Shimano’s VariableBitePoint®️ brakes

basically a brake that causes this much hassle bleeding, is a bad brake.

To butcher the old adage; powerful, light, simple, pick any two. The higher end Shimano brakes are expected to be light and powerful. The Servo-Wave levers help with this by increasing the leverage ratio after the dead throw is taken up. Problem is, this magnifies the problem of any air in the system.

Trying to miniaturize the levers and calipers probably also resulted in the transfer ports not being optimized for bleeding. Thing is, they aren’t impossible to bleed, they are just a bit tricky and need some care. As long as trained mechanics can successfully bleed them, Shimano have made an acceptable product. It’s not possible for companies to guarantee that their products are completely user-serviceable.

On top of that, Shimano have made millions of sets of brakes over the years. It’s inevitable that there will be a lot of users with problems if you sell huge volumes of any product. The users who don’t have any issues don’t post about it on web forums so it’s impossible to judge the proportion of users that have experienced problems.

As long as trained mechanics can successfully bleed them, Shimano have made an acceptable product.

So we’re all agreeing they aren’t acceptable then when new bikes come with crap bleeds along with brakes that have been bled in the factory?

The users who don’t have any issues don’t post about it on web forums

Erm, didn’t you notice that about 50% of the comments on here seem to be “they work fine for me, you must be doing it wrong”?

I had this on the rear XT brake of a new bike back in 2017. Did a regular bleed, it went away, rode that bike hard for four years and it never came back.

I had this on the rear XT brake of a new bike back in 2017. Did a regular bleed, it went away, rode that bike hard for four years and it never came back.

So you didn’t have the problem then did you? Your brake needed bleeding, you bled it, then it worked. Easy. That’s not what people are complaining about. There are Shimano brakes out there which can not be made to work acceptably for any length of time no matter how much you bleed them.

I swear the most annoying thing about this saga is that people who have never experienced it still don’t believe it’s a problem and are willing to write everyone off as idiots who don’t know how to bleed a brake.

And as for being a ‘trained mechanic’, well I’ve spent more years working in workshops and bleeding brakes than most people on here. I’ve put dozens of hours into problematic Shimano brakes and I’ve also sold stacks upon stacks of Tektro brakes to people who just needed their entry level bike to work reliably.

Erm, didn’t you notice that about 50% of the comments on here seem to be “they work fine for me, you must be doing it wrong”?

I’ve never seen a thread titled, “I bought Shimano brakes and they just work as advertised,” yet that is many users’ experience.

I swear the most annoying thing about this saga is that people who have never experienced it still don’t believe it’s a problem and are willing to write everyone off as idiots who don’t know how to bleed a brake.

I’ve had the problem. I bought some second-hand Shimano brakes, they worked fine when I fitted them but got all weird when I laid the bike on its side, but would then magically start working properly again after a bit of riding. I figured it must be an air bubble in the reservoir so I gave them a bleed to ensure they were properly full of fluid and had no air, they’ve been faultless since.

The wandering bite point problem is caused by not having them filled properly. If you bleed them properly and make sure the reservoir is full and doesn’t have any air in it, you will fix the problem.

Five year old XT, four year old SLX – no problems here! Bleed them once a year or so. Had the issue once after replacing the rear SLX hose and refilling with a Marshy bleed. Did the refill again caliper up with an Epicbleeds kit, sorted (over two years ago).

Me too 🤔

+1. Most of my disc braked bikes have been Shimano, currently have 4 bikes hung on the wall with Shimano discs, never had the problem at all. Had a horrible experience with Elixirs, and more recently with Guide sticky pistons, so Shimano definitely winning for me and that’s before you consider the safety of the finish on your inconsequential workshop furniture.

I’ve had the problem. I bought some second-hand Shimano brakes, they worked fine when I fitted them but got all weird when I laid the bike on its side, but would then magically start working properly again after a bit of riding. I figured it must be an air bubble in the reservoir so I gave them a bleed to ensure they were properly full of fluid and had no air, they’ve been faultless since.

