#46
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This! 180 pound me pumps up my 38c gravelkings to 40 psi on the dial of my pump. I then check / adjust it with my digital pressure gauge that will read 32psi.
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#47
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Ideally, a heavier rider should use a 25mm IW rim and 30-32mm tires to keep the pressure down, but there's nothing wrong with using 73. I'd be sure that my pressure gauge is accurate. My old Silca read 8 psi high, so 80 was really 72. I installed a new, larger gauge. I just recently added a 7 inch round base, so it doesn't tip over easily.
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#48
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Like I said.
I linked that simply to educate you. Are you still in the 80's thinking 32H 3x box rims with tubies are as fast. If so, why bother asking your question? Let's take them one by one Lower rolling resistance: Internal width of 25 and external width of 29 mm vs typical 21 mm and 25 mm for hooked, why would you think the narrower contact patch would have lower rolling resistance? It doesn't. Lower CdA: We'd need Hambini to explain. The tire and rim transition is critical for airflow. Swisside even has taken out a patent for the tire that is most efficient for its rims. A narrow rim with a sharp tire transition is slow. I've tested this myself. There are countless wind tunnel tests for you to confirm. Everyone likes wider tires, they work best with wide rims and hookless rims naturally support wider tires vs inherently narrower hooked. Lower weight: Firecrest 303 hookless are way lighter than the hooked version, is there a dispute? Lower cost: Is there any dispute? Retail prices are lower and mfg costs are lower (mostly due to lower scrap rates) Higher stall: I have no independent data but tell me how a cleaner transition from rim to tire would not have an effect on the airflow. And if so, what would be that effect. In my seat of the pants testing, the transition is at a lower speed. That is good, if my seat of pants is correct Quote:
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#49
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Woah we're talking wind tunnels now?
I assure you I strive for the least aero setup possible with my death tires. |
#50
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OP I would stick to what the tire manufacturer says else... Why risk it? |
#51
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I'm fairly sure the molds are just out of date. Tire molds are surprisingly expensive - a Maxxis product manager on the pinkbike podcast awhile back mentioned they range up in the hundreds of thousands of dollars. My guess is that they just didn't bother to re-do the molds for existing sizes. The new sizes they've released of the exact same tire design lack the warnings. Last edited by EB; 03-13-2023 at 10:38 AM. |
#52
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#53
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I can say, with confidence, that when I look at carbon wheels I really dont see a trend in lower costs over the last 4-6 years even though hookless has become more accepted. There are certainly more lower cost(under $1k) carbon rim wheelsets now compared to 2017-2019, but I think that is more tied to Chinese direct brands gaining traction in the marketplace. You mention Firecrest wheels and I understand the hookless version is lighter than the old hooked version. Is that what you are basing your weight comment on? They switched from brass to aluminum nipples, which as 24spokes front and back, is about 40g lighter. Plus the layup changed...which I would think impacts weight. Not sure how much of the weight difference is based on the lack of a couple small carbon hooks? I cant say Ive looked into that. |
#54
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U
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Here's the image from Hunt web page: Notice how they distort the hooked tire into an oval shape to make it look wider than the hookless tire. In reality, the hooked tire would be just as round as the hookless, with just as clean a transition. Here's the image from the Envy web page: Notice how they put the hooked tire onto a narrower rim than the hooked, to make it look like the hookless tire has cleaner transitions. If they swapped tires and rims (the hooked tire on the wider rim), the hooked tire would have the cleaner transition. Just like many other marketing claims, most of the technical claims for hookless rims don't hold water. |
#55
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Rode em. Didn’t die. Great combo too!
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#56
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Let's just say I'd like to see an objective evaluation of hookless VS hooked, bicycle, tubeless bicycle rims. Not the TSE or whatever sram came up with. I kinda think sram/Zipp isn't the most objective source for info..if the past is any indication. -Lower rilling resistance-how about rims that are the same ID and OD? -Lower cda-'are slow? I'll bet similar sized tires and rims, the difference is lost in the noise and bambini-yikes, that speaks volumes. Wind tunnel..w/o a rider..check. -Lighter-'Way' lighter. For BTLOS, the hooked rims and hookless rims are not only the same weight, but the same prices. Maybe the zip 303 is 'way lighter, but not all are. -Lower Cost-see above -Higher 'stall'..yikes.. Ya love them hookless, sram wheels..groovy but like I said, something more 'objective'... Say hookless is way cheaper, way lighter, way more 'aero', implies that hooked rims of the same dimensions are expensive, heavy and not aero. I think the differences are small, if there at all(BTLOS)... Quote:
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Chisholm's Custom Wheels Qui Si Parla Campagnolo Last edited by oldpotatoe; 03-14-2023 at 06:26 AM. |
#57
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So, a LOT of tubeless, hookless 'performance' advantages is the stuff of coffee shop points at that Sunday 25 mile ride. And those guys with $, eat that stuff up..fine and dandy...whether they can 'feel' it or 'see' it or not. But, discuss....or not....this 'trend' in today's toys is interesting to me, not a bother at all.
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Chisholm's Custom Wheels Qui Si Parla Campagnolo |
#58
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I run these at just over 40 psi because most of my riding is pavement and I don't like how the tires feel cornering at lower pressures. At an event like D2R2, or the 4 day dirt road trip I did last June in VT, I run more like 35 psi. Tubeless with Stans sealant. |
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