tire pressure chart

[djconnel]

The SF2G page recommends 100 psi for pressure.  On the roads we ride, I find that way too high.  It depends on rider weight and tire size, though.  Here's a nice plot from Michelin:

http://www.michelinbicycletire.com/michelinbicycle/index.cfm?event=airpressure.view

I tend to run 80 psi (or 85, accounting for air loss before I pump up my tires again).  This is right on with the recommendations for my 25 mm tires and my weight.  Lower pressure gives a much smoother ride.  Part of the advantage of 25's versus 23's is you can run them lower pressure without pinching.

Dan

[jtaby]

What about running 25s on 23mm wheels (which I was assured at the time of purchase was fine?) Riding at less than 105/110 feels like riding through sludge for me, maybe I'm crazy?

[djconnel]

Do you mean 23 mm rims, or rims typically associated with 23 mm tires (ie 19-20 mm rims)?  Wider rims make the tire sit slightly wider and reduce the pressure you can optimally run.  I suspect these recommendations are for 19 mm rims, since these are the most common.

I think the "sludge" feeling is mostly psychological.  Measurements I've seen have shown fairly low pressures still have relatively low rolling resistance: the difference is too small to feel without careful measurement.   Pros ride very low pressures, as low as 65 psi (on tubulars which are much less likely to pinch), in Paris-Roubaix even though it's mostly paved roads because these low pressures work better on the cobbles.  If the rolling resistance was sludge-like on the smooth road, though, they'd be dropped.

I think the high pressures feel lively, but that's not necessarily faster except on smooth roads, which we don't encounter.  In hillclimbs I run 140-150 psi to get low rolling resistance, because speeds are low and I can avoid potholes so the suspension effect of optimally deflected tires isn't so important.  This seems to work fairly well for me.

[Scott Crosby]

It's funny to me that Michelin's chart tops out at 180 lbs. Sacre bleu! Who could be heavier than that?!

Per the chart, the 100 psi rec is low for the non-Ramesh/djconnel contingent, ahem.

My est avg SF2G dude weight is 165 lbs. For 23s, that would be about 112 psi.

I'm about 180, so only 10 lbs fatter than I wanna be. 100 psi is luxurious in my book.

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[Maciek Wojciechowski]

my 197lbs feels very comfortable on 25s with ~95psi. never had a pinch flat.

[BenrySF]

180lbs is ~2/3rds of my weight with clothes and bags.  France just called me fat and told me to ride >32c's.  Screw you, France.

On Wednesday, May 1, 2013 6:26:37 PM UTC-7, djconnel wrote:

[Patrick Kitto]

Did you pinch flat today??

[Jonathan Kibera]

I used to run 23s - switching to 25s has made for way more comfortable riding at ~100psi. Feels like the tires maintain contact better, especially on chip seal. I also run tubulars, but that's another story.

On Thursday, May 2, 2013 9:02:32 AM UTC-7, Patrick Kitto wrote:

Did you pinch flat today??

On May 1, 2013, at 9:56 PM, Maciek Wojciechowski <maciekwoj...@gmail.com> wrote:

my 197lbs feels very comfortable on 25s with ~95psi. never had a pinch flat.

On Wed, May 1, 2013 at 9:46 PM, Scott Crosby <scr...@gmail.com> wrote:

It's funny to me that Michelin's chart tops out at 180 lbs. Sacre bleu! Who could be heavier than that?!

Per the chart, the 100 psi rec is low for the non-Ramesh/djconnel contingent, ahem.

My est avg SF2G dude weight is 165 lbs. For 23s, that would be about 112 psi.

I'm about 180, so only 10 lbs fatter than I wanna be. 100 psi is luxurious in my book.

On Wednesday, May 1, 2013, djconnel wrote:

Do you mean 23 mm rims, or rims typically associated with 23 mm tires (ie 19-20 mm rims)?  Wider rims make the tire sit slightly wider and reduce the pressure you can optimally run.  I suspect these recommendations are for 19 mm rims, since these are the most common.

I think the "sludge" feeling is mostly psychological.  Measurements I've seen have shown fairly low pressures still have relatively low rolling resistance: the difference is too small to feel without careful measurement.   Pros ride very low pressures, as low as 65 psi (on tubulars which are much less likely to pinch), in Paris-Roubaix even though it's mostly paved roads because these low pressures work better on the cobbles.  If the rolling resistance was sludge-like on the smooth road, though, they'd be dropped.

I think the high pressures feel lively, but that's not necessarily faster except on smooth roads, which we don't encounter.  In hillclimbs I run 140-150 psi to get low rolling resistance, because speeds are low and I can avoid potholes so the suspension effect of optimally deflected tires isn't so important.  This seems to work fairly well for me.

On Wednesday, May 1, 2013 6:35:55 PM UTC-7, jtaby wrote:

What about running 25s on 23mm wheels (which I was assured at the time of purchase was fine?) Riding at less than 105/110 feels like riding through sludge for me, maybe I'm crazy?

