# Rider weight vs Tire pressure



## mariomal99

Just wondering what tire pressure everyone else is riding?

6 Ft tall
200 pounds
23mm Michelin Pro3 @ 120psi Rear and 110psi Front


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## Doolab

Try this tire pressure calculator for some answers
Bicycle tire pressure calculator


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## bayAreaDude

Doolab said:


> Try this tire pressure calculator for some answers
> Bicycle tire pressure calculator


Ok, I'm a moreon and will admit it. I'm 170 and ride 25mm tires and this calculator says I should be at 156 psi. Am I supposed to halve my weight because the calc is designed for a single wheel?

Reading the linked to PDF says your weight is distributed 60/40 back to front for a racing bike which gives 56 psi for my front tire. I'm scared they'd peel off the rims around a turn with pressure that low. I think I'm with the detractors of the 15% drop here Tire pressure (Jobst Brandt) . I'll stick with 90 front and 100 back - plenty comfy for me.


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## tazzmacd

well according to the web site it is per tire, their note reads

If the calculated pressure exceeds your tire’s rated maximum, choose a wider tire. If the calculated pressure is below your tire’s safe minimum, choose a narrower tire.

So I guess you need to choose a wider tire


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## jmorgan

That site is per tire with the weight of the bike included, half the weight or 40/60 f/r


or use the 2nd calculator or the 3rd one which is general


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## Peter P.

135lbs. 75-80psi., front and rear. 23mm tires.

I think most people WAY overinflate their tires, even for racing.


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## Doolab

bayAreaDude said:


> Ok, I'm a moreon and will admit it. I'm 170 and ride 25mm tires and this calculator says I should be at 156 psi. Am I supposed to halve my weight because the calc is designed for a single wheel?


The first one is giving you the calculated tire pressure if the whole rider's weight was on one wheel (a la unicycle). The second calculator gives more realistic tire pressures for road bikes.


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## Bizman

Depending on the tires you are using there may be different reconmendations for weights and pressures. I am using the Hutchinson "Intensive" tubless tires (25 mm) front and rear. I weigh 130-135 with clothing, shoes, pack, etc, I run 90 psi fr & rear. The ride has been comfy! 

I just got 2800 trouble free miles until the sidewall split on the rear tire, this tire was also getting a pretty good flat spot on it but the cords were not showing. The front tire looked like it could have went quite a few miles longer. 

As a guide on the instructions for these specific tires (the way I understand it) is:

Up to 130 lbs is 87 psi
130 - 150 lbs is 95 psi
150 - 175 lbs 101 psi
175 - 195 lbs is 109 psi
195 up says 116 psi 

I am sure these are only guidlines but it has worked well for me. If you are running "tubed tires" you will probably want to ride them higher to avoid pinch flats.


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## NextTime

Me - I weigh 175. I ride 24mm Vittoria Open Pave clinchers at 95-97 psi on the front and 100-103 psi on the back. Works great for me.


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## Andy Pancroft

bayAreaDude said:


> Ok, I'm a moreon and will admit it. I'm 170 and ride 25mm tires and this calculator says I should be at 156 psi. Am I supposed to halve my weight because the calc is designed for a single wheel?
> 
> Reading the linked to PDF says your weight is distributed 60/40 back to front for a racing bike which gives 56 psi for my front tire. I'm scared they'd peel off the rims around a turn with pressure that low. I think I'm with the detractors of the 15% drop here Tire pressure (Jobst Brandt) . I'll stick with 90 front and 100 back - plenty comfy for me.


+1!!!! Standard for me has always been 10psi lower in front than rear. I'm 190 lbs and run 100/110 - the cal says I should be 77/156!!!


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## cxwrench

mariomal99 said:


> Just wondering what tire pressure everyone else is riding?
> 
> 6 Ft tall
> 200 pounds
> 23mm Michelin Pro3 @ 120psi Rear and 110psi Front


you need bigger tires. *for sure*. get some 25mm tires, and if you're not the type that runs into every hole in the road try about 100rr/90frt. if you are the type that hits every thing, go to 28mm tires at about the same pressure.

and there is a 'wheel/tire' section of the forum for stuff like this.


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## Drew Eckhardt

mariomal99 said:


> Just wondering what tire pressure everyone else is riding?
> 
> 6 Ft tall
> 200 pounds
> 23mm Michelin Pro3 @ 120psi Rear and 110psi Front


180 pounds + 5 pounds of clothes and stuff + 15 pounds of luggage commuting = 200 pounds

25mm Continental GP 4 Season and/or Gatorskins. I up-sized to match the girth I gained graduating from 145 pound climber status, dropped my pressures close to what I ran as a light guy, and regret not doing that sooner.

90-95 front and 95-100 rear (I add air once a week and the five pounds is what it actually looses. Each time I measure my gauge eats 2.5psi; that's taken into account here and I don't measure after pumping the tires up. I do _not_ run latex or other light tubes that outgas faster).

Pleasant ride, pressure high enough it doesn't feel sluggish, no pinch flats in spite of not doing the best job avoiding sunken utility covers.


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## Gimme Shoulder

I'll give you a different perspective.... Don't overthink it. It's not that tough. Find pressures that feel good to you that are below the max pressure stamped on the tire. I'm 5'-11, 195, and run 23mm GP4000s at somewhere between 100-110ps, with zero problems. I've run them as low as 90psi with no issues, but I like them a bit firmer. The roads around here are good, but not great. If I run into a pothole or ridge that is bad enough to pinch flat at 90psi, it's because I'm not paying attention. (My opinion, of course). The Continental chart tells me to use the max pressure of 120psi for my weight, but at that pressure they are super ball bouncy, and I don't like that.


