Why Don't Specialized Pathfinder Pros get more love on the forum? Are the BRR Rankings legit?

53 replies · 12,449 views

ridetiltheend
7 posts
#21Jul 30, 2021, 2:15 PM
Familyridz wrote:The criticism I have of the BRR approach is they are comparing tires with significantly different measured widths, inflating the smaller tires to higher pressures that do much better on rollers, and not factoring in bumps and how much bike+rider weight each set up can suspend. The suspension examples were just for an analogy to the trade offs of a bigger lower pressure tire over bumpy terrain.

Let’s say you are riding a washboarded road, 1/2” to 1” stones or tree roots. The 42mm tire at 30 psi is going to “spring” or soak up a lot more of that upward force without lifting the bike upward than a 33mm at 10-13 psi higher pressure. The 33mm then causes more forward force/momentum to be redirected into lifting/vibrating the combined bike & rider weight by several mm per bump more than the larger, lower pressure tire. The upward energy has to come from somewhere.

That is the extra wattage lost with smaller, harder tires on gravel that doesn’t come through in smooth roller tests. The larger lower pressure tire will also grip better on loose and wet surfaces, making energy transfer more efficient, but that won’t show up in a dry, clean roller test either.

All of which is why the BRR tests should only be considered as predictive of smooth pavement performance, and to a lesser extent, very smooth gravel. But I don't see any way around inflating the smaller tires to higher pressures though, after all that's what we do in the real world to equalize tire performance and would likely end up penalizing the smaller tires without necessarily giving valid data for performance on rough terrain.

To really solve the issue you'd need some other tests in addition to the current one, perhaps a very large rough drum that simulates a rough gravel ride, and some sort of test of traction in a few types of situations.
0
stu
646 posts
#22Jul 30, 2021, 3:43 PM
I think a reasonable real-world test would be pulling loaded bicycle wheels behind a car or truck with a fairing attached to eliminate air resistance. The mounting arrangements could be equipped with strain gauges and integrating electronics to measure the force required. I suppose 6 or 8 independently mounted wheels would fit side to side and could be tested together.

This would involve some variability due to changing road conditions, temperatures, etc but would be easy to do on different surfaces without issues from the radius of a drum. Ideally several samples of each tire would be tested with different surfaces, loads, speeds, temperatures, and pressures; that would take a lot of time and produce a lot of data. In other words, it wouldn't be cheap. 🙁
0
mtgrvl
23 posts
#23Jul 30, 2021, 4:45 PMedited
It's just one small anecdote about the Pathfinder Pro 42, but I think one worth sharing given the conversation:

There's an old forest service (closed to cars) road near me that's a little rocky, but not technical. The first part is 4.7 miles and about 700 vert of climbing. There are some steep sections in there, and a few spots where you can get going fairly fast between climbs. I spent this spring on the Gravelking SS 38 and routinely rode that segment on those tires around 19:30. As you likely know - the SS38 is one of the lighter/faster tires in this segment.

In prep for a 100-mile race where I wanted a more comfortable tire, I threw the Pathfinder Pro 42 on my bike and went to that same road. There was no wind, so with the larger/heavier PP42 on there I was thinking I'd finish that climb between 19:30 - 19:45. I was dead wrong. Finished in 19:10 and set a PR.

The lesson? Not totally sure, but my guess is the larger/heavier/softer PP42 is faster as I didn't have to pick my lines through rocks as cleanly as I would have on the SS38. I'd still likely choose the SS38 for super smooth and hard-packed gravel roads, but I don't really have those around me so I'm leaving the PP42 on the bike.

Just to add more to this - going downhill on that same segment the PP42 crushes the SS38. For the same reason - the PP42 can plow over stuff that the SS38 can't, and (in my opinion) the SS38 side knobs don't engage nearly as well as the PP42 - leading me to brake more on the 38's going downhill. So, sure, the SS38 may have less rolling resistance, but in the real world, on rough roads, where you're racing both up and downhill - the PP42 is way faster.

