Have Your Tires been Lying to you?
#26
Senior Member
One thing I take real issue with is anyone telling me I should be using less than 5 psi lower in front than in back. That was what we all were taught back when we came from eggs (remember the dinosaurs). But there is a really good reason for so much pressure up front. There might just come a day when you have to slam on the brakes and do maneuvers to save your butt. At that moment, all your weight is on that front tire. Not 40-45% of your total. Not the 55-60% that the rear tire sees. No, that front tire is looking at 67% more weight than either tire sees normally. And at that moment, control is paramount. A blowout or rim failure disaster.
#27
Senior Member
I have problems with some of the points in this video. The first is the statement that tire pressure is set to 1/2 the blowoff value of a "standard rim". I've heard this stated in lots of places but I have yet to find a credible citation of where that comes from. Yes, it's higher than the maximum pressure but twice as much? I find that very hard to believe for all tires in all widths and all possible rim widths. I've had tires that blew off at the nominal highest pressure setting.
#28
Senior Member
Join Date: Jul 2013
Location: Missouri
Posts: 2,689
Bikes: Giant Propel, Cannondale SuperX, Univega Alpina Ultima
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 672 Post(s)
Liked 413 Times
in
246 Posts
My earlier reply didn't post. So this time with brevity.
Then - 'He is talking about what is faster' - means someone is dreaming about going faster over XX miles on a rough road or off-road or gravel road (how about CX, too? - that's a natural follow). And I would offer that there are so many variables to FASTER as to be a subjective and highly variable answer, requiring far more analysis than tires.
Then - 'He is talking about what is faster' - means someone is dreaming about going faster over XX miles on a rough road or off-road or gravel road (how about CX, too? - that's a natural follow). And I would offer that there are so many variables to FASTER as to be a subjective and highly variable answer, requiring far more analysis than tires.
__________________
Formerly fastest rider in the grupetto, currently slowest guy in the peloton
Formerly fastest rider in the grupetto, currently slowest guy in the peloton
#29
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,274
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 150 Post(s)
Tagged: 1 Thread(s)
Quoted: 6147 Post(s)
Liked 4,092 Times
in
2,325 Posts
Do you have an actual citation for that? A "standard" that can be quoted? I've heard the same thing from lots of people but have never been able to find any kind of reliable source. Additionally, how does that "test fixture rim" compare to a general rim?
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
#30
Senior Member
#31
Senior Member
Join Date: Apr 2012
Location: Nor Cal
Posts: 6,016
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1814 Post(s)
Likes: 0
Liked 923 Times
in
569 Posts
I'm almost to the point of not correcting misinformation about low pressure and big tires being faster simply for the fact I'll be up 20w over the schmuck who shows up to the race.
Oh, cute, 28's at 40psi. Have fun!
Now, comfort, do whatever floats your boat. Sure.
Oh, and the evils of latex. Tell me how evil it is. Or how it isn't any faster. Right.
Oh, cute, 28's at 40psi. Have fun!
Now, comfort, do whatever floats your boat. Sure.
Oh, and the evils of latex. Tell me how evil it is. Or how it isn't any faster. Right.
If you had an advantage over the 40 psi guy, then you would be down 20w, right? 20 watts less to go as fast/faster.
#32
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,274
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 150 Post(s)
Tagged: 1 Thread(s)
Quoted: 6147 Post(s)
Liked 4,092 Times
in
2,325 Posts
The problem is that without knowing the differences in blowoff pressure between a test rim and a "regular" rim, you can't jump to the conclusion that it's okay to exceed the recommended maximum pressure. He states that it is a legal requirement by a standards and testing agency. If there is such a test and even a "legal" requirement, why is it impossible to find the standard? I work with standards a lot and can easily find them through Google. I have never been able to find any kind of standard for maximum bicycle tire pressure or a method for testing it.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
#33
Senior Member
Thread Starter
Join Date: Jun 2017
Posts: 1,019
Bikes: Diamond Back Apex, Mongoose IBOC Aluminum Road Bike, SR road bike
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 515 Post(s)
Liked 166 Times
in
116 Posts
That really has an impact on your overall speed, doesn't it? The number of bent rims I see at my co-op because people are running low pressure on tubleless is staggering. This is one of the more egregious examples I've run across.
