MulliganAl

I've searched everyplace I could think of but I can't find the recommended tire pressure for a set of Panaracer Pasela PT 700x35c. I'm finding everything from 70+ to 100+.

I pinched a tire on a turn last year and almost went over the handlebars, so now that the weather is nice I've switched from my CF race bike back to my commuter and started commuting again but want to make sure I don't pinch another tire on a turn. I weigh about 200 lbs. and ride a Rivendell Hillborne with saddlebags so the combo is on the heavy side I'd guess. Any recommendations for the best PSI with these babies?

I really wish I had gotten the 32c since there seems to be more information out there on those and I probably wouldn't be having rubbing with my hammered Honjo fenders. The Honjo's sure do look nice but they are a PITA for commuting.

NashvHeel52

My LBS recommended 70-75 psi (I weigh ~213 lbs).

**Edit** Posted to soon... My Panaracers are T-Serv, not Paselas.

2 Piece

Its not written on the tire sidewall?

PatrickGSR94

Every bike tire I've ever seen has recommended pressure on the sidewall. To further dial it in, I find the weight on each tire with me on the bike, using a bathroom scale, and then use the "Tire Drop" article to determine what pressure I should run, then dial it in farther based on what I want for comfort, load I might be carrying, etc.

ypsetihw

213lbs on a 35 tire, run like 75-80 psi and you'll be fine and comfy and won't pinch

ThermionicScott 

https://www.bikequarterly.com/images/TireDrop.pdf (I disregard the "racing bike" and "city bike" categories and use 45/55 ratios when inflating my tires.)

rm -rf

I measured closer to 40% & 60% weight distribution (testing with one wheel on a scale in a doorway), but then I thought the front was too low and the rear a little too high. The 45% & 55% method comes pretty close to my current inflation amounts.

For group rides, or night rides, I add some more psi since I get less warning of potholes. For solo or small groups on rough chip-seal roads with minimal chance of potholes, I'll drop the pressure a little.

curbtender

When used on non hooked rims you want them no more than 75 psi. Otherwise, I'd guess they recommended that pressure for comfort? Being a heavier rider, I try to keep them around 5-10 pounds under max.

ThermionicScott 

That's how I came to it, too -- I tried 40/60 for the bikes with more upright setups (or luggage carried in the back), but the front tire just felt too squishy when riding out of the saddle. And there's more weight on the front wheel when descending, so 45/55 struck me as a pretty good compromise for comfort.

Bike Gremlin

To what pressure should I inflate my bicycle tyres? - Cycle Gremlin

79pmooney

The 35c Paselas are so forgiving re: tire pressure that it hardly matters. 30 psi will keep your rims off pothole edges and protect you from pinch flats. I am sure they are plenty strong enough to handle 100 psi. I ride with ~70-75 psi on smooth roads and closer to 60 on rougher roads. (At my 155 pounds, there is too much bounce if I go higher pressure.)

Play with the pressure until you find one the feels the best for you and your riding.

Edit: I keep seeing the 60-40 balance and the suggestion the tire pressure front and rear should vary that much. Hogwash. That's saying the greatest coaches in pro bike racing the past 100 years are wrong. A 5 psi difference front and rear, maybe 10, no more unless you never move about on the bike and never get out of the saddle to go up hills. (Also never brake hard as this will load up your front wheel a lot.)

Ben

Joe Minton

Here are a couple of links you might try:

https://bccclub.org/documents/Tireinflation.pdf

https://www.bikequarterly.com/images/TireDrop.pdf

There's a lot of misinformation 'out there' about tire pressure. The information provided in the above-referrenced links are based on actual testing and engineering analysis. My own experience supports those analyses.

Trust the engineers; they can back-up what they reccommend.

An example:
For years the tire engineers have reccommended larger tires and lower pressures for racing bikes, but --- they had to beat the 'teams' over their collective heads with facts before said teams responded with "Duh, -- Okay, -- I guess you're right. But I'll check it out anyway." LOL.

Bicycle racing and the the retail fall-out is a bit like politics --- (i.e. very little/nothing to do with verifiable facts).

Joe

pdlamb

I have a hard time dropping below about 80 psi, even on 35s, because I don't want another pinch flat when I hit one of the early spring potholes around here. Maybe it's just psychological?

Joe Minton

pdlamb:
Have you considered larger tires?

Joe

Darth Lefty 

I'm 220 lb and I've never had pinch flats running my tires well under the recommended value from most calculators... I just don't like it feeling too squirmy (which is a matter of preference, not the objectively optimum thing). For 38's or 42's that pretty much comes out to 60-ish.