That said - the SS38 is always faster than the PP42 on the pavement. No questions there. The PP42's feel like boat anchors on the road.
2
edraven
122 posts
#24Jul 30, 2021, 5:16 PM
Familyridz wrote:
So, why doesn't the Pathfinder get more love?

I would assume because that center slick tread looks like you'd get zero traction on the steep stuff, and would wander on the loose over hard stuff. Am I wrong in my assumptions?
0
Familyridz
70 posts
#25Jul 30, 2021, 6:35 PM
Maybe at max pressure with a tube those would be concerns, but the same is true for all the low RR tires. On pavement and dried hard dirt, the profile is like my old Schwalbe Hurricane (or the Town & Country reverse knobby) and the center ridge keeps the smaller knobs and big side knobs off the road to go fast. As soon as the road gets a little soft or loose, it sinks in. Lowering pressure a little or a lot (60 psi is a 50% increase over 40), and it flattens out and the small knobs and bigger side knobs make contact.

Going straight in loose stuff is no different than other small knob low RR tires, but curves downhill are where things get sketchy, and like my old Hurricane, it has larger side knobs than most or all of the tires ranked above it. It might be that some of the sidewall stiffness is needed for these to work properly at lower pressures.
0
mtgrvl
23 posts
#26Jul 30, 2021, 7:13 PM
edraven wrote:

I would assume because that center slick tread looks like you'd get zero traction on the steep stuff, and would wander on the loose over hard stuff. Am I wrong in my assumptions?

For sure wrong on those assumptions. The PP42 does fine on the grip side. And it's locked in on loose stuff. No issues.
0
imwjl
304 posts
#27Jul 31, 2021, 11:57 AM
For one earlier comment, indeed lots of segments or segmenting what a gravel bike is. Knowing engineers, product, and marketing managers in this I'm also aware the larger makers gear up production for what sells. My Trek friends are quick to point out there are niche and small makers great at what they don't do.

For the bicycle rolling resistance fans and addicts, the tire and wheel people I know - wheel/tire engineers, OEM reps to the big name brands - have brought up rolling resistance and weight are only parts of what makes winning products. Part of Trek's sealant needing less than others is less weight that also makes a wheel and tire behave differently.

This is all I could find in a hurry, it's about a then new road tire release, but they test more than road tires this way.
https://www.youtube.com/watch?v=gYaWetHzejQ
Something that entertained me and struck home was telling Trek staff friends how I like stuff I used to think the company didn't do a good job at. I was told they can't get away with selling crappy stuff by the millions and they don't like riding crappy stuff personally.

I still think most of the bike brands have pretty good stuff and it's easy for amateurs to overthink it. What I don't like about that style of Specialized tire in the start here isn't something against them as much as I just like an all slick or tread in center tire.
0
stu
646 posts
#28Jul 31, 2021, 12:47 PM
I also consider the location and details of manufacture. I once ordered a pair of Terrene Honali tires. They came covered with a smelly, oily substance and a California carcinogen warning. I put them back in the box, washed my hands thoroughly, and returned them.
0
ccand51997
265 posts
#29Jul 31, 2021, 11:23 PM
I've been following the BRR website for years now and if you read all of the things he writes, you understand that Jarno knows tires as well as just about anyone. People get hung up on the absolute values and if you don't know how to look, it can be confusing.
Also, trying to discount his work saying it is not like the real world shows a lack of understanding, IMO.
He always qualifies his rankings and says why he would or would not recommend some tires. He does not say things like, "this 35mm tire is always going to be faster than this 40mm tire in ever condition."
What really baffles me is that people somehow think that a thick, inflexible tire that is slow on the road is going to somehow transform to a world beater in dirt. The opposite is likely to happen; the rougher conditions are going to expose a slow tire to an even greater extent because dirt and gravel is going to ask it to conform, roll and cushion even more.
Flexible casings are not the only consideration either. Take the WTB Byway. I rode one for more than a year but was not shocked to find out it was a very slow tire despite the smooth center strip and flexible casing. Why? Well, the center rubber on that tire is THICK, like 3mm or greater. In all the time I rode it as a front tire, I never saw sealant seep through holes in the rubber, like say the Conti RaceKing Protection or Schwalbe G One Speed snakeskin. Those are thinner, much faster tires and always showed signs of holes that the sealant fixed. I had to throw away the Byway when it would no longer seal becaue, IMO the casing was to fragile and the center rubber way too thick. If the casing did not fail, that tire would probably last 10000 miles.
There are a lot of layers to the information on the BRR website. There may be reasons to buy the Pathfinder, but one of the is not because it is going to be the fastest rolling tire. I'm pretty sure that is whay he said himself.
1
Familyridz
70 posts
#30Aug 1, 2021, 8:28 AM
Cool video—I was just thinking some of those returned baby and pet squashing Peloton treadmills could be converted into whole bike test beds, oh well. If Trek’s got it on YouTube, then all the top manufacturers do it.

