I know this subject has been touched on before, but I did searches and I'm still confused. I own a '84 fuji del rey with 23 mm tires. I weigh 165 lbs and I pump up 80-90 psi on my tires because the pressure gauge on my pump only reads up to 100 psi, and the tire indicates a maximum capacity of 100 psi. However, most people on here go way above 100 psi to avoid pinched tires.

Should I get new tires and a new, better pump? Please shed some light on this

80-90 will work fine at your weight. I weigh 200lbs and I inflate my 23s to 100psi and I ride on many rough roads without pinch flats

it always helps to steer around bumps/pot holes and to get your ass off the saddle

Get a better pump.

I ride at 105psi front and 110psi rear and I am heavier than you. 80psi is way too low for anyone.

The pressure rating on your tire is well under what is actually safe to use. Any decent road tire will certainly handle 100psi.

where do you suggest I get better pump and tires? I'm a broke college student, so I want to go cheap

If cost is a concern, I suggest you just keep doing what you have been since it is apparently causing you no problems.

https://www.performancebike.com/bikes...8_20000_400032

Decent pump for $30 @ Performance.

Or just max yours out assuming that gauge is accurate.

You can get a very reliable gauge for around $15.

Most broke college students don't have broke parents. They simply tell their parents that by cycling, it saves money but there is a little upkeep needed to keep the bike in good running condition.

Some college students have roomates who do have good floor pumps. Some colleges have a cycling club and their members have pumps.

Going too high isn't great either. 100-110 is good.

It also depends upon tire construction. Vredenstein tricomps have a max of 145 lbs. I used to get pinch flats when the pressure dropped to 100.

Here's a link to the Bicycle Quarterly article on tire pressure. I have found quite useful. For me, it resulted in using lower pressure than I used to. I am 167, and I run my front 25mm at 70 and rear at 100.
https://www.bikequarterly.com/images/TireDrop.pdf

According to the chart, I should actually be running things a bit lower, like 60/90. I bet Bob's not going to like that!

For 23mm at 165, assuming a 40% 60% weight distribution, the chart puts you at about 70 psi in the front, and 105 psi in the back. But it isn't gospel, just a starting point. Are your teeth rattling out of your head? Lower your pressure. Are you getting pinch flats? Raise the pressure.

Back in the bad old days, people used to just pump up their tires and give them a squeeze with their thumb, and say "that's about right" and never give it a second thought, so don't worry too much about it.

I believe this calculator uses the same math: https://www.dorkypantsr.us/bike-tire-...alculator.html
A started using this a couple months ago, and wow!
This is the greatest improvement I've made on my bikes in a long time, and it cost nothing!

are pinch flats in the inner diameter of the tube? or at lease near the intersection point between the rim and the tire bead? What is a pinch flat, is it what is sounds like?

all my flats have been caused by holes in the outer diameter of the tube. But I think that problem has been solved now that I got baby powder running over the tube.

My minimum inflation: 100f/110r. I'm about 10 lbs heavier than OP and would not recommend going any less than 90/100.

Pinch flats usually give you two holes close together, as if your tire was bit by a snake.

This directly from PRO-LITE website:

"There is so much garbage talked about the ideal tyre pressure you can write a lifetimes reading on the subject. The bottom line is what
do the pro’s do? They get their tyres pumped up as hard as they can go. Why? So they use less energy to go as fast as possible. Bear in mind they also get their tyres for free.

Carbon clincher rims are subject to tyre pressure limits due to the fact they flex and over inflating them will increase the chance of it coming off the rim under heavy braking. Not everyone can afford the tyres top pro’s ride.
Don’t let famous brand of wheels or tyres tell you that you might feel you are going fast but actually the vibration will wear you down and
sap your energy. This could only be written by people who have never actually raced as pro and had to pedal tens of thousands of kilometres to get a pay cheque each month.
So we recommend you buy the best tyres you can afford and pump them up hard. Even on our test bikes we will fit cheap tyres that say 110 psi max pressure. We always pump them up to 150 psi minimum without problems."

That's very nice of PRO-LITE. Now let's see what pressures the pros actually ride at:
https://velonews.competitor.com/2011/...rations_181775

This article does list mostly the wet-weather pressures, but for some teams dry-weather pressures are also listed. Omega-Pharma goes with 123 psi for example. Astana uses 123-130.5, Team Sky also 130.5. Quite far from ridiculously high 150 psi.

Edit: From Nick Legan, a pro tech:
https://velonews.competitor.com/2010/...uipment_149851
Example:
"At RadioShack, we inflated to 8 bar each dry race day (that’s 116 psi at sea level). And we would only go down from there for lighter riders or if it rained."

I like 95-100 psi rear, 90-95 psi front and switched from 23 to 25mm tires after growing to 200 pounds.

That's enough to avoid pinch flats and provide decent rolling resistance, but works better with rough roads than higher pressure.

I'm not paying for your tires or tubes so I really don't care what tire voodoo you follow.

I worked with Continental for several years and never heard the word 'tire drop' or any concept similar to it discussed. My guess is that it is something that comes to us from the automotive world where tire design and function differ substantially from bicycle tires.

Also note the thrust of the article is on comfort, not performance.

Others have already posted links to a more correct range of inflation.

Interestingly, the data that the graph was generated from comes from a study done by Frank Berto, which you can read here.https://www.bccclub.org/documents/Tireinflation.pdf

He says that his inflation advice
"was based on discussions with the bicycle tire experts at Michelin, National, IRC, and Continental. They agreed that "Tire Drop" is the key criteria in matching tire size and inflation pressure to rider weight."

Frank Berto was either the engineering editor for Bicycling Magazine or a voodoo high priest, I forget which

Hey 90# is great - also note that a good stiff tire also helps with the integrity of the wheel - Maybe not so much in a light weight (165#er) but in a heavy weight it is real important...

You seem to be baiting me. Do I know you sister?

I'm on the iPhone so I'll keep it brief.

Quoting anyone from Bicycling magazine as your authority is like quoting Vogue on health related issues.

I LO fricken' L at that.

I worked with one of the companies you mentioned. I went to Germany on their dime and spent time in the factory talking to the guys designing the compounds used in their tires and the chemistry involved. I also spend time with people designing not only the tires themselves but the production methods that were to be used to manufacture those tires.

Tire drop was never mentioned. Not once.

Perhaps it has become a new marketing buzzword for certain segments of the market like the novice riders who would read a magazine that has a "ten things to..." and a " the greatest..." or "secrets of..." on it's cover. I don't rely pay too much attention to what goes on in that segment of the market so I may be off the mark here.

What I can say with certainty is the guys designing the 700c performance tires intend them to be used between 90 psi and 110 psi. In fact, the person responsible for design of the GP 4000 when Black Chili was introduced told me specifically ( in answer to my question) that those tires seemed to perform best, under most conditions at 110 psi.

I think I'll choose him as my voice of authority. You're free to believe what you wish

Sorry Bob, I'm not trying to bait anyone, just a little friendly banter in response to your 'Voodoo' comment.
I'm not the only one on this board who has found the articles quoted useful. I'm not sure why the level of venom for Frank Berto, though. He seems like a knowledgeable guy who did a careful job on the article. And I don't get the sister comment at all???

To the OP and anyone else, the obvious thing to do is just to try some different pressures and find what works for you. For what it's worth I've been running 70/100 for two years (since reading that article), and I haven't had any problems with increased tire wear or flats (used to run 100/100), just noticeable difference in comfort.