Interesting idea.
One problem I see is what about all those goat heads or thorns you already have in your tire that self sealed? Once you inflate your tube, it’s going to run into anything already stuck in the tire casing.
I guess riders at this level probably have new tires/tubes/sealant for every race so maybe it’s less of an issue for someone like me who’s gravel tires has been on the bike for 2 years.
Yeah, he mentioned this in his video. Plan for next year should be to put out a bunch of “It super muddy” disinfo on youtube. 
Agree, but it’s a problem using a tube any way you slice it in that situation. There is one race I do every year that has so many goat heads pre-riding (before traffic really clears it out) that I don’t even bother bringing a tube for the race or pre-riding. The inside of the tires I use on that course literally have hundreds (maybe thousands) of sharp little needles sticking through by the time I’m done pre-riding a few times.
Reminds me of this too https://www.pinkbike.com/news/first-ride-the-odyssey-optis-is-a-tunable-tire-insert.html
If you installed one of these with a gravel tire and left it uninflated until needed it might serve the same purpose as the dual valve setup without the drilling.
This may have been the thing I had seen earlier this year and couldn’t remember where! Thanks!!
Agreed, however when you swap in a tune in those situations you take the tire partially off the rim and can clear out or remove anything sharp poking through. In the case of this setup you are inflating the tube directly into it with no ability to remove any of the foreign objects.
I think it’s clever but I’d definitely be concerned about damaging the tube while it’s in there. I’m imagining it could quickly be cut if you run the tire flat for any length of time, which is a high likelihood of the puncture is one that’s going to need a tune to fix.
Could it work with inserts as well?
This doesn’t make any sense to me, too many downsides. Using dynaplugs and co2 seems much faster for most larger punctures that don’t seal, this would prevent that first fix option and make it harder to remove anything stuck in the tire before putting a tube in if really needed. Would love one of them to explain the logic as I just can’t see any upside.
I guess some people could use it as an alternative to plugs, but I primarily see it as a faster way to deploy a tube when it comes to that. In what way would it prevent anyone from using the “first fix” plug option? It’s just a tube sitting loose inside the tire, I can’t think of any type of plug that would be hindered by a loose tube in the tire. And why would it make it harder to remove anything stuck in the tire? Even if you still had to break the bead to insert a boot or something, it seems like having the tube already in place just saves time vs. pulling one out of your bag or downtube and removing the tubeless valve stem (often a pain), etc.. Where is the downside besides potentially damaging the tube in a really bad incident?
I guess I’m mainly thinking of this from a racing perspective where even saving 30 seconds can be the difference between getting back to a group or chasing all day. Having the tube already in place could save minutes. And honestly, most people try to plug a hopeless tire for way too long because a tube takes so long to deploy, so this would probably result in a faster/better decision to go with a tube when plugs are hopeless. And even in my race last weekend at Unbound where I had a valve core issue resulting in a 10+ minute stop on the side the road, I could have been up and running immediately by airing up the tube and swapping a new wheel at the next aid station. That was a weird/rare situation, but obviously fresh in my head.
Keegan getting a flat and then swapping wheels is probably all you need to know of whether the tube idea works!
I don’t think it ever got to the point where a tube would be needed. And I think it was sidewall, so a tube might have bulged out without a plug or boot already in place, just speculating. Maybe they did try the tube and it failed, but it seemed like it was a fairly quick plug job from what I heard. And then they swapped wheels at some point. That’s why Tobin is there and runs the same tire setup. Tobin rolled that wheel fine with the plugs in it until the second aid station I believe (then swapped a fresh wheel), but better safe than sorry for Keegan when a wheel swap is cheap/quick insurance. Most of us don’t have the luxury of a teammate ready to swap a wheel, but I always have spare wheels at the aid stations and will take the ~10 seconds to swap a fresh wheel on any time I have questions about the wheel I’m on. I personally don’t read too much into the swap indicating whether the tube thing is effective or not, it’s just something they do.
Has anyone categorically even stated there’s a tube in there, rather than just 2 valve stems? Possibly (more) useful in case one gets damaged/blocked, or maybe a different type compatible with a sealant spray. Personally unless I see photos of a tube I’d be doubtful that’s what’s going on, even if they (possibly jokingly) claimed that’s what it is…
Yeah, fair, if I had spare wheels I’d also rather have a fresh one than one with broken tyre and a tube in.
I guess we’ll have to wait and see if they use that setup again!
Given the amount of equipment/setup misdirection in bike racing, it’s certainly a possibility. But either way, it seems like an approach worth considering from my perspective.
TUbliss Motorcycle Dirt Bike Durable Tires | Tubliss runs two valve stems. Since the internal chamber inflates as a bead lock they have to do some tricky stuff with the valves that the “store a spare tube in your tire” approach doesn’t..
How far would you get at Unbound as a pro with a tube? If you need to put in a tube, you have already lost…
5 seconds. I stopped for 5 stupid seconds on a first day of La Grind this year. And then I was chasing you guys down for 90 miles… I should’ve stopped for 30, just to save myself from trouble of even trying. haha.
Odyssey has come out with a 2 valve system for MTB wheels, which works as an insert/ rim and sidewall support. One valve pumps up the insert and the other the rest of the tire. So it’s a tube inside tubeless. My own opinion is I don’t like inserts, I’d rather run higher pressures and tougher tires.
It actually looks pretty interesting.
Once you’ve used a Dynaplug for example you’d then have to remove the Dynaplug before inflating the tube - kind of defeats the point if you have to pull the tyre off the rim anyway..
Just use different kinds of plugs, duh. As much as I love dynaplugs myself, there are plenty of others that are safe to use with a tube.