Welcome, Guest. Please login or register.
January 19, 2018, 12:20:14 PM

Login with username, password and session length
Search:     Advanced search
BRITISH COLUMBIA CLASSIC MOTORCYCLE CLUB
97424 Posts in 7007 Topics by 421 Members
Latest Member: showmanager
* Home Help Search Calendar Login Register
+ 
|-+  BC Club forum boards
| |-+  General Chat and Ideas
| | |-+  tire pressure
« previous next »
Pages: 1 [2] 3 Go Down Print
Author Topic: tire pressure  (Read 667 times)
Sandy
New
*
Offline Offline

Posts: 42


« Reply #15 on: November 02, 2017, 10:11:36 PM »

So, which oil do you guys used on your tires?  Evil Evil

Ohhhh it looks like this is the start of a long cold winter. LOL.
Logged
MJ
1000 Class
******
Offline Offline

Posts: 3721



« Reply #16 on: November 02, 2017, 11:32:03 PM »

That got dumb fast. An oil thread, lol. It’s about air pressure not tire brand, duh.
Logged
Galactica
1000 Class
******
Offline Offline

Posts: 2312


« Reply #17 on: November 03, 2017, 02:48:13 AM »

That got dumb fast. An oil thread, lol. It’s about air pressure not tire brand, duh.

It could be that tires with modern rubber compounds prefer synthetic oil, regardless of pressure.
Logged

79 Kz1000 LTD
79 Kz1000 Police
73 z1 900
hardrockminer
1000 Class
******
Offline Offline

Posts: 1986


« Reply #18 on: November 03, 2017, 09:54:16 AM »

Your Z1 does what?

"why don't tire MFR's specify tire pressure based on loading ..."  There is a chart on the rear inner fender of all Z1 bikes that specifies tire pressure.  It then suggests a higher pressure for two up riding or for heavy riders.

That was my point - the label (which all bikes have) only applies to the tires that originally came with the bike.

Ahh!  I see my mistake now.  You said "why don't  TIRE manufacturers..."  I misread that and thought it was BIKE manufacturers.  Sorry about that.  I thought the cataract surgery would improve my vision but I guess not! Embarrassed
Logged

Past rides include a 1973 Suzuki GT380 & a 1975 Kawasaki Z1B

I currently ride a 1975 Kawasaki Z1B - Classic Plated
I also ride a 1980 Kawasaki KZ 1000 LTD - Classic Plated
I'm currently restoring a Z1B

My Sweetums rides a 1981 Kawasaki KZ550 LTD
Bucko
1000 Class
******
Offline Offline

Posts: 1577



« Reply #19 on: November 03, 2017, 11:20:23 AM »

It could be that tires with modern rubber compounds prefer synthetic oil, regardless of pressure.

Bad idea; synthetic oil will make your tires leak.
Logged
MJ
1000 Class
******
Offline Offline

Posts: 3721



« Reply #20 on: November 03, 2017, 12:00:13 PM »



do the math
Logged
kaw74
BCCMC Star (5K)
*******
Offline Offline

Posts: 6754



« Reply #21 on: November 03, 2017, 01:00:06 PM »

https://www.youtube.com/watch?v=d64XP3Ha044
Logged
hardrockminer
1000 Class
******
Offline Offline

Posts: 1986


« Reply #22 on: November 03, 2017, 01:17:10 PM »


They should have hired a midget to do that film.  He would have needed to bend over to be in the camera.
Logged

Past rides include a 1973 Suzuki GT380 & a 1975 Kawasaki Z1B

I currently ride a 1975 Kawasaki Z1B - Classic Plated
I also ride a 1980 Kawasaki KZ 1000 LTD - Classic Plated
I'm currently restoring a Z1B

My Sweetums rides a 1981 Kawasaki KZ550 LTD
Jodea
Jr. Member
**
Offline Offline

Posts: 179


« Reply #23 on: November 03, 2017, 03:45:57 PM »

Tire manufacturers have their pressure suggestions listed on their websites. They are usually a couple of pounds higher than what is listed  under the seat, or where ever the decal is hiding. Do a google search and you shall find.
Logged

77 xs650 roadster
80 xs850sg
MJ
1000 Class
******
Offline Offline

Posts: 3721



« Reply #24 on: November 04, 2017, 04:02:14 PM »

....or I think I'll give this a try

A technique for those wanting to get the most out of their tires on the street is to use the 10/20% rule.

First check the tire pressure when the tire is cold. Then take a ride on your favorite twisty piece of road. Then, measure the tire pressure immediately after stopping. If the pressure has risen less than 10% on the front or 20% on the rear, the rider should remove air from the tire. So for example, starting at a front tire pressure of 32.5 psi should bring you up to 36 psi hot. Once you obtain this pressure increase for a given rider, bike, tire, road and road temperature combination, check the tire pressure again while cold and record it for future reference.

