What Tyre Pressure Is Best? | How A Tyre Insert Can Help

Summary

This video explores the benefits of tire inserts for mountain biking, focusing on their ability to prevent punctures, protect rims, and improve grip at lower tire pressures. It discusses the use of closed cell foam inserts and their impact on handling and stability. The script also compares different types of inserts for various riding styles, from downhill to cross country. A hands-on experiment tests tire performance at different pressures with inserts, revealing insights on optimal setup for aggressive riders.

Takeaways

• 🚴‍♂️ Tire inserts are used in mountain biking to prevent punctures and protect rims, especially popular in downhill and enduro disciplines.
• 🔄 Inserts are becoming increasingly common in cross-country biking as well, where weight is a more critical factor.
• 🧼 Inserts are made of closed-cell foam, which is durable and doesn't absorb moisture, unlike open-cell foam or everyday foam products.
• 🛡️ They serve as a barrier between the tire and the rim, preventing damage from sharp edges and impacts, enhancing the tire's durability.
• 💨 Inserts allow riders to run lower tire pressures for better grip and control without the risk of pinch flats.
• 🏞️ They can act as a 'run-flat' system, enabling riders to continue riding even after a puncture, providing a safer ride home or to the finish line.
• 🏍️ For aggressive riders, inserts provide structural support to the tire, reducing deformation and improving handling and cornering stability.
• 🔑 The size and shape of inserts are crucial; larger inserts offer more damping but may limit tire flexibility and performance over rough terrain.
• 🔄 Different types of inserts are available for various riding styles, from downhill-focused with high-density foam to XC inserts that are lighter and use lower-density foam.
• 📉 Experiments with tire pressure and inserts showed that dropping pressures can improve ride feel but going too low can lead to loss of control and safety risks.
• 🤔 The decision to use inserts involves a balance of weight, protection, and performance, with personal riding style and preferences playing a significant role.

Q & A

What is the primary function of tire inserts in mountain biking?

Tire inserts serve as a barrier between the tire and the rim, protecting against punctures and rim damage, and allowing for lower tire pressures to improve grip and control.

Why are tire inserts becoming popular in cross country biking?

Cross country bikers are using tire inserts more due to the added security they provide, despite being traditionally associated with downhill biking where weight is less of a concern.

What type of foam are tire inserts made of and why?

Tire inserts are made of closed cell foam because it doesn't absorb moisture, liquids, or sealant, making it more durable and suitable for this application than open cell foam.

How do tire inserts help with tire puncture prevention?

Tire inserts prevent punctures by acting as a barrier that stops the tire from compressing fully against the rim when hitting sharp objects, thus protecting both the tire and the rim.

Can tire inserts act as a 'run flat' system for mountain bikes?

Yes, tire inserts can act like a 'run flat' system by maintaining tire volume even when punctured, allowing the bike to be ridden back to the car park or to finish a race.

How do tire inserts improve handling and grip?

Tire inserts improve handling and grip by adding structural support to the tire, preventing excessive deformation, especially during aggressive riding, and providing better stability and control.

What is the difference between downhill and cross country tire inserts?

Downhill inserts are thicker and use higher density foam for maximum protection, while cross country inserts are lighter with lower density foam, offering protection and stability without adding too much weight.

What is the recommended tire pressure when using tire inserts for cross country biking?

The recommended pressure can vary, but the script suggests experimenting with lower pressures than usual, such as 19-21 PSI front and rear, to take advantage of the added protection without compromising performance.

What is the 'faf' factor mentioned in the script in relation to tire inserts?

The 'faf' factor refers to the added weight and potential inconvenience of having to install and remove tire inserts, especially for those who frequently swap tires.

What is the impact of tire inserts on tire damping properties?

Tire inserts change the damping properties of the tire by occupying some of the air volume, which can firm up the tire more quickly, similar to adding more tokens to a suspension system.

Outlines

00:00

🚴‍♂️ Tire Inserts: Mountain Biking's Secret Weapon?

