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WIDE AND WIDER, HUB FLANGES, TUBELESS

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WIDE AND WIDER, HUB FLANGES, TUBELESS

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前の投稿 - 次の投稿 | 親投稿 - 子投稿.1 .2 .3 .4 .5 .6 .7 | 投稿日時 2021-5-13 15:34

xysoom

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WIDE AND WIDER, HUB FLANGES, TUBELESS

Since around 2015, there has been a move to wider tires and wheels in road cycling. Back then, most wheels had 15C rims (meaning a 15mm inner width) and 23C tires were speced for them. In the years since then, rim brake wheels have widened to 17C and 19C (some even to 21C). 25C and 28C tires have become all the rage.To get more news about Road Cicycle Wheels, you can visit zpebicycle.com official website.

In past years, riders used to be overly focused on weight. Now we seem to have become overly focused on width and mostly on tire width.

Unfortunately, you can’t really upgrade your stock wheels merely by putting a set of wider 25C or 28C tires on them. Doing this will make your ride on these typically less forgiving wheels more comfortable and that is one of the reasons why many new bikes come with 25C tires regardless of the wheel size. Another big (bigger?) reason is that it’s the trend now to have wider tires and without them, bike makers appear to be behind the competition.

With wider tires, you can inflate them to a lower air pressure while still having the same amount of air needed to hold your bike and body weight in what is now the larger volume of space between your tires and wheels. Lower pressure tires are more comfortable because they absorb more of the road’s imperfections.Why? A tire that is wider than the outside width of the rim at the brake track will create a wheel that has more drag than one whose tire is less than or about equal to the outside rim width. Most 15C wheels have an outside width that is 20-21mm wide measured across the brake track. Most 17C wheels are 22-23mm wide and 19C wheels are 24-25mm wide at the same location.

Once mounted and inflated on 15C or 17C rims, most 25C tires will expand by 1-2mm creating a 26-27mm wide or wider tire mounted on a rim that is somewhere between 20mm and 23mm wide on the outside. That extra 1.5mm to 3mm of rubber on either side of the rim will cause air hitting the tire to get turbulent or stall as it passes across the tire to the rim. With a tire that is narrower than the rim, more of the air will re-attach to a rim after it passes by the tire and continues with a more laminar flow, reducing drag.

A traditional 23C tire will still be wider, once mounted and inflated, than a 23mm wide rim but only by about 0.5 to 1.0mm on either side at most. Racers or those looking for the most speed will put even narrower tires on their wheels.

Over-wide tires that add drag and reduce speed is less of an issue for shallow alloy bike wheels that aren’t really intended to give you more speed through better aero performance in the first place the way deeper, rounded profile carbon wheels do. But more drag leading to slower speeds on a shallow wheelset certainly doesn’t help.

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