Tubeless tyre inserts – lengths of foam fitted inside the tyre – are becoming increasingly common for both mountain bike and gravel bike setups, but could they be set to appear on road bike setups too? We've already heard about them being used in the pro peloton and here’s how we think roadies might use this tech.
What the hell is a tubeless insert?
If you’ve no idea what we’re talking about, a tubeless insert is a length of foam that wraps around the wheel, sitting inside the tyre. Most will not fill the whole tyre and many claim to avoid soaking up tyre sealant. The two most common reasons cited for using tubeless inserts is rim protection when a tyre 'bottoms out' and improved bead retention to help keep the tyre on the rim at low pressures.
Mountain bike inserts have come down in weight recently, with a good insert adding a little under 100g to each wheel. With a narrower profile for use with road tyres, this weight would come down even more, although there will still be a weight penalty associated with tubeless inserts.
The current thinking on tubeless foam inserts
In the world of mountain biking and gravel, foam inserts are generally a protective measure to guard against rim impacts when using super-low pressures for added traction. Some are also claimed to aid tubeless bead retention, again a benefit when running lower tyre pressures as ‘burping’ air is often an issue for mountain bike and cyclocross tubeless setups.
Over to the pros
You can always count on pro team mechanics to come up with innovative solutions to bike problems and when The Cycling Podcast featured EF Education First rider Mitch Docker chatting to team mechanic Jac-Johann Steyn, it transpired that the EF mechanics had come up with a few nifty hacks when running tubeless tyres in races.
The EF solution, as we will name it, is born out of a problem that is quite specific to pro racers. Tubular tyres are generally considered to be quite safe as the rider can continue to ride on a deflated tyre should a puncture befall them in the middle of the peloton. This is because the tyre is glued to the rim and requires a significant amount of force to remove when installed correctly.
A tube-type clincher or tubeless tyre is not glued to the rim and relies mostly on air pressure to keep the tyre safely on the rim. When a puncture reduces air pressure in the tyre, safety can be badly compromised and if you keep riding on a deflated tubeless tyre, there’s a risk of the bead unseating.
So Steyn, when explaining some secret tech that EF has been using, appears to show how the mechanics have navigated past this problem. Steyn starts talking about tyres at 41 minutes in, but the whole podcast is well worth a listen.
“We have, I call it a sponge inside. I can’t go into detail about it because it’s always a secret to other teams, but that’s basically our safety and you can still ride it.
“It feels like you’ve almost got 2.0 Bar (20 psi) in your tyres so you can still ride with it wherever you need to go.”
Docker then says that he punctured the day before when using the system and was able to continue riding, only noticing the tyre was punctured when he went through a couple of corners.
Steyn says, “That’s basically the purpose. It’s to help you get to some point where you can get a new wheel. In the future, I think that’s what we’re going to go. And it’s also a safety thing. Like for what we’re using, if you don’t use that foam insert and the tyre’s deflated, and it comes off, you may crash.”
Vittoria is the tyre sponsor for EF Education First and so, with the gravel version of Vittoria’s Air-Liner already on the market, it isn’t a huge stretch to imagine that a narrower version, probably for use with 25-28mm tyres is at the prototype stage of production at the very least.
When we consider that The Cycling Podcast episode where Steyn reveals the trick was recorded during the Classics races in August, it could be that we see a finished product in early 2021.
What use is that to me?
How relevant is this to non-professional riders? Well, if you were to have a sudden loss of pressure when travelling at speed, then having something to stop the tyre bead from unseating is surely a good thing. Non-pros might also be attracted to a tyre insert as a 'get-me-home' option.
Steyn talks about the lack of sealant being used when combined with the tubeless liner. This could be an interesting approach for riders looking for the fastest setup.
“We basically brush the tyres with sealant before so it dries out. It’s just like the small bubbles of air escaping, we just seal that off. That’s something we’re experimenting with now, because tubeless is obviously a new thing on the road for us, just to make sure. Is it working? Is it not working? Do we need to put sealant? Do we not need to put sealant?”
The ability to simply ‘brush’ sealant onto the inside of a tyre will depend on the sealant that you’re using and the tyre that you’re brushing it onto.
If Steyn is brushing the sealant onto a Vittoria Corsa tubeless tyre as we’d expect then this is unlikely to be for puncture sealing purposes and more to do with making a slightly porous casing properly airtight.
This could be giving a pro a fast setup with a bit of security in the event of a puncture. Unlike the rest of us, they can simply roll along at the back of the peloton and await a new wheel from the team car.
Your options as things stand
You haven’t got many insert options for standard road tyres, at least not for those that are under 28mm wide. Vittoria has the Air-Liner Gravel that we think EF might have been using in a slimmer profile. This currently comes in only a gravel version and Vittoria claims it will fit tyres from 31mm to 40mm. You’ll need a relatively wide internal rim width, though; Vittoria says that this works with inner rim widths of up to 25mm. We’d be surprised if it fits a rim that is less than 19mm wide internally.