Each manufacturer is different. Each tire model is different. A tire design that runs cooler needs to run a lower pressure (2-3 psi front) to get up to optimum temperature. The rear tire runs hotter than the front tire, road and track. So the rear tire cold-to-hot increase is greater. Dropping air pressure has the additional side effect of scrubbing more rubber area.
Logged
Galactica
1000 Class
******
Offline Offline

Posts: 2312


« Reply #25 on: November 04, 2017, 04:29:59 PM »

....or I think I'll give this a try

A technique for those wanting to get the most out of their tires on the street is to use the 10/20% rule.

First check the tire pressure when the tire is cold. Then take a ride on your favorite twisty piece of road. Then, measure the tire pressure immediately after stopping. If the pressure has risen less than 10% on the front or 20% on the rear, the rider should remove air from the tire. So for example, starting at a front tire pressure of 32.5 psi should bring you up to 36 psi hot. Once you obtain this pressure increase for a given rider, bike, tire, road and road temperature combination, check the tire pressure again while cold and record it for future reference.

Each manufacturer is different. Each tire model is different. A tire design that runs cooler needs to run a lower pressure (2-3 psi front) to get up to optimum temperature. The rear tire runs hotter than the front tire, road and track. So the rear tire cold-to-hot increase is greater. Dropping air pressure has the additional side effect of scrubbing more rubber area.

You gotta be really pushing hard, like on a race track, to use the 10% rule. Few of us would run hard enough to get consistent readings to truly aplly the 10% rule.
Logged

79 Kz1000 LTD
79 Kz1000 Police
73 z1 900
Galactica
1000 Class
******
Offline Offline

Posts: 2312


« Reply #26 on: November 14, 2017, 03:27:03 PM »

OK. Here’s the dope from Dunlop.

Unless you’re running radial tires, the tire construction basically has remained basically the same as the 70s & 80s. While the rubber compounds and tread designs may have changed, bias ply tires of today are not much different from back in the day. Because there is no test data of older (70s) bikes with new tires, Dunlop says to use the motorcycle manufacturer’s pressure recommendations. They will say no more than that.
Logged

79 Kz1000 LTD
79 Kz1000 Police
73 z1 900
Timtone
Super Member
*****
Offline Offline

Posts: 532



« Reply #27 on: December 15, 2017, 10:12:19 PM »

....or I think I'll give this a try

A technique for those wanting to get the most out of their tires on the street is to use the 10/20% rule.

First check the tire pressure when the tire is cold. Then take a ride on your favorite twisty piece of road. Then, measure the tire pressure immediately after stopping. If the pressure has risen less than 10% on the front or 20% on the rear, the rider should remove air from the tire. So for example, starting at a front tire pressure of 32.5 psi should bring you up to 36 psi hot. Once you obtain this pressure increase for a given rider, bike, tire, road and road temperature combination, check the tire pressure again while cold and record it for future reference.

Each manufacturer is different. Each tire model is different. A tire design that runs cooler needs to run a lower pressure (2-3 psi front) to get up to optimum temperature. The rear tire runs hotter than the front tire, road and track. So the rear tire cold-to-hot increase is greater. Dropping air pressure has the additional side effect of scrubbing more rubber area.

I have used this system for as long as I have ridden. Works for me.
When I change rubber species, new loads, hotter day, no load, touring /camping load, I am on it.
I love the details.
I keep a piece of masking tape on the underside of my port side box (where my tire gauge is) and record the pressures.
The difference is like night and day.
Not just cornering speed....but braking as well. All good stuff.
Or....
I could just be my imagination.
...or beer.


Logged

Men do not stop playing because they get old....they get old because they stop playing.
Growing old is compulsory; growing up is optional.

Current Bikes:
1999 CBR600 F4 hotrod / truck
1999 VFR800 Fi  for riding with my buddy.

Past bikes:
1981 XJ 650
1984 XVZ 1200TD
2012 NC 700s
MJ
1000 Class
******
Offline Offline

Posts: 3721



« Reply #28 on: December 16, 2017, 12:10:11 AM »

Thanks for the input
Logged
Steve G.
1000 Class
******
Offline Offline

Posts: 1683



« Reply #29 on: December 16, 2017, 09:16:00 AM »



  The engineers of tire manufacturers, and motorcycle manufactures of a motorcycle designed/made 45+ years ago could not in any way envision the changes and improvements in tire technology in 2017. IMO, using tire pressure recommendations from a 45 year old owners manual to a new tire today is incorrect, especially street tires. High heat, very slow steering, bike wandering, and pothole damage are all confirmed when running low pressure. Of course, everyone has their own opinion on this, and will live with the benefits/negatives of their chosen psi they run. I choose to have a quick handling and precise as possible machine, taking advantage of modern high silica compound rubbers, never running less than 80% rated tire maximum. Remember, the tire was made by the tire manufacturer today, not the motorcycle manufacture 40-45 years ago.
Logged

Garage Residents:
'74 Honda CT70
'74 Norton 850 Interstate
'81 Laverda Jota Mk11 180
'89 Honda RC30
'91 BMW R100GS
'08 Honda XR650L
'08 BMW R1200GS
Pages: 1 [2] 3 Go Up Print 
« previous next »
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!