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dony

Tire Pressure

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dony
I recently picked up my bike and have about 300 km on it. I read through the manual and decided to check the tire pressure. my bike has the Michelin tires on it. The rear is at 42 psi and the front at 36. This seems a little high compared to the manual specs. I am assuming the dealership checked them prior to me picking it up. It does say max psi 42 on the tires. Any one have any advice ?

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grahamfz07
Ive got mine at the pressures shown on the sticker on the bike frame, i believe its 36/33 r/f when cold. Michelins too. 42 might be a touch hi if your measuring when tires are cold

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dony
Ya I thought that was high too. I think I will call the dealer to see why the pressure was so high, I don't want to cause any wear problems.

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bmwpowere36m3
Ya I thought that was high too. I think I will call the dealer to see why the pressure was so high, I don't want to cause any wear problems.
 
 
Because they didn't check it or just set it wherever or your tire pressure gauge differs from there's (i.e., "error").
 
Just set it to factory recommendations...

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aeisan
Or the newb mechanic at the shop just read the max pressure off the tire and set it to that. Dealerships have some of the worst mechanics ever known to man.
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yamahaha
Or the newb mechanic at the shop just read the max pressure off the tire and set it to that. Dealerships have some of the worst mechanics ever known to man.
Not so much bad mechanics. They hire kids part time to do the mundane tasks like changing oil, adjusting chains, and checking tire pressure. Cheap help. 
I don't mind running a couple pounds over in the hot weather with lots of highway riding. Tires will run cooler with a little extra pressure. But then I'm heavier, a lighter rider should stick to factory pressure.
 
Low pressure is bad. Tires will generate a lot of heat and can reach formidable temperatures depending on load and ambient temperatures.
 
Ever see those pieces of truck tire on the highway? Low air pressure coupled with an aging tire = blowout. Dragging brake will do the same.
 
If you ever catch up to a heavy rig on the highway and smell hot brake, burning rubber, or see smoke; stay way behind or stop for awhile. If a tire blows out on the drivers side while you are passing, you are dead meat. The concussion alone can kill without the tire shards.
 

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mjh937
I once heard a bus tire blow as aa result of a dragging brake. I thought a bomb had gone off. It was surprisingly loud.

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dony
I checked the check list they gave me at pick up and they had checked of that they checked and adjusted the pressure, lol.  I set it today to manual specs, rear 36, front 33.

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wickedtwister
Heat kills tires. If you set pressures at factory spec you will be fine. It was probably higher because it was set in colder month and now that it's warmer the pressure goes up. When setting tire pressure always set it on a cold tire that has been in the shade preferably. Most tires will gain about .7psi per every 10 degrees of internal tire temperature. NEVER ever bleed pressure off of a hot tire without checking the cold pressure before you ride it again.
 
If you set pressure above factory specs and below the max listed on the side of the tire you will be fine. I found that the pilot power 3's that I put on my bike like 36 psi cold f/r the best. Also when I got them mounted I asked the lady mounting them to put 42 psi in them and when I checked with my calibrated race guage it was only 35psi on both so that is how far off cheap gauges can be.
 
I had a nail in my pilot road 3 tire. I was about 75 miles from the closest gas station when I noticed it was low. When I got the the gas station I checked pressure and it was 7 psi. I filled it up and headed home slowly because at that pressure internal tire damage occurs. I took the old rear tire to work and cut it apart because that's what I do and noticed damage to the carcass from the heat generated from the low pressure. So if you ever get a nail and can't say for sure how long it's been at low pressure get your rear tire replaced. The 150 bucks is far cheaper than what happens when you have a failure on the road...
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NICKY NEON
someone from another forum that has this bike races it at a track and told me to take 2 psi f/b so ive been riding with 34 psi rear and 31 psi in the front.
claims you will get better traction in cornering.

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wickedtwister
Cold pressures or hot? If cold I bet he's dropping to compensate for the gain due to temperature. In my road race camaro I start with pressures cold about 24 and when I come off the track there are about 38. I highly doubt you will be pushing you tires on the street as hard as the poster on the other forum is on track. If they do track days I'd be imagine they have softer compound tires as well. If you reduce pressure you also reduce the load carrying capabilities and high speed limit capabilities of the tire. It can also affect wear life as well.
 
I design automotive race tires for a living and we have to anticipate what people are going to do with loads and pressures on tires. You would be surprised how truly stupid some people get with pressures for just a few tenths of a second faster in lap time. 80% of the time they go the wrong direction.
 
When Yamaha tested the tires for this bike I'd be willing to bet they did a test at that defined pressure on the swingarm and at the max load rating of the bike at wide open throttle for as long as a tank of gas will last. When you reduce pressure from the placard you sort of enter a world of unknown. Just something to keep in mind.
 

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bmwpowere36m3
Cold pressures or hot? If cold I bet he's dropping to compensate for the gain due to temperature. In my road race camaro I start with pressures cold about 24 and when I come off the track there are about 38. I highly doubt you will be pushing you tires on the street as hard as the poster on the other forum is on track. If they do track days I'd be imagine they have softer compound tires as well. If you reduce pressure you also reduce the load carrying capabilities and high speed limit capabilities of the tire. It can also affect wear life as well.  
I design automotive race tires for a living and we have to anticipate what people are going to do with loads and pressures on tires. You would be surprised how truly stupid some people get with pressures for just a few tenths of a second faster in lap time. 80% of the time they go the wrong direction.
 
When Yamaha tested the tires for this bike I'd be willing to bet they did a test at that defined pressure on the swingarm and at the max load rating of the bike at wide open throttle for as long as a tank of gas will last. When you reduce pressure from the placard you sort of enter a world of unknown. Just something to keep in mind.

+1
However I bet the OE doesn't only look at performance/grip, they have to consider things like people loading the bike to the MAX, extended high-speed runs and tire life.  What I find interesting is the tire pressure for "normal" and max load are the same on the FZ-07.  Most vehicles I've seen, have various pressure recommendations depending on load and speed.
As far as running lower pressures... you'd need to look at the tire for wear patterns, i.e., rippling, cupping, tearing, abnormal wear at crown or edges, HOT pressures, surface temps, lap time, etc....  Beyond the scope of what most street riders need or will do.
I remember in my track days with my BMW I would lower the cold pressure or adjust the HOT pressure right off the track.  However you were putting much more load/heat into the tires and thus the higher pressure increase needed to be adjusted for optimal performance.
 

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rick
running lower pressures on the track is fine and will likely give better traction - but there are no potholes on racetracks to ruin rims. So do this on the road with caution. If you are carrying some hefty weight, considering the crappy suspension's inability to soak up hard edges, you are putting those wheels (and your hide) in harm's way in the mean streets.
 
 

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howworkclutch
Ya I thought that was high too. I think I will call the dealer to see why the pressure was so high, I don't want to cause any wear problems.
techs run the tire pressure up after install to help seat the bead.  usually they let it sit for a few minutes and let the excess pressure off.
 
i run a lot of pressure on the bridgestones. i like a hard tire.
 

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pattonme
I run 30 +/- 2 (front and rear). The street 'tards are 28/28-30. The SV650 32:30 (34R if heavy luggage). The 'prillers 32/30-32.
 
I'm 250lb light and girth-enhanced. Or something.
 
 

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