Page 2 of 2 FirstFirst 12
Results 36 to 65 of 65

Thread: tire pressure conspiracy

  1. #36
    Join Date
    Jul 2011
    Location
    Isle of Mull, Scotland
    Posts
    3,800

    Default Re: tire pressure conspiracy

    I think the label on the door jamb would be the starting point for the informed decisions.
    As mentioned previously, your insurance could possibly be null and void if the pressures differed very much from the manufacturer's recommendations.

  2. #37
    Join Date
    May 2002
    Location
    MD
    Posts
    47,738

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    I always run 50-60 psi in my MTB tires for two reasons:

    1) I like a rounded carcass with firm shoulders, and I want it to stay the EXACT shape I want. As close as possible, anyway. It helps tremendously with contact patch feel at speed, say above 20mph.

    2) I do NOT want to blow a tire landing from a jump, and under inflated tires bend rims, pop beads, and/or explode. My buddies were just telling me about a new jump they built. Itís about 30 feet from lip to lip.
    No, I havenít been thinking of going there. Iíve already been. Itís glorious. No, I havenít thought about jumping it.

    Peace,
    Yes, I Have.

    P.S. I only run 90 in my road tires. I ran 120-150 on the track.
    What width are your mtb rims?

  3. #38
    Join Date
    Jun 2003
    Location
    Central Coast, Ca
    Posts
    21,636

    Default Re: tire pressure conspiracy

    What hasn't been mentioned (I think) is the stated "max. inflation pressure" is combined with a "maximum weight" per tire.
    The actual inflation pressure unless you are at that listed weight will be significantly less, until you get it right. which Lew explained perfectly.

  4. #39
    Join Date
    Nov 2011
    Posts
    5,620

    Default Re: tire pressure conspiracy

    Fuel around here is over $5.00/gallon. I run our tires on the F150 and the Ranger inflated to max cold all year long. I figure the savings in fuel will far outweigh the cost of the tires wearing out a little faster.

    We don't overload and we don't drive fast, ever, and have never had any problems due to tire performance. You racing drivers make it hard on yourselves bombing all over the place. If you're traveling so fast that a bit of tire pressure is enough to cause a blowout or an accident due to poor handling you should simply slow down and make the road a safer place for everyone. Speed kills.

  5. #40
    Join Date
    Mar 2010
    Location
    central cal
    Posts
    15,754

    Default Re: tire pressure conspiracy

    Quote Originally Posted by LeeG View Post
    What width are your mtb rims?
    29mm.

    Peace,
    Robert

  6. #41
    Join Date
    Oct 2018
    Location
    lagunitas, ca, usa
    Posts
    102

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    I always run 50-60 psi in my MTB tires for two reasons ...
    At the opposite end of the spectrum, we'd frequently run 4 psi in the left rear and maybe 8-10 in the right. Fronts didn't matter much, they're mostly for decoration anyhow

  7. #42
    Join Date
    Sep 2005
    Location
    new zealand
    Posts
    3,360

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    I always run 50-60 psi in my MTB tires for two reasons:

    1) I like a rounded carcass with firm shoulders, and I want it to stay the EXACT shape I want. As close as possible, anyway. It helps tremendously with contact patch feel at speed, say above 20mph.

    2) I do NOT want to blow a tire landing from a jump, and under inflated tires bend rims, pop beads, and/or explode. My buddies were just telling me about a new jump they built. It’s about 30 feet from lip to lip.
    No, I haven’t been thinking of going there. I’ve already been. It’s glorious. No, I haven’t thought about jumping it.

    Peace,
    Yes, I Have.

    P.S. I only run 90 in my road tires. I ran 120-150 on the track.
    Interesting. I came late to mountain bikes, after the 2011 earthquakes left the roads so messed up that the road bike was going to get trashed. So I went from 90-100 psi on the roadie, to 50-60psi on the MTB - around the max pressure.
    I rode it like that for several months, before doing an AC joint when the bike and I went different directions one day. While the shoulder was fixin, I had to resort to biking magazines for inspiration, and came across an article on tyre pressure.
    Well, what a revelation! When I got back on the horse, it was running around 30psi both ends, and the difference was night and day better, in every respect.
    Better grip climbing on loose gravel surfaces, way less sketchy going through rock gardens and slippery bits, and far more progressive when letting go, especially the front end - to the point that I have ridden through front end washouts, that I think would have had me eating dirt again at higher tyre pressures (which is what happened when I sprangle the shoulder).
    I flirted with 25-20 psi, but found way too much tyre deflection and squirmy handling with the pressure that low.
    Ps, I have a big mental block on even quite baby jumps, so that isn't really a factor in my tyre pressure requirements :-)


    My car, recommended 32, seems better at 35.

