Handling woes

[BRENTTODD]

Always keep the motorcycle manufacturer's recommended air pressure in both tires.

 

 

Hey those guys should have told Ford and Firestone that could have save a ton of law suits

oh wait Bridgestone, Firestone Who do we believe what do we do oh no

[rocker59]

Always keep the motorcycle manufacturer's recommended air pressure in both tires.

 

 

Hey those guys should have told Ford and Firestone that could have save a ton of law suits

oh wait Bridgestone, Firestone Who do we believe what do we do oh no

 

 

You another one of the 36/42 crowd ??? <_>

 

I just thought I'd print Bridgestone's info since the OP is running 020s.

[Guest ratchethack]

Wot Rocker said. And BTW, Rocker, kudos on backing up your point with a credible source. I've seen way too many riders use the MAX PRESSURE RATING on their tires for normal riding! Besides being one of the most common examples of how ignorance kills on the road, I can't imagine how anyone thinks that the road manners of tires inflated to MAX PRESSURE RATING is the way any motorcycle is supposed to handle! On top of being a forfeiture of most of the available grip engineered into the tires -- how is it possible they can't tell their bike's more skittish than a cat passing a kidney stone??!!

[dlaing]

Never use owners manual settings for tire pressure always use the settings provided on the tire itself. I usually run 35 fand r

I usually run somewhere between what Mandello recommends for some jockey two thirds my weight and the maximum recommended, embossed(or whatever the correct term is) on the side of the tires, but much closer to the Mandello recommendations.

Guzzi recommends 35 psi front and 36 psi rear solo at extended high speeds, which I often ride.

The M1s on my bike say maximum pressure 42PSI at a maximum load of 520 pounds front and 716 pounds rear.

Since I weigh about 250 pounds with gear, that probably makes me 100 pounds heavier than what Guzzi had in mind, so instead of maybe 250+50=300 pounds on the front tire and oh maybe 300+100=400 pounds rear, we need to add another 100 pounds and get somthing like 333 front and 466 rear.

520 - 300 = 220

while

520 - 333 = 253

so if 42psi - 35psi = 7psi

we could divide 220 by 33 and get 6.67 which is pretty close to 7psi, so I need roughly one more PSI than what Guzzi recommends on the front.

Of course this is making many assumptions such as the infamous alleged 150 pound jockey with 50 pounds over front wheel and 100 pounds over rear wheel and the Guzzi weighing 250 pounds front and 300 pounds rear (I recall Ratchet has real numbers)

On the rear

716 - 400 = 316

while

716 - 366 = 350

316 divided by 66 = 4.8

and since 42 - 36 = 6psi we can divide 6 by 4.8 and get 1.25 so the rear should be increased by 1.25 psi.

Inconsequential for lighter riders like Ratchet, but some of us might weigh 350 pounds in leather, so they might be better with 2 more psi front and 2.5 psi rear

Again, the math is very rough and will certainly vary by tire model.

There are better ways to set tire pressure, involving measuring the effects of how riding increased temperature and pressure on the tires and using subjective analysis to look at factors such as how the bike handles and how it grips, but I have never nailed down that method.

Now that I have analyzed(over-analyzed?) it, I realize that the 36 front 38 rear that I settled on should be more like 36 front and just over 37 rear. But I guess that makes me somewhat better prepared for the rare passenger.

Another issue is that I have an assortment of gauges that vary in reading by about 4 or 5 psi.

I tend to go with the more expensive gauges which seem to read lower, so if my cheap gauges are correct I could be at 42PSI

I ain't too worried about it. I think there is a pretty wide range of acceptable pressure, but would not push the bike if the pressure were not well set.

Keep in mind that the bike's maximum load is lower than the tire's 48kg 106# front and 166kg 365# rear, so if your pillon is too heavy, make them hitch a ride.

I do like lower tire pressures for cool or wet conditions. I have heard some suggest higher pressures are better for rain, but I don't think so. Any ideas on that? Reduced chance of hydro-planing???

[Ouiji Veck]

And if you have a Yammaha you should only use YammahLube...

Else your bike may incur serious bla bla bla.

 

I really don't see how Guzzi or anyone else can say tire compound,

bias, vulcanizing process, profile and riding style makes no dif. what so ever...

Jeepers ..I'm not even running the size they recomend... HA!! (As well as half the crew here) let alone air pressure...

Their numbers are in the ball park.

This ain't the space shuttle.

 

 

I go with the guys that make and test the tire, and have a lot riding on

their dependability and safety.

 

I run mine per / ""Our test riders/engineers in Germany recommend the following for your bike:

-120/70ZR17 Road Attack = 36 "cold" psi.

-180/55ZR17 Road Attack = 42 "cold" psi."