It’s also interesting that the 32 mm tire for cobbles in the video is a solid bar center, raised knobs on the side like the PP. Trek is selling this Challenge on their website that is pretty similar to the PP, just without the smooth center:
https://www.trekbikes.com/us/en_US/equipment/cycling-components/bike-tires/gravel-and-cyclocross-bike-tires/challenge-gravel-grinder-race-gravel-tire/p/21856/

What tire does Trek Segafredo ride at Unbound? The development project Domane-like Checkpoint they rode looks cool but saw no mention of what tires they rode.

For most of what I ride on most of the time, a full slick would be best. It’s the inside lane of a sweeping downhill/uphill curve where the gravel has drifted deep on that side, downhill braking on loose gravel, or getting caught on a loose or dirt stretch in the rain that makes me want those side knobs for control in the 5% of situations most likely to cause a wreck—especially if another trail user goes knucklehead right in front of me. I’m also guessing those knobs might be part of race performance or the PR mentioned earlier.

Please tell your Trek friends that an aluminum Checkpoint with full isospeed, GRX 2x and a higher weight limit (Jamis has no limit on their metal bikes) would be a great offering for someone who wants a gravel bike that can be a loaded bikepacker, and who doesn’t want to worry about damaging a carbon frame on another continent on vacation or overloading its rear rack limits (for grocery shopping, commuting with a computer and change of clothes, etc. frame bags aren’t near as practical).

For those interested in the unsprung vs sprung weight issue or a Isospeed vs Future shock, the Specialized video embedded in this comparison of Domane vs Roubaix explains it.
https://www.theproscloset.com/blogs/news/specialized-roubaix-vs-trek-domane
Thanks to all for some great info!
0
Shurlock
40 posts
#31Aug 1, 2021, 9:50 AM▲ Top
There are far too many excellent tires to fall in love with any of them.

Also, never love something that is incapable of loving you back.
3
Familyridz
70 posts
#32Aug 1, 2021, 10:12 AM
Where were you when I met my first wife😊?
1
mtgrvl
23 posts
#33Aug 1, 2021, 8:22 PM
Familyridz wrote:
What tire does Trek Segafredo ride at Unbound? The development project Domane-like Checkpoint they rode looks cool but saw no mention of what tires they rode.

Quinn Simmons is on a Pirelli here: https://www.velonews.com/gallery/new-and-unreleased-trek-checkpoint-felt-breed-and-cannondale-gravel-bike-spotted-in-kansas/

