Running a non-tubeless tyre as tubeless, OK or madness?

[I like Skol]

I have a bike with tubeless ready rims and standard non-tubeless Continental Grand Sport Race 700x28 tyres. When the tyres are fitted then inflated with tubes they locate on the shoulders of the rim with a reassuring pop, just like a car tyre. I can't see any reason why these tyres can't be used tubeless.
I have googled this and the unfailing message is "don't do this, you will die!"
Why? As far as I can see all I need is the valve and sealant then I am good to go. The only possible snag will be getting the tyre to seal in the first place so I can inflate it but how is that any different to fitting a tubeless specific tyre?

 

[lpretro1]

I have a bike with tubeless ready rims and standard non-tubeless Continental Grand Sport Race 700x28 tyres. When the tyres are fitted then inflated with tubes they locate on the shoulders of the rim with a reassuring pop, just like a car tyre. I can't see any reason why these tyres can't be used tubeless.
I have googled this and the unfailing message is "don't do this, you will die!"
Why? As far as I can see all I need is the valve and sealant then I am good to go. The only possible snag will be getting the tyre to seal in the first place so I can inflate it but how is that any different to fitting a tubeless specific tyre?

You will need some tubeless rim tape to replace your ordinary rim tape - several brands around - I use Stans No Tubes tape myself. It may or may not work with that tyre - whether or not it is safe to run it tubeless I don't know - tubeless tyres have the sidewalls 'beefed up' for this very reason

 

[screenman]

I run tubeless on two bikes, I do not and never have used tubeless specific tyres, or rims for that matter. I do use the Stans kits, I am not sure you will need this on tubeless ready rims, some do not.

 

[Yellow Saddle]

This is a relatively narrow road tyre and I'd be cautious in running it tubeless. Reason is that narrow tyres have much less air in them than fat tyres and your margin for error when losing air is small. It isn't the same as losing air in a tubed tyre. With tubeless, you sometimes also lose air from a "burp" - either a snakebite strike or a roll-off in a corner. With such a low volume of air the loss will be super-sudden.

Tubeless road bike tyres are not the same as tubeless MTB tyres. The tyre/rim's hook and bead lock is different and the bead is super juicy. By that I mean it has lots of squidgy rubber to create an excellent seal. The bead is so rubbery that you almost cannot slide a tyre lever through it to install the bike.

If you still feel you want to do this, try on the rear wheel first and ride many miles before committing.

 

[I like Skol]

I run tubeless on two bikes, I do not and never have used tubeless specific tyres, or rims for that matter. I do use the Stans kits, I am not sure you will need this on tubeless ready rims, some do not.

Are we talking about MTB or road bike here?

This is a relatively narrow road tyre and I'd be cautious in running it tubeless. Reason is that narrow tyres have much less air in them than fat tyres and your margin for error when losing air is small. It isn't the same as losing air in a tubed tyre. With tubeless, you sometimes also lose air from a "burp" - either a snakebite strike or a roll-off in a corner. With such a low volume of air the loss will be super-sudden.

Tubeless road bike tyres are not the same as tubeless MTB tyres. The tyre/rim's hook and bead lock is different and the bead is super juicy. By that I mean it has lots of squidgy rubber to create an excellent seal. The bead is so rubbery that you almost cannot slide a tyre lever through it to install the bike.

If you still feel you want to do this, try on the rear wheel first and ride many miles before committing.

I have considered the 'burp' factor but I tend to run my tyres quite hard so think deformation sufficient to break the seal is unlikely.
I am not considering this to run lower pressures but mostly out of curiosity. Will I experience less punctures? Will I save weight (not a massive consideration but interesting to see if throwing the tubes away alters the bikes feel at all)? Will a tyre without a tube feel or ride any better, I suspect the tyre will be more supple without tube? Can it be done, my logic tells me that the pop I get when inflating the tyre is telling me I have the interference fit needed from this tyre/rim combo to run tubeless.
Lots of questions and not many answers on the web. I feel like experimenting but had already considered maybe just trying the rear for a while first

 

[Yellow Saddle]

Are we talking about MTB or road bike here?

I have considered the 'burp' factor but I tend to run my tyres quite hard so think deformation sufficient to break the seal is unlikely.
I am not considering this to run lower pressures but mostly out of curiosity. Will I experience less punctures? Will I save weight (not a massive consideration but interesting to see if throwing the tubes away alters the bikes feel at all)? Will a tyre without a tube feel or ride any better, I suspect the tyre will be more supple without tube? Can it be done, my logic tells me that the pop I get when inflating the tyre is telling me I have the interference fit needed from this tyre/rim combo to run tubeless.
Lots of questions and not many answers on the web. I feel like experimenting but had already considered maybe just trying the rear for a while first

If you feel the tyre seats very tightly, why not try? It has been pointed out otherwise here once before, but my experience is that thin, high-pressure tyres don't respond well to sealant. There isn't enough meat (depth) in a puncture hole to retain any sealant and high pressure just shoots it out. Hence, the relatively thickness of true tubeless (UST certified) tyres.