This paragraph introduces tire inserts as a crucial accessory in mountain biking, particularly for downhill and enduro riders where weight is less of a concern. It discusses the growing trend of cross-country cyclists also adopting tire inserts for their benefits. The narrator plans to conduct an experiment to test the impact of tire inserts on ride performance by lowering tire pressures with inserts installed. The audience is encouraged to engage by liking, subscribing, and commenting on their experiences with tire inserts. The paragraph concludes with a brief explanation of what tire inserts are: closed-cell foam barriers placed inside tires to prevent punctures, protect rims, and enable lower tire pressures for better grip and control.

05:00

🔍 Exploring the Benefits of Tire Inserts

The paragraph delves into the protective role of tire inserts, acting as a barrier between the tire and the rim to prevent damage from sharp edges and impacts. It explains how inserts can function as a 'run-flat' system, maintaining tire shape and bead stability even after a puncture. The discussion then shifts to how inserts can enhance handling and grip by providing structural support to the tire, which is especially beneficial for aggressive riders. The narrator also touches on the damping properties of inserts, comparing the effect of different insert sizes on tire compression and performance. The paragraph ends with a consideration of the importance of insert shape and size, with a focus on how Victoria, a sponsor of the channel, offers a range of inserts tailored to different riding styles and terrains.

10:00

📉 Pressure Drop Experiment: Riding with Inserts

The final paragraph details a practical experiment where the narrator rides a black run mountain bike track at varying tire pressures to assess the impact of tire inserts. Starting with stock pressures, the narrator progressively lowers the tire pressures to observe changes in ride feel and control. The experiment reveals that while lower pressures with inserts provide better grip and tire deformation, they also increase the risk of tire squirm and potential damage. The narrator concludes that their initial tire pressures were too high and decides to try slightly lower pressures in the future. The paragraph ends with a call for audience feedback on the use of tire inserts, the importance of weight in cross-country biking, the need for additional sealant, and personal preferences regarding tire damping and insert maintenance.

Keywords

💡Tire inserts

Tire inserts, also known as tire liners, are round pieces of foam that are placed inside a tire. They act as a barrier between the rim and the tire, providing protection against punctures and rim damage. In the video, the host discusses how these inserts are becoming increasingly popular among mountain bikers, particularly for downhill and enduro disciplines, due to their added security and the ability to run lower tire pressures for better grip and control.

💡Closed cell foam

Closed cell foam is a type of foam used in tire inserts because it does not absorb moisture, liquids, or sealant, making it ideal for use in tires. It is also more durable and tough compared to open cell foam. The video script mentions that tire inserts are made from closed cell foam, emphasizing its importance for the functionality and longevity of the inserts.

💡Puncture protection

Puncture protection is one of the main benefits of using tire inserts. They prevent the tire from compressing fully against the rim when hitting sharp objects, thus reducing the risk of punctures. The video discusses how tire inserts can act as a barrier, particularly when running lower tire pressures, which is a common practice in cross-country biking.

💡Lower tire pressures

Lowering tire pressures is a technique used by mountain bikers to improve grip and control, especially on rough terrain. The video explores how tire inserts allow bikers to run lower pressures without increasing the risk of punctures or rim damage, thus enhancing the bike's performance on the trail.

💡Rim protection

Rim protection is another key function of tire inserts. They help to prevent damage to the bike's rims from sharp edges, rocks, or heavy landings by absorbing the impact. The script describes how the foam in the insert compresses to shield the rim, which is crucial for maintaining the bike's structural integrity during aggressive riding.

💡Run flat system

The term 'run flat system' in the context of the video refers to the ability of tire inserts to allow a bike to continue to be ridden even after a puncture. The insert maintains the tire's shape and volume, enabling the bike to be ridden back to the car park or to the end of a race. This is highlighted as a significant advantage of using tire inserts, especially in racing scenarios.

💡Handling and grip

Handling and grip are crucial for bike control, especially at high speeds or on challenging terrain. The video explains how tire inserts can improve a bike's handling by providing additional structural support to the tire, preventing excessive deformation and rolling during aggressive cornering or riding over obstacles.

💡Damping properties

Damping properties refer to the ability of tire inserts to affect how the tire compresses and rebounds. The video script uses the analogy of suspension tokens to illustrate how larger inserts can increase damping, making the tire firm up quicker and thus altering the ride feel and responsiveness of the bike.

💡Sweet spot

The 'sweet spot' in the context of the video is the optimal balance between tire pressure, insert size, and damping that provides the best combination of grip, control, and protection without sacrificing performance. The host discusses the need to find this balance when using tire inserts, as too much or too little of any of these factors can negatively impact the bike's handling and ride quality.

