Home > Other Fun Stuff > Gadgets & Hacks

Tubolight Diamana, the Fastest MTB Tire Liner because of Venturi Airflow INSIDE Your Tires!

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner
25 Comments
Support us! Bikerumor may earn a small commission from affiliate links in this article. Learn More

Tubolight says their Diamana is not only the fastest & lightest mountain bike tire liner on the market – but they also claim it is “the winningest tire insert [on the] World Cup, and the only one winning in both downhill and cross-country“. Its secret though is NOT just its light weight or some unique material. Tubolight says that it is the special shaping of their Diamana liner that manipulates the flow of air molecules INSIDE your tire to better control local tire compression & rebound as you roll over rough terrain.

Tubolight Diamana is the fastest, most advanced MTB tire liner

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, race proven by Mathias Flückiger
(Photos/Tubolight)

I’m always a bit skeptical of a product we’ve not heard much of, claiming to be the fastest and winningest. But besides sealant itself, tire liners are the least outwardly visible component on a race bike. (To be fair we did hear about, but not physically see them on Thibaut Daprela’s Commencal Supreme DH V5 downhill race bike last summer in Leogang.)

So we’ll just take Tubolight’s word for it on the wins if only based on the rainbow jersey photos of 2021 XC World Champ Evie Richards, 2021 Olympic Gold medalist Jolanda Neff, and 2021 DH World Champ Myriam Nicole on their homepage. Not to mention 2021 XC World Cup #1 Mathias Flückiger and 2022 DH World Cup #1 Amaury Pierron. Those 5 riders alone have apparently racked up a slew of wins on Tubolight tire liners as well as several other riders on 5 solid MTB teams. There’s also the curious sponsorship of pro conti road team Q36.5, since Tubolight’s top Diamana tech isn’t yet available in road tire sizes.

So, we all know about MTB tire liners. What makes a Tubolight Diamana liner different?

What happens inside a mountain bike tire when you hit an obstacle?

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, how it works

Many mountain bikers are on board with the idea that tire liners can make you faster in the long run. You get improved low-pressure grip & lower rolling-resistance without losing time trailside fixing flats. But Italian tire liner maker Tubolight has a more nuanced take on how tire liners can make you faster…

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, tire section

When your mountain bike tire hits an obstacle, the tire deforms at the site of impact. That locally increases the air pressure in the tire, which in turn quickly rebounds, bouncing the tire back out toward the point of impact. This can often happen quicker than the bike’s suspension can even start to react.

Lower tire pressures and supple tire casings can delay that fast rebound. But there’s only so low or supple you can go without sacrificing stability, control, or durability – even with most conventional tire liners, which are already a big improvement.

How does the Diamana solution work? And why?

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, up close powered by Venturi effect

The Tubolight Diamana aims to essentially create 2 layers of air pressure inside the tire volume and to control the speed at which air flows from one to the other. This creates a dual benefit of slowing local tire rebound with lower outer pressure near the site of impact and spreading the force further around the rim for better impact protection with a higher pressure zone next to the rim.

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, side profile powered by Venturi effect

From the side, the blue Tubolight Diamana doesn’t look anything like other liners. Its undulating shape rises and falls in waves around the wheel, leaving gaps of space above the rim. From an angle, you can see the unique scooped nature of the Diamana liner, with dimpled ‘star’ shapes stacked on top of each other.

Tubolight claims that when an impact hits the tire from the outside, these scoops direct airflow into the rim bed under the liner via those lateral channel openings. Their shape takes advantage of the Venturi effect to speed up and compress the air as it moves under the liner. The dimples also claim the same boundary separation principle we see on golf balls and Zipp wheels, so more air goes into the lateral channel openings, and does not reflect back into the main tire volume.

That means air flows into the rim well faster than it can escape, delaying the fast rebound effect that otherwise makes the tire bounce off an obstacle.

Tubolight’s claimed results?

