OMG, leave it to the engineers to solve a nonexistent problem.

 

Where do I input the type of dirt I am riding on and my riding style (flow vs attack)??? I love Wolf Tooth, but this seems truly pointless unless the target is an absolute beginner rider. But then, anyone that new wouldn't be looking for a tire pressure calculator app.

 

You can pick from:

XC/Trail soft
XC/Trail medium
Enduro/steep/rocks
Big jumps or pavement

 

Still too high

 

Actually, unlike the SRAM and Silca calculators, this one is spot on (within 1 psi) of the pressures I've settled on for MTB, gravel and road. I like it.

 

I don't get the hate. People seem to like Silca's calculator but that one spits out numbers that make zero sense for MTB (like 13psi for front tires), where the Wolftooth one seems to be the right ballpark. It will compensate for different inflation and riding temps--great for here where winter mornings are in the low 40s but it is 70 by mid-ride. And it will even compensate for 29er vs 27/MX. Obviously not going to help anybody who has already decided on their preferred pressure, but it's a well-executed tool. And free.

 

I don't get the hate.

It's MTBR, there WILL BE HATE. PERIOD. 🤣
But yeah, I get ya, it does what it does, but it's pretty much right on as far as my pressure preferences go. I got no beef, didn't cost anything, doesn't weigh anything.

 

New and improved but still no way to input inner rim width?

 

It seems ballpark-ish for what I do.

Although for me personally, its low in the rear, and high in the front. Perhaps I have a very rearward weight bias?

Its suggesting 25psi rear, 23psi front. I usually am more like 25-30psi rear, and 18-21psi front.

I did think it was interesting how it called out the difference between inflation temperature, and riding temperature.

 

It seems ballpark-ish for what I do.

Although for me personally, its low in the rear, and high in the front. Perhaps I have a very rearward weight bias?

to their credit, and why I love that company, they did say it is a starting point and to adjust. In that regard, not really different than the little charts Fox puts on their forks.

I've been using their products for a long time. They reached out to me after reading a review I posted in a group I used to run. They were super cool and asked about my experiences with the company. Sent me some cool swag for being a vocal supporter! I am buying their new minipump/tools once Jenson refunds me for the wrong WolfTooth dropper I bought.

 

I don't use it much for normal riding, but it is actually really helpful for fat biking, where there can be a huge swing between my garage temperature and the temperature I'm actually riding at.

 

Its off exactly 1 psi but my pump might be off. So that's pretty good.

 

I have found it useful for a starting point, especially when you're getting started on new tires with different dimensions than you're accustomed to.

I'm glad things like this exist and Wolf Tooth's seems to be one of the better options out there.

 

This seems pretty dead on to me, 27 rear, 24 front. I run 27 rear, 23 front. Big dude on rocks.

 

I used it for the control runs in my suspension setup tests just so that I was consistent across bikes based on measurements but it seems pretty spot on to me as well. Don’t misunderstand, I will adjust if things don’t feel right but I think it’s a great starting point for a lot of people.

One thing I don’t like is the lack of an MX setting for wheel size. As is you have to flip it back and forth. Easy enough but seems like low hanging fruit.

 

Pretty accurate, though I run more towards the enduro end of their spectrum even on the bike I use for more moderate XC. One mistake on a rough section can equal an expensive rim shot. Also agree with those that suggest greater differential between the front and rear. 19f/24r is common for me, for example.

 

There is a decent amount of riders that just don't get tire pressure, and don't understand how important it is.

SRAM also has a pressure calculator that I find is very accurate. I've used it several times to get a starting pressure for the gravel bike when I install new tires, it's always essentially dead on. The pressures it comes up with for my MTB have also been spot on to what I typically settle on.

SRAM | AXS

axs.sram.com

 

There is a decent amount of riders that just don't get tire pressure, and don't understand how important it is.

SRAM also has a pressure calculator that I find is very accurate. I've used it several times to get a starting pressure for the gravel bike when I install new tires, it's always essentially dead on. The pressures it comes up with for my MTB have also been spot on to what I typically settle on.

SRAM | AXS

axs.sram.com

I'll be darned, that guide spat out nearly my identical pressures on my enduro bike.

 

Ok this is interesting, comparing the different calculators to each other. They have some radically different results, with Silca being the lowest (and closest to accurate for me) by far--even though it's the one that isn't really meant for MTB. I know that the Silca one is based on extensive real-world data gathering and analysis. They have some detailed blog posts on their site describing the process leading them to the realizations about lower pressure. They were one of the first mainstream advocates for lower roadie tire pressures, and that advocacy led to a revolution in road bike tire pressure understanding. I also believe Silca was the original tire pressure calculator/tabulator.

