Rolling resistance

[warthog101]

I'm not sure if you can tell that from those numbers?

They aren't testing the tubeless tires with a tube as far as I can understand.

https://www.bicyclerollingresistance.co ... s-clincher

A comparison between tubeless, latex and other tubes. As you can see latex wins.

yes thats exactly why I asked here. If somebody has information about that. But the fastest tire is a tubless tire. So coupling that tire with a latex inner tube results into what?

You need to specify an equivalent tire and the circumstances - simply saying "xyz tire is faster" has no meaning whatsoever.

As an example......which is "faster"; a GP5000 TL with a tube, or a GP5000 clincher with the same tube? The answer is that the clincher is faster, because of it's construction.

Also a heavier set up than using clinchers, this is WW after all.
Given how tight the GP5000 TL's are, I'd hate to try and fit them with latex tubes.

I have read this in multiple places. So must be true for some combos.
Have prime rr v3 50mm carbons on my tcr. 19mm internal and 27.5 external
Have 25mm wide GP5KTL on the front and 28 on the rear.
Went on by hand. Seated with a track pump.
Roll and grip well. Durable. I'm sold on em.
I used Hutchinson fusion5 previously. Had to get the compressor out and also used CO2 catridges successfully.

[warthog101]

1.3 watts better latex tubed 25c v 25tl for a pair of tyres;
https://www.aero-coach.co.uk/time-trial ... tance-data
Good luck picking that.
I'll take the puncture resistance in preference thanks.
Granted the clinchers may be a mouthful or two of water lighter also.
Punctures shit me. I am happy to avoid them and still have a fast tyre.

[HenryH]

Why would Continental make two tires if the tubeless tire is faster in every configuration?

To sell more tires? Not everybody buys the fastest tires. I know guys that put Gatorskins on $2000 carbon wheels because they don't want to get flats. I've tried to tell these club mates that they are giving up 20 watts with those tires but they don't care.

I mean two tires that are supposedly the "same" - as in GP5000. If the GP5000 TL works better using latex than the normal one - then the normal one is rather pointless (other than possibly being easier to install). I see no reason why the part of the tire that touches the road would be any different between the two? Not that I know. TL got different beads and is thicker, but that shouldn't improve rolling resitance (would be my assumption - again I don't know).

Gatorskin is different as it isn't supposed to be the same as GP5000.

[Mocs123]

I'm legitimately intersted into what the advantages are of a GP5000TL with a latex tube vs. a GP5000 with a latex tube. Per Bicycle Rolling Resistance the puncture resitance is practicly the same (actually with the regular GP5000 winning by a razor thin margin without sealant. I can only assume that the GP5000 is faster than a GP5000TL with a tube installed, but I don't think I've ever seen a test done.

I've never fitted GP5000TL. but have fitted GP5000's on two bikes. One was the hardest set of tires I've ever installed on a bike the next bike I installed them on they wen't on by hand, no issues. Both were Bontrager wheels, though differnt models, and both were 700x25 tires. The first set I installed have 5K miles on them so I'm about ready to replace them and I'm not looking forward to it!

[MikeD]

I wanted because tubeless tires have lower rr. Just wondering if those are also achieved with latex tubes.

btw Im already running latex and GP5000 and I would never go back to butyl. Pumping every day is zero issue for me.

I'm not sure if you can tell that from those numbers?

They aren't testing the tubeless tires with a tube as far as I can understand.

https://www.bicyclerollingresistance.co ... s-clincher

A comparison between tubeless, latex and other tubes. As you can see latex wins.

There's only 0.8 watts per tire comparing latex to light butyl tubes. I doubt I'd notice that little difference in the real world. I'm using latex now but will probably switch back to lightweight butyl at some point. After about 3 days, latex tubes leak so much, the tires are almost flat. I'm wearing out my pump. Then, they don't take the heat as well as butyl.

