[mag]

imported post

78 Gl1000. Both tires say max 41psi. What should it be at? The bike is naked, no luggage/fairing. Mostly riding solo. The front was at 36 and the back was at 28psi! Maybe this is why mileage suffered? Both are at 36-37 now.

 

[Goldwinger1984]

imported post

Hi Mag, it all depends on which tires you have on your bike.

Vic

 

[mag]

imported post

VIc,

Front: Bridgestone Spitfire -----100/90/19
Rear: Durotour IRC RS-310R ---130/90/17

 

[exavid]

imported post

That's an eclectic selection!:waving:

 

[Goldwinger1984]

imported post

Your front tire should be inflated to 38-40 psi. I can't find any listing for your rear tire, but, if you had the stock 120/90/17 it would require 40-42 psi.A Metzeler 130/90/17 for your bike requires 46 psi for proper inflation so I'm not really sure on what to advise you because I'm not familier with a Durotour tire at all.

Try contacting the rear tire's manufacturer to give you specifics on that particular tire on your bike and ask them if the front tire is compatible with the rear tire just to be on the safe side.

Vic

 

[axelwik]

imported post

Don't ever go by the tire manuracturer's rating for max tire pressure...the tire pressure printed on the sidewall is the maximum rating for the tire, not the bike.

Tire pressure is dependant on what the engineers who designed the motorcycle recommend!It's calculated in accordance with the weight of the bike and what the bike is carrying.

For example, the manual (as well as the sticker on the rear fender) for my '77 GL1000 recommends 28PSI for the front, and 32PSI for the rear with a light load, and 40PSI for the rear with a heavy load. I'm running Bridgestone Spitfire S11's, and with these pressures the bike handles like a dream... the way it's supposed to.

Check the owner's manual for correct tire pressure... the pressures I see on this post seem too high for a GL1000. High tire pressure might save a little in gas mileage, but will sacrifice safety. An overinflated tire is far too hard, and will not corner or brake very well... and is your only connectionwith the road.It can also cause the tire to bounce and overwhelm the suspension system, further reducing it's contact with the road. Motorcycle tires also need to warm up to the correct operating temperature for proper traction. With too much air in the tires this might never happen, leading you further downa slippery slope.

The bottom line is; overinflated tires can quickly land you in the ditch! You're tempting fate by not following the MOTORCYCLE manufacturer's recommendation for tire pressure.

 

[Goldwinger1984]

imported post

Axelwik, using original inflation pressures that were good for a bike that was built over 25 years ago may not apply if you are using modern day tires. I my humble opinion it's best to use the tire manufacturer's recommended inflation pressure for the specific application and loading, although I do fully agree that maximum indicated tire inflation is not always the best choice, but, it usually does give better load carrying ability, performance, fuel economy and safety margin than running a tire slightly underinflated..

Itcertainly is akward when mixing modern technology with old technology and really needs the touch of the factory engineers and the expert rider's who can take the bikes to the limits and come up with overall safety inflation averages for everyday blokes like us.

Vic

 

[mag]

imported post

Clymer Manual says:

front 28psi
rear 40psi

both for over 200lb load

 

[axelwik]

imported post

Goldwinger1984 wrote:

Axelwik, using original inflation pressures that were good for a bike that was built over 25 years ago may not apply if you are using modern day tires. I my humble opinion it's best to use the tire manufacturer's recommended inflation pressure for the specific application and loading, although I do fully agree that maximum indicated tire inflation is not always the best choice, but, it usually does give better load carrying ability, performance, fuel economy and safety margin than running a tire slightly underinflated..

Itcertainly is akward when mixing modern technology with old technology and really needs the touch of the factory engineers and the expert rider's who can take the bikes to the limits and come up with overall safety inflation averages for everyday blokes like us.

Vic

Vic,

You can gamble if you want, butI willalways stick with the motorcycle manufacturer's recommendations. Tires might have changed a bit (different tread patterns and rubber compounds), but the weight and loading of the bike have not. Any tire manufacturer will tell you to inflate according to what the motorcycle manufacturer recommends. One size tire will fit on many makes and models of bikes, and to inflate to the maximum sidewall rating is foolish.

 

[mag]

imported post

Axelwik,

I tend to agree with you. However, going by honda's specs puts the rear tire at 40psi, to the max recommended 41psi by the tire manufacturer!

 

[axelwik]

imported post

mag wrote:

Axelwik,

I tend to agree with you. However, going by honda's specs puts the rear tire at 40psi, to the max recommended 41psi by the tire manufacturer!

Yes, that's fine.

The max for my bike is also 40PSI for the rear, for a load >200 pounds. For a light load (ie. riding solo, <200 pounds) the recommended pressure for the rear is 32PSI. The front stays at 28PSI.

