New GP5000 S TR coming soon
#51
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Lots of this has to do with keeping the tire sizes aero matched to the wheels they'd be run on. Folks running this tire aren't exactly 100kg dudes trying to make the front group of the B-group weeknight hammer ride. It's folks racing or in time trial or triathlons.
If the CRR and aero does appear to pan out, I'll go TL on my front HED 9+ TT wheel with and buy a newer rear HED disc that I can run tubeless. The disc I have now they claim cannot run tubeless for some reason.
Not sure why the HED Belgium in older 23mm width cannot do it but newer in 25mm can. That's the spoked wheel under the skin of a HED disc. I couldn't get an answer as to "why" from them the 23mm cannot do it.
If the CRR and aero does appear to pan out, I'll go TL on my front HED 9+ TT wheel with and buy a newer rear HED disc that I can run tubeless. The disc I have now they claim cannot run tubeless for some reason.
Not sure why the HED Belgium in older 23mm width cannot do it but newer in 25mm can. That's the spoked wheel under the skin of a HED disc. I couldn't get an answer as to "why" from them the 23mm cannot do it.
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It could also mean you might just fit the next sized up tire and negate these differences. But indeed curious. In fact the new TR shows an inflated height measurement of only 22mm -- not sure if this is maybe the lowest profile '25mm' tire I've seen in his testing? I guess the size is part of the contributing reason for lower weight. Puncture resistance is down, but importance of this is lesser I suppose if you're running sealant and not a tube.
This is all in the context of steel drum tests. I think steel drums do a great job of illustrating the *minimum* amount of power loss from a tire. I believe real world tests have shown that the power loss is greater than steel drums show and that more supple tires tend to have a disproportionate advantage on rougher roads relative to how they do on steel drums. I'd still go with a corsa speed for a TT.
Hell, I know a guy who uses the old 32mm (34mm actual - huge) GP5k for gravel. It's preposterous.
Last edited by smashndash; 10-15-21 at 01:24 PM.
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https://www.bike-discount.de/en/buy/...702/wg_id-8922
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https://www.bicyclerollingresistance...prix-5000-s-tr
Interesting. BRR measured the same-ish rolling resistance for a given pressure, but the tire has also gotten ~1.5mm smaller, which means you'd have to run it at a slightly higher pressure. So the tire is probably slightly faster. Maybe like 1 watt.
Jarno also mentions that the casing is stiffer. afaik the old gp5k wasn't exactly known to be supple (relative to other race tires) so this might not be great news.
Interesting. BRR measured the same-ish rolling resistance for a given pressure, but the tire has also gotten ~1.5mm smaller, which means you'd have to run it at a slightly higher pressure. So the tire is probably slightly faster. Maybe like 1 watt.
Jarno also mentions that the casing is stiffer. afaik the old gp5k wasn't exactly known to be supple (relative to other race tires) so this might not be great news.
The new 25mm GP5000s should fit on my rims better aerodynamically which is welcome news indeed. Got a lot of mileage left on current ones so no hurry to toss them.
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Lots of this has to do with keeping the tire sizes aero matched to the wheels they'd be run on. Folks running this tire aren't exactly 100kg dudes trying to make the front group of the B-group weeknight hammer ride. It's folks racing or in time trial or triathlons.
If the CRR and aero does appear to pan out, I'll go TL on my front HED 9+ TT wheel with and buy a newer rear HED disc that I can run tubeless. The disc I have now they claim cannot run tubeless for some reason.
Not sure why the HED Belgium in older 23mm width cannot do it but newer in 25mm can. That's the spoked wheel under the skin of a HED disc. I couldn't get an answer as to "why" from them the 23mm cannot do it.
If the CRR and aero does appear to pan out, I'll go TL on my front HED 9+ TT wheel with and buy a newer rear HED disc that I can run tubeless. The disc I have now they claim cannot run tubeless for some reason.
Not sure why the HED Belgium in older 23mm width cannot do it but newer in 25mm can. That's the spoked wheel under the skin of a HED disc. I couldn't get an answer as to "why" from them the 23mm cannot do it.
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Aerocoach just published their findings that new GP5000 roll 1.2W better per pair at 45 km/hr. So, really not much in it, but better.
I like they're slightly narrower and lighter, too.
I like they're slightly narrower and lighter, too.
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I have a set of 25 mm GP 5000 S tubeless on their way, going to try tubeless once again after a miserable 2016 on them. Should have them early next week.
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have fun and ride safe!
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I plan to get a set of these for next season. Will 25 mm work on my rims which measure 29/22 or would a 28 mm tire be safer? Thanks!
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Too small of a tire = more sidewall cuts, more exposed rims to gravel, and potentially compromised handling. These tires are just not designed for such wide rims.
Also, there is almost no change in tire height with wider rims. Which means that the effective height of the "spring" (tire) is almost the same regardless of rim width. So going with a narrow tire on a wider rim is not going to give you the same cushion as a wide tire.
That being said, I highly doubt you're at any risk of a blowout purely due to the rim width. If all you care about is aero, go for the 25.
Last edited by smashndash; 10-25-21 at 01:04 AM.
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I would go with the 28. I have a 25mm corsa control on my 23i rim and that tire has a carcass width of 70mm. The GP5k S has a 64mm carcass.
Too small of a tire = more sidewall cuts, more exposed rims to gravel, and potentially compromised handling. These tires are just not designed for such wide rims.
Also, there is almost no change in tire height with wider rims. Which means that the effective height of the "spring" (tire) is almost the same regardless of rim width. So going with a narrow tire on a wider rim is not going to give you the same cushion as a wide tire.
That being said, I highly doubt you're at any risk of a blowout purely due to the rim width. If all you care about is aero, go for the 25.
Too small of a tire = more sidewall cuts, more exposed rims to gravel, and potentially compromised handling. These tires are just not designed for such wide rims.
Also, there is almost no change in tire height with wider rims. Which means that the effective height of the "spring" (tire) is almost the same regardless of rim width. So going with a narrow tire on a wider rim is not going to give you the same cushion as a wide tire.
That being said, I highly doubt you're at any risk of a blowout purely due to the rim width. If all you care about is aero, go for the 25.