My brakes work and always have done (I have old M676 levers paired with the newer M7100 callipers) but have just been reading up on ‘spongy’ brakes and wonder whether mine are thus affected.

The the levers firm up, the pads bite quickly and the power is fine (and they don’t need pumping up to get going) but I have noticed that if I continually apply more and more pressure to the levers I can move them further back (to within about an inch of the bars). I get the feeling that once folks’ pads bite, the levers should be effectively immoveable.

I seem to recollect that they’ve always been this way and I’ve ridden them without issue for years, but I’m wondering whether they do need a full bleed (I did a quick, funnel only bleed recently when I changed the pads but only shifted a single bubble of air).

I get the feeling that once folks’ pads bite, the levers should be effectively immoveable.

In an ideal world, perhaps. But in reality, it doesn’t work like that, there’s squishiness throughout the whole system (hoses expand slightly, rubber seals buckle a bit, pads themselves compress etc etc).

The question is whether the squidge is excessive. Which is really hard to know unless you have some sort of benchmark to compare to. If you do a bleed correctly, you can feel the brake firms up. Then over time, that firmness may diminish as air gets into the system. It’s not inevitable IME. Sometimes brakes work fine for years without needing a bleed.

Basically, compare with other people’s brakes and see if yours are different to theirs.

Alternatively you have modulation.

Do your brakes brake more as you pull harder or just move back to the bar?

“if it aint broke, dont’t fix it”

Your brakes work, leave them alone.

I bleed mine once a year as dot fluid has a tendency to absorb moisture over time.

Don’t compare your brakes to others, brake set-up is very personal and what feels good for one person won’t necessarily feel great for another!

for example i run my SRAM code RSC levers with the contact point adjust wound in so the pads bite when the lever is about an inch from the bar, whereas a mate runs his codes to feel like his old shimanos – instant bite!

Once the pads hit the disc, you are compressing the oil to a higher pressure, so will still have lever movement and it will probably be flexing the master cylinder assembly at the bar clamp.

My brakes work and always have done (I have old M676 levers paired with the newer M7100 callipers) but have just been reading up on ‘spongy’ brakes and wonder whether mine are thus affected.

Stop reading things on the Internet. Do not ever visit a site discussing illness and symptoms., no you do not have necrotising fasciitis, white nile, marburg, lassa or ebola.

Most of the flex is in your levers and is totally normal if a bit annoying.

The bit I’m worried about is that your levers, under full pressure, are still an inch away from the bar? That seems huge to me. How far out are they before you pull them?

I think those are Servo-Wave levers. They never feel as firm as normal levers because the mechanical leverage increases as you move the lever. If they’re working ok, just ride the bike. However, giving them a bleed is never a bad thing.

I have old M676 levers paired with the newer M7100 callipers

Not an issue.

Great, thanks, I’m clearly overthinking it and shall leave well alone.

I’ve never understood the obsession with bleeding brakes. Car system is far less sealed and gets touched how often??

Sure…brake fluids absorb water to some extent but XT brakes on my first “proper bike” never got bled in the 10 years i owned it.

Change in feeling is more to do with set up and pad wear.

If you have the caliper set so the pads hit unevenly then you’ll start braking but still get lever travel until the second pad bites properly. And you’ll see the disc bending one way off the bike and pulling the lever.

Time worry is when you’re brakes stop slowing you down and / or the lever travels back to the bar and you’re still accelerating!! 😁

Sure…brake fluids absorb water to some extent but XT brakes on my first “proper bike” never got bled in the 10 years i owned it.

That’s more myth than reality. MTB brakes are a sealed system, they can’t absorb water from the air because they aren’t exposed to the air. If you leave a bottle of DOT fluid with the cap off, it will absorb moisture but nobody does that. Mineral oil based brake fluid doesn’t absorb water.

If you have the caliper set so the pads hit unevenly then you’ll start braking but still get lever travel until the second pad bites properly. And you’ll see the disc bending one way off the bike and pulling the lever.

This is a symptom of a sticky piston. The pistons should automatically reset themselves so the pads are centered on the rotor. If one piston seizes in its seal, you’ll get this sort of problem. Cleaning the pistons and then lubing them usually fixes this.

This is a symptom of a sticky piston. The pistons should automatically reset themselves so the pads are centered on the rotor.

Not necessarily. If it starts doing that then yes. But swapping wheels for example or just tinkering and moving the caliper or just bad setup from the outset then the pads will centre, the caliper isnt and you get the squishy feel.

I switch my winter / summer wheels and the hub width is different so rotor on one set no longer sits central in the caliper. One pad hits first, pushes the disc and can visibly see disc move then second pad hits. Accompanied by squishy horrible feel. And usually noise too!

Once the caliper is centred relative to the disc again then all back to feeling nice.

On 6 bolts i use disc shims to always get the same relative disc spacing.

I switch my winter / summer wheels and the hub width is different so rotor on one set no longer sits central in the caliper. One pad hits first, pushes the disc and can visibly see disc move then second pad hits. Accompanied by squishy horrible feel. And usually noise too!

This is caused by a sticky piston. Try levering the pads apart with a flat bladed screwdriver and then clamping the brakes on hard to reset the pistons. The two pistons act independently of each other so it’s not necessary to center the caliper perfectly, the pistons will center themselves.