💡FAF factor

The 'FAF factor' is a playful term used in the video to describe the 'Faff Factor', which refers to the inconvenience or hassle of having to install and remove tire inserts, especially for those who frequently swap tires. The video script raises this as a consideration for bikers who value convenience and ease of maintenance.

Highlights

Tire inserts are considered unsung heroes for mountain bikers, offering protection against punctures and enhancing wheel security.

Downhill and enduro cyclists commonly use tire inserts for added security despite the weight being a less significant concern.

Cross-country cyclists are increasingly adopting tire inserts for their benefits, including better grip and control at lower tire pressures.

Tire inserts are made of closed-cell foam, which is durable and does not absorb moisture, liquids, or sealant.

Inserts serve multiple purposes: protecting from punctures, shielding rims from damage, and allowing for lower pressures to improve grip.

Tire inserts act as a barrier between the tire and rim, preventing pinch flats and damage from square-edge impacts.

They also protect rims from sharp edges and heavy landings by compressing and absorbing the impact.

Tire inserts can function as a run-flat system, allowing riders to continue riding even after a puncture.

Inserts improve handling and grip by providing structural support to the tire, enhancing stability and control.

The shape and size of the insert are crucial for achieving the right balance between protection and performance.

Different types of inserts are available for various riding styles, from gravel to downhill, each with unique profiles and densities.

Downhill-focused inserts have a T-shape for better bead retention and use higher-density foam for maximum protection.

Trail inserts offer a middle ground with dense foam for impact protection and stability without adding excessive weight.

Cross-country inserts use lower-density foam for lighter weight while still providing protection and stability.

Experiments show that tire inserts allow for lower tire pressures without compromising performance, enhancing grip on various terrains.

The added weight from tire inserts and sealant is a consideration for cross-country cyclists, but the benefits often outweigh the drawbacks.

The personal preference for tire feel, whether damped or undamped, plays a role in whether a cyclist chooses to use tire inserts.

The convenience of tire inserts can be offset by the faf (faff) factor of having to install and remove them, especially for those who frequently change tires.

Transcripts

Tire inserts the unsung hero of the

mountain bike vanquisher of punctures

savior of wheels or are they just extra

weight and extra

[Music]

faf in the word of downhill and injo

they're pretty common place with the

weight not really being an issue and the

added security being nothing but a bonus

but the people in the cross country

world are starting to use them as well

that's right even though weake conscious

like her clad lovelies including myself

in XC are starting to use them a lot

more too so today we're going to do a

little bit of experimenting we're going

to try inserts myself front and rear on

this bike start to drop some pressures

and see just how much difference it

really does

make right before we dive on into the

video why not show us a little bit of

love by liking and subscribing get

active in those comments down below and

let me know what you think of inserts do

you use them don't use them thoughts and

feelings please people

all right let's crack on what is a tire

inser or tire liner what are they well

it's essentially a round piece of foam

that sits inside the tire and kind of

acts as a barrier between the rim and

the top of the tire now they're

generally made of foam but not just any

old foam they're not like pool noodle or

some kind of foam you'd find in your

cushions oh no they are in fact made of

something called closed cell foam now

this is done so because it doesn't

absorb any moisture liquids or sealant

or anything like that and is actually

far better for this kind of application

than an open cell phone it's also much

tougher and more durable as well they

fill up the void inside the tire

partially sort of making a barrier if

you like and they come in all sorts of

shapes and sizes so what are the main

reasons that we would use an insert well

there's a few protect from punctures

protect our rims from damage and to run

lower pressures for kind of better grip

and control so let's dive into those a

little bit more

[Music]

a tire inser then acts as a barrier

between the tire and the rim so

effectively when you hit a square Edge

bump it stops that tire from compressing

all the way and pinching against the rim

causing damage to the tire this is

especially beneficial running an insert

if you are someone who runs lower

pressures having that sort of added

bonus of a protection is going to stop

either damaging the top of the tire or

if you had no inserts pinching the

sidewalls as well which can be an

absolute game over for your

[Music]