So you haven’t had the problem then. You had a brake that needed a bleed.

The wandering bite point doesn’t magically fix itself mid-ride, it can change (for better or worse) many times a run.

FWIW I found Elixirs easy to work on, and you dont tend to find many people saying that

I’ve had it with some shimano brakes, not with others. Some reports suggest its either down to the viscosity of the oil in lower temperatures (which could explain why some people don’t get it), or slight engineering faults in the master cylender allowing a small amount of air in.

I give up trying to post an image…
Used to work!

Fixed it for you..

Nope, looks like the websites broken.. Again.

Linky

Let me help you with that…

Is there another set required of “Those who can’t post images”?

I find it very curios that the engineering giant that is shimano haven’t managed to find the root cause of the VBP condition and instead persist with the same basic design year after year after year 🤔

Unless of course… User error 🧐

The wandering bite point problem is caused by not having them filled properly. If you bleed them properly and make sure the reservoir is full and doesn’t have any air in it, you will fix the problem.

folk with the problem are saying that with some sets of brakes this can’t be achieved.

i’ve experienced WBP. a bleed fixed the issue, but i do find the xt levers harder to bleed than the 501 non series

Unless of course… User error 🧐

But then remember you’ve got to include Shimano themselves in there as they send them out the door with the issue already happening

Brakes of all brands benefit from a bleed from new.

When I worked in a shop, the Sram tech guy advised draining Avid (yes – a while ago) brake’s fluid and replacing with better brake fluid from new, so a bit more involved than a bleed.
As others have said, Servowave in the upper end levers amplifies any poor bleed symptoms, and it’s unsurprising that rears are more often affected given the length of hose and the less vertical route from caliper to lever.

It feels like I have been bleeding my Shimano 4-pots since the last post on this thread…

I have massivlely annoying variable bite point on the rear brake. The front is perfect.

The first pull is always nearly to the bar, and then a couple of pumps and it firms right up.

Today I have tried a different lever, done multiple bleeds using all sorts of different methods. I have ebven tried a bastardized SRAM vacuum/pressure method. Each time I can get the lever to be rock solid with the bleed block in place, but the VBP returns when the pads are inserted.

Pump-pump-pump and the lever is solid. Pump-1-2-3-pump and it pulls almost to the bar. Literally 3 seconds between pumps and it pulls right back.

There are no leaks, and there are no bubbles to be seen at either end, no matter which way the fluid is put through the system.

I am about to buy some cheap Tektros from Merlin.

To add insult to psychological injury, when I reinstalled the the test lever from another bike back to the original bike (2-pot), Boom! – it bled perfectly and firmly immediately.

WTAF is going on with Shimano 4-pot calipers?

Never had this

I think it’s a bubble getting stuck in the outboard piston pockets. I had a similar XT issue that took multiple bleeds to solve and then I somehow managed to hold the caliper at the right angle with the right frequency of tapping with exactly the right pressure of fluid with the pistons in just the right placement and a sizeable bubblee popped out.

Still haven’t managed to solve it on my Xtr rear though.

I have seen similar on some Clarke’s brakes where the pad spring was too strong and pushing pistons back kn

Put a solid spacer in without pads to check if it still does it

Share your voodoo Jonny! Quantify the angle, frequrncy and pressure…

I have bought the Tektros.

I had this for months on my rear XT8120 4 pot.

I can bleed brakes but multiple standard bleeds wouldn’t sort it.

I finally cracked it last month with a gravity bleed, front of the bike raised, rear caliper hanging down.

Fill the funnel on the master and remove the full bleed port nipple on the caliper, let the fluid pour out while moving the caliper around. Obviously stop before you empty the funnel.

Then do loads of lever bleed, flicks.

My brake is rock solid now with no variation on the bite point.

As said above, fairly sure it’s trapped air in the caliper.

I am about to buy some cheap Tektros from Merlin

If the ones you’re thinking of getting are the Gemini HDs they come with extremely short hoses, Euro style levers and the hose is a non standard size which is not easy to find. I’m about to send mine back because I can’t be bothered to change everything round.