Tire Inflation & Rider Weight

[ACiveE]

Greetings, ladies!

I am wondering if someone can provide me guidance on how high to inflate my tires. I never really thought about it and just inflated to around 100psi but I recently had a big tire failure and it got me thinking about it. My tire failure may have had little to do with inflation(I think) as I have a nice clean 3" slice through my brand new tires and tube. After reading reviews on the tires I have, I opted to purchase a whole new set and after dropping that $$ I'd like to properly inflate them to a level that avoids puncture as much as possible.

So, I'm no featherweight rider . I weight in at around 170-180lbs and ride on 23cm tires. I purchased some vittoria rubino pro tires after reading their many praises for a cheapo tire and they have a max inflate rate of 120psi. Should I have gone with a higher max rate?

How high should I inflate them to? I know the higher psi, the faster, but at my weight how high is high? And how high makes them too puncture prone?

Thanks so much!

[Pedal Wench]

My BF just sent me this:
Tire Width=20: Pressure(psi) = 0.33 * Rider Weight in lbs + 63.33
Tire Width=23: Pressure(psi) = 0.33 * Rider Weight in lbs + 53.33
Tire Width=25: Pressure(psi) = 0.33 * Rider Weight in lbs + 43.33
Tire Width=28: Pressure(psi) = 0.33 * Rider Weight in lbs + 33.33

[SadieKate]

I know the higher psi, the faster, but at my weight how high is high?

Not necessarily. Lots of factors go into the "speed" of a tire. And you might find that 25mm tires give you a lot more comfort and durability. Your weight and max psi don't correlate. Max psi has to do with the tire construction, just like the rolling resistance.

Over-inflated tires are susceptible to gashes and have a harsh ride. Under-inflated tires are susceptible to pinch flats.

http://forums.teamestrogen.com/showt...ycle+quarterly

PW, that chart is pretty good! I just ran the numbers and they is spot on for Bubba and me.

[ACiveE]

Many thanks!

So how close to max psi should you go? My calculated psi is like 110psi and the max for the particular tire is 120. Should I have gone with a higher rated(?) tire?



...this is all too complicated. I just want to get on my bike and riiiiiide!

[SadieKate]

Use Pedal Wench's chart and go ride.

Don't worry about the max psi.

[AnnieBikes]

PW,

Your chart is super! I have always wondered what inflation amount I should use. I always heard that I should make them 100-110 to avoid flats but based on "the chart", I should be about 96, so though 100 is close to it, I am often just "pumping up" and go to 110 or 115. I guess I will use the 100 and see how it goes.

Thank you so much for this very informative piece of information.
I love this forum!!!

[HoosierGiant]

ACK! Following the chart puts my tires under 85 psi -- at that pressure I'd feel like I was riding through wet concrete!

[indysteel]

I don't flat much (well, at all, knock on wood), so I could be terribly wrong, but my understanding is that underinflation can lead to "pinch flats." A 3-inch gash in both your tire and tube suggests to me that you ran over something nasty.

For what it's worth, I run my Rubino Pros around 100 psi. According to the chart, I should run them at 92 psi.

[Cataboo]

I run my tires around max, so 120. The chart says I should be running less than that, but I can't say that I find the ride harsh.

I used to run about 90-100 psi and I was having pinch flats constantly.

[SadieKate]

ACK! Following the chart puts my tires under 85 psi -- at that pressure I'd feel like I was riding through wet concrete!

I have plenty of wider road tires that I run below that. They're meant to be.

[OakLeaf]

I definitely notice increased rolling resistance if my 700x23s are below 110 psi.

Does higher pressure really make tires much more susceptible to cuts? I might be persuaded to take the pressure down a notch if that's true.

[Biciclista]

i have purchased tires which had a weight chart on the packaging.
Since i am a light weight, I keep my tires under 100psi.

[TxDoc]

Hi ACiveE,
I am no expert but here's my personal experience: usually I inflate tires very close to the max. And, I tend to buy high pressure tires: Vredestein tricomp (clincher tires) and Vittoria Crono EVO (tubulars). My weight is under 130lbs and I've never had problems. A couple of my riding buddies are heavier (in the 190-230lbs range), and they also use mostly Vredestein tricomp or fortezza and inflate their tires close to the max.
Hope this helps

[salsabike]

ACK! Following the chart puts my tires under 85 psi -- at that pressure I'd feel like I was riding through wet concrete!

Multiply it this way: (.33 x rider weight) + whatever number. It'll work that way. I tried it the other way first too, and thought....no, 75 can't be right....

[HoosierGiant]

Multiply it this way: (.33 x rider weight) + whatever number. It'll work that way. I tried it the other way first too, and thought....no, 75 can't be right....

That is the way I did it. (Please Excuse My Dear Aunt Sally and the Order of Operations reign supreme!)

Anyway, tire pressure, like shorts and saddles, is a personal thing. What feels like sloggin' through the mud to me might be someone else's comfort zone...