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tubeless tyres

Posted: 16 Jul 2014, 12:14pm
by simonineaston
Earlier today, I posted on the subject of recommendations for touring tyres... after a quick wander round t'internet I see I am behind the times - we have entered the world of tubeless tyres without me noticing!
Anyone link me to a quick primer on the subject, or maybe Brucey would be kind enough to write one of his essays?! ;-)
Only joking Brucey - you're as entitled to a day off as anyone!! :lol:

Re: tubeless tyres

Posted: 16 Jul 2014, 7:03pm
by reohn2
Other than weight saving I can't see any other plus for tubeless.
If I puncture I have to either repair the tyre,by fitting a patch on the inside of the tyre for small thorn type punctures,or fit a tube and tyre boot for a bigger cut/slash etc.
Add to that having to make an air tight seal between rim and tyre every time the tyre is deflated making things even more complicated,tubeless don't seem to have a lot going for them :?

IMO tubeless tyres may have a place in racing but other than that I can't see them being worth the hassle TBH.

Re: tubeless tyres

Posted: 16 Jul 2014, 7:11pm
by Mick F
reohn2 wrote:Other than weight saving I can't see any other plus for tubeless.
There's simplicity too.

I've said on another thread that punctures are rare for me, so if a tubeless tyre could be produced that is even more puncture proof than the tyres I use now, it can only be a good thing.

Trouble is, won't tubeless tyres have to go on tubeless rims?

Re: tubeless tyres

Posted: 16 Jul 2014, 7:19pm
by Mr. Viking
Mick F wrote:Trouble is, won't tubeless tyres have to go on tubeless rims?

yes, I would guess they are more difficult to maintain at home. I was having a look at them until I realised new rims would be needed.

Read something about a sealant system that can be used, but it seems very fiddly and doesn't satisfy me it will be more leakproof than tubes

Re: tubeless tyres

Posted: 16 Jul 2014, 7:50pm
by robc02
Trouble is, won't tubeless tyres have to go on tubeless rims?


http://www.notubes.com/Road-Tubeless-C78.aspx

Not so staightforward as with mountainbike tyres, though - have to use tubeless specific tyres. I wonder how it would work with 37mm, or thereabouts, tyres which are somewhere in between "road" and "mountain"?

Re: tubeless tyres

Posted: 16 Jul 2014, 8:15pm
by iandriver
Just watching the tour de France. They all use tubs and seem to get their fair share of punctures. Unless I can get the wife to follow me around in a Skoda with mavic written on the side, I'd probably give 'em a miss.

Re: tubeless tyres

Posted: 16 Jul 2014, 8:29pm
by mattsccm
Seems to me that people are mixing tubeless with tubular. Tubs are tubular and have an inner tube stitched in side and are then glued on.
Tubeless is the same as your car. Can't see many people objecting to them. Its just a bit mark one at the moment. Tubeless does to a great extent remove the pinch puncture. Not for everyone but equally not anything wrong with them

Re: tubeless tyres

Posted: 16 Jul 2014, 9:16pm
by reohn2
mattsccm wrote:............. Tubeless does to a great extent remove the pinch puncture.

But I've never had a pinch puncture.

Not for everyone but equally not anything wrong with them

There's a list in the above posts.

Re: tubeless tyres

Posted: 16 Jul 2014, 11:20pm
by Brucey
I'm not right for it, not on bicycles.

Some MTBers love them but when you do have to deal with them there is all the stinky gloop to deal with... yeuck. If there are major benefits in terms of reduced Crr, less weight etc I can't really see it myself. There might be a benefit in terms of punctures, but I note with interest that the people that really love them were the ones that could never find the thorns in their tyres. If you are getting pinch flats then you are doing something horribly wrong and/or you are a gnat's away from boshing your rims in anyway....

So as yet I can't really see the point.

A significant downside is that (in MTB form anyway) they leak air. You need to pump your tyres up every ride with some systems. And if the tyre comes off the rim mid-ride, you usually can't reseat it using a hand pump. I think some systems use a profiled rim and better tolerances but this just makes the tyre a right PITA to get on and off. A possible benefit in these cases is that the tyre won't easily come off the rim when you get a flat, so theoretically you have a little more control in the event of a blowout.

A friend punctured on tubeless in a race and found they couldn't get the valve stem out of the rim, which made fitting a tube impossible. They had to pack because of this.

