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Author Topic: Tire Pressure???  (Read 5448 times)

drewboid

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Tire Pressure???
« on: December 17, 2008, 08:28:14 AM »
OK - not the dreaded tire discussion but almost as bad!
Tire technology has improved in the past 20 years - is everyone still running the originally recommended tire pressures?  
At present with BT45s I'm running front 28 to 30, rear 30 to 32.

I notice some decrease in handling if the front pressure drops any lower. I'm thinking of running it higher.

Any comments?

Offline Justin B.

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Re: Tire Pressure???
« Reply #1 on: December 17, 2008, 08:31:17 AM »
The old tire pressure recommendations no longer apply with modern tires technology.  I can feel my R100 getting squirrelly when the front gets under 32 psi.  I run about 38 rear and 35 front on it and the r65s seem to be fairly happy with this as well.
Justin B.

2004 BMW R1150RT
1981 R100RT - Summer bike, NEKKID!!!

Offline nhmaf

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Re: Tire Pressure???
« Reply #2 on: December 17, 2008, 04:35:32 PM »
I am also running BT45s and one night I decided to go out for a brief ride after having left the bike unused for over a month.

I violated one of my cardinal rules right off the bat and didn't check the tires before heading out to the road.  I didn't
notice anything odd until I pulled out of my dirt road and onto the highway (tarmac) and accelerated toward highway speed (55 MPH).
Between 35 and 40 the front end became very "squirrely" and it felt like the bike wanted to shake its heads pretty strongly.  At 55 it
seemed OK, but decelerating again through 40->35 cause it to try to oscillate again.   I pulled off the road and found that the front tire was soft,
between 20-25 pounds of air.

I took it easy and headed back home, checked and filled both tires up with my usual 34 - 36 PSI front & rear and rode back out - problem solved !

I agree - the old tires were made of single compound, stiff rubber and had to be run with less pressure to have compliance.   I don't think that the sidewalls were
especially stiff, but they relied more heavily on less air pressure to allow some deformation to keep the tread pattern on the road surface.  Modern tires often have
different compounds of differing qualities in the areas that need them, and have softer, more compliant rubber for better grip on the road - running them too soft
is a big no-no and they really like/want to have more air pressure than you would be happy with if you were still riding your old motorcycle tires from the 60s, 70s, or even 80s.


Airhead #12178 ? BMWMOA #123173 ?BMWRA #33525 ?GSBMWR #563 ?1982 BMW R65LS ?1978 BMW R100/7 1998 Kawasaki Concours

Offline Rob Valdez 79 R65

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Re: Tire Pressure???
« Reply #3 on: December 17, 2008, 04:55:53 PM »
Yeah, I keep my Bridgestone S11's at a minimum of 35/35.

not-so-fast-ed

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Re: Tire Pressure???
« Reply #4 on: December 17, 2008, 06:47:36 PM »
I'm still playing with tire pressure on my BT45's.  Currently 32 front, 35 rear.  Of course I only weigh 140 and seldom put much weight on it.     :-/

Offline beemer

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Re: Tire Pressure???
« Reply #5 on: December 18, 2008, 05:06:33 AM »
Quote
I'm still playing with tire pressure on my BT45's.  Currently 32 front, 35 rear.  Of course I only weigh 140 and seldom put much weight on it.     :-/
Is that the weight of just one buttock ;D

not-so-fast-ed

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Re: Tire Pressure???
« Reply #6 on: December 18, 2008, 09:25:53 AM »
Actually got on the scale after dinner last night.  What with all the holiday snacks and a great dinner I'm now up to my all time (this century) high of 147.  May have to add more air in the tires of all my vehicles.

 ;)

Offline montmil

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Re: Tire Pressure???
« Reply #7 on: December 18, 2008, 05:22:09 PM »
Quote
Actually got on the scale after dinner last night.  What with all the holiday snacks and a great dinner I'm now up to my all time (this century) high of 147.  May have to add more air in the tires of all my vehicles. ;)

They're just jealous, Ed. Us slim guys create less drag. Buck nekkid I tip the scales at 146. I stick with light beer...  [smiley=beerchug.gif]

Monte
Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Altritter

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Re: Tire Pressure???
« Reply #8 on: December 20, 2008, 03:29:31 PM »
montmil: << I stick with light beer... >>

Monte! A Texan drinking light beer??? Especially when Shiner Bock is available!  ;D

OT, but somewhat related: Though a bit dated, Philip Van Munching's 1997 book Beer Blast — The Inside Story of the Brewing Industry's Bizarre Battles for Your Money (long out of print, but likely available  used (maybe at a high price, but sometimes available at a bargain, so check repeatedly) on Amazon[dot]com, is informative, gossipy, and very funny. (Van Munching, grandson of Theodore Van Munching (the original USA importer and national distributor of Heineken) and himself a former executive of Van Munching & Co., tells insider dirt about both the history of the beer industry in the US and his family's former brand.)

