Sounds like a useful workaround for those really struggling OP.

But I have to agree with Sillyoldman (great response), that there’s a confusing mix of technique and luck in resolving the issue with most units I’ve owned.

I’m sure there are a few really duff ones, but all of mine have responded well to a bottom-up bleed (or three) and I suspect the majority of observed cases are due to the above-mentioned design flaw which makes it quite tricky to get and maintain a good bleed. And Shimano pushing the funnel/lever bleed so strongly hasn’t helped the public perception.

My Zees are still my favourite brakes ever, even though my Codes have been less temperamental.

Its not the bleed – Many examples of magazine reviews featuring wandering bite point on bikes that have come straight from the factory.

Its a product of the design – specifically the interaction of the servo wave mechanism in the lever and the caliper seals. Brake power is determined by the ratio of the size slave piston in the caliper compared to the master piston in the lever. With a normal brake power is limited by the need for the pads to sit far enough away from the rotor. If you have too big of a size difference between the 2 pistons then the lever wont push enough fluid to move the pads far enough and they will rub on the disc.

Servo wave is a clever way to get round this problem. The Cam mechanism causes the master piston to move further at the beginning of the lever throw and then ramps up the power at the end of the stroke where the pads bite down. Using this method the shimano lever can push more fluid than a regular design which means it can have a larger piston ratio and more power while still maintaining good pad clearance.

The downside of this is that the Caliper seals have to work harder in between applications of the brake in order to return the pads to the starting point. (It is the springiness of caliper seals that is responsible for returning the pads)

So a wandering bite point can happen to any brake but the design of Shimano brakes makes it more likely and more noticeable.

Personally I think the power increase is worth it. I had a particularly bad set of XTRs once that I bought second hand. I was able to vastly improve them by swapping out the caliper seals and pistons. Unfortunately due to Shimano not selling spares I had to buy a complete set of XT calipers to do this.

Its not the bleed – Many examples of magazine reviews featuring wandering bite point on bikes that have come straight from the factory.

Its a product of the design

Ah, so great idea in theory, fails in practice?

I had yet another failed rear XT9000 last week, but the only brake I could get locally to ride the next day was a new SLX 2-pot. The Zee on the other hand that replaced the previous failed front XT9000 I’ve never had an issue with. And the XT’s were warranty replacements…

@ndthornton The factory bleeds aren’t particularly thorough IME, and far worse on bikes where the line has been fed through internal frame routing and reconnected. They always work better with a further bleed once hose length has been set for the bike they’re going on etc.
Reviews are by journalists rather than mechanics – they often get it wrong!
The servowave mechanism exaggerates bite point softness and vagueness due to the cam action on the mechanical advantage – that’s why the lower end brakes and most of the road brakes are known to be easier to get a firm and consistent bite point on – they lack the servowave (or in some cases have a less pronounced cam action.

As I say – there are bound to be occasional issues in such prevalent brakes, but in most cases the symptoms aren’t due to a design fault IMO, but due to inadequate bleeds and/or poor bleed techniques.

I suspect that the alternative oil is less viscous and so allows bubbles to move up and out of the system more readily.

Deore have Servo Wave don’t they?

Just wondering why they seem to be the most reliable of the decent Shimano offerings. The set I had were faultless for five years – and I’d got them secondhand.

M615, M6000 and M6100 do, while others below them don’t.

The servowave action isn’t the same across all models though and the progressiveness has been altered – M8100/20 and M8000 are more progressive/less grabby than M785 for example, and so it could well be that Deore level servowave differs from other “higher end” levers.

My 2019 m8000 rear suffered the wandering from new just like my 2017 SLX. I solved it by removing the full brake, hanging it lever up calliper down and used an electric tooth brush to ‘vibrate/dislodge’ trapped air.

Still sharp after 8 months 🤞

Sounds to me like overly complex design.

Could be worse, could be Scott Pederson Self Energising Caltilevers… Ask me how I know

They always work better with a further bleed once hose length has been set for the bike they’re going on etc.

Agreed

Reviews are by journalists rather than mechanics – they often get it wrong!

Yeah but a wandering bite point is pretty easy to detect – Evan a journo could work that out

I suspect that the alternative oil is less viscous and so allows bubbles to move up and out of the system more readily.

