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I've made and observation that I don't understand. After a long steep descent, my rear rim and tire is much hotter than my front rim and tire. Since I first discovered this, I have been deliberately using my front brake more, but the rear rim is still much hotter. I am running DA 7800 brakes with DA pads and Kinlin XR200 aluminum rims front and back. I've always heard that the front brakes are more effective than the rear. So why is the rear rim getting so much hotter? Any thoughts?
 

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tantra said:
I've made and observation that I don't understand. After a long steep descent, my rear rim and tire is much hotter than my front rim and tire. Since I first discovered this, I have been deliberately using my front brake more, but the rear rim is still much hotter. I am running DA 7800 brakes with DA pads and Kinlin XR200 aluminum rims front and back. I've always heard that the front brakes are more effective than the rear. So why is the rear rim getting so much hotter? Any thoughts?
'Cause you're dragging it more. Simple as that.

Most folks instinctively avoid their fronts, even in when they try to use both equally. Because the front is so much more effective, people instinctively don't use it as much, even when they think they are using both equally. And if you are the sort to apply both at the same time, it's doubly true.

Also, a bit of adjustment difference can yield a big difference in pressure applied.

Part of the calculation that's not always obvious: A brake applied firmly for a quick stop generates less heat than one that is dragged to scrub speed. Effectiveness <> heat generated.
 

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Heat transfer

tantra said:
I've made and observation that I don't understand. After a long steep descent, my rear rim and tire is much hotter than my front rim and tire. Since I first discovered this, I have been deliberately using my front brake more, but the rear rim is still much hotter. I am running DA 7800 brakes with DA pads and Kinlin XR200 aluminum rims front and back. I've always heard that the front brakes are more effective than the rear. So why is the rear rim getting so much hotter? Any thoughts?
If indeed your braking was equal on both wheels, it probably is that your front wheel is "out in the wind" more and therefore is getting better cooling. Without that effect, your front wheel should actually be hotter since it is almost surely doing more of the "work" of braking and therefore dissipating more energy.
 

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I try to pump rather than drag if I'm on a long decent to avoid excess heat (just like in a car). Of course this isn't always an option if you are in a group. My guess on why the back wheel is hotter is because of the drag. Try only using your front brake, if you back wheel is still hotter, you have a problem (lol).
 
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