rubiksoval

You keep regurgitating the same nonsense and not a single person agrees with you.

Really, what's your point, here?

Go ride slow. No one here cares.

rubiksoval

Nah, we know.

aclinjury

no one cares huh? keep affirming to yourself that, cat1. You seems to be invested in this responding to me, 3 consecutive post in a row in short span, all dedicated toward me. Fragile ego much, mr cat 1 cyclist? lmao

rubiksoval

Don't confuse my lack of concern for your below-average riding exploits as investment.

i'm just here for the lulz. Still hoping for that fourth .

genejockey 

Road Cycling Subforum - Come for the cycling information and camaraderie, stay for the endless urination competitions.

rubiksoval

On bike?

guadzilla

To be fair, he clarified his point in a subsequent post - for him, the slightly lower RR of GP5ks isnt worth the reduction in cornering confidence and ride quality. That's fair enough.

For someone who isnt at the pointy end of things, riding comfort and price are reasonable tradeoffs to make vs marginal gains. I ride GP5ks on my TT bike instead of Corsa Speeds because for my MOP ass, I'd rather give up 15-20 seconds due to the tires than risk losing 5 minutes due to a flat (especially given what utter bastards TL tires are to mount and dismount).

guadzilla

Paging triathletes... yo Bah Humbug , you are up.

colnago62

I agree. It does tend to derail things sometimes.

Bah Humbug

Never once done that. I know it happens, but I haven't.

Bah Humbug

Eh, that's still just part of the same decision matrix that he claims leads to analysis paralysis when applied to RR; he's taking a pile of data and picking the tire he thinks will serve him best. I still tend to think he's wrong; I've run GP4000S, SII, GP5000S, multiple Michelins, Hutchinsons, and VIttoria Corsas, and damned if I can find these supposed handling issues. Maybe they exist, but I have a hard time taking it seriously.

merlinextraligh

The mounting issue is a matter of technique. Once you know how to do it, they aren’t difficult. Key is the side of the tire that’s on first has to be pressed to the center, which is lower than where the tire seats when inflated. If you allow that side of the tire to seat before you get the second side on, it can be extremely difficult.

Same thing taking them off, you have to push in and unseat the offside first.

oh and sorry to interrupt the peeing match, I hadn’t gotten this far reading when I posted. Please carry on

NoWhammies

Thanks merlinextraligh I'll keep my eye out for when the tyres go on sale again. Maybe I'll pick up a set. Cheers,

aclinjury

because I was replying to this thread with the OP's original question in mind. There is a value judgement at play.

As I see it, people in here take one aspect of tire performance (rolling resistance) in a lab and bank their entire argument on it to a question asked by someone asking a question involving value and tradeoffs. People in discussing in "absolutes" about equipment performnace in a TT (a pretty damn specific discipline), is not answering the OP's question about value and tradeoffs, does it?

But if you wanna talk competitive race scenario (not the OP's position), then I expect that in a high competition, everyone is on the same or very similar equipment already. Just look at Rchung's example, the top finishers are so precisely bunch together should clearly indicate that they're on very similar equipment, then there's not much gains to be had from an equipment route anymore (not if you keep using the same data and approach). There is absolutely no guarantee that tires alone will make that difference at a highly competitive event.

This whole "rolling resistance" emphasis being forced on newbies and weekend warriors is approaching a bit ridiculous level. There's also a lot more aspect to riding, like cornering is fun too. But speaking of "science", I haven't head anyone discuss about using different tires for the front and rear? People just casually talk as if there's not gains to be had by going this route? Surely, the front and rear tire/wheel operates in different set of forces and that slapping the same tires on the front and rear may not be optimal? But I digress from rolling resistance, aren't I

WhyFi

It's funny that you keep saying that people are making it in to a one-aspect argument; this is a summary of the first five posts that discuss the tire attributes -

It didn't turn in to a rolling resistance pissing match until you came in banging on the "it doesn't make a difference" drum.

Steve B.

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.

aclinjury

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??

guadzilla

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..

WhyFi

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.

guadzilla

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!

aclinjury

(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.

asgelle

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?

aclinjury

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.

rubiksoval

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?

aclinjury

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