[Hexsense]

I'm legitimately intersted into what the advantages are of a GP5000TL with a latex tube vs. a GP5000 with a latex tube.

There isn't, for most configurations.
Continental design GP5000 with 110tpi x3 layers (marketing as 330tpi) casing. This casing is not airtight (or even completely water tight) at all. Which is fine for clincher with tube inside.
But they also need to release tubeless version too because the market demand it. So, they revert to 60tpi casing x3 (market as 180tpi) for tubeless version.
The 60tpi casing increase weight by a lot. And it is less supple. Probably effect grip too as the tire conform less to the road. However, as we seen often in rolling resistance drum test, stiffer casing can test faster than a more compliance one.

The 180tpi version (tubeless) GP5000 has thicker and more secure tubeless bead. This can fit more secure on some loose rims. That's the only reason I can think of for someone to use TL version with latex tube rather than the 330tpi version (non tubeless compatible).

[tjvirden]

Why would Continental make two tires if the tubeless tire is faster in every configuration?

To sell more tires? Not everybody buys the fastest tires. I know guys that put Gatorskins on $2000 carbon wheels because they don't want to get flats. I've tried to tell these club mates that they are giving up 20 watts with those tires but they don't care.

Something I see quite a bit of, and practise myself on occasion, is putting on tires that have high rolling resistance not so much for improved flat resistance, but exactly because of the extra work required - this is not during competitive riding of course, but if you are considerably "quicker" than some of those you ride with it can work well. Of course, using lower pressure can also work and the risk of pinches is not huge using tubeless unless you really drop it down a lot.

I'm legitimately intersted into what the advantages are of a GP5000TL with a latex tube vs. a GP5000 with a latex tube. Per Bicycle Rolling Resistance the puncture resitance is practicly the same (actually with the regular GP5000 winning by a razor thin margin without sealant. I can only assume that the GP5000 is faster than a GP5000TL with a tube installed, but I don't think I've ever seen a test done.

I've never fitted GP5000TL. but have fitted GP5000's on two bikes. One was the hardest set of tires I've ever installed on a bike the next bike I installed them on they wen't on by hand, no issues. Both were Bontrager wheels, though differnt models, and both were 700x25 tires. The first set I installed have 5K miles on them so I'm about ready to replace them and I'm not looking forward to it!

One reason I might use a tube in a tubeless tire (other than after a non-sealing/non-bootable flat) is if I specifically wanted to reduce the chance of flatting from a cut sidewall - that's one thing sealant doesn't do well. However, I don't really think that's of much relevance to many people, and isn't something I actually do much of.

In my experience the GP5000TL has noticeable "bead creep" from new - after decent use the bead stretches a tiny bit and the tire is then easier to remove and reseat. At a guess, it settles after around 1200 Km.

The 5000 TL uses a 60 tpi casing (so 2x60 in the sidewall and 3x60 under most of the tread), as well as its "air-proof" inner layer, so it should offer marginally better flat resistance from those two differences, compared to the plain old clincher, at the cost of higher rolling resistance than could otherwise be the case.

Edit: sorry, duplicating some of what Hexsense has posted

[tjvirden]

...........
The 60tpi casing increase weight by a lot. And it is less supple. Probably effect grip too as the tire conform less to the road. However, as we seen often in rolling resistance drum test, stiffer casing can test faster than a more compliance one.
.........

I just can't quite agree with this - I can't think of having seen any test data that confirm it either; however my proposition is "absence of evidence". I'd be interested to hear Tom Anhalt's view, if we can persuade him to chime in.

[Hexsense]

I might interprete wrong from the data. But here is what I observe. It's not conclusive. Just what I see.

The ultimate property from the casing to achieve low rolling resistance is to have low energy loss. Doesn't matter if the casing is stiff or soft.

Most stiff casing have two things going for them:
-less deformation -> this reduce energy loss
-more material to deform -> this increass energy loss
The net result is usually more loss. But Continental can strike utopia of thin casing (low material to deform) that is structured such that it deform less than usual at low tire pressure.

