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Author Topic: K75s Tyre Pressure  (Read 15159 times)

Offline Martin

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K75s Tyre Pressure
« on: November 29, 2015, 09:37:43 PM »
 :dunno Have previously ran Michelin Macadams,Avon Venoms and Bridgestone BT45s. Wasn't to happy with the mileage 10,000 Km on the the last  BT45s.Asked a local tyre dealer for his recommendation.He suggested Michelin Pilot Activs.I have had them about 2 weeks, and am happy with the way they handle.The only slightly confusing thing is when I asked him what pressure to run,he said 42 psi as written on the side wall (this is Maximum recommended pressure)  and 36 psi in the front.I have previously run 38 psi rear & 36 psi front.I weigh 65kgs (143 lb ).I have looked a a Michelin website and they recommend 36 psi rear & 32 psi front.A couple of mates also give conflicting pressures.
Can anybody help clarify.
Regards Martin
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Offline Laitch

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Re: K75s Tyre Pressure
« Reply #1 on: November 29, 2015, 09:55:12 PM »
If you stay equal to or greater than Michelin's minimum specs and equal to or less than the maximum specs on the tire with the front and rear tires at the specified proportions, I'd think you'd be good to go, Martin. The max specs are probably for two up, hulks, folks who like a pretty firm ride, and to prevent over-inflation.
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Offline Martin

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Re: K75s Tyre Pressure
« Reply #2 on: November 29, 2015, 10:12:16 PM »
Laitch the guy ( Ex BMW Technician) who put on the tyre knows I only ride solo. I appreciate your input and will ignore it completely and probably run what i have always run, unless I find anything to the contrary. I just find it strange that there is so much off a differential.
Regards Martin
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  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline F14CRAZY

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Re: K75s Tyre Pressure
« Reply #3 on: November 29, 2015, 10:34:00 PM »
I personally run the max as indicated on the sidewall
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  • Grand Rapids, MI
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Offline Scott_

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Re: K75s Tyre Pressure
« Reply #4 on: November 29, 2015, 10:36:39 PM »
Don't forget that too little tire pressure can result in bent rims from pot-holes, road debris, etc......
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Offline The Mighty Gryphon

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Re: K75s Tyre Pressure
« Reply #5 on: November 29, 2015, 11:03:37 PM »
Are there any reasons why we shouldn't use the tire pressures listed on the name plate.  Weren't these pressures determined by the designers, engineers, and test riders as best for the safest operation of the bike knowing the product liability issues that could arise from posting incorrect information? 

These bikes were intended for sale in the U.S. from the very beginning weren't they?  The most litigious society in the world.
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  • In my garage in Marilla, NY
  • '91K100RS White/Blue
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Offline Scott_

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Re: K75s Tyre Pressure
« Reply #6 on: November 30, 2015, 07:53:19 AM »
Quote from: The Mighty Gryphon on November 29, 2015, 11:03:37 PM
Are there any reasons why we shouldn't use the tire pressures listed on the name plate.  Weren't these pressures determined by the designers, engineers, and test riders as best for the safest operation of the bike knowing the product liability issues that could arise from posting incorrect information? 

These bikes were intended for sale in the U.S. from the very beginning weren't they?  The most litigious society in the world.

What you say is true, from when the bikes where built 20-30+ years ago.
Tire manufacturing processes have (hopefully) improved, material quality equally should be better, though lately I'm beginning to wonder considering the downward trend in manufacturing quality as a whole.
If you are still running Bias ply tires, then by all means start with the listed/published name plate pressures.

Those of us running Radial tires, well, the name plate pressures weren't calculated for use with Radials. I guess we are on our own there, as long as you don't exceed the printed Maximum pressure or weight rating of the tire.