    Pete
    Don't underestimate the power of stupid people in large numbers!

  8. #43
    Join Date
    Oct 2006
    Location
    Livin' in the Golden Triangle
    Posts
    56,735

    Default Re: tire pressure conspiracy

    Gawd, we share the road with these devices. You guys scare me.
    "Travel is fatal to prejudice, bigotry and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome and charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime" Mark Twain... so... Carpe the living sh!t out of the Diem

  9. #44
    Join Date
    Nov 2016
    Location
    Kingsville, Ontario
    Posts
    322

    Default Re: tire pressure conspiracy

    What hasn’t been mentioned is that your new truck rides like a waterbed because it was designed that way. Trucks aren’t designed as the work vehicle of old they are the new family sedan, soft ride lots of gadget. Gone are the days of am radios, three on the tree ,vinyl seats and eight foot beds as standard equipment.

    All I know about tires is they’re round, black and there’s one on each corner of my truck.

  10. #45
    Join Date
    May 2002
    Location
    MD
    Posts
    47,738

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    29mm.

    Peace,
    Robert
    Just guessing you ride a bit fast. My eye ball muscles are out of shape for fast riding and I have too much mass to manage rapid deceleration well.
    Do you remember when Araya came out with 26” rims based on the 20” BMX rims and a few people like Bontrager were cutting down Rigida and Mavic 700c road rims to 26” diameter? It was kinda nuts having 2.1” tires on rims with 13 mm internal width. Do you ride tubeless on the mtn bike?

  11. #46
    Join Date
    May 2002
    Location
    MD
    Posts
    47,738

    Default Re: tire pressure conspiracy

    Quote Originally Posted by L.A Marche View Post
    What hasn’t been mentioned is that your new truck rides like a waterbed because it was designed that way. Trucks aren’t designed as the work vehicle of old they are the new family sedan, soft ride lots of gadget. Gone are the days of am radios, three on the tree ,vinyl seats and eight foot beds as standard equipment.

    All I know about tires is they’re round, black and there’s one on each corner of my truck.
    yup. My daughters friend has a basic ten yr old F150 with passenger tires. Its as comfy as an Oldsmobile Custom Cruiser.

  12. #47
    Join Date
    Mar 2010
    Location
    central cal
    Posts
    15,754

    Default Re: tire pressure conspiracy

    Quote Originally Posted by LeeG View Post
    Just guessing you ride a bit fast. My eye ball muscles are out of shape for fast riding and I have too much mass to manage rapid deceleration well.
    Do you remember when Araya came out with 26Ē rims based on the 20Ē BMX rims and a few people like Bontrager were cutting down Rigida and Mavic 700c road rims to 26Ē diameter? It was kinda nuts having 2.1Ē tires on rims with 13 mm internal width. Do you ride tubeless on the mtn bike?
    That is actually WHEN I developed my love of round tires. And narrow bars. I HATE the modern trend of bars 9í wide. Haha.
    Oh, and I STILL donít like Araya rims.

    Last race I did had a gate that needed passing through right on a hot section of downhill single track. The marshals were adamant about slowing down, as the gate was only 30Ē wide.

    I blew through that sucker at full speed (well, full speed on a single speed going downhill...) and people were amazed. 18Ē wide bars are the bomb!
    Narrow bars are nice for jumping, too. On my bmx bikes (street style dirt jump bikes, not racing bikes) I ran no brakes, and just pushed my grips all the way in to the crossbar, and cut the bar off there. S&M Slam Bars, please...

    I digress. I donít run tubeless because it holds no advantage for me. I only run low pressure in the trials bike and it has beefy enough tires to preclude wheel bite. On a regular MTB I run high enough pressure it donít matter. And tubes are simpler, in the long run.

    I also donít like really wide tires. 2.1-2.2 is fine.

    And, I despise 29ers. They are great for hotlap ďcross countryĒ racing, but lame for jumping, trials, or technical work. You know, mountain biking. Hehe. I think the 26Ē wheel was a perfect compromise for off road.

    Ah, well.

