Are all rotors equal?

Just got some second hand avid brakes, but there are no rotors.

There are plenty on eBay, but apart from getting the right size is there anything worth considering when looking for a pair?

Depth of braking surface, whether they’re true and straight(you’d be surprised how many aren’t), thickness, material composition (some give more bite than others), and fancy shapes (prefer round myself),just a few to start you off.

plus weight can vary upto almost double

Blimey, I just thought they were round metal things!

So next question, if i wanted to keep things lightweight are there any brands to look out for or avoid? No many companies list the weight of just their rotors

I find my pads last longer since I changed from Shimano to Hope Sawtooth, don’t know why.

I have a set of these on my 29er and they works indistinguishably from my genuine Hope ones.

http://www.readytoridecycles.co.uk/160mm-disc-brake-rotor—fits-most-systems-hope-mini-shimano-hayes-etc-21-p.asp

Id avoid Ashima Airrotors due to the failure I’ve seen on here, other than that whatever fits in the right diameter.

Thanks for the advice guys

Clubber- cheers for the link, they look pretty good I might go for a pair

and fancy shapes (prefer round myself)

When you inadvertently lean the rotor against your calf after a long descent, fancy shapes do give a better quality of burn / branding.

I genuinely found the uber lightweight ones (SS flame as an example) simply didn’t have enough braking surface to be effective.

DrP

Being a bit sad I “borrowed” some digi calipers from work once to measure thickness of the rotors I use on my bikes…

As follows-

Avid – 1.80
Formula – 1.75
Alligator – 1.74

Yep, I musta been bored that day 😳

got an airotor, I reckon there’s noticeably less braking power than with the shimano it replaced. I’ve tried a few different standard* round rotors, can’t say I’ve noticed any differences. Hope floating rotors don’t save as much weight as I thought and seem more susceptible to minor warping.

*ie not spindly like the airotors

Personally I’d avoid anything that isn’t discernibly circular. In my experience, wiggly stuff like that thing posted up there^^ can give mental ABS style judder, even when set up properly…

I have found that for some but not for the one I posted above. Presumably because the actual surface in contact with the pads is fairly consistent as it turns.

I’ve found Alligator rotors to be better than standard Avid’s. More bite, more powerful and better in wet weather. Pads do seem to wear a little faster though, but not by a crazy amount.

May I also suggest you use swissstop brake pads, best I’ve used.

I use mostly hayes brake rotors because i got a bunch cheap…

Don’t think it really matters though, just get somethign that suits your riding. Lightweight rotors for racing and you’re light. 180f/160r for most xc if weights not an issue and floating rotors if you’re a heavy lard arse or drag your brakes a lot.

/me goes to order some thinner rotors.
i have real problems with pad clearance using Avids in mud
a good thin, round, true rotor?
maybe something more wavey to clear the mud?