If you consider the self-sealing in the event of a puncture a compelling advantage, you can fit tubes with gloop in them that do the same kind of thing. When they finally give out most of the gloop is still in the tube, so you can bin it and there is no stinky mess. It might be a little heavier but it is a load easier to live with.

cheers

Re: tubeless tyres

Posted: 17 Jul 2014, 8:22am
by Thomas125
I'm sure I read somewhere that tubeless give a more compliant ride, kind of similar to latex vs butyl tubes I guess.

I've no experience of them though so can't comment on how significant this would be. Might be a factor worth considering.

Re: tubeless tyres

Posted: 17 Jul 2014, 10:48am
by simonineaston
I found this last night which is quite informative once you've made allowances for the fact it's written by a manufacturer...
http://www.schwalbe.com/gb/road-tubeless.html

Re: tubeless tyres

Posted: 17 Jul 2014, 11:11am
by Brucey
In response;

Schwalbe wrote:We have worked for a long time on a road bike tubeless tyre and are excited about the benefits. The tyres are extremely fast. Tyre and tube are combined in one component and this saves a lot of unnecessary friction, making rolling resistance even lower than the super lightweight Ultremo ZLX.


well, let's see some proper data then...

At the same time the tyres are extremely safe. There can be no sudden air loss caused by the tube bursting, as it is no longer there.


duh.... this isn't what worries me, it is a the carcass failing that causes the worst kind of blowout. This is a bit of a red herring.

Resistance to Snake Bites is almost doubled.


are you sure you were using the right tyre to start with? If you start having incidents that would normally cause a snakebite, each and every one risks carcass damage and therefore the worst kind of blowout. Snakebites can be regarded as nature's way of telling you that you are doing something stoopid, and that you should stop right now.

Tubeless tyres combined with puncture protection liquid offer optimal functionality, making the tyre more resistant to punctures.


than what? A slime-filled tube would work as well for most users...?

Lower pressures are possible with tubeless tyres and with a little less air pressure, they exhibit much better riding characteristics, especially on degraded pavement where tyres can have much better road contact.


yada yada yada.... you need to be running wider tyres to allow this without other problems and then the tyre would surely (by current standards) be at risk of being regarded as 'underinflated' and incapable of carrying the same kind of load safely. Schwalbe tyres (like most others) already tend to fail in various interesting ways if they are run underinflated. Without some examples and data this is just a lot of words; a lot of words that could encourage people to run their tyres in such a way as to encourage blowouts.

If there is any good data concerning Crr changes then I'd like to see it. Otherwise their claims don't really make sense; if you are running low pressures and avoiding snakebite punctures etc then other forms of carcass damage seem more likely and this will mean more blowouts, not fewer.

So, I for one still need to be convinced about 'the benefits'.

cheers

Re: tubeless tyres

Posted: 17 Jul 2014, 11:41am
by keithb
Though I run tubes on my MTBS, I believe the primary benefits of the tubeless/sealant systems are:

1: Ability to run lower pressures without risk of pinch-punctures. This provides increased grip through larger contact patch and easier deformation of the tyre due to the lower pressure.

2: Improved traction from better deformability of the tyre itself compared to tyre/tube combo (as stated above - frictional losses)

3: Reduced risk of thorn punctures due to sealant in tyre.

Now, there are definitely downsides to tubeless systems (messy, leakage, cost, faff, sealant life, "burping" at very low pressures) but it is actually quite a mature technology in MTB terms, with acknowledged benefits (note that I didn't use the word proven there...).

Weight is a bit of a red-herring, as the tyres are heavier, and the sealant weighs something, off-setting the removal of the tube form the system, I believe.

Generally, if a tubeless system goes wrong on a ride, (ie puncture too large for sealant to work) people tend to throw a tube in, but the frequency of punctures requiring intervention is, generally, much reduced.

The application to road bikes is potentially somewhat less beneficial as pinch punctures are a relatively rare occurrence, and the traction benefits are likely to be less pronounced due to the (relatively) smooth surfaces involved.

Cheers,
Keith

Re: tubeless tyres

Posted: 17 Jul 2014, 9:17pm
by RJS
Just a small point, a friend is running a disk brake Linsky, with Stanns rims, but tyres and tubes, he has found that the lack of a well in the rims makes it very hard to get a tyre off in the case of a puncture, so a tube back up might suffer similarly.
Cheers, Rob.