Wildguzzi.com
General Category => General Discussion => Topic started by: fotoguzzi on May 20, 2016, 10:00:19 AM
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My Dr came with not stock size street tires..
stock size is 90'90 21 and 120/90 17
manual says inflate to 22/25 psi
Tires on now are Shinko Tour Master..
80/90 21 and 130/90 17
on the tire it says inflate to 42psi (both tires)
so I should follow what it says on the tire right?
(https://photos.smugmug.com/DR-650/i-6szgvL7/0/M/IMG_1841-M.jpg) (https://fotoguzzi.smugmug.com/DR-650/i-6szgvL7/A)
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Isn't that a maximum PSI suggestion ?
Dusty
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I was going to say the same thing.. I think that's the Max pressure for that tire. I'd inflate to what the bike recommends.
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The only sure way I know of to find ideal tire pressure is to pick a starting point cold and look for a 4-6psi increase when warm. Too much increase means tire pressure is too low, (heat makes pressure) too little increase means pressure too high. Once you know these things you can adjust pressures while warm and then correlate a cold pressure. The pressures listed on a tire are recommended operating maximums, doesn't mean you can't go higher, but caution is advised. You can go much higher to attain bead seating, again caution advised. These are the things I learned from tire manufacturers and from crewing race bikes and cars. YMMV
Brian
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The only sure way I know of to find ideal tire pressure is to pick a starting point cold and look for a 4-6psi increase when warm. Too much increase means tire pressure is too low, (heat makes pressure) too little increase means pressure too high.
Brian
thanks I'll do some experimenting..
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22.. 25 is just fine if you are riding pavement , off road drop them 10 to 15% , i used to carry a pump on my DR 650 came in very handy to air up and down for Street and Trail ...
they are great motorcycles wish i still had mine
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The rating is for the tire, and not the tube.
If you're doing a lot of off road riding, I'd keep the pressure low. If you're street riding, I'd bump it up to 32 psi, and adjust from there. It sucks to try to ride over a huge log, and too much pressure causes your tube to burst.
Ken
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The tire sidewall number is rarely ever the correct spec to run a tire, unless you've actually gotten to or near the max load rating.
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I shoot for 10% from cold to hot. Works for me.
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I shoot for 10% from cold to hot. Works for me.
:1:
Dusty
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Tires are complex. The sidewall numbers are nothing but the most weight a tire can carry, at what pressure, for a given (DOT mandated) distance safely.
The pressure a tire works best for you, is the pressure at which the tire works best for you. If you're roadracing, tread rubber temperature is the most important data, but you have to know it (hard) and you have to know what temperature the rubber wants for best performance (impossible without manufacturer's input)
When I was racing H-D 883's, we ran our Metzelers (at Daytona, no less) at about 18psi front/13psi rear to get the rubber where it needed to be. It was a little scary but damn did it work.
For most all my vehicles, I let road feel and best rubber mileage be my guide. If you're actually off-roading, the least pressure that doesn't feel sloppy or threaten to come off the rim might work.
There is no right answer.
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I'm not off roading, street tires.. here's what I did today..after the front valve core got stuck in when checking pressure.. tire deflates as I put in a new core.. the first one had a bent stem from me I guess..
set both at 33psi. Ride to lake, 45 miles above 70mph.. check pressure and both tires are still at 33
(https://photos.smugmug.com/Guzzi/i-Kxt76ds/0/L/IMG_1905-L.jpg) (https://fotoguzzi.smugmug.com/Guzzi/i-Kxt76ds/A)
so I let a little out to 30.. but then the rear core sticks in.. I had spare cores along so I swap that out and fill it up..
no problem on the ride home with a stop at the Rocker Social..
(https://photos.smugmug.com/Guzzi/i-8Gtsx8D/0/L/IMG_1909-L.jpg) (https://fotoguzzi.smugmug.com/Guzzi/i-8Gtsx8D/A)
(https://photos.smugmug.com/Guzzi/i-HKDsxvg/0/L/IMG_1908-L.jpg) (https://fotoguzzi.smugmug.com/Guzzi/i-HKDsxvg/A)
(https://photos.smugmug.com/Guzzi/i-nJH4vtT/0/L/IMG_1915-L.jpg) (https://fotoguzzi.smugmug.com/Guzzi/i-nJH4vtT/A)
I've never had a problem with valve cores before.. are there good and bad types I should be aware of? note to self, check tire pressure only when near a compressor not on the road.
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I've got Shinkos on my EV and my R100 beemer. They're 731s on the R100 and 230s on my EV. The 230s beaded fully and easily on the EV. The 731s were a biotch to get fully seated on the R100's snowflakes. The front tires witness lines looked ok whe I finally popped the bead fully using damned near 100psig(kids don't this at home). Later after noticing a little wheel hop at around 35mph I measured radial runout of that front tire. Had about 1mm max runout.....yried reseating the bead again and again and again...I think Ive got it as far as it will go and runout down a bit.
did you have bead seating problems with your Stinkos?
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I've never had a problem with valve cores before.. are there good and bad types I should be aware of? note to self, check tire pressure only when near a compressor not on the road.
FYI, it looks like my tire gauge has a offset/bent push pin and that is probably what bent the stem in the valve core.. I need a new air gauge.