Tire pressure for a big fella

Discussion in 'Clydesdales 200lb / 90kg + riders' started by Audiokat, Feb 16, 2016.

  1. Audiokat

    Audiokat New Member

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    I'm curios if there are any out there that have done some thinking about tire pressure as an overweight rider.

    I'm 6'1 and about 280lbs. It seems to me that 90psi to a 180lb rider is likely going to be different than it would to be for a 280lb rider. I can only assume that the lower the pressure the more road surface contact and the more work needed to turn the pedal.

    Conversely it also seeks an overweight rider is putting more stress on a highly inflated tire. I currently keep my back tire at 110psi and front at about 100psi


    Do any hefty fellers out there go with higher pressure or am I just overthinking it.
     
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  2. Leo001

    Leo001 New Member

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    So I"m about 255, I stay right around the recommended pressure on the sidewall (max inflation) I font get many flats, I ride numerous types of bikes with varying tiers (road, hybrid and occupationally.
    mountain)
     
  3. Corzhens

    Corzhens Well-Known Member

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    When I first started biking, I was a bit skinny so I have no problem with that. But when my friend came and rode my bike, I was teasing her that the tire of my bike is flat. That flat tire line is a normal joke to mean you are overweight. But seriously, I don't think the tires would complain unless you weight more than 200 pounds and that's not common for small people like us.
     
  4. Weatherby

    Weatherby Well-Known Member

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    Go with a wider tire.

    28 mm or 32 mm width if your frame has the clearance
     
  5. Bicycleman

    Bicycleman Well-Known Member

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    I ride Continental Ultra Sport folding tires, and I keep my tires pumped up to 120 psi. Now, I don't check the inflation every day ,though. I always re-inflate on Friday night before Saturday's long ride.
     
  6. Rob Tunes

    Rob Tunes New Member

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    http://www.dorkypantsr.us/bike-tire-pressure-calculator.html

    I highly doubt you have the same loaded weight on each wheel, so you should not have the same pressure. If you ride a race bike, you may have 55/45 Rear/Front ratio, or perhaps a 60/40 ratio if you are on a more relaxed road bike. The best way to find out is to get a friend to help, and weigh each wheel with you on the bike , in kit. Be sure to level the wheel not being weighed. (A wall helps). Then, write down the loaded weight per wheel, and determine your ratio.

    Why? Rolling resistance on most tires only increases after a 15% "drop" in tire height, under load. That 15% "drop" varies by the width of the tire, as wider tires need less pressure to maintain that 85% height threshold.

    Determine the weight per loaded wheel, and then use the link. Use the pressures listed. I generally do, and add about 3 psi to each tire. I wouldn't recommend it if it didn't work for myself and my riding friends. Most of us used to run 105-120 psi based on our weight and what we "thought." Now, we run a proportional psi based on our weight, at least with some background information.

    If you are on this Clydesdale forum, you likely need 90-100 in the front, and 130+ in the rear. You'd be surprised how much nicer the bike rides, and you won't see any increase in harshness. I was skeptical about this method (180lbs) but it's worked well for me, both on 700x23's, 700x25's, and tubulars from 700x23 to 700x24.
     
    #6 Rob Tunes, Mar 20, 2016
    Last edited: Mar 20, 2016
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  7. Jcycle

    Jcycle Active Member

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    Bah! People really overthink crap sometimes. Just use the recommended pressure on the sidewall and be done with it.
     
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  8. maydog

    maydog Well-Known Member

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    Your pressure is only too low if you are experiencing handling problems, excessive rolling resistance or pinch flats. I am 100+kgs and usually run the pressures at or near the max recommended for the tire on my 700x25c tires.
     
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  9. Froze

    Froze Well-Known Member

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    No you cannot use the recommended psi on the sidewall, bike tires are a lot like car tires. Inflation of a car tire is based on the weight of the vehicle which is why you look on the door sticker to get the PSI they recommend regardless of the fact the max pressure on the car tire may be 45 or so. Bicycle tires are the same way, the problem is bikes don't come with a sticker because the bike's weight is not as important as the rider's weight but both are added into the calculation. So what is the recommended PSI for a rider vs the tire size? see this calculator, but use the second one only:

    http://www.dorkypantsr.us/bike-tire-pressure-calculator.html

    So how this works is you enter the total weight of your bike in ready to ride condition and your weight with cycling clothes on and enter that total in the first box. Skip the second box. In the third box you enter your front tire size, and do the same for the fifth box for the rear tire. When you finish that the calculator automatically calculates your idea pressure give or take 5 psi depending on your own personal likes of how a tire should feel or road conditions, rough roads you should drop the psi by 5, in rain as much as 10 drop, on very smooth streets a 5 psi increase could be fine.

    Now note those PSI figures, if they exceed the maximum psi on the tire label then you need the next size up, so to find out if the next size up works simply go to the drop down and enter the next size up tire, if it still exceeds the max rated psi then go to the next size up. On my commuter bike I have a wider tire on the back then in the front, you can do that too but you won't be able to rotate tires (more on that at the end of this). You can see from the calculator the front tire doesn't need to be as wide as the rear IF you don't want it to be.

    The subject of rotating, some people do and some don't there is no right or wrong. What I do is when the rear tire wears out I move the front to the rear and put a new one on the front since a front flat is potentially the most dangerous. However on my commuter I have two different size tires, what happens in this case is the rear tire will last close to same as the front because of the size difference, so I don't rotate those tires. If by chance the front tire does last longer then I'll put it on another bike. Again this is just how I do it, others don't rotate at all, but I'm a tightwad and I get as many miles as I can from a tire instead of throwing away a half worn front just because the rear is worn out.
     
  10. Froze

    Froze Well-Known Member

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  11. Mr. Beanz

    Mr. Beanz Well-Known Member

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    120 psi for 20 years, never a problem on trail or paved roads. 35 centuries, numerous rides through the mountain roads. Never a problem in 80,000+ miles that I have logged.
     
  12. Brent Lytle

    Brent Lytle New Member

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    I weigh 315lb. I run 28mm tires. 100psi front, 110psi rear. 2500miles this year so far. No pinch flats. I’m sure my rolling resistance is way higher than a 150lb guy, but I can move along between 18-20mph on the flats. Now that’s a tire torture test!
     
  13. LONGPATH

    LONGPATH New Member

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    I ride on Specialized Armadillos and I am an uber Clyde. Just pump them up to high end of pressure. No problems.
     
  14. Froze

    Froze Well-Known Member

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    You may not be running into any problems except tire wear is quicker than it should be. Before we get into a tug of war here please see this site: http://www.dorkypantsr.us/bike-tire-pressure-calculator.html This is a long known idea pressure calculator based on the 15% drop method that has been proven time and time again over the last at least 40 years and is still recommended today. If you go to the second calculator and enter your weight including wearing your cycling kit PLUS your bike's weight including water bottles you'll find something interesting which I'll address in a bit. For example, you said you weigh 315 pounds, I'm assuming that's you naked, add say another pound for clothing and shoes, now let's add in your bike weight, I have no ideal what bike you have but let's assume fully loaded and ready to ride it weighs 20 pounds, so 315 plus 1 (not a big deal but should be noted) plus 20 equals 336 so enter that number in the first box that says Rider + Bike. Next the second box that says F/R Weight distribution leave at 40/60 if you have a typical road bike. Next enter in your tire size front and rear which you said was 28mm. When you enter the tire size the calculator automatically will provide the PSI level you should be at with in 5 PSI plus or minus depending on rider preference toward comfort or speed.

    Here's the interesting part I promised I would discuss. Note the recommended psi, the front is 101 psi so your current 100 is fine for you and your 28mm tires your using. However the rear is not fine, note for the rear it says 154 psi, I guarantee you that your rear tire will not allow you to put that much air into it. So what does this mean if your running over 30 pounds less than you should? You did answer that by mentioning rolling resistance, so that is one issue; the other issue which I'm surprise you haven't encountered is snake bites but you might be riding on really good roads so that may not be an issue; but in addition to low of PSI in a tire will allow the tire to pick up more road debris increasing your chances of a flat because you are riding partially on the sidewall of the tire and most flat protection belts are only on the tread and not the sidewall, and the rear by nature of its position is more prone to flats anyways so you need to find ways to reduce those chances and not increase it; also you will suffer from decrease handling, and increase and uneven tire wear with the fastest were happening on the sides instead of down the middle.

    For wet road conditions your tires will have better wet handling response by lowering the pressure all around by about 10 psi in the front and 12 in the rear.

    So now you're screaming at me, sorry. But there is a simple solution, go back to the tire calculator and put in a 32mm tire for the rear and see what happens...BOOM...suddenly it's only 119 psi, which should be close to the max PSI on the sidewall. Another option, if riding comfort is your priority you could go with 32's all the way around which of course means lower front psi which will reduce road vibration, but a lot of road bikes won't accept a 32 on the front so you have to check your bike. Having mentioned what a bike may or may not take in tire size it's also highly possible you can't put a 32 on the rear either, so now what? Some tires are rated for heavier riders, tires like the Conti Gatorskin Hardshell, Panaracer Pasela, Specialized All Condition Armadillo, or All Condition Armadillo Elite, and Bontrager Race Lite Hardcase, there may be some others out there as well but I that's all I can think of right now. Anyways that list of tires you can use in a 28c but you would have to use the max psi on the rear that's listed on the sidewall. Also using a bit thicker tube, meaning not a racing tube, but a cheaper tube, will help with keeping the sidewall a tad stiffer.

    Please note; this is only my opinion, what you do is up to you, but to have the best handling, flat protection, and wear you should seriously consider making some changes, if none of that is important to you then just keep on keeping on.
     
  15. cyclintom

    cyclintom Active Member

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    I have 32mm road tires on my gravel bike. I don't have to pay the slightest attention to it off-road but the 80 psi tires are too high friction on roads. I use 23 mm road tires at 120 for my 210 lbs bike rider combo. I'm about to try 90 psi on some 28 mm's to see how that turns out. I'll let you know in a couple of weeks.
     
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