My tl;dr is that it's good Woolftooth is encouraging people to benefit from lower tire pressures, but they don't go far enough.

I appreciate these tire calculators for getting people started in the right ball park, and mainly convincing many riders (beginners to pros) that they can and should run lower tire pressures than what they've gotten used to and never questioned. That was one of the things the Silca calculator contributed to for roadies, including riders all the way up to Tour de France winners (so no, it's not a beginner thing for sure).

I do like Wolftooth being clear about what "optimal" means to them, and what they are shooting for:

"Lower Tire Pressure is Better ... The Wolf Tooth philosophy is based on the idea that lower pressures are better for performance. The Bike Tire Pressure Calculator is built around this point of view. Perhaps a better way to state it is 'the lowest possible pressure consistent with terrain, riding style and equipment is better'. It’s certainly possible to go too low and the difference between 'just right' and 'too low' can be small." ​

But, I wish they were clearer what they meant by "too low" -- is it just based on the risk of rim impacts? Is it maybe based on the pressure where the tire will start squirming and burping (in which case it would matter a lot what rim size is used, which is something they don't have as a variable). Is there a point where one of the three benefits (traction, comfort, rolling resistance) no longer improves or worsens?

Either way, the Wolftooth and SRAM answer for my situation is much too high. 200 lbs total, XC/Trail Medium, 27.5 Wheels with 2.8 inch tubeless tires and they are 5-8 psi too high for what you can safely run. That's a lot when dealing with a higher volume tire/wheel combo like I have. My personal pressures are much lower based on having no risk of rim impacts and getting pressure as low as I can. With i35mm rims, there is no concern of squirm or burp and my informal testing tells me I'm just as fast or faster as tire pressure lowers. If I do an enduro course or bigger jumps, I raise pressure a few psi, but the Wolftooth calc is still about 5 psi higher.

It is interesting that the Silca one is not meant for MTB but is much closer to my experience. The Silca one doesn't let you pick MTB trails; I'm pretty sure Gravel 4 or Cobblestone is still not as rough as many trails. The Silca calculator also maxes out at about 2.56 inches, which is worlds different from 2.8 for tire performance believe it or not. The Silca data is based on years of data collection and analysis. It would be interesting to know what the other calculators are based on.

 

Ok this is interesting, comparing the different calculators to each other. They have some radically different results, with Silca being the lowest (and closest to accurate for me) by far--even though it's the one that isn't really meant for MTB. I know that the Silca one is based on extensive real-world data gathering and analysis. They have some detailed blog posts on their site describing the process leading them to the realizations about lower pressure. They were one of the first mainstream advocates for lower roadie tire pressures, and that advocacy led to a revolution in road bike tire pressure understanding. I also believe Silca was the original tire pressure calculator/tabulator.

My tl;dr is that it's good Woolftooth is encouraging people to benefit from lower tire pressures, but they don't go far enough.

I appreciate these tire calculators for getting people started in the right ball park, and mainly convincing many riders (beginners to pros) that they can and should run lower tire pressures than what they've gotten used to and never questioned. That was one of the things the Silca calculator contributed to for roadies, including riders all the way up to Tour de France winners (so no, it's not a beginner thing for sure).

I do like Wolftooth being clear about what "optimal" means to them, and what they are shooting for:

"Lower Tire Pressure is Better ... The Wolf Tooth philosophy is based on the idea that lower pressures are better for performance. The Bike Tire Pressure Calculator is built around this point of view. Perhaps a better way to state it is 'the lowest possible pressure consistent with terrain, riding style and equipment is better'. It’s certainly possible to go too low and the difference between 'just right' and 'too low' can be small." ​

But, I wish they were clearer what they meant by "too low" -- is it just based on the risk of rim impacts? Is it maybe based on the pressure where the tire will start squirming and burping (in which case it would matter a lot what rim size is used, which is something they don't have as a variable). Is there a point where one of the three benefits (traction, comfort, rolling resistance) no longer improves or worsens?

Either way, the Wolftooth and SRAM answer for my situation is much too high. 200 lbs total, XC/Trail Medium, 27.5 Wheels with 2.8 inch tubeless tires and they are 5-8 psi too high for what you can safely run. That's a lot when dealing with a higher volume tire/wheel combo like I have. My personal pressures are much lower based on having no risk of rim impacts and getting pressure as low as I can. With i35mm rims, there is no concern of squirm or burp and my informal testing tells me I'm just as fast or faster as tire pressure lowers. If I do an enduro course or bigger jumps, I raise pressure a few psi, but the Wolftooth calc is still about 5 psi higher.

It is interesting that the Silca one is not meant for MTB but is much closer to my experience. The Silca one doesn't let you pick MTB trails; I'm pretty sure Gravel 4 or Cobblestone is still not as rough as many trails. The Silca calculator also maxes out at about 2.56 inches, which is worlds different from 2.8 for tire performance believe it or not. The Silca data is based on years of data collection and analysis. It would be interesting to know what the other calculators are based on.