 

This is hearsay @ this point but I trust the guys over at Ducatisuite and it

concurs with the original info I got from Continental when I started running the Contis'.

 

I'll let you know if I fall down...

So far I've only been able to grind a half inch off my kick stand.

(I've only seen 4 or 5 people "fall down" in 39yrs...and it wasn't due to air pressure)

If 4 or 5 lbs of pressure was a deadly safety hazard I'm sure we'd have official

state tire inflation inspectors every 10 mi.

I check my air every time I go out for more than just a few miles. Especially in changing

weather like now. My concern being tire ware....not sticking like a GP rider.

Softer would be stickier but not as sticky as slowing down 5mph.

 

Sorry but my #3 hero is Chuck Yeager...he use to pound 16p nails into the cowl

of his P-51 to steady his gun sight...I love that kinda stuff. Otherwise I'd have a Beemer.

I'm not trying to rattle your cage. It's just my Pure anecdotal opinion with

several hundred thousand miles to back it up.

[orangeokie]

Gyroscopic Precession (disambiguation) . . . That's all I got to say.

 

 

Torque-induced precession (gyroscopic precession) is the phenomenon in which the axis of a spinning object

(e.g. a part of a gyroscope) "wobbles" when a torque is applied to it.

(Seat of the pants feel - wot makes it a Guzzi, just like Ouiji Veck says).

[Guest Smudge]

Grrr, wasn't allowed out to play today!! She say's petrol (gas) is "too expensive to just play around on". FOR CRYING OUT LOUD! How am I supposed to test all these theories?

Anyway I am totally ok with the whole "This is what Guzzi's do" theory, Just don't want to settle for less than Guzzi has to offer through my ignorance, hence my gratitude for all these great suggestions.

Ah well weekend over and I can at least ride to work 'n back tomorrow, 50km of Kiwi country roads, now to find a bumpy left hander and NOT over cook it

[JFK]

And if you have a Yammaha you should only use YammahLube...

Else your bike may incur serious bla bla bla.

 

I really don't see how Guzzi or anyone else can say tire compound,

bias, vulcanizing process, profile and riding style makes no dif. what so ever...

Jeepers ..I'm not even running the size they recomend... HA!! (As well as half the crew here) let alone air pressure...

Their numbers are in the ball park.

This ain't the space shuttle.

 

 

I go with the guys that make and test the tire, and have a lot riding on

their dependability and safety.

 

I run mine per / ""Our test riders/engineers in Germany recommend the following for your bike:

-120/70ZR17 Road Attack = 36 "cold" psi.

-180/55ZR17 Road Attack = 42 "cold" psi."

 

This is hearsay @ this point but I trust the guys over at Ducatisuite and it

concurs with the original info I got from Continental when I started running the Contis'.

 

I'll let you know if I fall down...

So far I've only been able to grind a half inch off my kick stand.

(I've only seen 4 or 5 people "fall down" in 39yrs...and it wasn't due to air pressure)

If 4 or 5 lbs of pressure was a deadly safety hazard I'm sure we'd have official

state tire inflation inspectors every 10 mi.

I check my air every time I go out for more than just a few miles. Especially in changing

weather like now. My concern being tire ware....not sticking like a GP rider.

Softer would be stickier but not as sticky as slowing down 5mph.

 

Sorry but my #3 hero is Chuck Yeager...he use to pound 16p nails into the cowl

of his P-51 to steady his gun sight...I love that kinda stuff. Otherwise I'd have a Beemer.

I'm not trying to rattle your cage. It's just my Pure anecdotal opinion with

several hundred thousand miles to back it up.

 

Rocker, looks like you may need a pressure gauge that goes up to 42 ...

 

JFK

[richard100t]

If you weigh less than 170lbs I'd say you may need to use longer spacers for your preload in the forks. My bike started doing almost the very thing you describe. What I found was that the forks werent compressing over the bumps in the road. Basically it was too stiff & wouldnt handle properly. Buy some pvc tubing & cut spacers...I'd say to start with one half inch longer than stock. Put them in, run the blue nut all the way down & go for a test run.

[rocker59]

Rocker, looks like you may need a pressure gauge that goes up to 42 ...

 

JFK

 

LOL! You'd think this was an oil thread, huh?

 

I'll keep running 32/35 solo and ripping up the mountain roads here in the Ozarks... And at the occasional trackday...

 

 

[JFK]

LOL! You'd think this was an oil thread, huh?

 

I'll keep running 32/35 solo and ripping up the mountain roads here in the Ozarks... And at the occasional trackday...

 

 

 

 

Yikes, check that sidewall flex!!

[GuzziMoto]

Grrr, wasn't allowed out to play today!! She say's petrol (gas) is "too expensive to just play around on". FOR CRYING OUT LOUD! <_ how am i supposed to test all these theories>

Anyway I am totally ok with the whole "This is what Guzzi's do" theory, Just don't want to settle for less than Guzzi has to offer through my ignorance, hence my gratitude for all these great suggestions.

Ah well weekend over and I can at least ride to work 'n back tomorrow, 50km of Kiwi country roads, now to find a bumpy left hander and NOT over cook it

Out of the two Guzzi's my wife and I have, neither steer easier one way then the other. There is a minor bit of torque effect where getting on the gas rocks the bike one way and getting off the gas rocks it back the other way. But this has minimal effect on steering. In fact the Guzzi layout steers lighter the others due to the orientation of the crank. So if your bike really steers easier one way then the other I would check it for what's not straight as Ratchet and others suggested or take it to someone who can do it for you.

For tyre pressure, do what you feel is right. I run in the 32/36 range myself.

And the Continental-esqe quote about our testers in Germany found that blah blah blah air pressure.... that is funny. Is anybody that naive to believe that? And RoadRacing World blew that line out of the water a while back when after doing a tyre test(and Continental did not fair well) they got complaints saying that the test was unfair 'cause they inflated all the tyres to the same pressures and Continental tyres are special and need to be inflated to 40-42 psi. So they retested Continentals at the original pressures and the ones they supposedly need and showed that they performed worse at the high pressures.

Having said that, my intent was only to share an amusing story. I do not care any longer what pressures you run in your tyres. If someone asks for advice it is fair to give it. But if you chose to run some high( or low) pressure in your tyres I don't care.

[Ouiji Veck]

Yup...If I was at the track I'd be running a different tire...(on a different bike)

at lower air pressure..........and if I was racing I'd be buying new tires

every 2 or 3 races.......

 

Are we talking about the safest tire to race on the public roads?

 

Ha! ....

 

I run what will get me from here to Cape Bretton and back in good order

and carve up some glorious corners on the way.

 

I'm more interested in NOT going through 3 sets of tires a year than running

what Joe Rockets running on his track bike.

Hey..all through the 70s and 80s I ran Dunlops...

I know what it's like to slide a tire around..

I switched to Metzlers finally...and now I run the Contis and have yet to

slide them through a corner. It don't matter much to me. All the new tires

are much better than back in the day.

I've spent a lot of time sliding tires on purpose.

Give me a tire that will grip on antifreeze or sand...then ya got something!

(or one that's easier to spoon off)

Hey...I'm an old school blood and guts caveman. I ride a Guzzi.

[GuzziMoto]

IThere are better ways to set tire pressure, involving measuring the effects of how riding increased temperature and pressure on the tires and using subjective analysis to look at factors such as how the bike handles and how it grips, but I have never nailed down that method.

Now that I have analyzed(over-analyzed?) it, I realize that the 36 front 38 rear that I settled on should be more like 36 front and just over 37 rear. But I guess that makes me somewhat better prepared for the rare passenger.

Another issue is that I have an assortment of gauges that vary in reading by about 4 or 5 psi.

I tend to go with the more expensive gauges which seem to read lower, so if my cheap gauges are correct I could be at 42PSI

I ain't too worried about it. I think there is a pretty wide range of acceptable pressure, but would not push the bike if the pressure were not well set.

Keep in mind that the bike's maximum load is lower than the tire's 48kg 106# front and 166kg 365# rear, so if your pillon is too heavy, make them hitch a ride.

I do like lower tire pressures for cool or wet conditions. I have heard some suggest higher pressures are better for rain, but I don't think so. Any ideas on that? Reduced chance of hydro-planing???

A good way of checking your tyre pressure to see if you are properly inflating your tyres is to check them cold then go for a typical ride. Then check them hot. The pressure should go up approx 15% from cold to hot. Not enough increase means your pressure was too high to start with and too much increase means the pressure was too low.

The bit about higher pressure in the rain comes from the days of bias-ply tyres. Increasing the air pressure would expand the tyre and open up the grooves in the tyre to help water escape from the contact patch. The one flaw that you had to consider was that running higher pressure would make the tyre run cooler. You had to decide what was more important, water evacuation or heat in the rubber. Todays radial tyres have a more stabile contact patch that is less effected by inflation pressure. The grooves in the tyre do not close down like the grooves in a bias-ply tyre did.

[Guest ratchethack]

A good way of checking your tyre pressure to see if you are properly inflating your tyres is to check them cold then go for a typical ride. Then check them hot. The pressure should go up approx 15% from cold to hot. Not enough increase means your pressure was too high to start with and too much increase means the pressure was too low.

This rule o' thumb (I always went by 10%, but that's just me) also went away with bias ply tires. Doesn't work with steel radials.