    Peace,
    Robert

    P.S. Of course, this is all theoretical, as I canít really pedal a bike in anger, anymore. I still tool around and do ďsmallĒ jumps, but nothing at all serious bike wise. Or skateboard. I ride around, but no more stunts.

    Although, since the pump track in the yard is getting bigger, I might just ďneedĒ to procure a bmx bike to help test it...

  13. #48
    Join Date
    May 2002
    Location
    MD
    Posts
    47,738

    Default Re: tire pressure conspiracy

    Thx for the response, I just got back from a meandering trail ride on the Clem Smith w 650B x 60 mm tires, I’m enjoying the fat tars.

  14. #49
    Join Date
    Mar 2010
    Location
    central cal
    Posts
    15,754

    Default Re: tire pressure conspiracy

    Quote Originally Posted by LeeG View Post
    Thx for the response, I just got back from a meandering trail ride on the Clem Smith w 650B x 60 mm tires, Iím enjoying the fat tars.
    Thatís not a bad wheel/tire size. The 650b is still imminently hoppable and flickable, and you ainít yet to 3Ē, which up getting very heavy...

    For the record, I own a 29er. I mean, itís not like Iím gonna go buy a bike if I still have one someone gave me free.

    Yes, Iíll ride a 29er if itís free.

    Peace,
    Bill Board

  15. #50
    Join Date
    Mar 2001
    Location
    Grosse Pointe, Michigan, USA
    Posts
    13,952

    Default Re: tire pressure conspiracy

    Might add that the "recommended" tire pressure is influenced by the fuel-economy testing numbers, which tends to make the pressure a little high rather than low. The max pressure would be unsafe.

  16. #51
    Join Date
    Oct 2003
    Location
    Hell
    Posts
    90,746

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    Thatís not a bad wheel/tire size. The 650b is still imminently hoppable and flickable, and you ainít yet to 3Ē, which up getting very heavy...

    For the record, I own a 29er. I mean, itís not like Iím gonna go buy a bike if I still have one someone gave me free.

    Yes, Iíll ride a 29er if itís free.

    Peace,
    Bill Board
    Would you ride a fattie if it was free????

    get on your bikes and ride!
    Simpler is better, except when complicated looks really cool.

  17. #52
    Join Date
    Mar 2010
    Location
    central cal
    Posts
    15,754

    Default Re: tire pressure conspiracy

    Quote Originally Posted by Paul Pless View Post
    Would you ride a fattie if it was free????

    get on your bikes and ride!
    No. Not unless I lived where it snowed regular. Some of my Oregon friends do fat bike rides together in winter for giggles.

    Me? Iíll pretty much ride any bike for the right price. But I do have limits. No Lefty suspension sticks, no weird clipless pedals, and no fat tired bikes.

    As to riding, well, I was today. The wet time is when the track grows and changes. We are increasing the size of the table top, adding 6 whoops in one spot, and 10 others interspersed through the double lollipop shape course. The ďcorkscrewĒ berm, and the ďmain turnĒ berm are also going higher, with steeper tops.

    I mean, someone has to test them. Right? Think of the kids...

    Peace,
    Robert

  18. #53
    Join Date
    May 2002
    Location
    MD
    Posts
    47,738

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    That’s not a bad wheel/tire size. The 650b is still imminently hoppable and flickable, and you ain’t yet to 3”, which up getting very heavy...

    For the record, I own a 29er. I mean, it’s not like I’m gonna go buy a bike if I still have one someone gave me free.

    Yes, I’ll ride a 29er if it’s free.

    Peace,
    Bill Board
    yeah, flicking and hopping aren’t happening these days. Btw, why the heck was 700c called 29’r?

  19. #54
    Join Date
    Mar 2010
    Location
    central cal
    Posts
    15,754

    Default Re: tire pressure conspiracy

    Quote Originally Posted by LeeG View Post
    yeah, flicking and hopping arenít happening these days. Btw, why the heck was 700c called 29ír?
    700c isnít a measurement, itís a size. There was A, B, C, etc. Rmember 27Ē rims? And how theyíre JUST different?

    Well, a 700c rim with a fat, knobbly tyre on it is about 29Ē. And, they needed a slick marketing ploy to sell their new idea. Saying beefy, flat bar cross bike sounded weird, and everybody knows mountain bikes have 26Ē wheels.

    Because I knew some cats who went on some Jobst rides, as I said elsewhere, and spread the idea to us, we rode road bikes and cross bikes on all the trails around here for years before the 29er was born. I actually rode drop bars on my mountain bikes for years.