ride so as I've previously touched on

they help protect your tires to a

certain degree but actually most of all

they help protect your rims as well from

any sharp edges clanging on rocks things

like that or particularly Hefty Landing

essentially the foam compresses as you

can see it kind of does here and what

that does is stop the tire hitting

straight down onto the rim damaging a

rim be it carbon or metal I've actually

taken inserts out from either WS races

I've done in the past where there's been

all sorts of gouge marks chunks missing

outside of the insert but absolutely no

damage to the wheel if I didn't have

that insert in it would definitely be a

game over for that race inserts can

actually act as like a run flat system

as well and what I mean by this is if

you are still unfortunate enough to get

a puncture something like this can

actually help you get home or finish a

race run how that actually works is it

means the volume or some of the volume

of the tire is still taken up so you can

ride that wheel or ride that tire and

wheel combo if you like back to the car

park end of a race run and not only that

it's going to help hold the bead of the

tire in place as well so you ever see

those people sort of snaking around

because the back tire is moving loads

when front is moving loads when they do

have a puncture this can actually help

avoid that as

[Music]

well now this is one of the biggest

tooling points these days is that

actually inserts can improve handling

and grip and it can do this in a number

of ways this is essentially achieved by

adding extra structural support to the

tire giving the rider better stability

and control now where this is going to

make a huge difference is especially if

you're quite an aggressive Rider it's

going to not sort of let the tire roll

and deform so much especially when

really pushing it into corners or

hammering it through those really gnarly

sections it does this by pushing

essentially out and up on the tire so

what an insert is doing you know whilst

you're just rolling around is one it's

kind of helping lock the bead in place

around the bottom of the tire so when

you are hammering it when you're leaning

that tire tire over it has a tendency to

deform like this either left or to the

right what the insert is doing is

pushing out on the bead holding it

nicely in place it's also then pushing

up and out on the side walls as well

stopping those from Rolling quite so

much and deforming under a lot of load

now inserts are also going to give you

some kind of damping properties what

does that mean think of your tires like

your suspension you have a volume of air

in there but if you put something in

that takes up some of that space it

changes the characteristics of how it

compresses think of it this way the

larger the insert you have in your tire

the more damping you kind of have it's

like adding more tokens to your

suspension it it firms up a lot quicker

so for example on my cross country bike

here if I was to run one of the biggest

inserts that Victoria make well then the

tire is not going to squish or compress

much before hitting that insert this can

be good and bad ideally you would want a

little bit of space because what it

means is you're not actually allowing if

that insert is really big you're not

actually allowing that tire to mold and

conform and compress over stuff it's

more going to deflect than anything so

you do need a certain kind of sweet spot

or balance if you like that's why the

shape and size of the liner is so

[Music]

important so on that note then not all

inserts are created equal and they're

certainly not all created of the same

size now here on the channel we're

sponsored by by voria and they make a

wide range of inserts everything from

kind of gravel shaped all the way up to

Big gnarly eite ones and you can kind of

see although they look very similar in

some ways they're very different in

others obviously for the smaller tires

of the gravel world and the different

kind of hits that it takes it's a much

sort of Slimmer profile the big bad boy

ebike one here is a a denser foam it's a

much bigger sort of size to take up the

volume but what are the more common ones

we use in the mountain bike world

starting off at the Burly end of the

scale let's take a look at some of the

key points of a downhill and Enduro

focused insert you can see the shape of

this insert slightly different a t-shape

that sits deeper into the rim and helps

keep the bead nicely in place the side

sections help press against the

sidewalls and give that sidew stability

and puncture protection we mentioned

before the biggest difference here is

the flatter profile giving the biggest

Air volume possible this uses a higher

density foam for the best protection the

downhill protect insert is that little

bit thicker to give you maximum

[Music]

security what if sort of trail riding

and smashing is your thing you want the

protection but you don't want to carry

around a lot of weight well here is how

the trail ones are different these then

are the trail airliners and they sit as

a middle ground between the heavyduty

downhill inserts and the lightweight XC

inserts they still have a dense foam to

help with impact protection and and tire

stability but don't add too much weight

the size and material help dampen Any

Trail Buzz which is great for those

longer days on the

[Music]

