Weight Weenies

TobinHatesYou wrote: ↑

Sat Jul 20, 2019 12:00 am

You should probably try the tires. Everyone who has tried them on these boards has come to the same conclusion...the grip is that good.

This.

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There is a good reason jumbo visma put theses tire on their team bike on Giro rainy stage. We might not be Rossi on a bike but the grip of Corsa Control is damn reassuring.

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When people say that a tyre has good grip, how are they judging that? Surely you don't take each tyre you try around corners faster and faster until the point where you slide out? If not, how do you know that tyre X could take a corner 5% faster than tyre Y?

This has always confused me, but enough people say it that there must be some perception of grip that doesn't involve making holes in your bibshorts.

I’m with ya on that @jih. Unless you’ve taken each to the limit in a turn and gone down, I think it’s pretty hard to really ascertain how good the “grip” is, and even then there would be so many variable factors that might have pushed it over the limit that vary in each case. I a much bigger factor in the sensation of “grip” one might feel is due to the actual road conditions at the time. Is the road wet? Is it dusty? Has it been raining for days/weeks and the road is just “wet”, versus has it been dry for weeks, allowing car oils etc to just settle then along comes a light rain to make everything a super slick mess. Yeah, I think the actual tire patch itself plays a relatively small role in the actual grip one feels compared to the role the condition of the road surface plays.
I do know that I feel much more confident in a turn on tubulars than I do on clinchers, but I’ve never wanted to test just how big a lean or aggressive a turn I can make in order for me to go down, at least not on purpose.

jih wrote: ↑

Sat Jul 20, 2019 5:28 pm

This has always confused me,

Same here...

It might be those that have very low rr also lack stickiness. Result on bicyclerollingresistance.com seem to corrrelate this, not exactly what I feel on road but what I feel with the thumb. Veloflex compound for example is very graby, Vittoria less so, Michelin Power or 5000 even less so. Coincidentally, I got a really unexpected fall on Powers. It involved a smooth concrete element but still, I had a decent angle and sufficient speed. I can also feel them gliding easily over the polished floors in my building.

It's subjective - just like the majority of everything else we argue about on forums.

FWIW, I've ridden only Veloflex tubulars the last couple years. I just threw some Corsa Control tubs on a set of wheels (because 30mm) and I have been super impressed by the (perception of) grip and the comfort. I'm a pretty handy bike handler, so it's not saying I was lacking any confidence or grip previously - these just feel pretty tremendous.

More relevant to the intention of the thread - I'm actually going to give the Corsa 2.0 TLR a try now. Due to arrive this week while I'm out of town. It's been a few years since I tried tubeless and, at the time, I tried the "best" Schwalbe available and the whole experience was terrible. I'm eager to see if the technology has evolved enough that I can actually enjoy riding this setup tubeless (aiming for more comfort) or if they'll end up on the wife's bike and me sticking with tubular. (To be clear, not entirely ditching tubular regardless of how this experiment shakes out).

Alexandrumarian wrote:

jih wrote: ↑

Sat Jul 20, 2019 5:28 pm

This has always confused me,

Same here...
... I can also feel them gliding easily over the polished floors in my building.

Ha, in order to try and test this once (safely), I took two wheels, one mounted with a Continental Competition and the other with a Veloflex (both tubulars). My kitchen floor is hardwood and I just kind of leaned them over gradually with the same pressure (not tire pressure but rather just pushing them out till they lost grip)until they would slide out. Ha, totally just for fun and curiosity. But it did seem like the Conti’s just would adhere a little bit longer. In a real life turn would it have mattered... probably not. But I do remember that one particularly wet Giro d’Italia, the Conti Comps (ltd edition pro only version with latex tubes) seemed to be the tire of choice for an awful lot teams during the heavy rains, even blacking out the Conti brand name if they weren’t sponsor correct. And I do like them for the winter, although I would never take one as spare for fear of actually ha omg to mount it in the wild. Although, it seems a lot of tubeless combos have that issue as well from reading what everyone’s been saying about how difficult they are to mount. It can only be harder in the wild, especially if they don’t play well when trying to reseat them etc.

jih wrote: ↑

Sat Jul 20, 2019 5:28 pm

When people say that a tyre has good grip, how are they judging that? Surely you don't take each tyre you try around corners faster and faster until the point where you slide out? If not, how do you know that tyre X could take a corner 5% faster than tyre Y?

This has always confused me, but enough people say it that there must be some perception of grip that doesn't involve making holes in your bibshorts.