    Peace,
    Rambler

  20. #55
    Join Date
    Sep 2005
    Location
    new zealand
    Posts
    3,360

    Default Re: tire pressure conspiracy

    Quote Originally Posted by amish rob View Post
    That is actually WHEN I developed my love of round tires. And narrow bars. I HATE the modern trend of bars 9í wide. Haha.
    .
    I fixed the wide bar problem on my previous and current MTB, with a hacksaw. There is plenty of room for all the junk on the stock bars, even with a couple of inches pruned off each end.
    Without that little mod, I feel like I'm doing a sort of gorilla impression on the bike.

    Pete
    Don't underestimate the power of stupid people in large numbers!

  21. #56
    Join Date
    Feb 2007
    Location
    Do you have a warrant?
    Posts
    4,216

    Default Re: tire pressure conspiracy

    Quote Originally Posted by Gold Rock View Post
    I bought a new truck this year. Drove like a waterbed. I checked the tire pressures; 36 psi. I looked at the sidewalls of the tires; "max inflation pressure - 51 psi". I immediately proceeded to inflate the tires to the tire manufacturer's recommended pressure. Everything improved. Everything. I went to the dealer to express my displeasure and shock at sending a new unit down the road with such grossly underinflated tires. Hadn't they learned anything? Don't they know that improperly inflated tires wear faster? run hotter? degrade mileage? I was told by the Ford factory technician that 36 psi was the factory recommended pressure for my vehicle. "Look at the sticker in your door jamb," he says, and he was right, there's a sticker right there stating that 36 psi is where they should be. What? My wife comes home yesterday saying her 2014 Corolla's dash light was advising of an underinflated tire. I check the pressure. 31 psi. I look at the sidewall; 51 psi. What the hell's going on here?? I look in the door jamb... there's a sticker saying "35 psi". My son has a new set of tires put on his car from Discount Tire (a local chain). Same thing; wildly underinflated relative to the stated max pressure on the tire's sidewalls. Since when have third parties decided they know better than the folks who engineer, test, and manufacture the tires? I spent many years selling tire related products and we were annually visited by representatives from tire makers; Firestone, Goodyear, Carlisle, etc. Every one of them would admonish stridently that it was of the utmost importance to maintain tires at their stated max inflation pressures for all of the reasons I mentioned above and more. What's going on???
    DO NOT overinflate beyond the VEHICLE recommendations. The max pressure on the tire is for just the tire which is used on multiple vehicles, each with their own characteristics. There are other factors in play:

    1) Handling balance. Inflation pressures are often used to keep the handling neutral, or understeer, which is easy to manage by the average Joe. Oversteer is bad, much more difficult to control, and can lead to spins and rolls. Old 911s and Deloreans ran much bigger tires in back and typically rock hard versus the fronts. The first model Ford Explorer (solid rear axle), had low pressures in the front tires to maintain understeer. So low that in hot states, the front tires blew. So why didn't they just raise the rear pressures? --->

    2) Overinflation can cause excessive wear of the tread center, and reduce the tire contact patch (hurting handling), and reduce ride quality, AND actually destroy the vehicle structure. The latter was a problem on Opel Mantas, designed in Germany (very smooth roads, no potholes) and sold through GM here in the states. The energy crisis hit and suddenly all tires were specifying 35 PSI max for reduced rolling resistance, and many of our states have a pothole problem. Mantas starting cracking at the front strut towers, shock mounts, etc.

    Caveats: My current car has a set of Michelins, only one tire available at Costco in 15" any more. Stiff sidewalls for good steering feel, but rode like iron at the specified pressure of 31. Lowered them 4 psi and were great, but I lowered all 4 tires the same amount to maintain handling balance. Likewise, if the steering feels mushy due to soft sidewalls, you may be able to raise the pressures if the tires allow it, you do it equally on all the tires, the overall stiffness of the tire is not a problem for the vehicle structure, and they don't start to wear excessively in the center of the tread.

    Don't even get me started on the fact that changes in pressure and therefore stiffness changes the slip angle of the tire, which also affects Ackermann steering. When a car is designed, the first thing they do is select the tire they plan to use, and design the chassis around that tire characteristics. It all starts with tires.

    Signed, a former suspension engineer.
    Last edited by Bob (oh, THAT Bob); 12-08-2018 at 01:25 AM.
    When you can take the pebble from my hand, it will be time for you to leave.