Tubolite’s Puncture Prevention Insert is another option, and at a claimed 22g it is also one of the lighter solutions on the market. This claims to work with rim widths of between 15mm and 22.4mm and is compatible with tyre widths of 28mm and above.
I don’t want to brush on my sealant, thanks
The life of a pro team mechanic might be about to change from brushing tubular glue onto rims to brushing tubeless sealant onto tyres, but what if you want to get the puncture-sealing benefits of tubeless while using a tyre insert? How much sealant do you need?
The world of off-road riding has a few theories on this one. Some brands, such as Cush Core, claim that no additional sealant is needed when installing tyres with their insert.
Other brands, such as Rimpact say that you’ll need to add additional sealant. Rimpact says to add 25% more and off.road.cc's Rachael Gurney says that when she fitted a Tannus insert, it needed a decent amount more while also noticing that it dried out quicker when using her normal sealant.
Unfortunately, it seems that a fair amount of trial and error is going to be required for any early adopters of tubeless inserts on road setups.
How much these pieces of foam will affect rolling resistance and the tubeless experience is unclear, but we’ll be the first to put our hands up to give it a go.
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31 comments
I don't understand those who think setting up tubeless is a 'faff'. It really isn't. I am not particularly 'hands-on' but managed to put two new WTB Resolutes onto Hunt 4 Seasons 650B wheels yesterday in about 10-15 minutes - 70ml of sealant injected into the valve with no spillage. Went up with a Joe Blow track pump and both still inflated this morning and no jumping out of my skin when a tube pops having been stuck on a bead - I don't miss that!
That says it all for me, the pleasant surprise that not just one but both the tyres managed to say inflated over night. I'll stick with inner tubes and do without the suspense.
I don't understand how you could fit an inner tube that wrong but here we are
This all seems like a load of unnecessary complications, so why not simply modify the experimental Michelin Uptis tire for bikes? No air, no sealant, no foam, no tube, and no liner, which makes the tire puncture-proof, and lightweight. Oh wait, they have made an airless foamless tire for bikes; see:
https://www.boredpanda.com/airless-flat-free-tire-bike-nexo/?utm_source=...
So I'm not going to buy into all tubeless technology only to find out in 10 years the airless tire comes out and would have to buy all new rims all over again. But I do feel the airless tire is the best thing to develop and market, when that comes out I will make the move from tubed tires to that.
Solid tyres. Sorted.
When I tried solid tyres a long time ago they had terrible rolling resistance and the ride quality was awful. Somehow they seemed to suck most of the fun out of cycling so I'll give them a miss.
With the above inserts, I'm puzzled as to how you fit them. They seem to be tight against the rims, but then how does the tyre get between the insert and the rim?
I think the insert is a sponge/foam-type material, so it sits flush with the rim but has enough give that you can tuck the tyre in between. But I've never tried one myself/seen one in person!
This is a stupid idea.
Never under estimate the cycling industry's ability to sell a solution few will need to a majority that won't.
Tl compatible tyre +80g (+20,-$)
Tl compatible rim +50g (+100,-$)
Tl valves +10g (+20,-$)
Tl rimtape +5g (+10,-$)
Tl sealant +60g (+10,-$)
This nature killer plastic foam +30g (+90,-$)
Re-seal every 3 month: 2h + 10,-$
Same puncture proofness but 250,-$ cheaper and much less weight and hassle :
Vittoria Rubino Pro Control tyre +60g
Conti supersonic tubes +0g
It's not though, is it? And I totally take your points, but any faff* is more than outweighed by the healing properties of sealant.
*And my God can they be a faff! I gave up on tubeless setups many times before I persevered/found systems that worked for me, and now I wouldn't go back. 2 (pinch) flats in 2 years since going tubeless vs. 8 or 9 in the same time period with tubes across 4 and 2 bikes respectively.
Is it the manufacture or lack of recycling that gives call for concern. Or something else? I'm not questioning your ascertain, I'm genuinely curious and concerned.
Supersonics are notoriously fragile and are so thin can they even be repaired? If not then the nature killer comment needs revisiting...
Yes. They can be! I run a pair with 4! patches since 5! years. Same on mtb.
Let me share with you the global recycling reality:
https://www.nationalgeographic.org/encyclopedia/great-pacific-garbage-pa...
Don't reassure ourselves, by our own artifical naivety.
Every piece of plastic we buy repruduced in the Far East in less than a second. (A recycle peroid takes months.)
P.S.: I'm not an antipollution activist just a thinking man.
Healing! You are right!
Not repairing!
To heal something is temporary, not with the same usability ever again, instead of repairing.
Since the sealant does not gives back the same integrity of a tyre, not any manufacturer recomends them continue to use as before. Just in case you put tubes under them!