I agree that it would be interesting to know this but my guess is that you are far off because you are an edge case (despite it clearly being within the bounds of the app settings). I probably know at least 50 people of various shapes and sizes that ride an MTB regularly. I think it is more but kept the number conservative. Not a single person I know would be on 27.5"/2.8 tires at the moment. Obviously nothing wrong with your choice, I just think that is likely why.

I wouldn't be comfortable riding that much below what it recommends for any of my bikes unless I was using inserts and even then I wouldn't be comfortable if I had to jump at any point. Based on casual banter I would guess that I run my tire pressures lower than virtually all of the people I ride with regularly but I have no facts to back that up. I say this to note that I'm not adverse to low pressures.

 

The biggest issue is getting people to honestly assess their own riding style and assigning a factor to that.

There are 240 lbs dudes who run <20 psi in their 29x2.4 EXO tires without issue. There are 140 lbs dudes who can peel tires off the rim at 25 psi.

I have no issues with new riders starting out using a calculator but ultimately you should just do some testing and find out what pressure works for you. Trying to make the perfect pressure calculator isn't that useful.

 

+1

Its more a ballpark/starting point that one should experiment from. I remember busting balls of guys in our group who ran DD tires... for the most part I was riding the same stuff. Sure enough, as I've progressed I've needed to run higher pressure and now myself run DD/DH tires.

Northeast rider, 195 lb geared-up, 35 lb enduro, Conti DH tires, I'm generally at 26/28 psi for proper smashing and sometimes up to 28/30 for certain shuttles/parks. In the wet I'll drop it 24/26 psi.

I basically run similar pressures on my trail bike, with lighter casing tires, but I'm also a bit less hard charging on it. For a very mellow trail/XC, kid shotgun ride I could run 20/22 psi.

The WT app is pretty close, seems like the terrain is more akin to "charging", cause jumps gives me my normal pressure.

 

it is definitely interesting the variety of riders that you meet / ride with over time. a good friend of mine knew absolutely nothing about bikes whatsoever, and hadn't even ridden a bike in a long time when a bunch of us decided to ride monarch crest. dude shows up with a schwinn 10-speed from the 70's, i **** you not. we are thinking this isn't going to work whatsoever. he totally smoked everybody on it. he looked like mary poppins flying down the trail, cackling his little high pitched laugh the entire time.

now - that being said, that poor schwinn was completely totaled by the time we got to salida. the rims looked like pancho villa's most embattled sombreros. luckily he had bought it at a thrift store for a few bucks, so he wasn't too upset.

some folks just have the knack, the rest of us, well, we spend our sleepless nights wondering if there will be some new invention that can dynamically adjust tire pressure on the fly - live valve phase 2 of sorts.

 

regarding the calculator - i find it interesting that it recommends lower pressures for XC type riding than enduro type riding. typically i run 20/18 on rocky/enduro stuff and 24/21 on more XC type stuff. i do have exceptions to this general plan - Palm Canyon Epic being a really good example - i run 24/21 on this due to there being so many sharp rocks. i feel like this gives a bit more protection against jagged rocks and i am willing to trade that for a bit more rattling-teeth.

 

That is exacly why the say to run more in enduro...higher pressure equals more tire support. Assuming the same tires, rider, rider style, but on an XC course vs Enduro (PCE is a great trail example)...you need less pressure to ride XC as the forces are lower. Enduro tires have a stiffer sidewall and can be run lower than XC tires. Regardless of the tire I am using, if my rides are mellow, pressure will be lower. For PCE, I go up about 2 PSI from normal.

 

Air up, squeeze the sidewalls. Done. If you're a Jedi.

 

I've been using the app for a while now and I find it, damn near spot on.

 

This is a cool little app! It was almost spot on for what I've been riding, and I've just been dialing it in on my current setup over the past 3 years. Very accurate pressures both front and back, IMO =]

 

Actually, unlike the SRAM and Silca calculators, this one is spot on (within 1 psi) of the pressures I've settled on for MTB, gravel and road. I like it.

Same for me, very accurate.

New and improved but still no way to input inner rim width?

This, and riding surface should probably be taken into consideration

 

This is cool. I’m running 1 psi lower than what this calculator tells me I should be running, for my newest main ride. I’ll increase by 1 psi and see how it feels.

 

Same for me. I increase both by 1 psi and liked it.

 

The calculator was about 4-5 psi too low for me.

 

I thought internal rim width is an important factor.

Well …in fact I still do.

 

for selecting a tire to match with it. Does internal rim width have any direct baring on tire pressure though?