I just installed new GP5000’s last night, replacing 25mm GP4S’s. Did a fast 2 hrs today and can say I do feel a difference. The 25mm 5000’s are actually 24.5mm on some older Mavic OpenPro rims that are 19.5 external width. The GP4S were 27mm. I could run a bit less air in the GP4S, but still felt like the 5000’s were smoother, less road buzz. Faster ?, anybody’s guess as that’s as much a result of how strong I’m feeling that day. Like the feel of the tire though. We will see how well they hold up, the GP4S were bombproof.

Why don't you go back and read the OP's original post and see if you have answered his question in the context of his question? Do you understand context?
Sometimes you have to take what people claim to be the difference with a grain of salt. People will say "the difference is quite noticeable", notice how vague this is, with hardly any realworld eviddence to back up this "noticeable difference"? And notice that in the lab (a controlled evironment), the difference is more like 1 second per kilometer? Is this what a big difference to the OP, in the real world?

Well "noticeable difference" demands noticeable proof. Convince me of such claim when someone get on the same bike, wore the same kits, with a power meter, and ride on a the real road for say 10 miles back and forth on the same stretch of road (to account for varied conditions encountered in the real world). Show me the telemetry of such experiment? And I have not even talked about cornering feeling yet, which does make a difference if you're fighting for position? Show me the hard real world evidence that 1) there is a difference, and 2) that difference is meaningful in the context of the OP's question.

Is this NOT a fair question to ask? or am I expecting too much from the scientists in here??

Fair enough - but each to his own. As i said early on in this post, I am one of the few people who has never bonded with the GP4k/5k series. For my daily riding, i prefer the Turbo Cottons and Veloflex Corsas, which purportedly have a slightly higher RR than the GP5ks - the few watts more or less dont matter in that case, and I just like how these tires feel (placebo or not, I cant say).

Speaking for myself atleast, I "get" the idea of someone making a non-optimal decision in terms of RR in favor of other, most subjective factors - especially in a non-racing setting. For race day, I agree it would be silly to use a less-optimal tire when racing. The one exception is people racing 70.3s in M45-49, where i recommend Gatorskins as the tire of choice..

I'm directly responding to your assertion that others have done the OP a disservice by making it a one-aspect comparison. They have not, as I have clearly shown.

As far as answering his question in context, yes - they clearly did that, addressing multiple aspects (RR, grip/handling, durability, longevity, etc) before you came along.

Looks like I've got a much better handle on it than you.

Actually, if i can go slightly OT - anyone here running GP5ks on a 21mm inner diameter rim - if so, can you share whether you are using as 25 or 28, and what the meaured actual width of the tire is?

TIA!

(I edited my post after you have replied)

But.. you're wrong buddy. Do you see any real world substantiated claim in here? None whatsoever. Rchung is the closest person to actually post something that could be used for analysis, but his data is not real world, is it?

I guess doing rigorous science to back up bold claims is not something most folks understand huh? Except for Rchung, the bro-science is strong in here.

In the 30's when so many Hungarian emigres were at the forefront of physics it was said that they were really aliens from another planet. That said, I've never heard anyone suggest Robert was from some alternate universe. If you think his results are not real-world, what world do you think they're from?

matter of fact I have the 25mm gp5k on a Zipp 30 (21mm inner diameter). It measures out to just over 25mm when pumped to about 80 psi. The GP5ks run smaller than their GP4ks for sure. I use it as my rear tire for wear. Front tire is Veloflex.

And btw, I just got the new Veloflex Corse tires (just relreased recently). It's nice. Feels almost as soft as their older ones (which you may have?). The newer ones use a slightly thicker bead (for safety with carbon rims), so it's a tad thicker and heavier. But still more supple compared to the GP5k, a lot more.

Your questions have been answered, your incorrect assertions refuted, your lack of knowledge and skills pointed out, yet still you reside.

Your resistance is epic, perhaps why you eschew acknowledging it in tires so much?

Don't be pedantic, read my previous post to WhyFi about "real world" data.

Got it - so you're moving goalposts wherein subjective, real world observation need to be quantified but stuff quantified in a lab setting don't count. ******g excelling work, man. :thumb:

i'm replying to say i'm done with you! It's obvious to me you don't understand science rigor, even though you pretend to talk science. Comical. Out!

Don't tease us.

So no real world evidence from you, either? Got it man, it's ok, I don't expect most folks to understand real science. Hey let's stick to broscience, okay!

Let's look at the the OP for context...

Funny. I'm not seeing any requests for observation if and only if it's backed by robust data. :foo:

Thanks! I am sticking to 24mm Turbo Cottons on my CLX64s, but was thinking of putting GP5ks on the CL50s, which are my daily riding wheels. They are 30mm OD, so i am hoping the 28mms will fit them well enough.