Just imagine a 80km/h descend with a tyre a filled hole on it. Especially in a case of rim breaks when heat-factor can delaminate the filling material far more easier.
So if you want to keep up tubeless after a puncture, you have to buy a tyre again. Thats polluting and wasting again.
Had 3 high-class road tubeless system in the past 2 years. I felt to be considered stupid by the manufacturers.
The only areas I see tubless legitimate is commuting and maybe(!) MTB. But this is road(!).cc.
My skin has a different definition of healing to you!
also if it's big enough to threaten the integrity of a tire it's big enough to need a worm or a patch out I the road.
I find myself unconvinced by your arguments.
Ask any manufacturer.
I'm trying to find this information, as I've never not carried on as before once they've sealed, and while I rarely hit 80km/h I'll routinely be at ~70km/h on sealed road tyres. Mavic tell you to check integrity of any roadside repair, but that's all: Is a near immediately sealing tyre classed as a repair? I'm not sure.
They do however say to change valve each year which was news to me!
I've run, albeit lower pressure, 'cross, gravel, and MTB tyres with either sealed or plugged repairs for years without issue. Again, I can find no warning against doing this.
The above is nonsense. When sealant stops a puncture it stays fixed. Keep riding without worrying.
I agree. Countless small nicks using gravel kings on flinty ridgeway. Integrity of tyre compromised even if sealant does temp job.
Sorry but I can't hold back myself on sealant's effect on evironment.
Manufacturers promote them as "easily washable". That means these are water-soluble, so can get to water's biological cycle and than right to your glass of water.
Don't worry! You can buy clear water in plastic bottle.
And these are only the tires of us, modern, wealth cyclist. A carbon structure is made of 50% epoxy resin, which is one of the most harmful plastic....
Sad, but true.....and
I'm sin too.
I thought tubeless sealant was more or less just latex.
Edit: just checked and Caffélatex is synthetic, despite the name.
I'm always astonished by the number of punctures people say they have. I'm not questioning that it happens, but what on earth are you doing to your tyres?
I've had less than 1 puncture/10,000km in the last 5 years. In my cycling friendship group, we collectively do ~60-70,000km a year total, and have had fewer than 10 punctures. With well looked after road tyres the number of punctures will never justify any faff - I'd have spent more time and money setting up one pair of tubeless tyres than I have on all the punctures I have in about 5 years.
Depends where you ride I guess. I ride suburban London/surrounding countryside almost exclusively, and rarely puncture. Once or twice every 5000km I guess, and that's riding 23mm race tyres all year round. I went into central London for work a few weeks ago and picked up 2 big cuts, a flat tyre and lots of glass shards/nicks in the rubber on a 20km round trip. I guess that would've been mitigated better by choosing appropriate tyres for urban use, prevention is better than sealant
'Just riding along!' Since moving north a few years back on the road it's mainly been hawthorn hedge cuttings to blame for 'puncture punctures', previously it was usually flint. On 'cross-like (I'm not going to use the G word) rides it's usually been pinch flats: the rocks tend to be less pointy but the tracks rockier.
Lucky you! I reckon perhaps one in three of my group rides is interrupted by a flat of some kind—either topping up a tubeless leak once it's sealed or putting a new tube in. To me, it's the fact that you can do the latter to the former if need be that adds to the benefit of running tubeless.
It does depend on where you live. I use to live in the Mojave Desert area of California, what grows out there is something called a Goathead thorn, these things when they dry up produce really sharp...well thorns that look like these things: https://www.google.com/search?
q=goathead+thorn&sxsrf=ALeKk03CbuWGzLL3gaSLm-hSBqjuMe4NdQ:1605915609120&source=lnms&tbm=isch&sa=X&ved=2ahUKEwibo67rpZLtAhVhGVkFHeV1DDIQ_AUoAXoECAQQAw&biw=1024&bih=494#imgrc=PSBMZo1_jmxzVM
Anyway, these things penetrate most bicycle tires like butter, and tires with sealant fail big time against these thorns. The only remedy I found was going to Specialized Armadillo All Condition tires, when I did that I went from 5 to 6 flats a week to none. Those flats I got were with a supposedly flat-resistant, howbeit lighter weight than the Armadillos tires, a tire liner, and thick thorn tubes with sealant.
When I moved from that area, I switched back to lessor flat-resistant tires and now only get a flat maybe once every other year.
So, yes it does depend on where you live.
I can't see it being practical for amateur roadies, however, I bet our CX and Gravel friends would welcome a bit more development in this.
I foresee a video involving me riding a CX bike with less than 10psi
Gravel racing will be all over these, no team support and pit stops being hours apart, means a flat can be race ending.
Ultra-distance too: I pinch-flatted a tubeless gravelking 2km into the first gravel section of a 1000km self-supported race, with ~900km to go.
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