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.
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.
That went super technical, superfast. TLDR for this comment – I find running tubed clinchers better than tubeless.I tested out road tubeless for about 2 years. I used Ultegra aluminum wheels with Hutchenson Intensive 25c tires. It wasn't too hard to set up, but seating the beads scared the cr*p out of me. But never had an issue with it. It did seem like I had the same amount of flats where I'd have to place a tube in during the timespan as I would have with a regular set up. A couple could have been prevented if I had FRESH sealant in (or topped up). Another time was a sidewall tear from hitting a chunk of concrete and required a boot and would have been the same with a tubed tire. As for flats prevented by running tubeless, only once did I ever hear the hiss-hiss-sss-sss then silence of air and sealant doing it's voodoo magic. I guess that's a positive. Now that's all good – to me no real benefit to running tubeless in what I said above. The killer to me is rolling resistance and ride quality. And from my test, it sucks. 1st the 25c Intensives actually measured about the same as the 23c vittorias I was running prior. Then – yes you can run lower pressure in the tires, but because the sidewall is so stiff, when you lower it enough to perceive a benefit in comfort, there is a noticeable amount of rilling resistance. I tried playing with the pressure going from my normal 110 psi down to as low as 80. I finally settled on 92-95 front to 98-105 rear was the best compromise. However I have since gone back to tubed tires. Clement Strada LGG in 25c. but I run pressure a hair higher (950-100 front / 105-110 rear) and I see both a more comfortable ride and similar if not lower rolling resistance. My feeling is this is because of additional sidewall for the tubeless tires. But it does mean there doesn't seem to be a benefit to running tubeless from this standpoint.
I went road tubeless back in 2009, and haven't looked back. Not a single wheel or tire since that point has been tubed, and I have had one flat that I recall that didn't seal, which was my fault for not adding/changing out sealant. I don't plan on ever using a tube again, unless on a fatbike, and even that is unlikely.
I'm very satisfied with my Pacenti SL23 November wheels mounted tubeless with Maxxis Padrone TR tires in 25c!!! After the initial learning curve in getting them mounted, they have been hassle-free and ride exceptionally!PS: as a side note, I mounted the Maxxis Mud Wrestlers on an OEM set of wheels on my Fuji Cross bike ;), and had a puncture free cross season (only 3 races) where a bunch of my mates had DNFs for punctures… I'm convinced! Haven't converted my commuter bike yet because I haven't had any punctures (knock on wood (Gatorskins)), so I'm a little hesitant considering that bike's nearly exclusive use…
Your experience isn't unusual. I will note that Hutchinson Intensives have consistently scored MISERABLY on rolling resistance tests, and they are also the tightest fit by far. So they're sort of worst case all around. Saying that all tubeless are high Crr because Intensives are is like judging all clinchers off of Specialized Armadillos (would rather ride a garden hose). Specialized Turbo blah blah whatever they call them tubeless are standouts in Crr. I know your intent probably wasn't to do that, but it's worth the clarity for others.As for Clement Strada LGG, man, that is the ONE tire I've used in the past year that I just really really really didn't like. Found them to be slow and wooden and just all around disagreeable. They also need far more pressure than I normally use. The reason I got them was because skin colored side walls, and maybe that's a variant that causes them to stink? I don't know. But I've heard one other guy sing the LGG's praises and it was the biggest "HUH?!?!?" of all time.GP4000s are pretty great, with latex tubes they're even better (although the pumping before every ride bit gets old). Also have a fresh pair of Specialized S-Works Turbo blah blah blah whatever they call them non-tubeless here staring me in the face from the Al33 width quiz, so maybe I'll use those for a while. Thanks
Tubeless/schmoobless. I decided long ago to stay away from the messing around with tubeless in all its forms – goop, ultra-tight tires and lowered spoke tensions. Just like I decided to stop using tubulars years ago (of the above three things only "goop" applies). I'll relinquish any real benefits to either form of tire system.As I average just one flat per year using tubes, even the flat resistance of both types of systems (tubeless and tubular) means nothing to me. Tubes 'r Me!