The calculator we’ve all been waiting for!
…and it appears to be telling us significantly higher than most of Josh and Silca’s blog posts would indicate. I know its just a beta version but I was under the impression from Josh’s hinting at this that there would be many more variables incorporated. Hopefully he’ll chime in here.
The calculator we’ve all been waiting for!
…and it appears to be telling us significantly higher than most of Josh and Silca’s blog posts would indicate. I know its just a beta version but I was under the impression from Josh’s hinting at this that there would be many more variables incorporated. Hopefully he’ll chime in here.
Quite a bit higher! Also not sure about the Wood Track recommendation. That is pretty Niche though.
Ditto… a boatload higher than I expected. My “Mild Pavement” recommendation is 101 PSI on a 25mm tire.
15 psi higher than I thought he would recommend. 100 psi for my fat ass is more than the rated pressure for my 7.8’s.
Doesn’t work… Keeps telling me to fill out the form info to use the calculator. Then nothing happens… I just see the same form again.
Doesn’t work… Keeps telling me to fill out the form info to use the calculator. Then nothing happens… I just see the same form again.
Yeah its a bit glitchy. I just refreshed the page after a few minutes and it worked.
I took “lbs” off weight and it worked
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Yes, same here. Basically in the 99 to 100 psi on the 25mm tires. Weird that it does not differentiate between latex, tubeless, etc setups.
I was at IM Florida a few weeks back helping some people pump up their tires after I was done since I had a pump. Every single European told me they wanted at least 120psi and I probably helped 6 or 7 people. One guy asked me if I was sure I wanted to pump my tires only to 100psi. I started second guessing myself but I held to my 100 tho.
Are people using the actual measured tire width or the stated tire size? It says measured, which you can pretty much add 2mm to the stated size if you don’t have calipers.
My complaint is there’s no rough & smooth chipseal option. That’s got to be somewhere between old asphalt and cobbles. Also surprised to see lower pressure recommended for smooth gravel than cobbles.
Yes, same here. Basically in the 99 to 100 psi on the 25mm tires. Weird that it does not differentiate between latex, tubeless, etc setups.
Those variables shouldn’t effect tire pressure choices (except maybe cobble for tubed setups if you are at risk of bottoming
Second—be sure you are using actual measured width on your wheels as measured with calipers. My 23mm on Roval is like 27mm actual
Are people using the actual measured tire width or the stated tire size? It says measured, which you can pretty much add 2mm to the stated size if you don’t have calipers.
My complaint is there’s no rough & smooth chipseal option. That’s got to be somewhere between old asphalt and cobbles. Also surprised to see lower pressure recommended for smooth gravel than cobbles.
Cobbles are a different beast. Can be bigger hits but lower frequency. “Smooth Gravel” is probably not dirt, more like heavy cinder/ small pebbles. Much higher frequency of deformation.
Hopefully Josh can chime in, because this is not really lining up with his previous recommendations or my experience.
My real world experiences aren’t lining up with the calcuations either.
The calculator is putting me 10-15 Psi high on my road setup and 5-8 Psi low on my gravel setup(s)
In what way does it not line up with your experience?
In what way does it not line up with your experience?
The calculator has me up around 100psi on conti 23s (yes, I even used 25mm in the calculator), and the ride is quite uncomfortable and a bit jarring that high. My by feel pressure for comfort, cornering, and flat protection is 80-85 psi.
My usual gravel tire setup is 650x42 and he calculator has me in the 25psi range. There would be too much squirm at this pressure and definitely a high risk of flatting. My usual pressure is around 30 -32 psi for my 42mm setup.
15 psi higher than I thought he would recommend. 100 psi for my fat ass is more than the rated pressure for my 7.8’s.
On the 7.8’s website they recommend pressured up to 115 psi (23mm and 250 lbs) and the wheel manual says 125psi is the max. Where are you seeing a 100 psi limit?
Looks like I am wrong. Not sure why I thought they were maxed out at 87 psi? I will take another look at my manual, but online it definitely says they can go much higher
In what way does it not line up with your experience?
The calculator has me up around 100psi on conti 23s (yes, I even used 25mm in the calculator), and the ride is quite uncomfortable and a bit jarring that high. My by feel pressure for comfort, cornering, and flat protection is 80-85 psi.
My usual gravel tire setup is 650x42 and he calculator has me in the 25psi range. There would be too much squirm at this pressure and definitely a high risk of flatting. My usual pressure is around 30 -32 psi for my 42mm setup.
Well, Josh is like the world’s expert on bike tire pressure and he has tons of real measured data of different tires, wheels road surfaces, riders… I would trust that a lot more than personal feel, assuming you fill it all out correctly. I use gp5000 23c tires but they measure 26mm on my wheels. Hardest thing to know is exactly what he means by “mild asphalt” etc…
Are people using the actual measured tire width or the stated tire size? It says measured, which you can pretty much add 2mm to the stated size if you don’t have calipers.
My complaint is there’s no rough & smooth chipseal option. That’s got to be somewhere between old asphalt and cobbles. Also surprised to see lower pressure recommended for smooth gravel than cobbles.
I am with you, Sean. I’d like to have guesses at more ‘real world’ types of surfaces and mixes. How about really narrowing it down to 50% old asphalt/50% chip-seal and other choices like that so we can really make more informed ‘guesses’. I don’t think I have any cobblestone races coming up…And while I’m whining like a biatch, how about adjustments for dry/light rain/heavy rain.
And everyone should use measured widths-come on really? Do people not own a paper clip and a ruler??
For the record, it’s about 5-10 psi higher than what I currently use, and I’m also a bit surprised by that.
In what way does it not line up with your experience?
The calculator has me up around 100psi on conti 23s (yes, I even used 25mm in the calculator), and the ride is quite uncomfortable and a bit jarring that high. My by feel pressure for comfort, cornering, and flat protection is 80-85 psi.
My usual gravel tire setup is 650x42 and he calculator has me in the 25psi range. There would be too much squirm at this pressure and definitely a high risk of flatting. My usual pressure is around 30 -32 psi for my 42mm setup.
Well, Josh is like the world’s expert on bike tire pressure and he has tons of real measured data of different tires, wheels road surfaces, riders… I would trust that a lot more than personal feel, assuming you fill it all out correctly. I use gp5000 23c tires but they measure 26mm on my wheels. Hardest thing to know is exactly what he means by “mild asphalt” etc…
If you listen to Josh’s podcast, he has detailed how to set your tire pressure by feel for road. He basically says you keeping going lower until you get squirm in the corners or others negative handling trails, and go up a bit from there. I have verified my road pressure with Josh’s ‘by feel’ method.
No need to go into detail on the gravel pressure side of things, but if the terrain you ride and the way you ride requires a certain pressure not to flat, and you don’t want to use more volume for various reasons, then you get a pretty damn good feel for off pavement pressure.
I’m sure Josh would agree, the calculator is giving you a good starting place and it’s up to the user to adjust up and down from there based on their actual conditions, speed of riding, and riding style.
For me I was just surprised the numbers were quite far from the pressures I’ve concluded to work best for me.
Edit: I forgot to mention, I am a Josh/Silca fanboy 😃