 

[mag]

imported post

well, that's what i'm going with too. 28/32

Thanks!

Mag

 

[rcmatt007]

imported post

mag wrote:

78 Gl1000. Both tires say max 41psi. What should it be at? The bike is naked, no luggage/fairing. Mostly riding solo. The front was at 36 and the back was at 28psi! Maybe this is why mileage suffered? Both are at 36-37 now.

I always try to stay with the tyre manufacture recommendation. underinflation can cause the front tire to cup which leads to a wobble in turns--no fun at all. just remember the ford/firestone issue with underinflated tires

 

[mag]

imported post

Interesting opinions -- split evenly between motorcycle vs. tire manufacturer's specs.

I tend to agree with the latter now, having gone on other boards for reference. It makes sense that Honda wouldn't know what tires are going on!

 

[exavid]

imported post

I don't believe the maximum tire pressure is a good normal setting, that pressure is what's required to carry the maximum load the tire is rated for plus a little extra to allow for maximum reasonable temperature buildup. The pressure Honda recommends should be pretty close since there isn't all that much room for vastly different physical tire sizes on the bike so the volume of air in the tire doesn't vary all that much with brand. Since all the tires for this bike are bias ply, roughly the same size, the amount of air pressure to carry a given weight shouldn't vary greatly. That said, it's safer to err a little on the high side than the low side, so I'd go with the bike maker's recommendation and it it felt a little low, adding two or three psi isn't going to make a dangerous condition. You can also get a good idea by looking at the tire track, with a full load on is the tread mark on the ground looking too wide, on bias tires especially if they look too low they usually are. This wouldn't be true on the 1800 since they are radial.

 

[mag]

imported post

Clymer says 28 on the front. Tire says 41psi. That's quite a range

 

[Goldwinger1984]

imported post

I just want to say thatproper tire pressureall depends on the specific tire that was built specifically for each application.

The only time that OEM tire pressures apply are when the tires being used are OEM spec. Any variation will require testing and experimentation to correctly determine appropriate pressure.

Cord, constructionmaterials and rubber compounds also affect best tire pressure settings, as do tire loading and max speed.

For best results I would follow the tire manufacturers recomendations because they have to live with the results of the tire's life, whereas the bike manufacturer only needs the tires to get the bike out the factory's door.

Vic

 

[axelwik]

imported post

There sure seems to be a lot of confusion about sidewall maximum pressure rating for a tireversus tire pressure based on the motorcycle's weight. I'm willing to bet that the OEM, original, tires that the GL1000 left the factory with said something like, "max pressure 41PSI" or something close to that. The proper pressure is 28PSI front, and 32 or 40PSI for the rear, depending on load.

Same thing with cars... too many people, including some of the mechanics who change tires, still don't get it. A tire's maximum pressure rating stamped on the side of the tire has nothing to do with the pressure that's supposed to be in the tire for your specific car. Almost all car tires will say something like maximum 32 to maybe 45 PSI on the sidewall. Look at the owner's manual or inside the driver side door jam for the proper pressure. The owner's manual and door jam on my new Toyota says to inflate the tires to 30PSI even though the tires (It still has the original factory tires) say "maximum pressure 44 PSI."

Putting too much (or too little) pressure in your motorcycle tires is dangerous.

Too much pressure reduces the size of the contact patch with the road. This results in less traction for braking and cornering. The bike will slide out easier and will skid easier, both of which can cause an accident.

Too much air will not allow the tires to properly warm up. Cold tires don't corner or brake as well as tires that are properly warmed up, and could result in a crash.

Overinflation could also cause the tire to bounce, overwhelming the suspension system and reducing the time that the tire is supporting the full weight of the motorcycle, further reducing traction for cornering and braking. This can land you in the ditch.

Wet weather amplifies this.

It also results in a rough ride. Do you like being jolted with every crack in the road?

Underinflation also has it's issues.

Underinflated tires can heat up and cause premature wear, tire failure, and also cause poor handling and braking.

The key is to maintain the pressure at the MOTORCYCLE manufacturer's recommendation.Check the pressure often.

The tire manufacturerdoesn't have a clue as to what motorcycle you are putting their tires on. All they know is how much weight their tire can handle and the maximum tire pressure for that tire... period.

 

[Brojees]

imported post

Personall I like the 40/28 setup and have ran it for some time. I watch sidewall temperature routinely and have had no problem with this mix. Running the front tire harder gave me chatter in cornering that I did not like...Maybe I imagined it, but then I imagined it went away when I lowered it, so I am sticking with the 28.

 

[Goldwinger1984]

imported post

I agreewith everything that's been stated in all of the above posts except for any portion that has been stated incorrectly..

Vic