SRAM Apex performance advice

Hi,

I recently purchased a Specialized Carbon gravel bike and have been very impressed overall. However, I’m concerned about the braking performance of the SRAM setup (SRAM Apex, hydraulic disc, 160mm G2 CenterLine rotor), especially compared to my previous gravel bike, which had Shimano Hydraulic GRX brakes with the same disc size. On the steep descents where I ride, I’ve noticed that I really have to pull hard on the brakes to bring the bike to a stop, and the rotors end up blackened.

I’d like to stick with the current groupset on my bike but am exploring ways to improve the stopping power. Here’s what I’ve considered so far:

• I tried alternative semi-metallic pads, which provided better modulation but didn’t significantly improve stopping power—perhaps I made the wrong choice.
• I’ve read that swapping out the discs for a different brand, like SwissStop, might help, but I’m skeptical about whether a disc of the same size would make a noticeable difference.
• I’m also considering bleeding the brake system since the bike is a 2023 model and the brakes have been in use for a while.

Other options I’m thinking about include:

• Switching to larger discs.
• Upgrading to different calipers.

I’d appreciate any thoughts or recommendations

Bigger disc, if the frame / fork will take it and (I imagine) flat mount callipers can go to 180mm.

Swapping callipers won’t make the slightest jot of difference if you stick with SRAM as they’re essentially identical, a bleed is always worthwhile but SRAM road are a bit of a PITA to bleed correctly, definitely watch the SRAM YouTube guides and follow them exactly.

I’ve had Apex for about 5 years, as steve_b77 said I’d bleed your brakes. Also sometimes I find the levers need adjusting.

That seems odd. 160mm should be fine unless you are big? If it’s true that the calipers are the same then the force/rival ones I have used are as good as Shimano.

Could it be a failed caliper or contamination?

A bleed might help but do the brakes feel spongy or otherwise odd?

Do you get the same problem front and rear?

I agree changing for equivalent rotor size will likely have no impact.

I’d give everything a really good clean with IPA/Disc brake cleaner. Then put in new pads.
Look for damage/defects and make sure everything is set up as it should be (alignment etc.).

Rotor turning black makes me think contamination. Would expect overheating to turn them blue.

I’ve had Apex brakes, abused in several CX races, for a good few years now and they are still plenty strong. If it’s not contamination then larger rotors would be the easiest change, but could also do Hope RX4 calipers

Swapping callipers won’t make the slightest jot of difference if you stick with SRAM as they’re essentially identical

Are they though?

1 I had Apex on my first gravel bike, then got Force for my second – definitely worked better.

2 Pals who also bought the same bike as my Force one got Rival on theirs, both have already replaced the callipers with Hope’s as they had loads of issues,

Just our experiences.

160mm should be fine unless you are big?

5ft 11 and 14 stone – i don’t see it making a massive difference as my last bike as I said with the same setup albeit running Shimano kit was fine.

The brakes do feel a tad spongy and yes I was going to attempt to bleed them as a starter for 10.

Hmm, reading with interest. Also on an apex bike, bit underwhelmed with the braking power, to the extent it makes me a little nervous on the bike. It’s my first gravel bike with little brakes so I’d put it down to that, but i might break out the bleed kit later and see how that goes.

Hmm, reading with interest. Also on an apex bike, bit underwhelmed with the braking power, 

I have a friend who has the same bike and has the same concerns about the brakes too.

For me i’m finding if i yank on the brakes all I’m getting it that the lever is getting closer to the bar – especially for the rear. My rear does feel more spungy than the front so a bleed is definitely required.

I can lock the rear wheel with a hard squeeze, I’m more surprised/disappointed at the lever force required to do that. Though I can barely pull an endo with the front brake. So it does sound a bit like you might also have a contamination issue. You can try sanding the pads and using brake/carb cleaner/IPA to clean the discs, but the surest path is to replace discs and pads. Either way, follow with a proper bedding in procedure. SRAM have some videos on YouTube for the recommended procedure.

I’m 95kg and running SRAM Apex. They’re fine and they do a lot of work on the hills around here. I’ve just bleed them as, after 3 years in use, both ends were starting to drag a little and I think it was the water absorbed over that time increasing the volume and pushing the pistons out a tiny bit, especially the front. They’re back to smooooth now :) I use Swisstop Endurance  pads. The levers have a couple of adjustments IIRC, but I set them up once and have never had to change them.

I think organic pads give the best performance and are quieter than sintered/semi-sintered.

Don’t last as long though.

You can also change the calipers to Hope, but this is not a cheap option.