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, Mona Mittlewallner

The apparent result is the local air pressure in the tire does not increase nearly as much at the site of an impact, so there is a much slower local rebound or bounce.

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, race proven by Mathias Flückiger

That means the deformed tire will continue to stay attached to the irregular ground surface for improved grip and control. Tubolight claims a “massive 60%” increase of consistent pressure against the ground for next-level traction. The slower rebound also claims 55% higher vibration damping, leading to decreased rider fatigue and a smoother ride.

They ultimately say 3rd-party testing confirms up to a 9% rolling-resistance reduction over rough surfaces.

Tech details

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner, XHD

Tubolight Diamana liners are made of high-density closed-cell EVA foam – guaranteed 100% absorption-free to work with any sealant. Relative to other liners, extra foam hardness for the Diamana liners is necessary to ensure they retain their unique shape for optimized air movement inside the tire, and to deliver “years” of reliable performance. This “leads to the longest-lasting tire insert ever made” according to Tubolight, “even after long runflat rides“.

These unique Diamana liners are available in three different versions, with different thicknesses & densities to suit mountain bike riding from XC to DH. Their unique shape also ensures they can be used with any tubeless valves.

Tubolight Diamana tire liners – Pricing, options & availability

Tubolight Diamana world's fastest MTB mountain bike tubeless tire liner: SL, HD or XHD

Diamana SL is the softest, thinnest & lightest for cross-country racing – at a claimed 97g per tire in 29″ only.

The thicker, medium-hardness Diamana HD is the most universal all-rounder tire liner at 145g in 29″ only, intended for rear downcountry, or front trail, enduro & DH tires.

Lastly, Diamana XHD features the thickest liner with the hardest EVA compound, specifically to be used with reinforced casing tires. XHD comes in both 27.5″ (205g) and 29″ (220g) sizes to suit hard-charging enduro & DH race bikes, as well as heavier eMTBs.

Tubolight Diamana tire liners are sold direct from Tubolight, available for 100€ exclusively in pairs. At the moment, only the 29″ SL+SL, SL+HD & HD+HD pairs are in stock. XHD liners are not currently available.

Tubolight.bike

Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

25 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
David
David
15 days ago

Vittoria Air-Liner Light is 55g per tyre, so at least one of the claims above doesn’t stack up to scrutiny.

blahblahblah
blahblahblah
15 days ago

“manipulates the flow of air molecules INSIDE your tire to better control local tire compression & rebound” yeah right

Dinger
Dinger
5 days ago
Reply to  blahblahblah

This is the way valving inside of shocks works, by controlling the flow of fluid as it passes from one side of a circuit to another. A difference between a shock and a tire is, the shock’s shaft movement causes a volume change inside of the shock’s chamber, forcing the fluid to have to move through the damping circuits. Since the inside of the tire is a sealed chamber with nothing influencing it’s volume, I cannot see how air would flow from one side of the insert to the other. Pressure would simply rise and fall on all sides of it.

Having used lighter weight inserts similar to this I can say they do improve tire performance, just maybe not in the way claimed here.

Chris
Chris
15 days ago

No one cares if they were used and won in ___ races. Literally, zero interest in that. We just want to know if they’re any less difficult to install.

Alex
Alex
15 days ago

Can you actually run them flat or not? Cushcore Pro and Octamousse can. Tannus cannot. There are a lot of claims out there and these guys don’t seem afraid to make claims!

Barry Walstead
Barry Walstead
13 days ago
Reply to  Alex

I’ve very successfully rode out 3 miles onba completely flat 2.6 tire on a Tannus Tubeless and it didn’t damage the tire or rim.

Veganpotter
Veganpotter
12 days ago
Reply to  Barry Walstead

With Tannus, I think their claims are to protect their product with riding on a flat. Your weight, the stiffness of your sidewalls, and the surface you’re riding on will all affect the survivability of that insert

Oliver
Oliver
15 days ago

These obviously look very different, but the road ones were total garbage. Ended up binning them after a few rides. PTN / Vittoria are much better.

