If you are descending then that generally points to having done some ascending first- and alloy rims with a carbon fairing/alloy-carbon hybrids (C24 aside) tend to be heavy.
They're also relatively pointless if you have a carbon rim that can deal with the heat- unless it's pissing down.
I've gone for disc brakes on my new bike in an attempt to render this a moot point- I think it makes more sense to move the braking to a seperate item that can be replaced independant of the rim, and doesn't introduce compromises to the rim design/safety.
If you are descending then that generally points to having done some ascending first- and alloy rims with a carbon fairing/alloy-carbon hybrids (C24 aside) tend to be heavy.
They're also relatively pointless if you have a carbon rim that can deal with the heat- unless it's pissing down.
I've gone for disc brakes on my new bike in an attempt to render this a moot point- I think it makes more sense to move the braking to a seperate item that can be replaced independant of the rim, and doesn't introduce compromises to the rim design/safety.