<-------->
That's a Hadley thru-axle hub on a downhill wheel. It's a $400 to $500 wheel that is just beat up. We got it because the idiot who did the beating didn't realize the value. Unfortunately, it's mostly scrap. I salvaged the hub but it's not something our clientele really ever uses.
If the idiot had run the tires at 35 to 45 psi, he'd still have the wheel.
<-------->
That's a Hadley thru-axle hub on a downhill wheel. It's a $400 to $500 wheel that is just beat up. We got it because the idiot who did the beating didn't realize the value. Unfortunately, it's mostly scrap. I salvaged the hub but it's not something our clientele really ever uses.
If the idiot had run the tires at 35 to 45 psi, he'd still have the wheel.
I posted this video for those, including myself, that are trying to learn a bit about tire pressure.
#34
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,611
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
The problem is that without knowing the differences in blowoff pressure between a test rim and a "regular" rim, you can't jump to the conclusion that it's okay to exceed the recommended maximum pressure. He states that it is a legal requirement by a standards and testing agency. If there is such a test and even a "legal" requirement, why is it impossible to find the standard? I work with standards a lot and can easily find them through Google. I have never been able to find any kind of standard for maximum bicycle tire pressure or a method for testing it.
#35
Senior Member
Thread Starter
Join Date: Jun 2017
Posts: 1,019
Bikes: Diamond Back Apex, Mongoose IBOC Aluminum Road Bike, SR road bike
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 515 Post(s)
Liked 166 Times
in
116 Posts
Both you and that Stuart guy are just guessing. The rider could have had proper inflation but suffered a big sidewall gash during a rocky descent, a decent sized tread puncture that slowly dropped pressure until the next rock garden, etc. Anyone who has ridden chunky stuff at speed knows that stuff can get bad pretty quickly.
Calling the rider an "idiot," as the Stuart guy has done, speaks volumes about Stuart, as opposed to the rider.
Calling the rider an "idiot," as the Stuart guy has done, speaks volumes about Stuart, as opposed to the rider.
#36
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,274
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 150 Post(s)
Tagged: 1 Thread(s)
Quoted: 6147 Post(s)
Liked 4,092 Times
in
2,325 Posts
Both you and that Stuart guy are just guessing. The rider could have had proper inflation but suffered a big sidewall gash during a rocky descent, a decent sized tread puncture that slowly dropped pressure until the next rock garden, etc. Anyone who has ridden chunky stuff at speed knows that stuff can get bad pretty quickly.
Calling the rider an "idiot," as the Stuart guy has done, speaks volumes about Stuart, as opposed to the rider.
Calling the rider an "idiot," as the Stuart guy has done, speaks volumes about Stuart, as opposed to the rider.
I’m calling the guy an idiot because he ruined a $500 wheel for a few minutes of fun. I’m also calling him...and I’m pretty sure it is a “him”...an idiot because he donated an exceptional wheel because he didn’t understand what he had. A wheel with a $350 nearly new hub isn’t one that you just throw out. It’s worth rebuilding...several times if needed. You can ruin and discard cheap wheels. Ruining expensive wheels get costly.
Of course a little bit of pressure in the tires would have solved the whole problem.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
#37
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,274
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 150 Post(s)
Tagged: 1 Thread(s)
Quoted: 6147 Post(s)
Liked 4,092 Times
in
2,325 Posts
That's one possibility. It's also possible that, as I noted above, he had a catastrophic failure at speed in a rock garden - that's results in multiple impacts as you try to slow down on the rim. It's also possible that he had a slower puncture and ran it out through the chunk. That's based on my 35 years of riding lots of chunk at speed.