I agree a less viscous oil could help but I think for a different reason. Going back to the caliper seals there are a number of factors that can increase the time taken for the seals to reset the pads after a lever throw – 1, more fluid to move like is the case with a servo wave mechanism, 2, poor quality or perished rubber seals, 3, greater viscosity forces due to a longer brake hose like with a rear brake, 4, greater viscosity forces due to a more viscous brake fluid.

I think this is definitely something worth trying

I solved it by removing the full brake, hanging it lever up calliper down and used an electric tooth brush to ‘vibrate/dislodge’ trapped air.

Still sharp after 8 months 🤞

And minty fresh too I’ll be bound.

Scott Pederson Self Energising Caltilevers – Did you fit them backwards like I did 🙂

Naah, the rear is a ubrake.

Just took bloody ages to get them working… as expected.

This thread has highlighted how bad I must be at bleeding brakes. Have tried several times with my M8000’s, and they still have the issue.

Aaaaaand were back.  “Bleeding doesnt solve it”  right at the end of the vid.  I beg to differ 😬

https://m.pinkbike.com/news/field-trip-ibiss-2999-ripley-af-is-a-precision-weapon.html

Maybe My Levy has a grudge against Shimano brakes – enough that he needs to raise the point on every video. I’m pretty sure they don’t bother to bleed the brakes on these test rigs and they come from the factory poorly bled.

Out of interest, people who have brakes that suffer from this, how much lever travel difference is there between the initial pull and the subsequent ones? a few mm, a couple of centimeters?

Out of interest, people who have brakes that suffer from this, how much lever travel difference is there between the initial pull and the subsequent ones? a few mm, a couple of centimeters?

I bought some used SLXs which worked ok at first, but then the pads wore down and they started suffering from wandering bite point whenever I laid the bike down on its side. It was a couple of centimeters difference. Standing the bike upright and pumping the lever would get them working again. Obviously, what had happened was that there was air in the reservoir and not enough fluid once the pads wore down, so the air would get into the master cylinder. Properly filling the system, getting all the air out, and fitting new pads sorted it once and for all.

sorted it once and for all.

Never say that. It’s bound to be back at some point.

Just got it again myself, not cured by a proper bleed – but I can feel something’s amiss in the lever.

Just got it again myself, not cured by a proper bleed

Problem with saying things like this is that you don’t actually know if you’ve bled them properly, you’re just assuming you did.

Problem with saying things like this is that you don’t actually know if you’ve bled them properly, you’re just assuming you did.

Did them the same way that’s solved the issue every previous time, that’s the best I can say.

I think there’s an issue with the lever piston now TBH.

You’re confident you’ll never see the issue again then?

You’re confident you’ll never see the issue again then?

I’m confident that there is no air in the reservoir and that I can lay the bike down or turn it upside down without any problems.

The levers aren’t too hard to dismantle and clean. I’ve done it a number of times and it’s surprising how much crap builds up behind the master cylinder piston.

I followed this guide originally:

prezet
Free Member

Maybe My Levy has a grudge against Shimano brakes – enough that he needs to raise the point on every video. I’m pretty sure they don’t bother to bleed the brakes on these test rigs and they come from the factory poorly bled.

Why should they though? Any manufacturer would be absolutely nuts to send out a test bike for a review, by the largest website in the business, in anything less than top condition. Which points towards brakes that even the bike builders cant get working properly.

Out of interest, people who have brakes that suffer from this, how much lever travel difference is there between the initial pull and the subsequent ones? a few mm, a couple of centimeters?

My old SLXs (2 pairs in a row after getting a warranty replacement on the first set – they didn’t even bother asking for them back) would just about touch the bars, then sit a cm or so off on the next pull. My Zees (front was fine from new, Canyon and myself couldn’t sort the rear) it was maybe half that difference

used an electric tooth brush to ‘vibrate/dislodge’ trapped air.

Nice!

My conclusion is that if your brakes have this issue then bleeding is a bit of a red herring. Yes a really good bleed will solve the issue, but for how long. I’d observed with mine that one could absolutely chase every last bubble out, get them feeling really good (either me or various pro mechanics) – then a few weeks later of big runs and they’d feel poor again. I bought the biggest supply of shimano mineral oil I could find and ended up bleeding regularly, each time I found I could chase out huge air bubbles that weren’t there before even though there was minuscule pad wear. My suspicion is that some units let air into the system through normal usage, either through dodgy pistons or the action of the piston seals, it does seems to be worse in cold weather which could alter the seals flexion – and when there’s big bubbles in the system it coincides with wandery bite point.