Bill Abol
Bill Abol
14 days ago

LOL

Alex Bramell
Alex Bramell
14 days ago

To achieve a hydraulic fit that would effectively retain two pressure chambers or inhibit airflow in a measurable way (relative to the forces required to resist body weight) you would need an airtight fit between the ‘malleable’ insert foam and the moving tyre carcass….

Under pressure EVA foam in the 100kg/m3 density they are most likely using (based on the claimed weights and size assumptions) has a compression set of 25% at 18psi meaning under normal pressures like 24psi the insert shrinks a significant amount, rendering the two air chamber claim inacurate at best. Combined with different tyre widths and tollerances, their claims are totally unfounded, especially given the lack of evidence brought forward in the article to corroberate their various percentage increase claims.

Finally rolling resistance happens at the carcass and is a combination of material harness, tread pattern and pressure, not chamber ‘ramp up’. The pressure inside your tyre barely increases by a single PSI under full flat spot compression as the relative surface area deformation is to small a ratio to the surface area of a 29″ tyre.

Jakob
Jakob
14 days ago
Reply to  Alex Bramell

I think they are saying that it restricts airflow rather than creates two chamber. Although this doesn’t make sense either as the tire rolls around and changes shape and airflow-uh-ability.

Dinger
Dinger
5 days ago
Reply to  Jakob

The only plausible “two chamber” claim is that the air in the tire = one chamber and the air trapped & separated in the closed cells of the foam itself = 2nd chamber. If they got the durometer of the foam right for the pressure range of the intended tire size then this works. Too soft and the foam collapses & shrinks a lot like Alex points out.

By changing the volume of the air chamber the “ramp up” (progression) described has the effect of lowering the tension on the tire casing while still properly supporting the rider’s weight and preventing the tire from flopping all over the place. I’ve used another lightweight tire insert for XC riding/racing and found it did almost exactly this and the tires performed much better. I’m a convert.

Doc Sarvis
Doc Sarvis
14 days ago

it was only a matter of time before Ceramic Speed found a partner in crime.

Dano
Dano
14 days ago

Also, in the picture with the DH racer, they state “dampening” which would mean to make something slight wet. I guess they meant damping? “Dampening: Engaging in the act of making something damp (wet). Damped: Prevented from vibrating freely.”

Tom
Tom
13 days ago
Reply to  Dano

If pictures of downhill racers makes someone wet, who are we to judge?

Tom
Tom
13 days ago

Hope these inserts come with a big fat spliff, ’cause there ain’t no way…

xalt
xalt
13 days ago

april 1st already ?

Yeah sure
Yeah sure
13 days ago

Peak bicycle marketing.

Ron
Ron
13 days ago

“Local pressure”? C’mon now. Pressure spikes in the tire are always occurring (positive and negative relative to the internal static pressure that tire is set at) and that pressure, whatever it is must and will be even within the tire. Huge red flag. And don’t get me started on the “two separate layers” and “venturi” stuff. Complete BS.

xalt
xalt
12 days ago
Reply to  Ron

I want to see evidences ! Slow motion captures of the rebound vs the same tire with same pressure and no insert

BigEarl
BigEarl
12 days ago

I see the Snake-Oil salesmen from the audiophile industry are branching out into the cycling industry.

Veganpotter
Veganpotter
12 days ago

Throw these all over your body for extra venturi effect. Hopefully the UCi doesn’t ban it!

Bnystrom
Bnystrom
12 days ago

They seem to be designed to ensure that you have 60% less money in your wallet.

Wild claims + pseudo-scientific terminology + no actual performance data = snake oil.

Jon
Jon
11 days ago

That is wild.

esc8engn
esc8engn
7 days ago

if this shish is so smart, you should all be spending your brainpower on fixing bigger issues. humankind is edging.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.