New tire rolling resistance test - 23mm, 25mm, 28mm & 32mm GP5000 tires

[froze]

Originally Posted by pritchet74

If you do long twisty descents that require heavy braking then don't do it. The rims can heat up and cause the tubes to POP. Otherwise do it. I use latex with my carbon clinchers and don't worry about it at all because I never ride where I would have a long twisty descent that would require heavy braking, so my rims don't get hot.

But if you're riding on aluminum rims descending long twisty mountain roads you have no worry about latex popping, I did that for years in hot S California mountains and never blew a latex tube...but that was using AL rims which dissipate heat far better than CF rims. But that does make me wonder about something, if the pros are using CF rims and latex tubes racing in mountains why aren't they worried about the tubes popping?

[vincenz]

Originally Posted by El Chaba

I concluded some time ago that the move to wider tires for the road was largely driven by the search for something...anything...that could mitigate some for the extra stiffness that was characteristic of the uber-oversize tubed frames that have come into fashion. It was convenient that a larger tire could be run at a slightly lower pressure for some comfort gains without a big hit in increased rolling resistance.

I agree, and also the larger tube shapes are more aero, which leads to the same shape developed for wheels, which tires could then match, and all made possible by better rubber technology.

What I would love to see is a plastic bike developed to have the SAME comfort of ti or steel, but with the aero properties and lighter weight.

[ColnagoC59]

i've thought about this.

Ride what feels good and makes you happy. For 99% of us none of this matters.

[Mark McM]

Originally Posted by froze

But if you're riding on aluminum rims descending long twisty mountain roads you have no worry about latex popping, I did that for years in hot S California mountains and never blew a latex tube...but that was using AL rims which dissipate heat far better than CF rims. But that does make me wonder about something, if the pros are using CF rims and latex tubes racing in mountains why aren't they worried about the tubes popping?

The pros are by and large still using tubulars. Their tubulars have latex tubes, but the tubes are insulated from the rim through several layers (glue, base tape, tire casing), as compared to a clincher, where a portion of the tube may be pressed against the rim sidewall. If the pros need to worry about anything regarding brake heat, its melting their tubular glue. (Rolled tires due to melted glue is a rarity with well glued tubulars, but it can still happen.)

[vincenz]

I believe tubulars are used by pros also because they are safer during a flat vs clinchers.

[saab2000]

Originally Posted by vincenz

I believe tubulars are used by pros also because they are safer during a flat vs clinchers.

They're also lighter and not insignificantly if that matters to anyone. But yes, deflated safety is not to a disregarded.

[sfo1]

If pro's had to change their own flats, tubs would have been abandoned decades ago....

[Mark McM]

Originally Posted by vincenz

I believe tubulars are used by pros also because they are safer during a flat vs clinchers.

And more specifically, they are safer to ride during a flat vs clinchers. Most cyclists have no reason to ride a flat tire, so being able to ride on a flat makes little difference.

[Mark McM]

Originally Posted by saab2000

They're also lighter and not insignificantly if that matters to anyone. But yes, deflated safety is not to a disregarded.

The small difference in wheel weight is insignificant, and besides, the lower rolling resistance of clinchers more than makes up for the weight difference (even when climbing and sprinting).

[froze]

Originally Posted by Mark McM

The pros are by and large still using tubulars. Their tubulars have latex tubes, but the tubes are insulated from the rim through several layers (glue, base tape, tire casing), as compared to a clincher, where a portion of the tube may be pressed against the rim sidewall. If the pros need to worry about anything regarding brake heat, its melting their tubular glue. (Rolled tires due to melted glue is a rarity with well glued tubulars, but it can still happen.)

Silly me I should have remembered that about tubs insulating the heat, thanks for the reminder.

I did hear of people who melted their glue, but mostly this occurred with tandem riders who were running tubs back in the day descending mountains, but some of those guys didn't know how to brake to try to prevent that by alternating brakes and stab braking; and some got the idea of using a rear hub drum brake in addition to rear calipers, the hub drum brake wasn't designed to stop the bike, it was more like a drag brake to slow down the bike a bit on long descents so to take some of the heat off the rim, but I don't recall too many using that drum brake I guess because of the added weight.

I looked up the cost of those Conti 5000's...ok then, I won't be spending about $150 for a pair of tires that's for sure, my god man a pair of those tires cost more then one tire for my pickup truck! And the tires on a vehicle are far more technologically advanced with far more material to make it then a bicycle tire.

I

[zap]

Originally Posted by Mark McM

And more specifically, they are safer to ride during a flat vs clinchers. Most cyclists have no reason to ride a flat tire, so being able to ride on a flat makes little difference.

We had a front tire blow out (@ 35mph) on our tandem as we were on a slight descent.........one of several thoughts during the event was.........wish we had tubulars. Aluminum rim (tire just got shredded) on pavement is pretty damn slippery........especially when you need to turn in order to avoid that guardrail.

[Expedited]

Check out the tubeless rolling resistance results, spectacular stuff. If it's just as puncture resistant as the previous model then the new TL tires are a huge win.

[El Chaba]

Any rolling resistance test that doesn't conclude that the Veloflex Criterium tubular is the world's fastest bicycle tire is a flawed test.....