Dave's road tubeless doubts

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This post deserves a TL:DR summary, which is: If you aren't super comfortable with road tubeless and willing to spend some time and expense figuring out exactly which combo works for you, and also willing to petentially suffer a reduction in the lifespan of your wheels, stick to tubes. With a whole bunch of data now showing superior rolling resistance with clinchers and latex tubes, that may be the best way to go in any case. The ability to use latex tubes is another bonus of aluminum rims. 

For mountain bikes, tubeless is mandatory. For cross, it has its challenges (which we've done a heck of a lot to help eliminate) but the benefits can be so profound that the juice is for sure worth the squeeze. For road, though Mike and I personally use tubeless, we haven't been evangelical. It comes with downsides, which we'll talk about here. 

A potential "do as I say and not as I do" instance

We've been observing and talking about spoke tension drop in clinchers for a couple of years now. Since I've done THE WORST job at tagging posts, it's hard to find all the posts on the topic, but these two posts from last spring are good examples. There were a bunch of forum discussions in the spring of 2014, but I can't even recall which forum they were on. We even made a video to show the effect last spring. 

Wheel Fanatyk has what might be the second best wheel blog out there, and they did a series of posts in the fall about this whole topic, including the outward splaying of brake tracks which we'd discussed in above-linked post called "Pressure Drop Follow Up." What they did in particular, for which I have huge appreciation, is measure a bunch of tires to find how tightly they will fit. Their whole methodology and execution of this is excellent. What their measurements reveal is something that anyone who's installed more than one kind of tire will already have known - tire bead circumference varies by manufacturer and model. 

They've also measured overall circumference of a number of different rims, but they haven't shown the more relevant tire trough and bead seat diameters (which are simple secondary measurements from what they've done and shown). The overall circumference is of little value in its own right as, for example, a Zipp 404 shows a large outer diameter, but 404s are known to be relatively easy to fit tires onto (perhaps too easy?).

In order to resist the higher inflation pressures of road tires, road tubeless tires need a tight fitting carbon bead. The carbon bead more or less doesn't stretch, which is critical to having the tire not blow off the rim, and thus to keeping your teeth in your head. In that respect, it works quite well, but at what cost?

Non-tubeless road tires have either wire or Kevlar beads (if you're reading this, you probably have Kevlar beads). You probably notice that your tires get easier to install over time, which is because the beads stretch a bit over time. This stretch reduces the constricting pressure that the tire imparts on the wheel. 

Compressive tire loads cause a reduction in the circumference of the rim. Wheel Fanatyk estimates a possible 1mm reduction in the circumference, and my calculation gave me an estimate of .1mm in diameter reduction, so they estimate a bigger effect but we're not that far off in the absolute. I based mine off of "the spoke tension drop is x, the thread pitch of a nipple is y, the spoke tension drop is equal to z turns of the nipple, therefore the diameter reduction must be..." The important thing is that we're both seeing the same effect, in the same direction, with reasonably similar magnitudes. 

Compression is bad for the wheel for several reasons. It takes more initial spoke tension to maintain the minimum necessary functional spoke tension. Compression changes the dish of a wheel. Compression puts stress on the rim that almost certainly shortens a rim's useful life span. 

At the risk of speaking against my book somewhat here, I have two road bikes in current use (one disc, one rim brake, otherwise more or less identical) and those four tires are all tubeless. It works fine for me, but on a scale of 1 to 10 in tubeless experience, I'm about a 643. So if you are willing to invest time and money into getting your road tubeless set up perfectly, knowing that it comes with the potential to compromise your wheels, then it may be worth it to you. Otherwise, tubes are your best bet. 


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  • BigEd on

    Hey Dave,Thanks for taking the time last week to talk through the removal of a set of Schwalbe pro one tubeless from my Rails. You wanted to hear about how it went so here it is. As you know, the beads were so tight that I could not move them out of the seat and toward the center groove. I tried the "dull butter knife" method. No, the leverage applied to the carbon had me fearful of damage. After some time and effort l decided I could sacrifice a tire. Didn't want to but I saw no other way. So I got a pair of channel locks and gripped the tire, squeezing the beads toward one another. Did not move even a millimeter away from their seat. Well the next evening, after an online search in vain, for any reported similar condition, I prepared a fresh razor blade on a utility knife and set to work. I cut through the sidewall each side, removing a section of tire about a foot long. I then carefully, surgically began to cut away the carbon bead. Using only the tip of the blade and making small short cuts, the bead came apart. It's like a brown string, but super strength. Finally after cutting away 90% of the fibers the bead of the tire let go with a bang, The wheel jumped in my hands, l flinched but the bead was free. Any way, repeat procedure three more beads and cleaned up the wheels removed the tape and checked my work. No damage to the wheels. As I was a little concerned and wondering just how these wheels would accommodate a traditional clincher, I mounted a clement lgg I had on hand. Well the tire went on so easy and quickly and I was happy! My first season setting up and running tubeless. This can't be a normal experience with tubeless,right? Anyway I enjoyed riding the wheels and tire combination immensely. I also set up the kinlin/November wheels I received last month with panaracer gravel king tubeless to run on my cross bike and I'm really happy with that ride. For now I'll set up the rails with some tubed clinchers until I get some more feedback on easier tubeless road.Either way I'm happy with the wheel sets. Great work and value by you guys!