The bottom line is you don't know exactly what happened any more than I do, yet you label the guy an idiot.
You also judge the guy an idiot because he donated a hub that you couldn't imagine donating. Everyone's financial situation is different...
The bottom line is you don't know exactly what happened any more than I do, yet you label the guy an idiot.
You also judge the guy an idiot because he donated a hub that you couldn't imagine donating. Everyone's financial situation is different...
That’s also my problem with the video and the pressure calculator that Silca has. It says that I should run 28 psi pressure on my loaded bikepacking bike on the roughest roads. My rims wouldn’t last 20 miles at those pressures. It also suggest that I use something like 70 psi in wide tires on a loaded touring bike. I had to do that once because the Continental touring tires blew off at the nominal pressure. It wasn’t “comfortable”. It was squishy and slow with corners being highly exciting because I was never sure if the tire was going to fold over or not.
And I can imagine donating a wheel of this quality...I have done so in the past...but I wouldn’t donate one in this shape. I also wouldn’t donate one this new. It’s a current model and the hub was absolutely pristine. It’s new enough and was clean enough that it could have been used only once.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Last edited by cyccommute; 01-11-20 at 09:54 AM.
#38
Senior Member
Join Date: Apr 2012
Location: Nor Cal
Posts: 6,016
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1814 Post(s)
Likes: 0
Liked 923 Times
in
569 Posts
Sorry but your scenario could account for a couple of dents or even just couple of large dents and smaller dents as the wheel slows down. Maintaining speed without air in the tires is very, very difficult. It can’t account for large dents all the way around the wheel. Like I said above, this is on the most egregious example I’ve seen. I’ve seen lots and lots more dented rims with dents about this size and all of the largest ones are on tubeless that are being run at low pressure. Tubed tires can’t be run at the low pressures that low because of the snakebite problem. People believe that snakebites are bad without realizing that they are an indicator of possible rim damage.
That’s also my problem with the video and the pressure calculator that Silca has. It says that I should run 28 psi pressure on my loaded bikepacking bike on the roughest roads. My rims wouldn’t last 20 miles at those pressures. It also suggest that I use something like 70 psi in wide tires on a loaded touring bike. I had to do that once because the Continental touring tires blew off at the nominal pressure. It wasn’t “comfortable”. It was squishy and slow with corners being highly exciting because I was never sure if the tire was going to fold over or not.
And I can imagine donating a wheel of this quality...I have done so in the past...but I wouldn’t donate one in this shape. I also wouldn’t donate one this new. It’s a current model and the hub was absolutely pristine. It’s new enough and was clean enough that it could have been used only once.
That’s also my problem with the video and the pressure calculator that Silca has. It says that I should run 28 psi pressure on my loaded bikepacking bike on the roughest roads. My rims wouldn’t last 20 miles at those pressures. It also suggest that I use something like 70 psi in wide tires on a loaded touring bike. I had to do that once because the Continental touring tires blew off at the nominal pressure. It wasn’t “comfortable”. It was squishy and slow with corners being highly exciting because I was never sure if the tire was going to fold over or not.
And I can imagine donating a wheel of this quality...I have done so in the past...but I wouldn’t donate one in this shape. I also wouldn’t donate one this new. It’s a current model and the hub was absolutely pristine. It’s new enough and was clean enough that it could have been used only once.
Are you talking about the wheel you posted with hundreds of paint nicks like a starry night?
That was some ride!
#39
Banned
Join Date: Feb 2008
Location: Mississauga/Toronto, Ontario canada
Posts: 8,721
Bikes: I have 3 singlespeed/fixed gear bikes
Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 4227 Post(s)
Liked 2,488 Times
in
1,286 Posts
Most of the time I don't use tire pressure gauge and I go by feel...When I ride on pavement I pump my tires just hard enough so they roll good without causing pinch flats...When I go riding off road I lower the pressure just enough to provide extra comfort and improve traction and handling but not too low to damage the rims. Tire pressure is not rocket science, it's common sense....I don't use tubeless, the biggest disadvantage of tubeless is that people think they can go as low as they want because they don't have to worry about pinch flats but they end up destroying their rims instead.
