tommyx

All,

I bought a used bike (Sun EZ Sport) recently and it has 100psi tires. When I ride the bike, I feel it is very sensitive to the road conditions. E.g. it will not be a pleasant expericence if you ride on the side walk

Could this due to the 100psi tires? I never had this issue with my other bikes with ~60psi tires.

Also, could I lower the tire pressure (e.g. to ~60psi) to see if this help? Will it damage the tires?

What's the advantage of having 100psi tires anyway?

Thanks a lot!

Tom

chasm54

Look on the tyre walls. That will tell you the minimum and maximum safe pressure for that tyre. Assuming it's a 23mm or 25 mm tyre, running it at minimum pressure will make it more vulnerable to pinch flats if you are a heavier rider.

Why would anyone over the age of eight ride on the sidewalk?

Craptacular8

Even if your max pressure (as noted on the sidewall) says 100 psi, you don't necessarily want to have them inflated to max pressure for comfort reasons. I generally run 5-15 psi below max pressure to make the ride more pleasant. If you're of average weight, this shouldn't cause pinch flats. If you are a heavier rider, I'd still drop the pressure at lest 5-10 and give it a try.

CliffordK

The sidewall rating is the maximum pressure.

I don't see a problem with using a little less pressure to where it is comfortable.

Does your bike have a 20/26" tires? How wide of tires? I doubt the front will get a lot of weight due to the recumbent design.

Anyway, try 60 PSI or so. If you start getting a lot of pinch flats, then go up some. Or, if it will take fatter tires, you might even be able to drop the pressure some.

tommyx

I won't ride on the sidewalk, just to give an example so people can understand what I was talking about easily

tommyx

Thank you all for the replies! Will check the sidewall rating again and lower the pressure to see how it goes.

Tom

yooperbiker

If you have 26" x 1.5" tire on rear, 100 psi is too much pressure. if you weigh around 180 lbs I would guess about 70 psi in rear tire is all you need, and would be much more comfortable.

Getting an appropriate tire pressure depends on size of tire and the weight load of the tire. Just because tire says 100 psi max does not make that the correct pressure.

Check this old article with chart, explains it well: https://www.bikequarterly.com/images/BQTireDrop.pdf

avidone1

1. There is no bike lane and traffic moves fast on said road
2. bike lane is narrow and traffic moves REAL fast on said road
3. crack
4. Texting
5 Octogenarians
6. cyclist is not a roadie or someone who rides at speed
7. drivers who view cyclists as sporting opportunities

Atakuweh

Tire pressures embossed on the tire sidewall often have little or no relation to the proper tire inflation pressure. Check on the actual tire manufacturer's website to determine the actual inflation range for a particular tire. Running less pressure than recommended can result in greater chance of puncture, either from road debris (glass, thorns, etc.), or from pinch flats due to running over things like curbs or manhole covers, and bike handling issues. Running a tire at less than the manufacturer's recommended pressure might be more comfortable, but can result in safety issues and increased risk of punctures. Narrower tires require greater minimum pressures within a narrower range, wider tires less so within a wider range, but consult the tire manufacturer to be sure the range for your specific tire. I run 700Cx23mm Conti Gatorskin tires on my road bike, and their recommended pressure is 110 to 120 psi — a very narrow range.

canklecat

Tire design matters at least as much as pressure. I just replaced a set of Specialized Hemisphere 700x38 tires (recommended 75-100 psi - I usually rode them at 85-90 psi) with Michelin Protek Cross Max 700x40 (36-87 psi - I ride 'em around 70-80 psi), for better flat resistance. The two are much more different than pressure would indicate. The higher pressure Hemispheres have far more flexible sidewalls and ride "softer" and felt faster on pavement without feeling squishy. The Michelins have very stiff sidewalls, rider harder overall but better on unpaved trails and grass.

My actual riding speed isn't significantly different, despite the very different feel to the rides.

thin_concrete

I'm not sure I would take out 40% of the pressure at once, but I would let air out slowly. Try going to 90psi, then 85psi, etc., until you find a comfortable ride quality. As others have said, balance the comfort with the increased risk of pinch flats and increased wear.

ltxi

I ride my 700x25 tires at 95 psi and 26x1.5 at 75/80. Works gud fer me.

Ghazmh

PSIA or PSIG. I always inflate to 134.7 PSIA.

ltxi

Gage pressure, of course...

Retro Grouch 

It's a bicycle. I assume that you bought it because you thought that riding it would be fun. Right now it sounds to me like riding it with your tires inflated to 100 psi is less fun than you anticipated. What do you think is the worst thing that would likely happen if you experimented with less tire air pressure? Keep in mind that, if you decide you don't like lower air pressures, you can always pump them back up.

ramzilla

Why would anyone over the age of eight ride on the sidewalk?[/QUOTE]

You're kidding, right?

Come ride with me in Atlanta sometime. Sometimes the sidewalks aren't even safe.

indiana_jane

8. Riding with someone who is actually under 8.

fietsbob

Simplifying .. High PSI tires are low volume .. skinny 1" or less .. larger volume tires are lower pressure..

habilis

Sure, if 100psi is uncomfortable, lower the pressure a bit. However, you are new to this bike. You might try adjusting to the different kind of bike this is rather than adjusting the bike to you. This won't sound so strange if you consider that the bike was designed for a different purpose than the 60psi bike. Also, suffering builds character. ("What doesn't kill us makes us stronger." - Friedrich Schopenhauer.) Try wearing a hair shirt, too.

The advantage of a narrow high-pressure tire is speed, and easier pedaling over long distances on the road. You can reduce seat discomfort with a well-designed saddle and a more forward-leaning riding position. Take pressure off your hands with padded grips.

ltxi

I think it's a bit more than that. Wider and/or lower pressure would feel really "off" on my road bike. Letting the pressure drop to 80 psi on a 700x25 makes the bike feel uncomfortable squirrely. Conversely, too high pressure on my mtb with hybrid tires doesn't work well at all, either.

charley2004

Road Bicycle Tire Pressure Calculators

Bicycle tire pressure calculator

JanMM

Based on 15% tire drop. The link above has links to info about determining optimal tire pressures. Worth reading. Currently running my long wheelbase bike (30/70 F/R weight distribution with 32mm/36mm F/R tire widths) at 45/70psi based on the calculator.

bobbyl1966

in my tires i use the max pressure. is safe i do that?

ltxi

Safe, yeah. Optimal, hardly.

SloButWide 

He's a recumbent rider, and the street has this sign: