So bought a pair of the Avid HSX floaty rotors (mostly cos they look bling – innit) in 180 mm to replace some perfectly good 185 mm cleansweeps. I’ve noticed in the last 6 months of riding that my brakes don’t feel as powerful. Whilst moaning about this in the LBS the other day they said maybe I’m too much of a girl to get them up to temperature or perhaps floating ‘heat shedding’ rotors are overkill for northern-ish Scotland…..I like to think it’s the Scotland thing…..

I was just wondering if anyone else had experienced similar? Should I just go back to the cleansweeps or use this as an excuse to upgrade brakes???

Current setup:
Avid Elxir R’s on 180 mm HSX rotor front and rear on Alpine 160 use for everything from a day a year of ft.bill dh course to all day XC rides around the highlands. Same pads used on both done about 400 – 500 miles on new rotors. Have recently bled brakes when changing frames (from swingarm routed sub5 to alpine 160).

Cheers,
Oli.

what pads are you using?

oliwb – Member
So bought a pair of the Avid HSX floaty rotors (mostly cos they look bling – innit) in 180 mm to replace some perfectly good 185 mm cleansweeps.

Could that be the problem?

Still on the standard Avid supplied pads…..

I’d be surprised if 5 mm difference in dia makes that much difference. The actual braking surface area seems less though as the HSX rotor is more wavey than the cleansweep…..

As above try a 180mm brake mount on the front rather than the current 185 as a starting point. Your pads are only probably 15mm top to bottom so you would be reducing it by a third at the top of the wave.

Other than that i’d be interesting to see how this thread goes as i’ve often wondered whether if getting the brakes up to temp is an important part of their operational effectiveness or whether its just bollocks for a moutain bike.

Almost certainly rotor diameter – you’ve lost about 20% of the braking power by going to a smaller rotor.

Already on the correct Avid 180 mm mount adaptors.

You can see what I mean about the difference in braking surface area when comparing the two…..the cleansweep is much taller:

(HS Rotor)

(Cleansweep Rotor)

Ben how do you work out that I’ve lost 20% by dropping 5 mm…..that’s total nonsense. If that were true by your logic a 165 mm rotor would mean I’d have lost 80% of braking power???

I reckon there’s something else at play here. Would be good to try a 180 mm HS1 (non-floaty one) and 180 mm std rotor side by side. Alas I’m skint! Think I might chuck the old 185’s on again to see what difference they make – in case I’m going insane!

Oli.