#40
Senior Member
Join Date: Oct 2018
Location: VA
Posts: 1,437
Bikes: SuperSix Evo | Revolt
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 733 Post(s)
Liked 815 Times
in
414 Posts
I have no clue what the max pressure is for any of my tires, I've never looked, because I would never run that much pressure. I run around 80psi in my 28's on the road, and 30-40psi in my 40mm tubeless gravel tires. I'm 185lbs and rarely pinch flat (even less so since going to 28s, had a few on my 23s at higher pressure), and have had zero issues offroad. I use a digital gauge and check my road pressure every other ride (if I'm riding daily, if it's been more than a day then I check it), and my tubeless pressure every ride.
#41
Jazz Aficionado
I run 100 lbs in my front and 110 lbs in my rear of my Waterford RS33 on 23's and have had excellent performance and wear with no issues. YMMV.
#42
Junior Member
I only ride for exercise now, but I still get discouraged if I'm not turning my accustomed gear. I pump up the tires, and feel young again.
#43
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,611
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
And this is part of the curiosity of the whole issue. Take Enve as an example, 80psi is the absolute max they recommend for a 28 tire on any of these rims -- SES 2.2, 3.4, 4.5, 5.6, 7.8. But 80psi is only recommended for those 240lbs or over.
#44
Newbie
Join Date: Nov 2019
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I have problems with some of the points in this video. The first is the statement that tire pressure is set to 1/2 the blowoff value of a "standard rim". I've heard this stated in lots of places but I have yet to find a credible citation of where that comes from. Yes, it's higher than the maximum pressure but twice as much? I find that very hard to believe for all tires in all widths and all possible rim widths. I've had tires that blew off at the nominal highest pressure setting.
Going over to the Silca calculator, I have definite problems with their pressure. While some of the pressures would be valid for racing conditions, they become invalid for people who have to actually pay for their parts rather than have a sponsor. The suggested pressure for a mountain bike for me is 23 and 24psi front/rear, respectively. If I add a bikepacking load of 40 lbs, the pressure suggestion is 26 and 28 psi, front/rear. First, I've ridden tires that have that little pressure in them for off-road without a load and it wallows. It doesn't turn well. But, more importantly, that kind of pressure is going to result in the tires bottoming out on hard edges which risks not just a pinch flat but a damaged rim. I've seen some very nice rims ruined because someone was using the "optimum" ride pressure and completely ignoring the other function that tires serve...to protect the rims.
Going over to the Silca calculator, I have definite problems with their pressure. While some of the pressures would be valid for racing conditions, they become invalid for people who have to actually pay for their parts rather than have a sponsor. The suggested pressure for a mountain bike for me is 23 and 24psi front/rear, respectively. If I add a bikepacking load of 40 lbs, the pressure suggestion is 26 and 28 psi, front/rear. First, I've ridden tires that have that little pressure in them for off-road without a load and it wallows. It doesn't turn well. But, more importantly, that kind of pressure is going to result in the tires bottoming out on hard edges which risks not just a pinch flat but a damaged rim. I've seen some very nice rims ruined because someone was using the "optimum" ride pressure and completely ignoring the other function that tires serve...to protect the rims.
#45
Newbie
Join Date: Nov 2019
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I have problems with some of the points in this video. The first is the statement that tire pressure is set to 1/2 the blowoff value of a "standard rim". I've heard this stated in lots of places but I have yet to find a credible citation of where that comes from. Yes, it's higher than the maximum pressure but twice as much? I find that very hard to believe for all tires in all widths and all possible rim widths. I've had tires that blew off at the nominal highest pressure setting.