That said, they arent my favorite tires either, and you now have my interest with this talk of the new Corsas. Are these the new tubeless versions that were announced recently? I gave my last pair of Corsas to my wife a couple of months ago - I have a pair of Wolfpack tires that are next in queue, but if the new tubeless Corsas have the same ride feel as the older ones, may jump on a pair as well.

The only real science that ANYONE has presented here has to do with rolling resistance. Everything else, including everything you've posted, is either subjective, or so loaded with uncontrolled variables as to be impossible to analyze. And yes, I do understand "real science" because it's what I've done for a living - and a pretty good one - for the last 4 decades.

I, for one, have found this thread particularly entertaining.
Thanks Bike Forums!
:thumb:
https://live.staticflickr.com/65535/...bb2aa1e7_o.pngmotivated_reasoning_olympics_2x by Richard Mozzarella, on Flickr

There it is.

:lol::lol::lol::lol:

I run GP5000 32c on 21.5mm wheels they ended up at about 32.75mm after they stretched out. So, much closer to stated width than the GP4000s II where a 28c on the same wheels ended up at almost 32mm.

Do you mean scientific rigor?

This is still going?

Veloflex new Corsa come regular clincher and tubeless clincher. I just got the regular clincher ones. But my buddy got the tubeless version. I haven't time to try out neither version yet so I can't really say much about how they ride. But but what I can say for fact is that based on weight and "feeling in my hands", the regular clincher is lighter (by ~30g) and more supple than their tubeless version, and this is to be expected. But if you think about it, their tubeless version being 30g lighter is actually very impressive, my only question is how will they wear for a tubeless tire (because generally, if I were to go tubeless, I wouldn't want it to be tooooo light due to fasting wearing AND possibly not sealing as well).

ok boys, i'm done arguing back and forth. I think i've stated my point clear by now.

This is for the OP (if he's still reading this thread!).

OP, by now you've heard "less rolling resistance = free speed". Well, no it's not free speed. What you're looking at is paying for more then DOUBLE the price for a set of tires, for 1 second of speed in a kilo based on a controlled test. Real world just riding around, hard to say if you'll get that 1 second or if at all.
But the price you pay is a real one, guaranteed to happen. Ultimately, less rolling resistance, in this case, is not free. There's a $$$ cost.

Free speed only is free if you pay for another set of tires at the same price and get to go faster. That's when it's truely free speed.

Are you sure that it wasn't a glute injury? 'Cause you don't seem to know your ass from your knee.

I thought you meant because he was butt-hurt. :roflmao:

For me, my thought process is the opposite - if i can run a lighter tire (like the Veloflex Corsa or most specifically, the Vittoria Corsa Speeds) tubeless and get better sealing in the event of small flats, that would be fantastic. I'd love to be able to use Corsa Speeds as my race tires.

The good thing is that the Veloflex tires are available at a pretty neat discount, so it's relatively low risk to pick up a pair and try out. Will order one as soon as i wear through the current tires on my Venge.

couple of pics,
New veloflex on the right, old one on the right. Both 25mm.
New one, 212g. Old 207g. These are regular clincher. The new tubeless clincher is 21g heavier than the new clincher (not 30g like I said earlier).
The inner side look and feel very much the same,
Here are some obsrvations. The new one is a tad thicker in the middle, where the meat of tire is (probably good for wear). The bead of the new one is slighter tougher (Veloflex said for compatiblity of all carbon rims, no exception like Enve). The tubeless version just feels a tad thicker and heavier.
Veloflex claims that the new clincher has a lower rolling reistance, right. If you just compare the tread pattern alone, you (well, I) notice that the new thread pattern is not as aggressive as the old one (you can feel this by running your fingers up and down the thread), makes me wonder if rolling resistance is mainly due to changing tread pattern, but hopefully this won't compromise the new one's handling? we'll see
https://cimg0.ibsrv.net/gimg/bikefor...515a2014db.jpg
https://cimg2.ibsrv.net/gimg/bikefor...9ade51d246.jpg

Damn, now i am seriously jonesing for a pair to run tubeless.... thanks for the detailed photos!

On a different note, since we are talking CRR, here is an interesting article:
https://blog.silca.cc/part-4b-rollin...-and-impedance

It shows the difference between the theory of drum tests vs actual riding on the road (where what they call "impedance" also starts to play a role). There are a couple of interesting take-aways that I see here:
1) It is better to err on the side of tire pressure being a bit too low vs a bit too high
2) Tires with more supple casings tend to have lower CRR and also more forgiving of over/under pressure

Does that level the playing field in the rear world, for tires like Turbo Cottons, which test 2-3W slower than GP5ks in the drum test but have a much more supple casing?