Not sure exactly which size/model, but looks like Cinturato GravelH to me.
0
GCCyclist
18 posts
#34Aug 3, 2021, 7:10 AM
Have been running them for over a year now including Dirty Kanza twice. I ran 42's at DK and my son ran 38's. Was told in the parking lot by another rider that the Pathfinder was "too soft" for flintrock...... No issues on steep climbs, traction is about your position on the bike. Zero flats........yes they are heavy, yes they will clog up in mud. Not sure there is a tire that doesn't clog up in peanut butter mud.
1
ridetiltheend
7 posts
#35Aug 3, 2021, 8:26 AM
ccand51997 wrote:I've been following the BRR website for years now and if you read all of the things he writes, you understand that Jarno knows tires as well as just about anyone. People get hung up on the absolute values and if you don't know how to look, it can be confusing.
Also, trying to discount his work saying it is not like the real world shows a lack of understanding, IMO.
He always qualifies his rankings and says why he would or would not recommend some tires. He does not say things like, "this 35mm tire is always going to be faster than this 40mm tire in ever condition."
What really baffles me is that people somehow think that a thick, inflexible tire that is slow on the road is going to somehow transform to a world beater in dirt. The opposite is likely to happen; the rougher conditions are going to expose a slow tire to an even greater extent because dirt and gravel is going to ask it to conform, roll and cushion even more.
Flexible casings are not the only consideration either. Take the WTB Byway. I rode one for more than a year but was not shocked to find out it was a very slow tire despite the smooth center strip and flexible casing. Why? Well, the center rubber on that tire is THICK, like 3mm or greater. In all the time I rode it as a front tire, I never saw sealant seep through holes in the rubber, like say the Conti RaceKing Protection or Schwalbe G One Speed snakeskin. Those are thinner, much faster tires and always showed signs of holes that the sealant fixed. I had to throw away the Byway when it would no longer seal becaue, IMO the casing was to fragile and the center rubber way too thick. If the casing did not fail, that tire would probably last 10000 miles.
There are a lot of layers to the information on the BRR website. There may be reasons to buy the Pathfinder, but one of the is not because it is going to be the fastest rolling tire. I'm pretty sure that is whay he said himself.

While I agree the BRR tests are valid as long as you understand the limitations of the testing, you have to keep in mind that it isn't just casing flexibility, or that overused word, "suppleness", that results in low rolling resistance on the road. A significant part of low rolling resistance on pavement is also the tire compound, and that portion of the equation does not necessarily carry over once you're on gravel. Yes, if you're talking a really stiff hard tire, it's not going to absorb the bumps and rocks as well. But we need to keep in mind that tire width and tread factors are not "magic," and a wider tire with a more aggressive tread is generally going to outperform a narrower but better rolling tire once you get onto rough and/or muddy terrain. The rougher the terrain, the more width and tread pattern are going to overwhelm pure rolling resistance in terms of overall performance.

I do agree that slick strips down the center of the tire do not automatically translate to good performance on smooth surfaces and that's a very valuable aspect of his test, showing that a number of supple and fast rolling tires with knobs actually outperform a lot of those tires with slick centers.

BRR is a good resource, folks should just not fall into the trap of allowing the rolling resistance rankings to drive a choice of tire that is too narrow and smooth for the offroad portions of their rides, as that can be a penny-wise, pound-foolish decision in terms of overall speed.
Familyridz
70 posts
#36Aug 3, 2021, 9:48 AM
ridetiltheend wrote:
All of which is why the BRR tests should only be considered as predictive of smooth pavement performance, and to a lesser extent, very smooth gravel. But I don't see any way around inflating the smaller tires to higher pressures though, after all that's what we do in the real world to equalize tire performance and would likely end up penalizing the smaller tires without necessarily giving valid data for performance on rough terrain.

First, credit where credit is due. I've found BRR to be a valuable source of a lot of data, and be really useful for road tires. It's actually because so much of the site is so smart and thorough, that it's kind of hard to square the thought and effort involved with the majority of the site with some of the ranking and testing approach.