  22. #57
    Join Date
    Mar 2010
    Location
    central cal
    Posts
    15,754

    Default Re: tire pressure conspiracy

    Quote Originally Posted by epoxyboy View Post
    I fixed the wide bar problem on my previous and current MTB, with a hacksaw. There is plenty of room for all the junk on the stock bars, even with a couple of inches pruned off each end.
    Without that little mod, I feel like I'm doing a sort of gorilla impression on the bike.

    Pete
    I feel like a little kid who stole big brotherís bike.

    Peace,
    Glad Iím Not Alone

  23. #58
    Join Date
    Sep 2009
    Location
    Saint Helena Island, SC
    Posts
    9,436

    Default Re: tire pressure conspiracy

    On the racecar I used to see a 3-4 psi increase cold to hot. DF64C8D3-C9B5-44B7-8297-816EB8A8CC83.jpg
    Fight Entropy, build a wooden boat!

  24. #59
    Join Date
    Jul 2011
    Location
    Isle of Mull, Scotland
    Posts
    3,800

    Default Re: tire pressure conspiracy

    And I bet they were not inflated to maximum pressure all round!
    Not many circuits where you are now though?

  25. #60
    Join Date
    Sep 2009
    Location
    Saint Helena Island, SC
    Posts
    9,436

    Default Re: tire pressure conspiracy

    Quote Originally Posted by birlinn View Post
    And I bet they were not inflated to maximum pressure all round!
    Not many circuits where you are now though?
    Think we ran around 20psi.
    Actually there are 3 within a couple hours drive. Roebling Road, Carolina Motorsports Park and the old Grand Prix track on Hutcheson Island at Savannah.
    Fight Entropy, build a wooden boat!

  26. #61
    Join Date
    Jan 2004
    Location
    Norwich,United Kingdom
    Posts
    5,771

    Default Re: tire pressure conspiracy

    Quote Originally Posted by Reynard38 View Post
    On the racecar I used to see a 3-4 psi increase cold to hot. DF64C8D3-C9B5-44B7-8297-816EB8A8CC83.jpg
    I believe I can guess who built the car.Formula Atlantic?

  27. #62
    Join Date
    Jul 2011
    Location
    Isle of Mull, Scotland
    Posts
    3,800

    Default Re: tire pressure conspiracy

    Quote Originally Posted by Reynard38 View Post
    Think we ran around 20psi.
    Actually there are 3 within a couple hours drive. Roebling Road, Carolina Motorsports Park and the old Grand Prix track on Hutcheson Island at Savannah.
    Failed to notice the SC at the end of your location. The other St. Helena Island is rather remote!

  28. #63
    Join Date
    Feb 2007
    Location
    Do you have a warrant?
    Posts
    4,216

    Default Re: tire pressure conspiracy

    Quote Originally Posted by Reynard38 View Post
    On the racecar I used to see a 3-4 psi increase cold to hot. DF64C8D3-C9B5-44B7-8297-816EB8A8CC83.jpg
    As you know, ideal gas laws at work, pressure change directly proportional to temperature increase in Kelvin degrees, slightly less ideal due to the elasticity of the tire.
    When you can take the pebble from my hand, it will be time for you to leave.

  29. #64
    Join Date
    Feb 2011
    Location
    U.K
    Posts
    703

    Default Re: tire pressure conspiracy

    Low tech way of checking tyre pressure, obviously needs to be rechecked when loaded/unloaded, but it gives a good visual indication of what is happening to your tyres at different pressures i.e too high/ low and you lose contact area, reducing braking etc
    https://www.intercotire.com/using_ch...etermining_psi

  30. #65
    Join Date
    Apr 2005
    Location
    Hills of Vermont, USA
    Posts
    26,050

    Default Re: tire pressure conspiracy

    Lots of differing opinions here - but at least all show that folks pay attention to tire pressure. What percentage of drivers would pay attention without TP monitors? 1% maybe? "Yeah, I've had that clunking noise in the front for months - I'm used to it." "Oh is that light on my dash supposed to look like an engine? It's been lit up for almost a year now". Etc. etc.

    As a person who does pay attention, I can say the Nokian, Hankook, & General AltiMax snow tires all need to be 4 or 5 lbs over factory recommendation or the handling gets really sloppy. Doing so also improves fuel economy by 3-4 MPG on the highway - bringing it back up to close to what summer tires deliver.
    "If it ain't broke, you're not trying." - Red Green

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •