"Road" Tubeless

Here is a very good discussion about tubeless tech. from Jan Heine of BQ and Compass tires:https://janheine.wordpress.com . It confirms some of my own observations about tubeless issues - especially with higher pressure road tires, as well as some concerns posted earlier about mounting Bon Jon's tubeless. Note also, what happens to a supple tire casing when run at too low a pressure. As you can see from the picture, the flexing of the tire at low pressure gradually breaks down the casing.
BTW - I've found that using Challenge Latex 28-35 mm tubes in my 35mm Bon Jon's is a very good (but expensive) alternative to running tubeless. I run my Bon Jon's at 35-40 PSI on maintained dirt and gravel roads, as well as pavement with no problems with pinch flats. And, I find that the tires perform as well as my 25mm Conti 4000 IIS's on pavement.

Anyone who admits to running 90psi in a road tubeless tire has lost all credibility. \n \nTry 65-70 for a 23, or 60-65 for a 25 or 28mm tire and ALL his so-called issues go away.

I read your blog post.. very well written. Thanks for sharing.

Mudge wrote:Anyone who admits to running 90psi in a road tubeless tire has lost all credibility. Try 65-70 for a 23, or 60-65 for a 25 or 28mm tire and ALL his so-called issues go away.

Not sure what your point is. In my reading of the JH blog, he heartily agrees with limiting pressure on tubeless road tires to about a max of 60 PSI. As far as why would a roadie like me be so foolish to inflate my 23mm road tubeless tires over 90 PSI, 7 BAR (100 PSI) was the recommended pressure for the original 23 mm Hutchinson Tubeless road tires! You'll see similar recommended inflation values stamped on the side of many road tubeless tires like Bontrager TLR. We were just following the manufacturer suggested inflation. Coming from a roadie background, where 8 BAR (120PSI) was considered a normal 23 mm clincher inflation, this seemed like a reasonably low pressure. With the evolution of tubeless tech and wider road tires, obviously, much lower pressures are advised. 

jamesdavis wrote:I read your blog post.. very well written. Thanks for sharing.

Thanks 

bobknh wrote:
Not sure what your point is. In my reading of the JH blog, he heartily agrees with limiting pressure on tubeless road tires to about a max of 60 PSI. As far as why would a roadie like me be so foolish to inflate my 23mm road tubeless tires over 90 PSI, 7 BAR (100 PSI) was the recommended pressure for the original 23 mm Hutchinson Tubeless road tires! You'll see similar recommended inflation values stamped on the side of many road tubeless tires like Bontrager TLR. We were just following the manufacturer suggested inflation. Coming from a roadie background, where 8 BAR (120PSI) was considered a normal 23 mm clincher inflation, this seemed like a reasonably low pressure. With the evolution of tubeless tech and wider road tires, obviously, much lower pressures are advised. 

\n \nThe point is that 90psi is well above the reasonable pressure run by anyone with even moderate experience with road tubeless, so when you complain of an issue like a tire blowing off a rim, your comments are taken with a grain of salt. \n \n \n

Personally, I agree w/bobknh.  I've been running road tubeless since 2010 and often at very high pressures.  I started w/Hutchinson and lately have been running Schwalbe - both designed as tubeless tires and used on tubeless ready wheels.  Most of my issues, especially the early Hutchinsons, have been getting the tire on the rim and not it coming off.  The Schwalbes though have been great.

The last couple of years, I've been using the Berto 15% drop pressures as advocated by JH on another of his blogs to set tire pressures.  Tire pressures are most directly related to weight and tire size.  Other factors include tire construction, road/trail conditions, tubes/tubeless, personal preference, etc.  I've developed a spreadsheet using the Berto formula as a starting point for use on the wide variety of bikes and tire sizes I use.  I have road bikes at 23 & 25 mm, gravel bikes at 28, 30, 35, 38 & 40 mm, and my mounting bike is at 60 mm front & 57 mm rear.  The chart allows me to not to have to try to memorize the various pressures

The first revelation after I started using the chart was that I was running my mtn bike tires at too high pressure, especially the front.  And when I changed them the difference was amazing - better traction, more comfort and no loss in speed.  Another interesting point was how much tire pressures change with only a few lbs in change of weight.  Corresponding to this, because of the weight distribution front to rear while riding, the psi differential between front and rear is often 15 psi or more at higher pressures.

I disagree with many of your comments.  The first is your "credibility" comment.  In general, I always disagree with those passing judgment on others.  I'll share my opinion all day long and even join in a discussion or a debate.  But I have a problem with the "I'm right, you're wrong" approach.  In this specific case, since psi is based on weight, I'm sure there are many riders on the heavier side that should be at or above 90 psi.  I'm at c. 180 lbs and the recommended pressures for 23mm tires is 95f/117r.  And with 25c tires it's 84f/104r.  I don't disagree w/you though that you can safely run lower pressures than these when using tubeless wheels/tires.

The 2nd is your recommendation pressure ranges for 23mm and 25mm tires.  See comments above re weight, tire size and psi.  The pressure ranges you recommend may work for you, but would be off to a very large degree for anyone heavier or lighter.  And even for you, your recommendations do not account for the differential in pressures from front to rear.  

The 3rd is the comment quoted re 90 psi.  As per above, 90 psi and higher are the recommended pressure for me and the bikes/tires that I ride.  I've been road tubeless for over 7 years, and road bikes for over 45 yrs, so I assume that puts me in the "even moderate experience" category. 

Mudge wrote: The point is that 90psi is well above the reasonable pressure run by anyone with even moderate experience with road tubeless, so when you complain of an issue like a tire blowing off a rim, your comments are taken with a grain of salt.

Mudge wrote: The point is that 90psi is well above the reasonable pressure run by anyone with even moderate experience with road tubeless, so when you complain of an issue like a tire blowing off a rim, your comments are taken with a grain of salt.

That's just wrong. Jan Heine completely ignored the idea of hoop stress/casing tension with his 60 psi "recommendation." Instead of explaining casing tension, I'll just link to Flo Cycling's excellent write-up. http://flocycling.blogspot.com/2014/11/flo-cycling-why-do-you-use-less-tire.html

Dr. Spoke has the best response thus far.

Basically, the argument here is how much pressure is needed to blow the tire off a wheel. 50 psi will blow some mountain bike tires right off a rim. 50 psi is nothing I would ever play with on a 23 or 25 mm road tire. It's right about where I run my front 30mm tire tubeless though. It's because psi is only one factor in tire blowouts. The tire size has way more to do with it.

A 35mm tire at 60 psi has the same stress/tension as a 23mm tire at 91 psi. That means they both exert the same force on the rim and tire bead in order to blow off.

Math and science aside, I have been on road tubeless since the second generation Hutchinson tires. They rode like crap, but I have certainly gained enough experience in that time to know the 60 psi recommendation from somebody trying to sell his tires is wrong.

While I have no experience with running sealant in tubes, I do have experience with tubed tires, and I do  now (this year) have experience with running tubeless.....on dirty/abrasive pavement and gravel I would completely avoid with skinny tires with tubes because flats were inevitable and often.

I waited entirely too long to go tubeless.

Just so I don't jinx myself .... I wont say the number of flats I have gotten tubeless compared to tubes ..... but the difference is nothing but miraculous for me, for my riding, for what I do.   The flat protection advantage (for me) running tubeless sealant alone is worth it for me..... with the eye opening added ride comfort of riding tubeless with a little less pressure making it an off the chart no brainer for me.   Again, that's for me ....... I am completely down with whatever works for anybody else .... whatever it takes to get people peddling is the answer.   ymmv, that's cool.

(Should also add .... My "skinny road tires" are only 30's, so there's that......my gravel tires are 36's)

Pretty much adding to what dangle says. It depends on the rim design as well, hookless or not. No hook needs to be at lower pressure or risk blowoff.

Smale Rider wrote:Pretty much adding to what dangle says. It depends on the rim design as well, hookless or not. No hook needs to be at lower pressure or risk blowoff.

I'm not aware of any evidence to support that statement. Please share if it's available.

Started riding tubeless on my Trek 4.5 Domane.  I bought some Schwalbe Pro One 28mm tubeless tires and mounted them on the Bontrager rims that came with the bike (took some effort to get mounted, but perseverance paid off) and started riding with about 90psi.  Over the summer I started lowering the air pressure a little bit every week and found that 55-60psi was the sweet spot for me (210lbs).  I did have a few punctures and the sealant did work, but at reduced air pressures (some where around 40psi).  I am 56 years old and comfort is my main concern when riding now, so riding skinny tires at 115psi is no longer acceptable for me.  I also have a Diverge that I ride 32mm to 36mm tires on with and without tubes, depending on the ride (gravel...)

So... Jan seems to be focused on the wrong question: will a random (his) tire on an un-named rim blow off when you exceed a certain psi threshold?

How is this helpful? Don't we all already know this?

If Jan wanted to use his expertise for good he could FIRST explore his actual thesis: that standardization is needed.  Well, guess what? Standardization actually exists... so, if he wanted to really move us forward, he'd first inform the following question(s):
-Do tubeless road systems actually work? In other words, does a branded/certified UST road tire stay mounted to a branded/certified UST road rim.... and repeat with the TCS standard, BST (if BST certified tires exist?) etc... Of course he'd need to define 'work' but... fine.

Once he had some data and IF an analysis of that data suggested that a system (or several) 'worked' he could then go to explore the questions that the real world wants help with... if 'working' generalizes between systems or where 'working' breaks down (basically, will a TCS tire blow off a BST rim, etc...).  

I realize that Jan doesn't sell TCS or BST or UST tires OR rims, so... maybe it is not to his financial advantage to tout/explore their benefits or, from a legal perspective, challenge their effectiveness.  But who knows... 