The elder Van Munching is quoted with some very strong opinions about specific brands. Examples:

   He once referred publicly to Corona as "Mexican soda pop"; and (paraphrased with trepidation, but in a style used by US newspapers recently —

   Regarding Coors: "What does Coors beer have in common with sex in a canoe?"
  [Out of respect for the high standards of this forum, I'll provide the answer in a PM to anyone requesting it. Please be patient for a response.]

[Regarding the wide swings in prices of used copies of the book: After reading good reviews of Beer Blast, I found a new copy on the bargain table of a US bookstore chain and bought it for $5. I loaned it to someone, but I never got it back. Went looking for a used copy recently and learned that used copy prices began at $80 US and ranged upward. I found a used book-on-tape copy for $5 (read by the author) and bought it, but it is significantly abridged. Sometime later, I checked again and discovered that used copies in good condition were available for as little as $11.95, and bought it. Sorry, guys — having been burned once, I decline to loan my copy.]

« Last Edit: December 20, 2008, 03:31:14 PM by Altritter »

Offline montmil

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Re: Tire Pressure???
« Reply #9 on: December 20, 2008, 06:20:58 PM »
Quote
montmil: << I stick with light beer... >>
Monte! A Texan drinking light beer??? Especially when Shiner Bock is available!  ;D

Oh, there's Shiner Bock in the 'fridge, too. My wife's fav. Along with some Fat Tire and a couple other "designer" brews. It's the calories, and volume, that I have to watch!  [smiley=beer.gif]

PM me with the answer...

My Bridgestone Spitfire's on the '81 get 35 at both ends. Still messing with the new Dunlops on my latest acquisition.

Monte
« Last Edit: December 20, 2008, 06:23:24 PM by montmil »
Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Offline Lucky_Lou

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Re: Tire Pressure???
« Reply #10 on: December 23, 2008, 04:11:24 PM »
We digress but when visiting a freind in texas in the eighties he introduced me to a bottled beer called little kings??/ is it still around.
ive just fitted new dunlops so will check what the tyre shop put in them i cannot remember but the handling seems ok not done any distance at speed on them yet though
Lou
« Last Edit: December 23, 2008, 04:12:46 PM by Lucky_Lou »
Ask questions later

Offline Rob Valdez 79 R65

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Re: Tire Pressure???
« Reply #11 on: December 23, 2008, 06:31:42 PM »
Quote
We digress but when visiting a freind in texas in the eighties he introduced me to a bottled beer called little kings??/ is it still around.
Lou

Knock yourself out!  Little Kings

Offline Semper Gumby

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Re: Tire Pressure???
« Reply #12 on: December 24, 2008, 08:39:43 AM »
32F 34R when light.
34F 36R with a load
36F 38R with everything and the kitchen sink.

Michelin Macadam 110/90H18 front Avon Roadrider 4.00H18 Rear.  These tires are rated to 40 PSI at their max Load rating so I base tire pressures on how much under the max load rating I'm putting on the tire.   8-)

Cutting down on the beer intake but still have time for the good stuff (Guinness, Samuel Smith's Winter Welcome).  Oh no .... ADBT*!

2 cents worth of advise.















(*Another D@mn Beer Thread)
Bill Gould ?1980/03 R65 When at first you don't succeed....Moo!

Offline Rob Valdez 79 R65

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Re: Tire Pressure???
« Reply #13 on: December 24, 2008, 05:48:54 PM »
Quote
 Oh no .... ADBT*!

(*Another D@mn Beer Thread)


NS...


« Last Edit: December 24, 2008, 05:50:14 PM by Rob_Valdez_79_R65 »

Altritter

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Re: Tire Pressure???
« Reply #14 on: December 28, 2008, 09:28:11 AM »
[Sorry, Rob, didn't see your comment until just after I posted. Move this if you must. JT]

Wow! I hit the Little Kings link out of nostalgia, and the first brand name I see is "Schoenling."  Three things that made the Cincinnati area a great place to live several decades ago were Schoenling, Hudepohl, and Strohs. (Yeah, I know, Strohs was brewed north of Cincy, but it was widely available there.) Did Schoenling survived the oligopilazation of the beer industry? It was my favorite.

BTW, Natty Bo bottled its own version of Little Kings in the Bal'mer area. If memory serves, Natty Bo called them "Ponies."
« Last Edit: December 28, 2008, 09:29:49 AM by Altritter »