Stratocaster

In order to get a more "cushy" ride on my 2 aluminum bikes, I'm considering lowering my tire pressures...but I don't want to go so low as to make the ride seem sluggish...or get pinch flats.
My tires are Continental GP4000 700x25.
I weigh about 155 lbs...will get down to about 145 during the summer.

What do you all think?
I used to put the pressure up near 100 psi.
Now I have them around 85.
How low can I go?

Abe_Froman

I'm 190 and used to have the same tires at 100 PSI. I'd be comfortable at my weight running them at maybe 90 in the back, 80 in front...

Adjust maybe 10 psi for your weight? I'm not sure I would try anything below 80/70. I think you're at a pretty good pressure right now...wouldn't change it drastically unless you get a bigger tire, but I'm assuming you're maxed with your clearance already?

WhyFi

Lower it by 5 psi and try it out for a week. If all seems well, rinse and repeat. If you get a pinch or if it starts to feel bouncy even when pedaling relatively smoothly, go back to the previous week's pressure.

Iride01 

Record your stats for 200 rides and post them. Make sure to record your tire pressures for each ride and post that as well. When you are finished, well get back together here and argue about it.

ThermionicScott 

Your current weight is my goal. If your bike and other accouterments weighs 25 lbs, then you've got 180 lbs total. At that weight, I'd leave 85 psi in the rear tire and keep dropping the front a little. Maybe 70 psi at the least.

Abe_Froman

Christ...I'm fairly certain I'd be dead if I weighed 145

Wildwood 

Why go below 85psi?
Do you want squishy handling? Lower mileage tire life?


If you want a softer ride go with a fatter tire than 25mm.


For a cushier ride = suspension seatpost or a big, big fluffy sheepskin saddle cover.

ThermionicScott 

I weighed about 147 lbs after completing PBP. It's probably the closest I've ever come to resembling a pro cyclist.

athrowawaynic

Hop on the bike, look down at the tire. I try to shoot for approx. 2mm of deformation/spread.

Bob Ross

The guy only weighs 145lbs, he's not gonna get "squishy handling" just because he goes below 85psi

datlas 

I would go to 75-80F 80-85R.

firebird854

take a single 100 mile ride, break it into 200 .5 mile rides with different pressures, provide data in each separate posts, quote him in each post

BarryVee

My bike and I weigh 190# and use the same tire. Scale indicates about 40%/60% of the weight F/R. Presently pump 70/85 psig F/R. Every ride gets logged. I don't seem any faster at 20 psig more. But I do suffer fewer flats or tires destroyed by cuts using lower pressures. No idea what minimum pressure is/not willing to make that experiment either. (I do not race).

therhodeo

I weigh in the high 150's in season and run 75 and 82 with 25's and our roads here are terrible. Have no problem keeping up and outriding geniuses who think that riding 120psi makes them faster.

datlas 

I know, right? Common newbie and/or know-it-all mistake is that "max" pressure printed on sidewall is best.

Wildwood 

Handling at speed suffers. Maybe not "squishy" at 155# but not ideal.
For just riding the smooth paved bike trails, the OP could probably run 40-50psi, if that's the style of riding.
Softer ride = wider tires designed for lower pressures. Or suspension post, sprung saddle, etc.


YMMV

indyfabz

Sound like the OP needs a carpet fiber bike for maximum comfort.

therhodeo

At what speed? I run those pressures in crits and the only time I've had any sketchiness in a corner is from pedal strikes.

HTupolev

Unless maybe if the the rims are really narrow, I don't think it would make much difference. 85PSI just isn't all that low for a 25mm tire under a 150lb rider.

Reynolds 

75F/85R probably will do if you are careful with potholes.

Wildwood 

The question was How Low? I wouldn't run a 25mm tire below 80-85psi, unless the style of riding was trails and/or moderate speeds. In post #16 I stated OP could likely run 40-50 for some rides. To what purpose, slick road, soft surface? Surely not better tire performance (or a criterium race???).


On any ride I may hit 35 - 40 mph on a downhill run, there may be irregularities or bumps in the road at speed, or a pothole to jump/dodge. For this type of regular riding I prefer to run a tire inflated near it's designed range - for performance and tire life.


If I want a cushier ride I ride a larger tire designed to perform at a lower pressure.


Simple as that.


edit: I'm running tire widths from 22mm (25, 26, 28, 30) to 32s with small knobs. All tubulars and my pressures run from 40 - 110psi. Then there's the mtb with 26" wheels (for where my 700c roadies prefer not to go) on which I vary the clincher tires and pressures based on terrain type.

Kontact

Not sure why anyone is arguing about the subject:



This is based on weight per wheel. Going under these pressures increases the risk of pinch flats.

WhyFi

This may have been the prevailing wisdom a handful of years ago, but not any longer.

Abe_Froman

Cuz real men are off the end of that scale

I'm 190 # plus the bike/gear and am on 28mm GP4000s. Kinda wondering how much below 80 psi I can go

Bob Ross

Note the fine print at the bottom where it says "This is based on weight per wheel"
You're still in the middle of the bell curve!