Tire chat (nerds only)

What is the consensus on new Continentals?  Sounds like they are excellent- grippy, long lasting and faster rolling than comparable Maxxis?

Only faults are hard to mount and hard to find in stock?  Any other issues?

https://patents.google.com/patent/US8568523B1/en#:~:text=These%20prior%20art%20tire%20treatments,%2C%20Naphthenic%20Solvents%2C%20Naphthenic%20Oils%2C

Keep that shit out of the environment. 

There’s a bunch of different treatments. I called and talked to someone at the company and he said Hot Laps2 was the least destructive.  As I started digging into more info, it seemed like every drag racers, flat tracker and road racer all have used it at sone point.

https://keysermanufacturing.com/product-category/fluids/tire-treatments…
 

My main goal was how to keep the tire feeling like “new” for more than a few rides. I think it works but definitely sacrifices durability. But I’m hard on rear tires at the bike park. 6-10 laps a day X 10-14 days and it’s toasted.

Take a look at RC tyre prep stuff. its called 'tyre sauce' think your Maxxgrip are grippy now... just you wait...

Theyre very good, super softs aren't great value (expensive and fast wearing, go figure, but it should be pointed out), honestly the main complaint is they're too square on 30mm+ rims, some may like that, others wont.

Honestly, seating is fine, but i also got use to Michelin DH34 bike parks (wire bead) so comparatively their easy.

In a hot take, I think the main brands all have excellent tyre choices currently with varying strengths.
Maxxis, Schwalbe, Conti all excellent, i have enjoyed WTB recent tyres, Specialzed are making some great tready patterns, but the casings and durometers often aren't what you want.

Ive thought about that stuff for years. And youve experienced the same that the dirt changes the compound. 
vee rubber say their soft 40 compound also rolls well for being so soft and grippy. Not experienced it or know why. Just repeating the claim

Something i found was with Conti's you dont need to lean the bike as much when in use with 30mm ish rims.
I found you need to alter how you ride them a little and once it clicks they are excellent

Ive gone down that rabbit hole and tried some 25mm rims - they feel very weird the tyre would wiggle quite alot when not fully loaded.(that feeling of low pressure when not running low pressure)

yep, that's the stuff.

We used to use straight MEK (Methyl Ethyl Ketone) and there was a science to it, leave it in too long you have no tyre left, also no fingerprints or brain cells.... that stuff was nasty.

I'm embarrassingly into RC Crawling competitions, I've made my own concoction that works well and doesn't give you cancer.

Basicly every soft/supersoft etc. becomes rock hard in proper winter conditions and start to crack. Been running butcher T9 trail front, butcher T9 gravity rear and now that temperatures are dropping, -10c atm and dropping for next days, its time to change my studded tires on as those specialized tires are losing all their qualities. Happens with all manufacturers, but yeah they are not really made for this weather so its expected.

I have no personal experience but I read somwhere that schwalbe isn't that bad in cold conditions.

I used to do advertising for one of the major automobile tire companies. Our most aggressive (softest) racing tread compound not only didn't work well when cold but we were told by the engineers that the tires had to be kept above a certain temperature when in storage because if they got too cold they would forever be altered and lose some of their grip. 

Don't know if y'all remember, but Spomer did a quasiscientific-ish lab test of rolling resistance with Maxxis tires, and found that the compound made the biggest difference, but wheel size and casing also impacted rolling speed. Tire test starts at 8:28 and for the love of all that's holy please don't try to explain all the ways this test isn't scientific. Trust me, we ALL know already: https://www.youtube.com/watch?v=je1UyJRYhIg

The rim width discussion is an interesting one. Ever since the days of the D3.1/D729 I’ve preferred rear rims to be 25-28 and fronts to be 29-30.

The narrower rear rolls faster, stronger rim, the profile feels great at slightly higher psi while giving that “good flex” feel through chunk.

Stability of 30mm feels good up front.

It just boggles my mind that most wheelsets have the same front and rear profile. 
 

I don’t like squared off tread patterns, so this rim preference might be related to that.