bike and last but by no means least then

the XC insert and kind of the one we're

most interested in today so let's check

them out in Greater detail these little

Beauties use a slightly lower density

foam to help make them around 100 G

lighter than the downhill insert but

still offer good protection and

stability Victoria claim actually on

these that if you get a puncture while

using these inserts the phone will

expand and help provide more support

helping their athletes get back to the

Tech Zone should we say much faster than

if they got a puncture without an

[Music]

insert well whil we're on the subject of

cross country then back in the day

Racers would jack up the tire pressures

to try and stove off any kind of

punctures these days with tracks getting

Wilder bikes being more capable and

races being gnarlier well Racers are

actually running pressures as low as 15

16 PSI but not really worrying about the

weight penalty of using an insert

because they'd rather have the security

but is it just a fad is it all talk well

there's only one way to find out and

that's an experiment I'm at the top of a

black run we're going to start dropping

pressures and let's see how we go so run

number one to set a little Baseline in

kind of thoughts and feelings I've got

my Ora o Victoria XE race tires Mescal

barazo combo we're running my stock

pressures at 23 three on the rear 21 PSI

on the front and I got Victoria

airliners front and rear as well let's

give her a hammer on down then we'll

drop the pressures let's

[Music]

go change okay hell of a run but do you

know what nothing too unexpected there

it's what I run kind of all the time so

it felt comfortable it didn't really

squirm it didn't ding or anything I had

no big nasty compressions so kind of

boring but kind of not to be expected

now I think we need to make things a

little bit interesting and drop it down

5 PSI front and rear and see if that's

maybe a little bit too much and go from

there the pressures are set 18 PSI in

the back 16 up front just for reference

I'm about 90 odd kilos kitted up I'm

riding this bike with a supension fully

unlocked so let's do a run see how she

[Music]

holds

flow become

one now work it don't stop let me see

you po at the part

Shop canot Hold

overflows

one now work it don't just stop

[Music]

right then that pressure there was kind

of optimal on the way back up the tires

were nice and soft and that they were

deforming and sort of molding around the

obstacles going up and gripping really

nicely however on the way down there was

a notable difference in terms of sort of

squirming under pressures especially in

the big burms you know when you hit the

compression of the takeoff and like

under breaking felt pretty good going

down even lower I think is a very high

risk strategy and going 5 PSI lower is

certainly way too much so we're not

going to go five I think if we drop it

another three front and rear that will

be sort of on the limits especially with

my riding star so you got to take that

into consideration as well I ride pretty

hard pretty wild on bikes so going too

soft is definitely not a thing for me

I'd actually go a bit firmer but let's

drop it down three each more get this

jacket off cuz it's flipping boiling and

do another run right I'm nervous on this

one there's only one way to find out

let's have

[Music]

it oh

soft yo right I've had to stop already

no way was I going to be able to jump

that safely or properly as soon as I

went to push into the take off like push

to then compress and pull out both tires

and especially the front just went and

just rolled over that would have ended

very

[Music]

[Music]

badly there we go drop oh no I do not

like the feeling of that that's how

squishy over the roots P little dong big

squish oh no

thanks

[Music]

o oh my Lord

okay that's proving to be a little bit

too live Lively for me at these

pressures I think we may have found just

going a bit too low so basically coming

down there I can feel tires squirming in

burms tires deforming up takeoffs the

odd ding where it's going through to

sort of not the rim but onto the insert

down some of the rockier bits I think we

need to go back up a touch I do think

what I've learned from this though is

actually with inserts my previous

pressures were a little too firm I think

2321 could be dropped down to 219 front

and rear I'm going to try that at

another date this uh this has been a bit

too wild for my liking but also some

other sort of great talking points

actually I think on this is that we we

kind of need to touch on and I want to

hear your thoughts in the comments down

below by adding an insert we obviously

add a little bit more weight does that

really matter when it comes to cross

country I'm not so sure when it comes to

track but also we do have to add

additional sealant as often recommended

by manufacturers so you have adding a

little bit more um some people do like

the the feeling of an undamped Tire as

well as in you know no insert in there

and you've just got the full squish if

you like and last but not least

obviously you have got the faf factor as

I call it have actually taken them in

and out especially if you swap tires

regularly insert your comments down

below let me know what you think when it

comes to them do you have an optimal

pressure did you not use them are you

going to now I want to hear your

thoughts and feelings people but for me

for now from Scotland I'll see you later