Would it be more supple without a tube? Whilst it is true that a tube contributes to hysteresis (frictional) losses within a tyre, road bike butyl tubes are so thin I doubt you will feel a difference. With sealant in there to also contribute to losses, there will be no difference. It may even be worse, depending on what concoction you put in there. There's nothing like good old experimenting. I'm not going to caution you because you're bright enough to not do what the hi-viz-and-goggles brigade will warn you not to do.

 

[I like Skol]

I run tubeless on two bikes, I do not and never have used tubeless specific tyres, or rims for that matter. I do use the Stans kits, I am not sure you will need this on tubeless ready rims, some do not.

@screenman are you talking about roadbike tyres here?

It has been pointed out otherwise here once before, but my experience is that thin, high-pressure tyres don't respond well to sealant. There isn't enough meat (depth) in a puncture hole to retain any sealant and high pressure just shoots it out. Hence, the relatively thickness of true tubeless (UST certified) tyres.

If I am not going to benefit from reduced risk of flatting with this then it kind of negates the main driver for the project and kills my idea dead. Is 70-80psi too much for the sealant to work? The tyres are neither skinny summer race only tyres or super heavy duty Marathon type tanks but, according to Continental, lie somewhere between the two extremes - http://www.conti-tyres.co.uk/road-and-track/clinchers/grand-sport-race

 

[Yellow Saddle]

@screenman are you talking about roadbike tyres here?

If I am not going to benefit from reduced risk of flatting with this then it kind of negates the main driver for the project and kills my idea dead. Is 70-80psi too much for the sealant to work? The tyres are neither skinny summer race only tyres or super heavy duty Marathon type tanks but, according to Continental, lie somewhere between the two extremes - http://www.conti-tyres.co.uk/road-and-track/clinchers/grand-sport-race

I just can't say if it will work, because there is sealant and sealant, and tyres and tyres. Even though you cited the specific tyre, I don't have on one hand to estimate by. But if you have all the stuff available, why not experiment? Fill the tyre with your desired brand of snot and zap it with an awl. Video or photograph it and post it here. It will certainly answer a lot of questions.
I've done similar experiments with Stan's sealant -a thin, latex-based sealant in a tubular tyre and it didn't work. It formed a mess between the tube and tyre and the plug shot out as the pressure was normalised after the initial partial deflation. If the goal was to get you home, I suppose it worked. I thought it was a mess and tubulars are an anachronism best forgotten.

 

[Andrew_P]

Having had a tyre bead break and the tyre blow off I wouldn't risk it. Stick the Conti on eBay and buy some Tubeless. Wiggle have been doing some cracking deals on Hutchinson tubeless I picked up 2 x All Season 25mm for £54 delivered.

Secondly if you believe tubeless manufacturer a standard tyre will leak air through the actual tyre, and a the bead in general are not reinforced so the potential is that the bead will snap and an immediate flat. I run tubeless in the first place due to a bead snapping letting a tube out and blew the tyre of the rim far enough that , midway though a 20mpg fast down hill semi right hand turn I had rim on road within seconds. Honestly if you have ever had that feeling of metal on road at speed in a corner you would never risk it again! I am reasonably confident that a tubeless with a massive puncture will still stay seated to give me half a chance of getting out of it but mostly even a fairly large hole will not be 100psi to zero in milliseconds..

I have been running tubeless on both my bikes for 3 years in Feb 2017 ands 16k+ miles. Some plus points and some downsides.

I have Stans sealant in both at the moment as I could buy the larger bottle locally and as per @Yellow Saddle Stans is struggling to plug holes while wheel rotating I have had to stop and let it stand with the hole at the bottom and then it will hold 80psi but go down to 30psi in hours. IMO is a low pressure product, they are promoting their race sealant at the moment. Orange is supposed to be good, but not tried it. Schwalbe Blue is supposed to be Stans and I got on better I think with the Hutchinson Protect air

 

[Andrew_P]

Lastly before you commit, take the conti off and put it on and then try and get a Schwalbe One 25mm tubeless on to your wheel and see the difference. Running tubeless for a while I have thumb muscles I never knew I had and a few broken bendy tyre levers!

 

[I like Skol]

Rapidly going off this idea, there seems to be more pitfalls than benefits. I don't really have any problem with the traditional tyre & tube system and puncture is only a minor inconvenience.