The concern I have is not about Specialized or this particular tire, but about undermining the market for" all road" tires for our "all road" bikes. Many posts here are in search of the best tire for a mix of pavement and gravel. At least in my browser without a paid subscription, the BRR rankings tables and charts don't mention the pressure differences by tire size used in the same summary table column or the same comparison chart X-axis value--you have to go into the details to find them. The approach punishes tires using a similar all road, multi-terrain design that uses smoother centers for better road speed and mileage and makes up for it off road with larger side knobs relative to more single terrain/uniform tread designs that will either wear faster in the center on the road or not grip curves as well on loose stuff. These tires are designed to be ridden at the upper end of the pressure range on the road--where a more compliant gravel frame doesn't need extra tire compliance to match narrow tire road bike comfort. Testing tires under inflated well below spec doesn't allow them to perform as designed. The pressure adjustments by size also punish larger tires that actually measure up to advertised tread width. Consider this BRR comparison:

https://www.bicyclerollingresistance.com/cx-gravel-reviews/compare/continental-terra-speed-vs-continental-terra-speed-40-vs-specialized-pathfinder-pro

Terra spd 35mm measured 33, 360 gr., spec min psi 44, tested at 40 psi, center knob ht. 1.1mm, edge knob ht. 1.2mm, 20.8 Watts.
Terra spd 40mm measured 38, 465 gr., spec min psi 44, tested at 36 psi, center knob ht. 1.2mm, edge knob ht. 1.2mm, 21.6 Watts,
Pathfinder Pro 42mm measured 41, 540 gr. (available in 38mm, 480 gr.) spec min psi 50, tested at 33 psi, center slick, edge knob height 2.4, 24.1 Watts

So the least under inflated tire was fastest and the most under inflated tire, in a larger, heavier size that measured closest to the stated size was slowest.

If you slide the Pathfinder Pro dot for low pressure (40 PSI) 2/3 of the way to the 30 PSI extra low pressure line where 33 PSI belongs, it hits the lines for the Contis while doubling the height of their edge knobs. No doubt had the much lighter 38 mm Pathfinder been used and tested 3 psi higher, it would be the same size but faster than the Terra Speed 40 (measuring 38) and only 15 more grams in weight, while offering edge knobs that are twice as high.
ridetiltheend
7 posts
#37Aug 3, 2021, 10:50 AM
Familyridz wrote:

Many posts here are in search of the best tire for a mix of pavement and gravel. At least in my browser without a paid subscription, the BRR rankings tables and charts don't mention the pressure differences by tire size used in the same summary table column or the same comparison chart X-axis value--you have to go into the details to find them. The approach punishes tires using a similar all road, multi-terrain design that uses smoother centers for better road speed and mileage and makes up for it off road with larger side knobs relative to more single terrain/uniform tread designs that will either wear faster in the center on the road or not grip curves as well on loose stuff. These tires are designed to be ridden at the upper end of the pressure range on the road--where a more compliant gravel frame doesn't need extra tire compliance to match narrow tire road bike comfort. Testing tires under inflated well below spec doesn't allow them to perform as designed. The pressure adjustments by size also punish larger tires that actually measure up to advertised tread width.

First, when I look at the Pathfinder Pro in their rankings, I don't think it's a slow tire; on the contrary, it's a fairly fast tire in their test. Now it does rank lower than the Terra Speed, for sure. I don't have any experience with the tire and can't vouch if the slick center tread/larger side knob concept works well in the real world. But I think it's a mistake to think that any tire that doesn't have a slick center tread isn't appropriate or going to be used for mixed rides with a lot of pavement; after all, IMHO these rating do a pretty good job of predicting smooth pavement performance and that to me is what is important, regardless if visually it doesn't look as if it should be good on pavement.
To me, the minimum tire pressure ratings from the manufacturer are useless and put in solely to keep the lawyers happy. To put a minimum pressure of 50 psi on a 42C tire is frankly just ridiculous. I wouldn't run that high a pressure even if I was riding the tire solely on really nice, smooth pavement. It seems you're advocating using a different tire pressure for testing for any tire with a smooth center strip compared with other tires of the same width and that's going to penalize any tire without a center strip. Given how drum testing works, if you ran the Terra Speed at a higher pressure it would show lower rolling resistance as well, I can't see the high pressure ratings as I'm not a member but I'm pretty confident that it would not show some major discontinuity in the rankings.
As I've said before, the BRR rankings should only be used as one factor in the decision making process and other factors such as width, tread, and puncture resistance are very important as well.
Shurlock
40 posts
#38Aug 3, 2021, 11:11 AM
imwjl wrote:

Something that entertained me and struck home was telling Trek staff friends how I like stuff I used to think the company didn't do a good job at. I was told they can't get away with selling crappy stuff by the millions and they don't like riding crappy stuff personally.

