msu2001la

I'm shopping for new rotors. The rotors that came with my bike are Shimano 160mm RT56 6-bolt and I have GRX hydro brakes.

Is anyone on here running the Ashima AI2 or similar type of lightweight rotor? These have a claimed weight of just 66g ea, which is less than half the weight of the Shimano RT56 rotors. They're also cheap (less than $25/ea). Light and cheap sounds good to me, but do they work?

I run about 165lbs, and live in a flat area and am not at all concerned about overheating my brakes. That said, these rotors look like they have a lot less surface area than most other rotors, so I'm wondering if there's a noticeable difference in performance? Do they wear out pads quickly? Noise? Wet weather performance? This bike sees a fair amount of foul weather riding and will be used for CX racing so lots of mud, snow, rain, etc so that aspect is important. The biggest hills around me are highway overpasses, so again... I'm not at all worried about cooling or having less metal to absorb heat, etc.

Ashima Ai2:


Shimano RT56 (for comparison):

tyrion

From what I've read those rotors with minimal braking surface give good modulation, less overall stopping power, and do wear out pads faster.

tdilf

I would assume the Ashima rotors are pretty easy to bend or warp and thus would probably need truing more often.

tangerineowl

I think these -and similar- lightweight rotors start with a 1.8mm width, compared to 2.0mm on many other heavier options.
Does give you a bit of a headstart in warping.

Haven't run those, but a similar slightly heavier KCNC rotor.
Yes, you kind of do hear/feel a 'cutting' motion across the pad when braking!

They are ok. I do need to true mine quite a bit as I have the pads pretty close to the rotor.

If you have full-hydro brakes and are on those grades you mentioned, they'd be fine if you don't tend to overheat the brakes a lot.

pipeliner

Ive got a set on my bike with grx hydroand Im a Clyde. They work fine, you do have a rough feel in the levers from the gaps in the rotors and some lever free play before engagement as well. If you do much descending in steep and technical stuff, Id advise against them. They get hot fast. They are ok for (gravel) road riding.

Koyote

Weight is overrated, and weight at the hubs is especially insignificant. And with less surface area, those rotors will not be as effective at stopping your bike...Which, umm, let me check....yep, that's it...Is the whole purpose of brakes.

If you've already got perfectly good Shimano rotors, buying those new ones would be a waste of money. But it's your money, so knock yourself out.

dwmckee

Sorry to be blunt, but those are junk for most applications (though your situation may be an exception). We have seen folks in our shop that try them and later switch back for better performance from more conventional SRAM or Shimano rotors. They do not have a sufficient heat sink for extended descending so pads are more prone to overheat and wear out fast too. The rotors warp more easily too. If it were me I'd save weight somewhere else. The only way these might work out for you if if you are a really lightweight rider. Otherwise they mess up an otherwise pretty good braking system. If you want to save weight maybe go to 140 MM rotors to maintain quality.

msu2001la

These are for a second set of wheels.

msu2001la

Blunt is fine. I don't own these and am looking for opinions.
Appreciate the feedback.

Koyote

I think it was Tom Ritchey who said, “light, cheap, strong - pick two.”

Those rotors are light and cheap. I’ll let you figure out what they are not.