 

^^  Well said.  It sort of reminds me of the "dark ages" when Stan was experimenting with mounting regular mountain bike tires on regular rims.  We've come a long way since then.  And thankfully those days are (mostly) gone.

Personally, I always use tires designed for tubeless use on wheels designed for tubeless use.  My first try, around 2010, was with Campagnolo Eurus wheels and Hutchinson Fusion tires - both UST.  The tires were ridiculously hard to mount but I only had one flat, a sidewall cut, over the years.  I'm still using the Eurus wheels but now with Schwalbe Pro-One tires and they mount, seat and seal quite easily.  This was a pleasant surprise as I thought the previous difficulties were caused mostly by the wheel or at least by the wheel/tire combination.

The article did remind me of the time when I bought and mounted a new Fusion tire.  I pumped it up and it blew off the rim - very much a surprise to me.  So I put it on again and it did the same thing.  After that I looked it over and realized that in my haste to buy a new tire at a good price that I had purchased the non-tubeless version of the Fusion.  This, it seems, confirms JH's theory

Guitar Ted has responded on this forum in previous threads about the different tubeless rim designs which was very informative.  That is, there still aren't standards as yet and some tires are more compatible, or not, with different wheels.

Currently, I'm using DT Swiss mtn bike wheels converted for use on my gravel bikes.  All the tires I've tried, various Schwalbe, so far have gone on easily and hold any air pressures I want to use.  That is, up to about 115 psi on the 23s.

I've been running Hutchison Sector 28 tires on Pacenti SL23 rims and some crappy no name "tubeless ready" OEM rims and I love em. I don't even use sealant on the SL23 set, they hold just fine! I've run pressures up to 90psi and never thought twice about it. Lower pressures are better, but the given the bike and tubeless for me 90psi is totally comfortable on the road. I love road tubeless. I would not go "ghetto tubeless" on the road, but if it is a real tubeless rim and a real tubeless tire then I'd feel fine.

jeredb wrote:I've been running Hutchison Sector 28 tires on Pacenti SL23 rims and some crappy no name "tubeless ready" OEM rims and I love em. I don't even use sealant on the SL23 set, they hold just fine! I've run pressures up to 90psi and never thought twice about it. Lower pressures are better, but the given the bike and tubeless for me 90psi is totally comfortable on the road. I love road tubeless. I would not go "ghetto tubeless" on the road, but if it is a real tubeless rim and a real tubeless tire then I'd feel fine.

Hi Jered - thanks for pitching in. I too had some success early on with Hutch tubeless road tires. In fact, I ran them on standard road rims as per advice of Stan's. With sealant, though. My issues with high pressure narrow road tubeless were echoed by other posters on this thread: they were very difficult to mount and remove, and they had very poor ride quality when compared to more supple high end clinchers -especially with latex tubes. The only advantage I could see was that they were more puncture resistant, and could be run at lower pressure. Good for daily training, commuting, etc. The downside, was it could be a nightmare to fix a flat in an emergency. Here is an announcement from Mavic addressing both of these issues http://www.velonews.com/2017/06/bikes-and-tech/mavic-road-ust-promises-hassle-free-tubeless_441191 .
I would like to apologize for the misleading title of this post "Road tubeless". The Jan Heine blog was really addressing wider, multi use, lower pressure tires of the sort his company - Compass - sells. The tubeless tires Compass sells are between 35 and 44 mm and are designed to run at well under 60 PSI. And, indeed, when set up tubeless, can blow off when anyone mistakenly inflates them to over 60 PSI. I can't imagine why however, anyone would want to inflate a Bon Jon, or Snowqualamine to such high pressure.

Mudge wrote:Anyone who admits to running 90psi in a road tubeless tire has lost all credibility. Try 65-70 for a 23, or 60-65 for a 25 or 28mm tire and ALL his so-called issues go away.

60-65, even for a 250-lb'er (115kg) guy like me?  Roval SLX24 tubeless rims with S-Works Turbo 28c 2Bliss tires

tubeless wheelset you can find in the carbonda sports.

dangle wrote:

That's just wrong. Jan Heine completely ignored the idea of hoop stress/casing tension with his 60 psi "recommendation." Instead of explaining casing tension, I'll just link to Flo Cycling's excellent write-up. http://flocycling.blogspot.com/2014/11/flo-cycling-why-do-you-use-less-tire.html

FLO (and others) just finished writing up a study that further debunks that 60psi recommendation nonsense. Check it out at http://flocycling.blogspot.com/2017/09/flo-cycling-casing-tension-study-with.html.

dangle wrote:

FLO (and others) just finished writing up a study that further debunks that 60psi recommendation nonsense. Check it out at http://flocycling.blogspot.com/2017/09/flo-cycling-casing-tension-study-with.html.

What is that article trying to say?

FYI, the link doesn't work.  Try editing the post to remove the period that is at the end of the URL.