You mean like using cheap hubs and the lousiest press fit BB on expensive aluminium frames? Please. Trek is still the biggest grifter in the business.

They absolutely continue to get away with selling a lot of crappy stuff to millions. It's their business model. Lots of flair and flash, direct to consumer marketing tactics and a cult-o-personality mindset vertically integrated into their corporate culture.
0
Familyridz
70 posts
#39Aug 3, 2021, 12:11 PM
Fair enough. It is probably also a rider + gear weight issue. Riding with a tube at 150-180lbs of rider plus gear and hitting a pothole at speed doesn’t have the same burp/pinch flat/rim damage issue as doing it loaded to 300 lbs. I have a 38 PP on the rear with a tube (just got the 42 to move the 38 to the front and go tubeless), and I ran it at 40 and naturally caught a larger than average rock on a fire road that made rim contact and broke a spoke.

I have noticed both in the older MTB gravelish tires I used to run and with the PP on pavement that they are faster at my weight at 55-60 PSI on the rear to reduce how much tread makes contact on pavement. Some, and I suspect the PP is this way, seem to have a shaped tread instead of round shape that is best held by a slightly higher pressure & more rigid sidewall. I wonder if the single row of larger edge knobs would bite as hard in a curve if much lower pressure or flexier sidewalls let the casing give more. They sure saved me twice this weekend having to make a couple sketchy last second line changes at speed.
0
imwjl
304 posts
#40Aug 4, 2021, 8:52 AM
Shurlock wrote:

You mean like using cheap hubs and the lousiest press fit BB on expensive aluminium frames? Please. Trek is still the biggest grifter in the business.

They absolutely continue to get away with selling a lot of crappy stuff to millions. It's their business model. Lots of flair and flash, direct to consumer marketing tactics and a cult-o-personality mindset vertically integrated into their corporate culture.

It's fine for you to have favorite brands but your are pointing out issues common across bike companies. With decades of neck deep time in bike infrastructure development, project management, fundraising, grant applications and board leadership I know about the bike companies ways where may might not know. Also from having a financial interest in a shop and friendships with people across bike companies and suppliers. It's pretty hard to see Trek as the grifters you say they are.
It's also very easy to be in a gapmider scenario not having up to date knowledge.
Having done events and fundraising with a few bike makers I see the cult part you bring up as legitimate but natural. I supervised a trail building project with Trek staff earlier in the year. It was a fine cult if that's what it is. Dozens of employees doing things in their own community, keeping at it outside of work time, and a few days of ears and eyes at people also working at delivering great stuff.

The place I'll see a Trek cult or parochial behavior I don't particularly care for is at their company owned and branded retail stores vs independent dealers. That may well be where some get a poor impression. In their own back yard, some of the corporate staff with our local posse blow that off. We all know who the cool kids are, where, and how they play.

With 6 bike brands in our family fleet I can show you plenty of pressed in bearings, and to me inane mixing of axle types, flair, and flash. I don't care.
0

Related threads

Newbie trying to understand rolling resistance tests, requesting assistanceGravel Tires · 77 replies · Mar 4, 2023
Pony Express 120 ride reportGravel Racing · 11 replies · Sep 22, 2017
One woman's experience with choosing a new gravel bikeBikes · 5 replies · Jul 19, 2019
Advice on new bike purchaseBikes · 26 replies · Jul 16, 2018
Rolling resistance of wide tiresGravel Tires · 90 replies · Dec 20, 2023