There is also that DT swiss test they did a while back about climbing efficiency, and how somewhat paradoxically low pressures tyres are more efficient at climbing in XC (due to weird spring force of climbing over obstacles?) that actually was a scientific paper.

Compound should make the biggest difference
 

Id love to find a way to do a fresh vs slightly used versus old test for grip levels, rolling resistance etc.

anyone have an idea how to do it? ive got more than enough tyres to try

That's the kind of thing I'm working on slowly when I get free time (actually working on the code for reading load cells right now!). Currently thinking of something like towing a fixture behind my car on a dirt road that's just a wheel with a weight on it. A load cell to measure the drag force and probably speed & braking sensors too. Vary the speed, weight and tyre pressure and see how it goes! Maybe accelerometers to measure vibration losses too. Like with that DT rolling resistance test - low pressures roll fast because there isn't energy lost from vibration, like the way you have to lift the whole bike over a bump if your tyres are super hard, but if they are soft then you only need to compress a small amount of tyre casing.

Thats a great idea for a straight line testing.

I guess relevant to racing though its all about cornering speed, I personally cant think of an easy test jig to simulate cornering grip.

I did think of just finding a berm and death gripping into it with different tyres repeatably and measuring exit speed

I have definitely experienced singing like this with some MTB tires, or at least I assume it was a temperature problem. I stored them in an unfinished, drafty basement over winter and the next spring when I went to mount them they felt awfully hard even after warming up. 

I assume this could also be an issue with changes in humidity too, especially if it swings from very humid to very dry. I guess I will find out since my new place this year is incredibly dry.

Someone with a durometer should:

1) buy some MaxxGrips

2) test hardness

3) throw in freezer/fridge

4) remove/bring to room temperature

5) test hardness

The only thing my wife would love more than storing tires in the freezer would be keeping my bike in the living room.

I’ll do this week on an old tire.

I used this stuff religiously when I raced motorcycles.  Absolutely does everything it claims.  The performance advantage is enough that in some kart racing series, they have banned the use of it and will test your tires.

I'd love an automated test that turned the wheel through different angles but figured a simple straight line test would be a good start to iron a few things out. This guy inspired the kind of thing I thought would be cool - https://youtu.be/5tQ6OTJdhns?si=YsMPSjKiFCYFNPRD&t=327

You could try it by measuring speed - part of the fun is just trying stuff and seeing what happens! I think an IMU (3 aixs accelerometer and 3-axis gyro) could help that kind of test. (hint: smart phones have them built in and can usually sample at least  100Hz!) I have an app on iPhone called sensorlog that record log bascially every sensor in the phone which can make it pretty dang useful!

It'd probably be best to document temperature whenever you test hardness that way conditions can be replicated for the after-the-freezer durometer testing. 

I've been using the newer Specialized Cannibals as front tires for the past year or so. Actually really impressed with the Cannibal as it has unreal grip in most situations and generally seems to wear pretty slowly when compared to a Maxxis max grip. The casing of that tire is way stiffer than their other tires or even Maxxis DH casing. I started with a butcher T9 gravity out back and moved to a dissector max grip DH when that wore out. Currently on a Conti Xynotal soft DH paired with the Cannibal up front and seems to work pretty well. Most of the area around where I live is relatively flat but super rocky, so a fast-ish tire setup with firmer casings is ideal. Debating on whether or not to buy another Cannibal to run as a rear tire. 

I recently ran an assegai maxxgrip dh front and butcher dh T9 rear for a few months- was a great combo for dry conditions.

Assegai lasts really well for me as a front tire- doesn’t seems as sensitive to losing the sharp edges as a DHF.  And the butcher T9 rolls better and lasts longer than any maxxgrip maxxis.  

I wonder if I'm not a nerd, because I find myself for the most part pushing back against mtb culture's urge to create content or distinguish brands by quantifying whatever interested parties can get their little calipers on. But in the hope of providing something constructive, my "I work in a lab but unfortunately not a tire-testing lab" perspective starts with this.

