It’s important to remember when looking at those rolling resistance websites that they are usually using smooth metal rollers to measure the power required to roll. This works okay for comparing one tire to another at the same pressure. But this doesn’t track 1:1 when you ride out in the road. A lot of your rolling resistance is not from the tire deforming, but from the tire bouncing over imperfections in the road (from small bumps to larger cracks and patches). The lower pressure will cause a tire to roll slower on a roller (or a smooth surface like a track) but will prevent the bouncing and therefore may roll faster in the real world.
They aren’t using a totally smooth drum, but one more representative of an actual road texture. I’ve seen tests done with drums with larger bumps but I don’t think those are representative of the average paved road seen by a road tire. Personally it would take more than 5w for the pros to start outweighing the cons, and I don’t see that kind of savings being realistic, at least not on the roads I ride
Hmm okay, that’s fair. If that is how they test these tires, I’m curious how much testing/correlation there is to how this affect the whole bike/rider system. If the lower pressure bounces less how much does this affect fatigue and speed. The rider being a large and very damped mass on top of the bike is not efficient at all when it comes to being bounced around.
Agreed, and I find myself getting physically beat up out on roads that are torn up and about to be paved, and freshly chip sealed roads, but those are more indicative of gravel riding than the typical paved road around me, and I rarely have to ride on them YMMV. One thing to note is it appears that their test protocol applies constant pressure, ie the drum/wheel/tire does not “bounce” as it might on the road, but that being said I also feel like I don’t “bounce” much either, aside from those few scenarios I mentioned. Those roads, a tire at a lower pressure would definitely be a bit faster and less fatigue inducing.
There’s a bit of info over on the Silca blog https://blog.silca.cc/part-4b-rolling-resistance-and-impedance
It’s also worth checking out Episode 23 of Faster (Flo Cycling podcast): Podcast – FLO Cycling for a bit more background.
Mike
And when you run latex tubes the watt savings with TL becomes a wash. Having run tubeless on one of my road bikes I find it a PITA and have now switched back to latex tubes.
I ran Latex tubes for a bit and couldn’t tell if I felt a difference or not, maybe I should have tried them on rougher terrain. Latex tubes tend to be more costly, and I will normally patch a standard tube if I can since pre-glued patches are super cheap, but they don’t work with Latex tubes, making them an expensive one time use affair. I also cannot find decent latex tubes with 80mm valves so I also have to use extenders. Lastly, running carbon clinchers, I worry about latex tubes blowing out due to heat, not that I ever do prolonged braking, but its always been a thought in the back of my mind.
Is it worth the hassle to try them again? I just picked up (3) Continental Race Lite 28s that are thinner (more comfy) than most, and weigh around 80g. Not sure if the above concerns are worth another 10-20g savings from these. I mostly got the thinner continentals because they fold up smaller in my jersey pocket, not for the weight savings, and I’m sure I won’t feel 1w of RR savings, or even 5 for that matter
Latex inner tubes can be patched with normal butyl patches and vulcanising cement if the tube is a good fit for the tyre. Too much stretch and it can cause problems at the patch.
Ideally you’d make some patches out of an old latex tube and use vulcanising cement as usual. At the cost of a tube, there’s no way you’d want them to be single use.
Regarding the advantage over lightweight butyl tubes, I’d say don’t waste your money on the lightweight tubes: Latex is MUCH more puncture resistant than even normal butyl tubes.
Mike
Mine seem a good fit but they haven’t held. Maybe I’ll fiddle with them again over winter while I’m not riding outside and can just see if they will hold pressure after a few days.
I have personally found them to be worth the hassle.
I suspect it depends on how you tend to flat? I don’t have goatheads or any of the other nasty things people report puncturing their tires, but I do have stretches of very rough road. So I am far more likely to pinchflat than puncture (so long as I occasionally make sure there’s no glass working its way into my tires) and I can’t remember ever pinchflatting on a latex tube.
I’d say pretty average. Mixed quality paved surfaces, the odd bit of gravel.
Most of my tubleless setups behave like clinchers in terms of pressure loss, i.e. they need a few pump strokes before each ride. A few seem to never lose pressure. If you’re going from 100 to 70 in a few hours, something’s amiss; the most common culprit for me is that the valve has a bit of gunk built up in it and needs to be cleaned or replaced.
Just stick a plug in a puncture. I’ve never taken a wheel and tyre off on the side of the road since going tubeless and carrying tyre plugs. Even a huge 10mm slash last Sunday, I managed to jam in 4 Dynaplugs that held well enough to get me home.
This might be of interest to some
That works until you slice the tire from glass. I was forced to remove the valve and throw in a tube to make it home!
Like I said, so far, I’ve never needed to stick a tube in (1-2 years). Even with a 10mm slice recently, I still managed to plug it. Although it did drop pressure on the way home. I have no idea if it was glass or not that caused the slice.
Could anyone running ENVE 7.8s possibly measure the width of these mounted? I’m thinking about picking some up and I need to know/guesstimate how wide a 23 might be on there with the 19mm inner diameter. 23mm GP 5000s with tubes are running at 23.9mm on my current wheels (17mm inner diameter). The widest I can run on my frame and have 3mm clearance on each side is 25.5mm. Do the tubeless run wider?
Thanks!
Now that winter has arrived, what do folks do for sealant to prep for the new year?
With my MTB I just throw more sealant in in the spring because i dont care about the added weight. What’s best practice for road tubeless? Clean the old stuff out? Just add and keep going?
I fitted these to my bike on DT Swiss R470 rims, and I would prefer never to have to remove them again so adding new sealant will be the way.