Strange issue with Pirelli recommended tires and pressure

[beRto]

I was checking out the Pirelli website (see link below) to find the manufacturer's recommended tire pressure for the new set of Sport Demons I installed for this season. The website gave the following info for a 1995 GS500:

SPORT DEMON

Front   
100/90 - 19 M/C 57V TL SPORT DEMON Front - 1.9 BAR (28 psi)

Rear
120/90 - 18 M/C 65V TL SPORT DEMON - 2.3 BAR (34 psi)

note: psi conversion values added for convenience

Why are the recommended sizes so far off of the manufacturer's specifications? In particular, how can they specify 19" and 18" tire sizes?! 

Also, the pressure values seem low to me. Although I don't trust them much because the tire sizes are so strange.

Do you guys get the same specs if you look up your bikes?

http://www.pirellityre.com/web/fitment/selectSearchTyresForm.do?mySelectActived=confirm&myEntryPoint=%2Ffitment%2FhomeMotoFull&brandVehicle=4623&modelVehicle=103732&versionVehicle=202421&consent=Y

[ben2go]

Yea their specs are off.Sounds like specs for a GS550E.You can't fit an 18 or 19 inch tire on a 17 inch wheel.Stock sizes for GS500 are 110-70-17 and 130-70-17 and PSI is 33F/36R solo.When I buy tires I look at size and rating.I don't look up a specific bike,but I don't run stock size tires either.

[gsJack]

That's Pirelli homesite, go to US site and check:

http://www.us.pirelli.com/web/motorcycle/default.page

click on GS500 E,EU 1989-2000 and the GM 51 model will come up.  We have GM51 models here, look at your serial number on title/registration.

Front  Rear
110/70 - 17 M/C 54H TL SPORT DEMON Front - 2.25 BAR 130/70 - 17 M/C 62H TL SPORT DEMON - 2.8 BAR

My paper copies I pick up at CW bike show have right data also.

32 psi front   36 psi rear

[gsJack]

I've run into that before at Avon site, they show a 84-88 GS500 with the 19" front and 18" rear wheels.  I'm not sure what they are exactly.

[beRto]

Thanks to all for the clarifications

Front  Rear
110/70 - 17 M/C 54H TL SPORT DEMON Front - 2.25 BAR 130/70 - 17 M/C 62H TL SPORT DEMON - 2.8 BAR

My paper copies I pick up at CW bike show have right data also.

32 psi front   36 psi rear

Hi gsjack, I get 2.25 bar = 32.6 ~ 33 psi and 2.8 bar = 40.6 ~ 41 psi

Is 36 psi from the paper specs you have?

[gsJack]

Yes, the 32/36 psi is from the paper copy and is about same as my 97 GS500E Owner's Manual which shows 33/36 for solo riding and 33/41 for two-up riding.  My 02 GS shows the same on label on bike.

I use this chart from Metzeler for general reference and it's about the same also:

[Jay_wolf]

THis is a question about my Little town run able , The 70cc

i have 140/50 on the front and rear , due to the 14 inch rims , There Pirelli Demons

Now i check my tire pressiure the other day on the rear , and i got 11 psi , i was shocked !!

I ussually run 36 rear , and 28 front , due to the bike weighing 15 stone and me being nearly 14 stone

Could i safely run it even further?

Thanks Day

[pbureau69]

I have Avon Azarro ST AV45/AV46 and I run as per Suzuki, 33 front 36 rear when alone 33 front 41 rear when 2-up.
never had an issue.

cheers.

[Jay_wolf]

Right im checking my tired and losing around 10 psi a day , is it a slow punchure , theres not leaks as i can tell

[pbureau69]

Right im checking my tired and losing around 10 psi a day , is it a slow punchure , theres not leaks as i can tell

if you had a puncture you probably would see it, I bet its a bead edge leak, I would get the tire pulled from bike, dipped in water I bets it leaking from the rim edge with tire.

if that is the case re-seat the tire bead again.

I would not ride on a slow-leaking tire, 10lbs a day is not a slow leak,  1lbs a day is a slow leak, 10lbs a day is 1/3 of pressure, forget to check one day, and you place yourself in a possible situation where the poorly pressured tire can cause an accident, I know I am preaching to the choir, but I would get that fixed asap.

Cheers Mate

[Jay_wolf]

No, Thank you very much , thats exactly what i thought it would have been . once i saw no puncture ,

Thanks for worry bout me to , 


Cheers Buddy