One of the supposed benefits of tubeless is that since you can't pinch flat per se, you can run your tires much softer.

HardyWeinberg

I run 35s about 70 front 75/80 back. Is it possible that your pinch on a turn was more related to skinny rims than low pressure?

Marc40a

That's interesting. I came to the same conclusion, independently.

I use Berto's chart as a guideline, but generally keep the difference to about 5 or 6 psi between the front and back. It just feels right.


In response to the original poster:

I'd probably start at about 68-70ish in the back and 63-65 or so in the front. I'm about 192 lbs.

noglider 

I suspect a lot of pinch flats come not from underinflation but from letting the tires go without topping them up for a long time since inflation. This is one reason in favor of overinflation: if you forget to top up your tires, you'll spend more time out of the dangerously low underinflation time. But you're better off inflating to a pressure suitable for your tires' widths and your weight than reading the sidewall. See the instructions in the posts above.

ypsetihw

interesting . . . I used to be around 215 and as low as 190 and I was on 25mm front and rear at the time, and always ran the front 10psi lower, usually 105f/115r. I found this to be a slightly less jarring experience and gave my front tire a tad more grip (I was on gatorskins so I was looking for anything I could get). I also found, with a simple visual inspection, that even at those pressures, my rear tire deflected substantially more than my front.

just to throw a wrench into your statement, it depends on the tire width. I went to more supple tires and 25f/28r and backed off the pressures to 95psi on both, with the tire width and overall larger volume in the rear making up for the lower pressure. the change in width and pressure and switch to a higher performing rubber compound made a bigger difference than any other mod I've made.

my point is that tire pressure matters a lot, but must be considered with respect to the actual tires in use. sometimes a softer tire up front is beneficial. look at the paris-roubaix leg, a lot of pros are riding a WIDER and lower pressure FRONT tire, for better grip and shock absorption. and they move around plenty AND get out of the saddle.

steeljunkie

I use these tires on my commute bike, and I'm right about 200 lbs. 70 to 75 lbs of pressure works great, but like all tires they do lose pressure so I agree with noglider - if you don't already have one get a good floor pump and check your tires often.

Angrybk

I run those exact same tires on my cross check and I'm about 210 pounds, carry anywhere from 5-30 pounds of cargo (depending on whether it's grocery day). I tend to run them at 80-85 psi, seems to work fine for me.

PatrickGSR94

I believe you misunderstood. The 60/40 being referred to above refers to weight distribution between the front and rear tires. I found similar results on my road bike commuter, and going by the chart in the "Tire Drop" article it gave me pressures of around 85-90 for the front on 25c tires, and 95-100 on the rear. That's only a 5%-10% difference between the front and rear, nowhere near a 60/40 split like the actual weight is.

Joe Minton

I measured the front/rear weight distribution of three of my bikes using a bathroom scale and some planks of wood to keep the wheels the same height above my garage floor. All three had the 40/60 distribution with me aboard and I have used that load relationship to set tire pressures for almost four years.
As the Brits say, "It works a treat."

I cross-checked my chosen pressures using the 15% (20% from rim to floor) tire drop recommendation given by Frank Berto. (https://bccclub.org/documents/Tireinflation.pdf) Both techniques recommended precisely similar pressures.

I do often alter pressures to accommodate road conditions, tire design and how I want the bike to feel but maintain the 40/60 front/rear ratio.

Joe

Ben: They were wrong. They were wrong about tire size too. I have often found that the term "Time-Honored" represents continued ignorance instead of wisdom. There's nothing quite like the scientific method for discovering truths and making progress.

noglider: I think you're probably right about the major source of pinch flats.
-- I was once a motorcycle mechanic. When folks would bring their bikes in for a Tune & Service, tire pressures were usually around 12psi. We often had them return immediately after the tune-up and ask/exclaim, "What did you Do?! It never was this good before!" Most of the improvement was from running tire pressures up the 35# or so they were supposed to have. JM

wphamilton

By trial and error I've come to almost the same pressures as the chart suggests, with one big objection. I am convinced that low end sturdy tires need a different scale because the more rigid sidewalls support more weight throwing the 15% off, and those same sidewalls cause sharply worse drag below some pressure. I'm talking Forte Strada, Nashbar Prima, low end Kenda, those kinds of tires.

Marc40a

Agreed. Mine get checked/topped off daily - only on the days I ride, of course.