  • Dave Kirkpatrick on

    I more or less expected that the comments would go this way – some love it, some don't. It's worked just fine for Mike and me over a ridiculous number of miles, but there is no overlap between that condition and me making the statement "therefore it will be a good solution for all." So it's kind of great to hear who it works/doesn't work for an why.But if you tell me you prefer tubes for mountain biking, ain't got no time for that. In that case, I'd call you wrong.

  • Jeff on

    I tried road tubeless for a while with some of the newer "fast' tubeless-ready tires (Pro One, SWorks Turbo, Corsa Speed G+). These tires all lack a butyl lining and therefore require sealant to be airtight, which is what makes them fast. But what I found is that I got more punctures using these tires than I ever did with regular clinchers and latex tubes. Usually the punctures would seal well enough for me to finish my ride on reduced pressure, but they wouldn't hold enough pressure for me to fully trust them without patching. And more than once I had to resort to putting a tube in because the puncture was too large to seal. For me, it just wasn't worth the hassle. The fast tubeless tires are too fragile, and the more durable tubeless tires are too slow. So I'm back to using regular clinchers with latex tubes (and I haven't had a flat since switching back).

  • Jeff G. on

    Another vote for Schwalbe Pro One tubeless. I've been on tubeless for 4 years and run aluminum Fulcrum Racing Zero's (Campy Shamal's basically). Four years ago tire options were more limited and I was on Hutchinson Fusion 3's. They were ok. I made the move to Schwalbe and noticed an improvement in the ride. Not huge gains, but a little bit. Overall, I'm with Dave on the whole tubeless game. I like them, and appreciate the ride, but sometimes wonder if its worth the hassle and worry. I say worry because I've been stranded twice after major blowouts. I ran over some glass once and the hole was too big for the sealant to do its job. I've heard people say that they just put a tube in and ride home, but I don't know how in the hell you'd get the tire on and off without having Andre the Giant riding with you. The fit on my rims is insanely tight. Mix in the sealant that has exploded everywhere, sitting on the side of the road under the hot sun, etc. and my only reasonable option was to reach for the cell phone. This has happened to me twice in four years. I now have a fancy plug system and fix-a-flat compressed air contraption that will hopefully get me home (haven't had to try it yet), but I still worry. They are great when they work, but there are lots of quirks when you compare the insanely easy tire and tube combo. * one thing to note that I just remembered, Schwalbe Pro One recently added "Tubeless Easy" to their lineup. This makes the install a little easier for sure. I just got them last fall, so no ride report yet.

  • dave on

    BigEd – Woof. I think we talked about how the more porous sidewalls of the Pro One allow sealant to get between tire and rim, and then combined with the heat from braking just glue that sucker on. Carbon makes a better gluing surface than aluminum. Annoying and I'm sorry you had to trash a pair of tires, but this is sort of exactly the point of my post – there are just so many uncontrollable variables out there in the wide wide world of sports. Harry – That's greatGreg – That's also great, but see BigEd's story for something not to like. S—t happens. Caveat emptor and all that.Jack – I'd actually say that our assembling other people's alloy rims reinforces how smart we are. As you say, we do all this research. You think we haven't learned from that? Au contraire, we've learned a TON from it. All the other wheel manufacturers don't have carbon (and the ridiculous majority of carbon out there is still sticker brands, and crap), a lot of them might not know or care that their insurance doesn't properly cover what might happen. Most carbon rims that you buy, the person you buy from has ZERO CLUE who the actual manufacturing entity is. If you really think the preponderance of sh-t carbon out there constitutes anything remotely resembling a "cutting edge," I just can't help. But we do build with Enve rims for those people who just absolutely must have carbon. Domestic company, in-house production, etc etc.



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