Going over to the Silca calculator, I have definite problems with their pressure. While some of the pressures would be valid for racing conditions, they become invalid for people who have to actually pay for their parts rather than have a sponsor. The suggested pressure for a mountain bike for me is 23 and 24psi front/rear, respectively. If I add a bikepacking load of 40 lbs, the pressure suggestion is 26 and 28 psi, front/rear. First, I've ridden tires that have that little pressure in them for off-road without a load and it wallows. It doesn't turn well. But, more importantly, that kind of pressure is going to result in the tires bottoming out on hard edges which risks not just a pinch flat but a damaged rim. I've seen some very nice rims ruined because someone was using the "optimum" ride pressure and completely ignoring the other function that tires serve...to protect the rims.
Going over to the Silca calculator, I have definite problems with their pressure. While some of the pressures would be valid for racing conditions, they become invalid for people who have to actually pay for their parts rather than have a sponsor. The suggested pressure for a mountain bike for me is 23 and 24psi front/rear, respectively. If I add a bikepacking load of 40 lbs, the pressure suggestion is 26 and 28 psi, front/rear. First, I've ridden tires that have that little pressure in them for off-road without a load and it wallows. It doesn't turn well. But, more importantly, that kind of pressure is going to result in the tires bottoming out on hard edges which risks not just a pinch flat but a damaged rim. I've seen some very nice rims ruined because someone was using the "optimum" ride pressure and completely ignoring the other function that tires serve...to protect the rims.
#46
Senior Member
Join Date: Apr 2014
Location: Maine, USA
Posts: 1,612
Bikes: Corvid Sojourner, Surly Ice Cream Truck, Co-Motion Divide, Co-Motion Java Tandem, Salsa Warbird, Salsa Beargrease, Carver Tandem
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 533 Post(s)
Liked 435 Times
in
227 Posts
The last thing I will do on a ride is to stop, measure psi, pump or deflate, measure psi depending on what the surface conditions changed into.
my fingers are the most precise psi gauge, squeeze and judge and pedal 😀
my fingers are the most precise psi gauge, squeeze and judge and pedal 😀
#47
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,611
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
Key information that was left out of your post:
"Note: Tire pressures are intended as a starting recommendation based on the listed wheel being set up with tubeless tire. The pressure value is calculated considering a tubeless set up, intended road surface, rider's weight, average bike weight, inner rim width, and tire volume."
"Note: Tire pressures are intended as a starting recommendation based on the listed wheel being set up with tubeless tire. The pressure value is calculated considering a tubeless set up, intended road surface, rider's weight, average bike weight, inner rim width, and tire volume."
#49
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,611
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
Here, I'll bold it so it's easier for you to follow along:
"Note: Tire pressures are intended as a starting recommendation based on the listed wheel being set up with tubeless tire. The pressure value is calculated considering a tubeless set up, intended road surface, rider's weight, average bike weight, inner rim width, and tire volume."
"Note: Tire pressures are intended as a starting recommendation based on the listed wheel being set up with tubeless tire. The pressure value is calculated considering a tubeless set up, intended road surface, rider's weight, average bike weight, inner rim width, and tire volume."
#50
Advocatus Diaboli
Join Date: Feb 2015
Location: Wherever I am
Posts: 8,611
Bikes: Merlin Cyrene, Nashbar steel CX
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Quoted: 4717 Post(s)
Liked 1,526 Times
in
997 Posts
I interpret the fact that when the rim manufacturer has a point in their inflation chart, where they stop increasing the recommended PSI for increasing rider weights, it's the same as the max pressure they permit. Though they don't actually come out and say this. Not sure what other interpretation you can make, as tire drop for given pressure and rider weight is a fairly mathematical progression, and if safety rating for the rim isn't a factor, then there should be no reason to not continue increasing recommended PSI as weight goes up.