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## donttazmebro

My bikes are around 18lbs and im 175lbs I ALWAYS ride in between 90-100psi. prior to this rule i would ride above 110 and would get flats fairly often. Now I can't remember the last time i changed a flat that wasn't my own stupid fault when putting the tube in (pinched)


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## PTJ

To give another point to think about...I have found most pressure gauges on the pump vary 5-10 psi.


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## danl1

Another thought to add: If one does choose to follow the calculation route, don't take the 60/40 split as a given. A bathroom scale and a block or roughly equal height will make it a short matter to calculate your own split.

The proponents of the calculation are focused on utility and long-distance riding, the detractors on old-school beliefs and fears in a racing context. I don't believe either group has a lock on the one ultimate truth, but bracket reality so that users can decide where they fit.

I'm also not completely comfortable with the outcomes of that calculator relative to the original research. I'd recommend finding Jan Heine's original articles and drawing your own conclusions. There are also a couple of places to input parameters for tire size, etc. so worth being careful there.


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## EuroSVT

I was waiting for this to get moved. Seems it's staying so I'll ask:

What about recommended minimum PSI? The tires I'm on now have a 100 minimum - 145 Max listing. I like the way they perform & feel near the minimum. Just seems strange that someone with my numbers (5'9" - 160) would ride at the minimum. I have played around with higher pressure but the only thing I noticed was a harsher ride. 

Vittoria Rubino Pro III's btw, with the 150 TPI casing.


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## danl1

EuroSVT said:


> I was waiting for this to get moved. Seems it's staying so I'll ask:
> 
> What about recommended minimum PSI? The tires I'm on now have a 100 minimum - 145 Max listing. I like the way they perform & feel near the minimum. Just seems strange that someone with my numbers (5'9" - 160) would ride at the minimum. I have played around with higher pressure but the only thing I noticed was a harsher ride.
> 
> Vittoria Rubino Pro III's btw, with the 150 TPI casing.


Those sidewall numbers of Vittoria's are interesting, because while the upper value is meant to be a limit, the bottom is meant to be a recommendation. If you bought them aftermarket, it's (sort of) discussed on the packaging. If not, here's some detail.

Recommend Tire Pressure « Vittoria

Note that their chart recommends pressures lower than their sidewalls say. You'd also notice that these are for weights lower than you, which is answered by the fact that they don't differentiate front to rear - these are essentially 'rear' starting points, and most riders will be able to move significantly lighter in the front. 

Their approach is solid - start in one spot, go softer until it feels squishy, go harder until it feels jittery, and you have a range to work within, depending on your use and conditions. Much better than generic calculations if you have the patience for it.


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## whason

Very fascinating thread. I thought my doing 105 front and back was pretty standard. Having not asked anyone had no idea this was so complicated.


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## cxwrench

EuroSVT said:


> *I was waiting for this to get moved.* Seems it's staying so I'll ask:
> 
> What about recommended minimum PSI? The tires I'm on now have a 100 minimum - 145 Max listing. I like the way they perform & feel near the minimum. Just seems strange that someone with my numbers (5'9" - 160) would ride at the minimum. I have played around with higher pressure but the only thing I noticed was a harsher ride.
> 
> Vittoria Rubino Pro III's btw, with the 150 TPI casing.


me too...it seems the moderators on this forum never actually look at it. i'm on a few moto forums as well, and posts in the wrong section never last more than an hour before getting moved. maybe some of use should volunteer to help out...i'll do it


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## VBKLINGEN

I think I need 32 tire in the back, as I have calculated that to 103 in front (25 mm) and 103 in the back (32 mm)

So maybe im just a few stones overweight ?

I know I am, so you dont have to point that out to me


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## looigi

Running 23mm tires on 24mm wide rims at 90 front and 100 rear at 165 lb. I ran it down as low as 70/90 front/rear but would get pinch flats hitting sharp edged holes or debris in the road so gradually worked up to where I am now.


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## gordy748

My combined weight is 195 ( 175 for me, 16 for the bike and 4 for the paraphernalia I end up headed out with). With 25 tires I'm bang on the rear at 95psi, but it says my front should be 76 whereas I run 85. I'll try it tomorrow and see how high 70s in the front feels...


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## darwinosx

VBKLINGEN said:


> I think I need 32 tire in the back, as I have calculated that to 103 in front (25 mm) and 103 in the back (32 mm)
> 
> So maybe im just a few stones overweight ?
> 
> I know I am, so you dont have to point that out to me


260 lbs. Conti 4000s 25c at 110 lbs.


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## looigi

I'll mention that a squishy front tire can affect handling during out-of-the-saddle efforts. If found that to be the case running pressures below 90 psi in the front.


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## gordy748

*Well cover me in flour and bake me for 40 minutes...*

So I went out today with my rear at 95 psi and the front at 76-78 like the website recommended...

OH MY GOD THE ROLLING RESISTANCE!!!!! My first sprint the front tire stuck so badly I went over the handlebars, plus I got 4 pinch flats by the end of the block. One pinch flat had a pinch flat on it.

Sounds like a crazy story, and actually it is. I found the front end of the bike was more compliant and less twitchy, with no loss of steering sensitivity or effective speed. It's something I'll definitely change to going forwards.:thumbsup:


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## darwinosx

darwinosx said:


> 260 lbs. Conti 4000s 25c at 110 lbs.


The calculator says 101 front and 157 back for me...I'll stick with 110.


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