic formula for tire pressure. It works with tires on bikes, cars, trucks what ever.
Set your pressure at what ever you feel is right. Go for a ride. up at road speeds for at least 15 minutes. This gets the tires warmed up good. Now pull over and check the pressure. It should go up 10% from cold to hot. If it goes up more then the cold pressure to low. To low allows to much sidewall flex and too much heat build up. If It doesn't go up the 10% then the cold pressure is too high. This won't allow enough sidewall flex.
The tires need the proper sidewall flex to properly handle the loads of straight line riding as well as cornering.
On my 75 I have the Bridgestone Spit Fire II's 130/90-16 on the rear and a 100/90-19 up front. to get the 10% I run 28 rear 23 front.
On the 81 with the same sizes but Pirelli Mt route 66 tires I run 30 rear and 25 front.
On the Harley I run Dunlop D401's Rear is a 150/80-16, front is 100/90-19. The book calls for 35 rear 30 up front, to get the 10% that's what I run.
This works with what ever load you carry. In 30 degree weather or 100 degree weather.
On my Van I to get the 10% I found the pressures listed on the door frame is right.
You need to test for your self. One set of tires may need more pressure than another.
Been using this method for years. Once found I write it down so I don't forget. On the bikes I use a Sharpie and write it right on the wheel next to the valve stem.
Leo
 
Yes there is a magic formula for tire pressure. It works with tires on bikes, cars, trucks what ever.
Set your pressure at what ever you feel is right. Go for a ride. up at road speeds for at least 15 minutes. This gets the tires warmed up good. Now pull over and check the pressure. It should go up 10% from cold to hot. If it goes up more then the cold pressure to low. To low allows to much sidewall flex and too much heat build up. If It doesn't go up the 10% then the cold pressure is too high. This won't allow enough sidewall flex.
The tires need the proper sidewall flex to properly handle the loads of straight line riding as well as cornering.
On my 75 I have the Bridgestone Spit Fire II's 130/90-16 on the rear and a 100/90-19 up front. to get the 10% I run 28 rear 23 front.
On the 81 with the same sizes but Pirelli Mt route 66 tires I run 30 rear and 25 front.
On the Harley I run Dunlop D401's Rear is a 150/80-16, front is 100/90-19. The book calls for 35 rear 30 up front, to get the 10% that's what I run.
This works with what ever load you carry. In 30 degree weather or 100 degree weather.
On my Van I to get the 10% I found the pressures listed on the door frame is right.
You need to test for your self. One set of tires may need more pressure than another.
Been using this method for years. Once found I write it down so I don't forget. On the bikes I use a Sharpie and write it right on the wheel next to the valve stem.
Leo

Source of your method?
 
I learned so long ago I can't recall the old guys name. If you doubt this works, try it. You can feel the difference between a tire with the right pressure and tires off a few lbs. When I had just the Harley on the road and using it as my main means of transport I could tell just by how the bike handled if the tires were only about 2 lbs low. Now with 4 bikes I don't ride each one enough to get that fine a feel.
Leo
 
I found that if I run my fronts too low, they're more prone to cupping.
 
I learned so long ago I can't recall the old guys name. If you doubt this works, try it. You can feel the difference between a tire with the right pressure and tires off a few lbs. When I had just the Harley on the road and using it as my main means of transport I could tell just by how the bike handled if the tires were only about 2 lbs low. Now with 4 bikes I don't ride each one enough to get that fine a feel.
Leo
We do the same thing racing... 10% is the magic #, and trust me--you definitely don't want to overheat a tire on a track. :)
 
Interesting - haven't come across this idea before but will give it a try.
 
I have a 75 with tubes running 24lbs front 26 lbs rear
Any idea if the tubes would need to be taken into consideration?
The tires say tubeless on the sidewalls since they are modern tires
 
I have a 75 with tubes running 24lbs front 26 lbs rear
Any idea if the tubes would need to be taken into consideration?
The tires say tubeless on the sidewalls since they are modern tires
We run with tubes in our tires as well...so the calculation is the same.
 
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