Is the fit between the bits nice and good? Any reason to think it wouldn’t hold up to use?
Because I ride to the trails and I hate my bike sproinging all over the show when I stand up on the pedals.
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I’ve only used it a couple times since it’s jammed in a tiny toolkit bag, but the bits do fit together well and I don’t have any reason to doubt its durability. I guess I liked it enough to back the chain tool addon when they emailed me about it a while back.
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I need a 135mm, QR Shimano 11 speed CL hub. What’s out there for me?
dt350. buy the TA one and 135 endcaps.
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There’s also deore
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i mean sure
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dq because I’m too lazy to look up the physics forumula(e) that would answer this for me: when a tire in a bicycle frame is weighted (like you get on the bike), does it deform and maintain the same pressure it held prior, or does the pressure inside the tire increase?
I was thinking about this as I consider what tires might be fun on my various cargo bikes.
The volume of air should remain constant when the tire is deformed. Pressure and volume are directly proportional, so the pressure should also remain constant.
If you want to have some fun, take a 200 psi tubular and leave it in the sun for a while.
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I just tried on my MTB tires and could get the gauge to jump 1 psi by pinching the tire with my hands.
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is that because, with the valve connected to the pump, you no longer have a truly fixed volume of air?
it was just a gauge, but it’s because the volume of a tire isn’t fixed because the casing is flexible
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PV=nRT
So, holding nRT constant, the tire deformation is reducing the volume of the tire meaning that pressure must increase.
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what I’m wondering is if deformation is a change in shape that does not alter volume, or if the ground is literally pushing the tire in towards the hub more than the tire is able to expand outwards
(also I mostly want to know if I’m going to explode a tire when I hop on a fully loaded longjohn)
Nerds
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Since the tire is a long donut, even if you are in the middle of pinch flatting, you’re only pinching it on one place, and that only takes like a couple percent off the tire volume.
Another tricky thing is that the amount that tires “sag” under load is way less than it would if you were putting the same amount of air in a cylinder and following pV=nRT.
One way to think about this is to say that “loads are carried by the casing, not the air” – the air pressure is putting preload into the casing, stiffness of preloaded casing is what carries the load from the tire to the rim.
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unlikely.
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I’d like to take this opportunity to say that I’ve been reading about “preload” since I discovered Sheldon’s site about 20 years ago and I still don’t understand what it is.
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The whole system is constant, though. The torioid still has the same volume, even if it’s deformed on one side.
I too have absolutely no idea what this means. I asked here and got a bunch of noninformative answers and then I felt bad about myself for a few minutes.
This might be an informative description though
Preload, also known as the left ventricular end-diastolic pressure (LVEDP), It is the amount of ventricular stretch at the end of diastole. Think of it as the heart loading up for the next big squeeze of the ventricles during systole.
So, preload is basically the stretch on the sarcomeres just before heart contracts for systoles.
The sarcomeres will stretch more if there is more blood in the chamber just before contraction.
Take an example of a balloon – blow air into the balloon and it stretches; the more air blow in, the greater the stretch and greater will be the preload.
So by extrapolation mechanical preload would be the amount of loading prior to putting any mechanical stress on the system?
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