On Wednesday, May 1, 2013 6:26:37 PM UTC-7, djconnel wrote:

The SF2G page recommends 100 psi for pressure.  On the roads we ride, I find that way too high.  It depends on rider weight and tire size, though.  Here's a nice plot from Michelin:

http://www.michelinbicycletire.com/michelinbicycle/index.cfm?event=airpressure.view

I tend to run 80 psi (or 85, accounting for air loss before I pump up my tires again).  This is right on with the recommendations for my 25 mm tires and my weight.  Lower pressure gives a much smoother ride.  Part of the advantage of 25's versus 23's is you can run them lower pressure without pinching.

Dan

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[kurt wallace]

I've found you can get down to 20 pounds around town and not pinch flat if you get off the saddle for bumps. Not that I recommend it - it feels super squirrely. But it does mean you don't have to freak out if your cheapo frame pump isn't up to the task. And 60 does feel mighty cushy.

kurt

[Nat Futterman]

Another article and chart on the matter (chart is by load per wheel): http://www.bikequarterly.com/images/TireDrop.pdf

(I hope bringing up Bicycle Quarterly isn't as flame-inducing as anything Grant Peterson says, despite being a bit tweedy also)

[Carlin Eng]

I'm a big believer in wide tires and lower pressure. The tires on my bike (Challenge Parigi-Roubaix) measure 29mm, and I run about 70 psi front and 75 psi rear. A very plush ride, and subjectively speaking I can't say I notice any difference in speed compared to the 25mm Conti GP4000s I used to run. They're about 100g heavier per tire, but I think the benefits outweigh (ha ha) the downsides.

[Alejandro Villarreal]

I should lower my pressure. 

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[Joe Faith]

I've just switched to gatorskins @90psi after riding bontrager slicks and found them soooooo slooooow (you may have noticed me being dropped a couple of times)

Can anyone recommend anything faster that will last 1000 miles?

Joe Faith | Product Manager | Google Cloud

[Carlin Eng]

1,000 miles is very short as far as tire lifetime goes. I got around 2,000 miles out of my Grand Bois Cerf 700x26 tires, which have a reputation for being thin and short-lived. I put around 4,000 miles on a set of Pasela TourGuard tires, and the rear tread still looks serviceable. Of course, it also depends how much you weigh and what sort of riding you do.

What tire width are you looking for?

[Judd Blair]

1000 miles is a pretty low bar IMO, tons of tires should (will?) last that long. I like Michelin, so the Pro 4 Endurance (previously Krylion) are my recommendation. Some people like Gatorskins, but I think they're giant pieces of shit - GP4000 4season seems to be the durable tire of choice for Conti guys.

On Tue, May 7, 2013 at 2:49 PM, Joe Faith <joef...@google.com> wrote:

[Jason Thorpe]

On May 7, 2013, at 2:49 PM, Joe Faith <joef...@google.com> wrote:

I've just switched to gatorskins @90psi after riding bontrager slicks and found them soooooo slooooow (you may have noticed me being dropped a couple of times)

Can anyone recommend anything faster that will last 1000 miles?

I'm a fairly big guy and I run 100 front / 110 rear on GP4000Ss (700x23).  I get ~2500mi out of the rear tire, and quite a bit more than that out of the front (unless a road hazard shreds it, which is what has happened on my last 2 or 3 tires).  I don't seem to have any trouble going fast on them.

-- thorpej

[Peter Colijn]

I had some 4000s that didn't last long at all. The 4seasons do seem to be more durable so far.

[Nat Futterman]

Can't speak to the continentals (though the tough feel of the casing of gatorskins is deeply unappealing to me), but I use Panaracer Pasela TGs as my standard higher-volume, fairly tough, fairly supple tire (in 28 and 32) also and they've lasted really well for me.  I've gotten a lot of miles out of  Michelin Pro 3 and 4s also, which have stuck as my favorite smaller-volume tire.  Thinking about going to fancier/thinner bigger tires like the Grand Bois or Parigi-Roubaix all around, though.

[Viet-Trung Luu]

What I find fascinating about charts that properly indicate pressure for load on a wheel is that they usually agree on two things (I run 23mm tires front and rear, me + bike + everything else = ~200 lbs these days, and let's optimistically assume a 60-40 rear-front split):

• I'm either okay-ish on the rear (I run 115-120 psi), or should run at even higher pressure (BQ's chart indicates ~127 psi -- which is really high, and nearing maximum pressure).
• I should run even lower pressure on the front (I run 100-105 psi; BQ's indicates ~83 psi -- which is pretty low, and nearing minimum pressure).

Maybe what it really indicates is that I should run 25mm on the rear and 23mm on the front. I'm surprised that this isn't suggested more often, since it seems like the sensible thing to do (other than the annoyance of having different tires front and rear).

- Trung

On Thu, May 2, 2013 at 9:46 AM, Nat Futterman <nat.fu...@gmail.com> wrote: