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• #6177
Wut? I like sealant fixing punctures for me.
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• #6178
Does it though? I mean, you lose some pressure, then you have a kind of sealed but not really sealed latex plug in a tyre trying to hold back 90 psi. I'm sticking with tubes for now.
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• #6179
sounds like a solid recommendation. 2” would be fine tbh... I’ll keep an eye out for some.
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• #6180
Maybe because I don't run anything at 90 psi, but never had an issue. The only faff is remembering to top up the sealant every now and then, which is the only time I've been caught out.
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• #6182
Tubs
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• #6183
Still angry the team car was nowhere to be seen
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• #6184
See my previous post(s) about tubs.
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• #6185
Now that it might be safe to take the mudguards off, i’m after a 35-40c slick tyre, tubeless (bc I’ve already got the stuff and it’s always worked fine before). Any suggestions?
Spotted the slick 38mm gravel king for £30, seems to be v light...is it going to fall apart on the first ride? £££s putting me off from going back to g one speeds. Thoughts on the g one allround just as a road tyre since it’s a bit cheaper?
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• #6186
g one speed? challenge also do a 36mm slick i think
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• #6187
Currently running 32mm Gravelking (non SK) file treads in tubeless setup and they're been great.
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• #6188
I've been commuting on 38mm slick gravelkings with tubes since Jan, loads of life left. I've had one puncture but that was an issue with the rim tape rather than the tyre. I may size down a little when they die but it's a good tyre.
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• #6189
i mean there isn't much aero benefit when you are above 1.05 of rim width right? these guys are already running 28 or 30mm tubs on rims designed for 23 or 25mm tires.
idk i'd guess they were much less likely to puncture. i've only rarely had tubeless punctures that didn't retain a rideable amount of pressure. seems like not having the tire come off the rim is a pretty low standard. with 50mm you wouldn't be bottoming out at all.
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• #6191
Sagan is running 30mm tubulars on 29.something mm rims so original point stands. There's also the fact it's not a CX/MTB race it's a road race with a portion on rough roads. Riders aren't going to choose poorer aerodynamics and poorer Crr for 200k of smooth tarmac just to have a comfier, maybe less puncture risk on the remaining.
Tubeless still means one spray of sealant that doesn't seal and you're fucked. Tubs at least will be rideable and that's the difference between being in with a chance of contesting a win and having to jump the fence to get into the velodrome. -
• #6192
the aerodynamics rule is rim must be > 1.05 of carcass width. as far as i know the only aero rim for 30mm tubs is the enve 4.5 ar disc. so i don't think there is much difference.
the crr for a wider tire with the same compound is basically the same for the same casing tension. https://www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison
in any case not bottoming out would massively reduce your probability of flatting. not like they are putting sealant in tubs either.
skeptical of the idea that the "rideability" of a flat tub is really that important. you can't ride very well. e.g., mvdp's flat at de ronde. but maybe i'm wrong.
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• #6193
I use 23c tubeless at high pressure and this is so true. Easy fix with glue and a tire worm if needed tough
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• #6194
As I said, the Rovals that Sagan was on are designed for the 30mm tubs he used.
The "more aero" for wider rims/tyres works because people are using wider tyres not because they are just more aero.
If you could run 20mm wheels/tyres without other issues they'd be more aero than 30mm.
Going to 50mm still means you have more frontal area and are less aerodynamic and in fact going so wide will need fork and frame redesign which will worsen aerodynamics even more.As the same pressure, a bigger tyre's Crr is better than a skinnier tyre's. But you don't run bigger tyres at the same pressure, you run them lower, which increases Crr. Even if you did run them at the adjusted-for-comfort pressure, as you say, the Crr is basically the same, so no advantage in going wider, just disadvantage due to worse aerodynamics.
Being able to ride at 20kph to your bloke with the spare wheel or until your car reaches you saves how much time vs. standing on the side of the road? Are you really using VDP's crash as a rideability example? He pinch flats failing a bunnyhop at 50kph+ and then rides one-handed onto the footpath but crashes because he hits a hole he didn't see because he was looking at his flat front tyre?
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• #6195
So you might fix some punctures with sealant but if you don't you have to have superglue and/or a worm kit with you. Even the ones that are sealed fast, you will still lose pressure, so presumably you will have to stop at some point to top up anyway. Yeah... nah.
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• #6196
@carrefor on sunday , sky support
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• #6198
oh are they? you said they were 29mm rims. if that is the case then my point isi more invalid.
obviously wheel aerodynamics are much more complicated than frontal area. obviously nobody runs 20mm tires anymore...
and no that isn't right about crr. the link i put in my last post shows this with the gp5000. if you inflate to the same tire drop, or casing tension, and the tires are made of the same compound, the crr is the same.
yea maybe mvdp wouldn't have pinch flatted in the first place, or maybe he'd of retained a more rideable pressure.
i watched the footage a few times and couldn't see really what took him down, and different news outlets have all said different things. his wheel was not in line with his bars when he hit the ground though, so idk what is going on.
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• #6199
obviously wheel aerodynamics are much more complicated than frontal area. obviously nobody runs 20mm tires anymore...
Yes it is, but generally if you have the same shaped object but that object's frontal area increases then so does its drag. Track bikes use 20mm tyres. Another example of where aerodynamics and rolling resistance are very important but since they're not worried about pinch flats, they don't need to widen tyres. Do you see any track teams running 30mm tyres? No, of course not, because they'd be slower. Wider tyres are used to deal with 'terrain' and wider wheels are more aero than skinny wheels with wider tyres, not simply because wider is more aero.
What isn't right about Crr? "Even if you did run them at the adjusted-for-comfort pressure, as you say, the Crr is basically the same, so no advantage in going wider" is literally what you said and everything else I wrote is lifted from the article you linked to.
Maybe. Or maybe he wouldn't have even made it to that point in the race on tubeless.
Slowing down one-handed with a flat front tyre is not the best way to remain upright no matter what your choice of tyre is. When the peloton is racing on tubeless tyres, maybe then I'll believe the hype.
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• #6200
When the peloton is racing on tubeless tyres, maybe then I'll believe the hype.
I'm not saying you're wrong about all this - but isn't this a poor metric? Pros will by and large race what they are told to, no?
I am with hippy, in pro peloton it makes zero sense to ride tubeless.
Tubulars are the best road tyre system if you can live with the caveats which pros can.
Also road tubeless (28mm and under) makes very little sense even for the n00bs like us.