It's generally not that hard to find the limit of adhesion, particularly for the rear tyre, and particularly under braking. And while trail braking is not the best thing to do when you are trying to maximize cornering traction, it does happen, more frequently on the road you don't know like the back of your hand, where judging the corner, camber and surface grip in advance is a bit of a challenge. So yeah, I do get rear lock ups and/or slides on occasion - once upon a time even remember my rear skidding out under me far enough, MTB style, to hit the rim (no damage and no fall, mercifully). And even with the front, you can feel it getting a bit squirrely under load in a turn, sort of maintaining the line but just barely and making small micro-slides on the tarmac - the actual limit admittedly being much harder to test without takin a spill. You could also stand up in the pedals in a steep-ish and damp or wet road and get your rear wheel to spin pretty easily. All of these instances do add up to your impression of a tyre grip, and the confidence with which you take the next corner or how hard you think you can brake. Usually the differences between tyre makes in this regard are very marginal. So it's rather hard for me to say whether, for example GP 4000s II has a better grip than Mavic Yksion UST (I think the former, but it aint' much). And then you put on Vittoria Corsa 2.0s, and all of those slides, slips and spins, even while braking in a manner that that you know would have previously resulted in a complete rear lock up (e.g.: panic stop before some douchebag very nearly opens the car door in your face) simply disappear. And suddenly you cannot find the limit of adhesion anymore, even while pushing through corners more aggressively, braking later and harder than usual and all of that - the tyre just stays planted. Then you know you've got a better gripping tyre.

It's not a tyre without compromise. I do wish they actually managed to improve RR on the Corsa's like they did with the Corsa Speed 2.0, and it'd be nice if it weighted a bit less (though those 50g per wheel of difference are vastly overrated as a performance differentiator). But as things stand, like THY, loosing a couple of watts of RR while gaining that grip is a trade off I will make. YMMV though.

jih wrote:When people say that a tyre has good grip, how are they judging that? Surely you don't take each tyre you try around corners faster and faster until the point where you slide out? If not, how do you know that tyre X could take a corner 5% faster than tyre Y?

This has always confused me, but enough people say it that there must be some perception of grip that doesn't involve making holes in your bibshorts.

I stopped to think about this today as well. I don't rail down tight switchbacks on a daily basis, but when I do, I back off way before I get to the perceived limit of tire grip.

I assume a more "supple" tire gives a ride which is perceived as "softer", which in turn inspires confidence. It may actually be grippier as well.

About grip I test it at a hairpin (180deg), with Corsa G2.0 I can take it at 30km/h vs 25km/h for a 120tpi tire with the same confidence basically.
That is not the limit of the tires but you can feel the difference. In wet conditions it would be even more noticeable.

Here’s an idea ... Let’s ask Hambini to do controlled skid pad testing on all these tires and then post the results. That’s about the only way we’d know which has “more grip”. Of course, that won’t work because people would criticize his results endlessly.

But grip does vary. My main bike with 32 mm Bontrager R3s at 55/65 psi feels substantially more planted in the corners than the 25 mm GP4000s at 100/105 psi I’m running on my second bike. I attribute that to the size of the contact patch more than the rubber compound or anything else. Of course, I go out of my way to avoid approaching the point of wheel slip so I’ll never know where the limit is.


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You can do static tests too by leaning your bike and applying a constant amount of force at decreasing angles until the bike begins to slide.

This reduces the number of variables as the force, the road surface, etc. will be constant.

But yes like I said, before the Corsa/Corsa Control G2.0, I attributed perceived differences in grip in the top race tires to placebo.

Alexandrumarian wrote: ↑

Sat Jul 20, 2019 5:44 pm

jih wrote: ↑

Sat Jul 20, 2019 5:28 pm

When people say that a tyre has good grip, how are they judging that? Surely you don't take each tyre you try around corners faster and faster until the point where you slide out? If not, how do you know that tyre X could take a corner 5% faster than tyre Y?
This has always confused me,

Same here...

I can feel it. The best way I can describe it is when the bike is leaned over, the connection to the road feels more direct as traction gets better. The best traction feels really hooked up, like being on rails - there is no lateral give. Less good traction has a "fuzzy" feel to it, like the tire is drifting a bit.

What's interesting is my brain responds to the sensation almost subconsciously and I feel safer and more confident when the traction is good. If something isn't right I start to feel a touch of anxiety and find myself backing off a bit in the corners. I'm sure many of us who spend ridiculous amounts of time riding and pushing the limits have this same experience.

Re: mounting tubeless in the wild. In most cases even the most problematic tire will have sufficiently stretched. The GP5Ks were horrid to mount as new tires on ENVEs, but removing them was super easy. Remounting then was even easier.

Still another tally for the Corsa TLRs vs GP5K TLs if mounting ease is important to some. It’s fairly important to me, just a nice cherry on top of a tire that I already like.

And at that point, if it’s stretched enough to be easy to get on then you might have the issue of getting it to seat and seal properly, especially without the use of a compressor. To be honest; the guys I’ve seen who run tubeless and have a puncture on the road that the sealant doesn’t seal, end up faffing about way more than if I’d had to replace a tubular. Especially if sealant’s getting everywhere while they try to stuff a tube in, if they even have one (cuz of course you don’t need a spare tube with tubeless, until you do). I know you guys talk about plugs and worms and stuff, which would be good if they work, but seems folks still like to carry a spare tube just in case in a lot of cases. I think I’d carry both, for the same reason I carry a spare tubular. But it just seems like a lot of hassle compared to a simple nice dry (no sealant) innertube along with a super supple clincher like the SpecialIzed Turbo Cotton. And after the 5 minutes it takes to replace the tube, it’s done. No having to remove a gucky coated tube once you get home and start the entire process all over again. Just kinda waiting for people to start saying... “why are we doing this again?”

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