1) Has someone already tackled the hardest problems (deciding just what to measure, figuring out how to do it)? It's enough work adapting a well-designed test from one context to another without losing what makes it valid; starting from scratch invites a lot of work and a thousand pitfalls (not that a You-tuber or a blogger has reason to care if all their findings are invalid, since the metric of success is engagement; being incorrect isn't a disincentive). Low-pressure pneumatic tire performance has been studied by better resourced groups than mtbers. This looks cool, for example https://par.nsf.gov/servlets/purl/10216180 (pun!)

2) A simple algorithm for getting started on an experimental design. How big a difference are you expecting to see? With that answer in hand, does the test have the resolution necessary to distinguish that size of difference? This isn't just a technical challenge that can be overcome with better equipment, though that's a place to start. As the fineness of the equipment and the data generated improve, at some point you can have numbers that are accurate enough to give confidence but differences between those numbers so small as to be meaningless, despite a statistical tool showing the difference to be "real." Effect size should always be on your mind in the design process.

3) Variability. This is where so much the bro-science in the mtb world falls down. If variation in the test equipment itself (say, anything with a human rider, randomly inaccurate measurement) introduces between-runs noise that's pretty big compared to the signal of what you care about (say, between tires), teasing those apart is going to take serious work (which is more than bro-work or it's-just-bikes-why-so-serious-bro work).

You can do it!

Those are all very good points and I mostly agree, especially on the proliferation of bro-science from a lot of places. However I would still prefer to see more people at least attempting to continue testing products in a more scientific way so I don't really want to discourage that!

The reason I do agree with you though is that science is boring as hell for most people. You will need to repeat the test over and over again and still not have an outcome. You spend hours, days, weeks on something and be completely wrong. You will discover that your measurements are filled with noise and errors and need to go back and do it again. If you go out and test something once and come to a conclusion straight away, you probably did something wrong. 

Theres some really good papers out there from the automotive world (I've saved that link to read later, looks good!) but not a whole lot of overlap with mtb and very little that is specific to mtb applications. So in reality starting from scratch is the only choice - it will take a lot longer but theres not much other option?  I would love it if someone else did all the work and made it easier for me but so far haven't found it

The reason I do it is there has been a woefully large gap between the actual science of bicycle physics and the knowledge of riders/media/mechanics. So the result of that is far too many people have a pretty disappointing experience of mountain biking because they spend an obscene amount of money on their bike but it wears out, breaks too soon or just awful to ride. And being able to quantify those experiences to turn it in to a more enjoyable time is a good reason to me! 

If you are in the small group of enthusiasts that visit a site like this then you might not see that, but when I look at the wider range of people that use mountain bikes this is definitely what I see. 

i used to work as a lab technician, and agree with all your points.  one of the challenges is that there aren't standardized test methods for everything (such as tire pressure, as there's a lot of independent variables).   So there's an inherent challenge due to lack of consistency (standardization) especially when companies have to establish their own in-house methodologies and it prevents meaningful comparisons without ways to benchmark against one another.  beyond that it's subjective speculation from riders as you've said. 

one means of assessment i've found useful - and have heard and applied out of cycling - is a simple evaluation tool - better, worse, or the same. in the absence of standardized evaluation methods, that's what a lot of assessments are based on. 

I am currently running a MM up front and a Kryptotal R in back. This lack of on-bike brand consistency makes the bro scientists very uneasy but I am unafraid—haven’t torn spacetime yet. Just putting cool looking tires on my bike.  
I want to come clean with this before I check back in to this thread…I fear I may not truly be on y’all’s level. 

 

I agree with the broscience that easily can infiltrate these discussions. It is kind of a catch-22, though, because anything in a controlled lab isn't real-world conditions and findings can fall flat on the trails, and anything on the trails has to introduce a million variables because of the human element, variable conditions, etc. 

It's almost like you have to combine the two, lab and trail, and see whether the findings reinforce or conflict with one another. Lastly, any trail testing must be double-blind—after working in marketing forever, I've come to the conclusion that people perceive what they expect to perceive, and everybody has priors.

Maybe tires are different, but I tend to be very skeptical when people claim they can tell the difference between things like bars, stems, cranks, etc. Has anybody ever done a double-blind test to see if your average Joe can tell the difference between MaxxGrip and MaxxTerra?