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  • My Garage
1995 K1100LT 0302044
2017 FLHTK Ultra Limited
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Offline johnny

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Re: K75s Tyre Pressure
« Reply #7 on: November 30, 2015, 08:39:53 AM »
greetings...

every tior on my motobricks are inflated to the maximum pressure as stated on the sidewall of the tior... i check them everyday that i ride...

when low... even by just a pound... they getts pumped up to the max...

differential... abouts rs eleven hundert rear tiors... the shinko podium rear max is 42psi... the metzger me880 rear max is 54psi... gotts to look on there and pump accordingly...

i gotts the shinko on the 1up motobrick and the metzger on the 2up motobrick...

cause just as important is the load rating at maximum pressure...

more here...

j o
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Offline beemrdon

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W last week told me to run my Michelin Pilot Road tires at front:36 and rear:42
« Reply #8 on: November 30, 2015, 08:08:38 PM »
The guys at MAX BMW in North Hampton, NH last week strongly suggested that I run my K1100 LT with Michelin Pilot Road radials at - Front: 36; Rear: 42. I had been running a few pounds lower pressures so that the last PR 2 rear cupped or scalloped before wearing out. I had MAX change it out for a PR4. The PR2 rear had 11,000 miles on it total. Coulda' been 12,000 if not for the scalloping.
I probably could have gotten another 1,000 miles out of it had I known to run at a higher pressure because there was still tread left.

The front has about 7,000 miles on it now,  I haven't changed it yet.  It has cracking between treads over an inch long, all along the side of the tire...same issue, too low a pressure.  I am going to get rid of it this spring, even though it is not nearly worn out. Safety first.
                                                                   
                                                 
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Offline F14CRAZY

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Re: K75s Tyre Pressure
« Reply #9 on: November 30, 2015, 08:23:15 PM »
I have yet to hear a drawback of running a tire at its max pressure, only issues with pressures too low
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  • Grand Rapids, MI
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Offline beemrdon

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Re: K75s Tyre Pressure
« Reply #10 on: November 30, 2015, 08:48:43 PM »
Smaller contact patch? Harder ride? Less traction?   Less stopping power?    :dunno

I have Hyperpro front springs and an Ohlins rear shock...if that's what you want to call it - it's almost like a hard-tail. The ride is very stiff and approaches jarring on rough surfaces. I am going to work on the suspension this spring to get a more of compliant ride. My running a lower tire pressure was to compensate for the uncomfortable discomfort of it all. BTW, I also have a Corbin seat on it which is also very hard. And yes, a Russell day-long would make a big difference....In my wallet.
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  • The South West... best motorcycling in the US! Longest riding season = 12 months per year
  • 1996 K1100 LT SE, Aspen Silver - Now with 159,xxx miles.

Offline K1300S

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Re: K75s Tyre Pressure
« Reply #11 on: November 30, 2015, 08:53:26 PM »
Quote from: F14CRAZY on November 30, 2015, 08:23:15 PM
I have yet to hear a drawback of running a tire at its max pressure, only issues with pressures too low

(the below applies to tires with street tread compounds, not race tires)
drawbacks
-smaller contact patch
-harsher ride
-less warning before breakaway
-decreased traction in wet conditions

advantages
-slightly lower rolling resistance
-greater rim impact resistance
-better handling feel (not necessarily better handling)

there is no "right" tire pressure.  every level is a compromise of many factors.  the best is what works for you.

there is a wrong tire pressure....below factory recommendation.  low pressure is dangerous due to tire sidewall flex affecting predictability, increasing heat build up and damage to tire.
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Project Thread "K75s Midlife Refresh"
http://www.motobrick.com/index.php/topic,7810.0.html

Offline Scud

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Re: K75s Tyre Pressure
« Reply #12 on: December 01, 2015, 01:19:25 AM »
On my street bikes, I generally run a few pounds above the motorcycle manufacturers' recommendations. I ignore the max pressure on the sidewall. I experiment a little until I find a front/rear pressure that I like. I run a couple more pounds of pressure if I know I'm going to be going straight for a long time and don't have any fun twisties on the route.
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  • Carlsbad, CA
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