Contrast that to many Vittoria tires.
Tire is soft and absorbant. But there is no stiffness in it at all. So, it tend to deform more than Continental tires. Net the more loss.

[tjvirden]

That's a very interesting explanation - I think I'll have to revise my ideas a bit.

Definitely, low energy loss is the goal. As you've pointed out, there's tradeoff between the amount of material and its deformation.

However your Conti-Vittoria example is a good one: Putting aside all the possible variables across manufacturers, I think what your suggestion comes down to may be the relative contributions to the losses from tread (the single biggest source of loss on most bicycle tires) versus other sources (casing [which includes fibres and elastomers], breaker and tube for non-tubeless of course). The Vittoria "Corespun" casings may, perhaps, be low-loss themselves, but if they allow the tread to deform more because they are less stiff, then that must result in a higher loss in the tread than would otherwise be the case. I find it difficult to make a 'quantified' guess though.

I wonder if this is at the root of the limitations of drum-testing. The Silca testing on a machine-roughened surface focused on pressure rather than tire type, but it might also be adequate to expose the effects of differences in casing construction. You just need that evenly milled road surface available for testing on!

One thing I would love to try is replacing the nylon fibres in a typical tire casing with Vectran or similar - that would be a specific test for the effects of casing tensile stiffness. I can't see it happening though. Definitely in the realm of marginal changes.

[uncle-gee]

Tubeless tires are still "in"?

Bought a bike early 2020 and it came with Tubeless tires. Pure junk. Always deflating, valves always clogged if not ejaculating sealant when trying to pump.
"Bring a spare tube in case the sealant doesn't work!" they say... Remove a Tubeless on the side of the road and try to put a tube; see what kind of mess it does.
I literally threw the wheelset into the garbage too embarassing to try to sell them. Never again.

[mgrl]

Tubeless tires are still "in"?

Bought a bike early 2020 and it came with Tubeless tires. Pure junk. Always deflating, valves always clogged if not ejaculating sealant when trying to pump.
"Bring a spare tube in case the sealant doesn't work!" they say... Remove a Tubeless on the side of the road and try to put a tube; see what kind of mess it does.
I literally threw the wheelset into the garbage too embarassing to try to sell them. Never again.

You don't sound crazy at all

[TobinHatesYou]

The 180tpi version (tubeless) GP5000 has thicker and more secure tubeless bead. This can fit more secure on some loose rims. That's the only reason I can think of for someone to use TL version with latex tube rather than the 330tpi version (non tubeless compatible).

Two other scenarios:
Most hookless rims should only be used with tubeless tires, so if someone wanted to run latex tubes on a hookless rim they would be using the tubeless version of the tire with a latex tube. Also the fastest tire besides the Veloflex Record is the Vittoria Corsa Speed, which doesn't come in a tubetype clincher version.

Of course neither is applicable to the GP5K TL...it's not hookless compatible.

[uncle-gee]

You don't sound crazy at all

Nothing too crazy to offer the best possible tribute to the worst and most frustrating piece of cycling equipment that I owned in the past 25 years

[tjvirden]

Two other scenarios:
Most hookless rims should only be used with tubeless tires, so if someone wanted to run latex tubes on a hookless rim they would be using the tubeless version of the tire with a latex tube. Also the fastest tire besides the Veloflex Record is the Vittoria Corsa Speed, which doesn't come in a tubetype clincher version.

Of course neither is applicable to the GP5K TL...it's not hookless compatible.

I'd love to know the thinking behind not being hookless compatible.
Starting from the perspective that Conti (surely?!) know more about wheel/tire fitment than cycling enthusiasts, what do they think the bead hook does, without an inner tube present?

If anyone has an EOL 5000TL, please could they cut the bead and post a photo that shows its construction? What I'm really wondering is whether it's an aramid-only bead.......