 

[Venod]

I run some Vittoria XN pro 31mm CX non tubeless tyres with Stans sealant on Stans Grail rims, they are fine at 40 psi, I did put 50 psi in once and whilst out riding the tyre blew of the rim, it was a very hot day and I had ridden up the canal towpath and then onto a tarmac path, the tarmac path was warm, I don't know if this produced a rise in pressure, the Grail rims are supposed to be OK with road tubeless, but I don't think I woukd risk the higher pressure of a road tyre with non tubeless specific tyres.

 

[Yellow Saddle]

Secondly if you believe tubeless manufacturers, [some paraphrasing done here for clarity] and a the bead in general are [is] not reinforced, then [potentially the bead will snap and an immediately [go] flat. I run tubeless in the first place due to a bead snapping letting a tube out and blew the tyre of the rim far enough that , midway though a 20mpg fast down hill semi right hand turn I had rim on road within seconds.

Pardon my paraphrasing here but I want to make it clear what I think I read and compare it to reality. A bead in a tyre is not what keeps it on the tyre i teh way you describe. It is not the bead's hoop strength that works against inflation pressure to keep the tyre on, but the bead's lateral pushing against and under the rim's hook that keeps it on the tyre. It is more than semantics, it is a big difference. This means, that even if you cut the bead (without doing too much damage to the tyre), then you can still inflate the tyre to full pressure.

The reason for this is not apparent, but I'll try and explain. Visualise how the air pressure inside the tyre pushes against the rim bed and the tyre with its bead, pulls outwards away from the rim wall. These two forces are opposite, but equal. In other words, the forces anchor themselves, for want of a better word, on the bead itself and the bead "feels no pressure either way - towards the rim or away from the rim. Like I said, this can be experimentally determined if a free force diagram doesn't do it for you.

However, we know there is still a net constricting force on a clincher wheel as it is inflated. This force is due to the shortening of the tyre over its length. The 45 degree angle of the cords in the tyre open up like a scissor jack when inflated. The tyre wants to go fatter but then the "jack" says it has to go shorter as well. This shortening is what causes constriction of the wheel when the tyre inflates.

A bead has to hook mechanically into the rim. Poor design on either one of these two components makes the bead lift, the tube escape and burst. Strangely enough, a tube has to be outside the tyre to audibly burst (explode). However, it retracts before the bead can retract and therefore most people think the tube bust inside the tyre.

 

[Andrew_P]

Pardon my paraphrasing here but I want to make it clear what I think I read and compare it to reality. A bead in a tyre is not what keeps it on the tyre i teh way you describe. It is not the bead's hoop strength that works against inflation pressure to keep the tyre on, but the bead's lateral pushing against and under the rim's hook that keeps it on the tyre. It is more than semantics, it is a big difference. This means, that even if you cut the bead (without doing too much damage to the tyre), then you can still inflate the tyre to full pressure.

The reason for this is not apparent, but I'll try and explain. Visualise how the air pressure inside the tyre pushes against the rim bed and the tyre with its bead, pulls outwards away from the rim wall. These two forces are opposite, but equal. In other words, the forces anchor themselves, for want of a better word, on the bead itself and the bead "feels no pressure either way - towards the rim or away from the rim. Like I said, this can be experimentally determined if a free force diagram doesn't do it for you.

However, we know there is still a net constricting force on a clincher wheel as it is inflated. This force is due to the shortening of the tyre over its length. The 45 degree angle of the cords in the tyre open up like a scissor jack when inflated. The tyre wants to go fatter but then the "jack" says it has to go shorter as well. This shortening is what causes constriction of the wheel when the tyre inflates.

A bead has to hook mechanically into the rim. Poor design on either one of these two components makes the bead lift, the tube escape and burst. Strangely enough, a tube has to be outside the tyre to audibly burst (explode). However, it retracts before the bead can retract and therefore most people think the tube bust inside the tyre.

My clincher the tyre came away from the beading enough that the tube could escape rub and then go bang, unfortunately I hadn't slowed down with the clicking before I went in to the corner! There is a picture on here somewhere and I found other people had the same problem with the tyre. My reason for converting to Tubeless was that it is stated that the tyre is likely to stay on even when flat and to date this has been the case I didn't convert on the basis of the bead although a faulty bead or user error caused my fairly big off I just wanted a chance of dealing with an immediate deflation and not have instant rim on road with no grip.

Although as I did say previously most suppliers do mention increased strength in the bead!

Pretty sure Hutchinson infer a strengthened carbon bead my assumption was from the sort of statements made by the people who make both clincher and tubeless tyres.


https://www.schwalbetires.com/tech_info/tire_types

Due to the necessary high inflation pressure for a road bike, it is absolutely impossible to convert classic tires to tubeless tires. A normal tire bead will not withstand these forces and the tire will almost certainly come off. Be sure to only use tires which are designed for tubeless fitting!

 

[I like Skol]

Having another ponder about this experiment today after yet another puncture in the Continentals

As this is rapidly heading towards me buying alternative tyres anyway I might get the stuff to do one tyre and see how it goes.