I’m going to put Hope brakes on a new hardtail trail bike build, but undecided on the configuration. I want to keep weight to a minimum and like the tiny sleek look of the Stealth Race levers. The X2 caliper is the lightest choice but I’m thinking the lack of power over the E4 would mean bigger rotors to compensate.

Option 1: Stealth Race E4 with 180 & 160 rotors

Option 2: Stealth Race X2 with 200 & 180 rotors

Anyone have any advice on this?

E4 on the front, X2 on the back. 180 rotors on both

But isn’t it better to put the extra weight on the caliper and not the wheel? Rotational mass and all that?

Option one is what I did. Rear doesn’t need an adaptor. Only one set of spare pads needed and smaller rotors give more ground clearance and take more force to bend.

Then, for big trips – adaptor and rotor from the front go to the rear and I bring in a 203 and an adaptor for the front. I take the 160mm as a spare, just in case.

The rotational weight is negligible between rotors only a few grammes and it’s near the centre of rotation not the outer edges where it affects things more.

Option one is what I did. Rear doesn’t need an adaptor.

The frame has IS mount so I would need a post mount adaptor anyway.

E4s look cooler.

I recently built up a new hardtail after many years on fs. The fs has Hope tech m4s both ends with 180 front 160 rear rotors.

After much deliberation I put some new tech x2s on the HT with the same size rotors.To be honest I can’t tell much difference in stopping power. I’m no dh hero though, so I suspect the m4s might have a bit in reserve on longer descents, but I’m happy as Larry with my x2s

Mixing the calipers gives you the power you want without the full weight gain. It’s also cheaper :). On hope’s site there is a power per model and rotor combo. Iirc it shows a x2 with 180mm produces more power then a E4 with a 160mm.