Its quite possible that using a different type of fluid solves the issue by altering the way the piston seal is lubricated…

I’ve yet to try this method of removing the actusal bleed nipple from the caliper..
Just waiting on been able to get hold of some mineral oil.

https://www.youtube.com/watch?v=piWBVDh1pTE&list=WL&index=13&t=6s

Aaaaaand…. you get the idea..

https://m.pinkbike.com/news/red-panda-release-lobster-upgrade-kit-thats-claimed-to-improve-reliability-of-shimano-brakes.html

No wonder there’s a Shimano brake oil shortage if that bleed is the only way to get them working.

https://www.google.co.uk/amp/s/www.mbr.co.uk/how-to-2/wandering-bite-point-shimano-405883/amp Was interesting

In essence we jerry rigged a small fridge pump and pulled a vacuum on the system it had a y splitter on the inlet that allowed filling with fluid, someone is going to say but brake systems don’t work under vacuum , it only had to be -2 on the scale not a full 14.7 psi

If it held a vacuum integrity at -2 psi then it go filled from inlet to caliper and locked off oddly we never had a single problem, we also used to pull a vacuum on the fluid in a jar to see if it would foam

https://www.mbr.co.uk/how-to-2/wandering-bite-point-shimano-405883

I likes that idea I do, will give it a go next time I need to bleed mine.

I’ve not bought brakes in over a decade, but just got some SLX ones from Merlin. They arrived as separate parts, no oil, whereas I was expecting them to come all connected, filled and bled like brakes always used to back in the day. Is this normal nowadays (since so many bikes have internal routing that wouldn’t be mad)? Having read this thread I’m just going to return them regardless, but just curious as to what is standard practice. I didn’t think to check before ordering so not grumpy, but if I have to find oil, get special bleed bits and have a load of faff then I might as well dig out my 15-20 year old Hopes from the loft and resurrect those instead!

They’re pre bled with a cap on the end of the hose.
You just need to cut the hoses to length and connect them.

Ahah! Thanks, hmm, now I’m unsure of whether to chuck them on or send them back anyway because there seems to be so much hate of them…

Got to admit uve not had to bleed any brakes in some time but recently upgraded to some Guide RSC’s (second hand) with the Bleeding Edge port and was expecting a bit of a tussle but they were an absolute doddle. Proper easy. You don’t even have to do that bloody degassing of the brake fluid anymore which used to do my head in.

Considering their great granddads were Avids made it even more miraculous.

Anyway, hope you guys get them sorted and that MBR bleed method linked to above seems promising.

https://m.pinkbike.com/news/red-panda-release-lobster-upgrade-kit-thats-claimed-to-improve-reliability-of-shimano-brakes.html

The fact this upgrade kit even exists, and from reading some of the comments on PB of familiar experiences, means perhaps we can put the idea that Wandery Bite Point is just a simple bleed issue firmly to bed…

Personally I think the issue is caused by one or a combination of:

– Poor bleed
– Misaligned calliper
– Sticky calliper piston seals causing pistons to not advance correctly for pad wear
– Debris in the hose (seen this in a friends brakes, when trimming the hose there seemed to be some sticky residue on the barb causing poor oil flow)

maybe, just not the top two. Its really easy to align a calliper properly, it is also really easy, or atleast should be, to bleed a brake properly….its much more complicated than that. From the comments on PB, lots of people are finding that changing the oil viscosity works…just like the OP said…

The fact this upgrade kit even exists, and from reading some of the comments on PB of familiar experiences, means perhaps we can put the idea that Wandery Bite Point is just a simple bleed issue firmly to bed…

That kit is designed to stop debris getting into the lever assembly. They seem to be claiming that the wandering bite point is because of premature wear. However, the complaints that brand new brakes suffer from the problem suggest that debris isn’t the major issue.

The OP’s original post points to bleeding being a big part of it – lower viscosity fluid should make bleeding easier.

That doesn’t mean that the design of the brakes isn’t problematic. They seem to have been designed around tolerances and quality control that the manufacturing side couldn’t deliver. When they are set up properly and bled carefully, they work fine. Problem is that customers expect brand new stuff to work out of the box, not require a fiddly bleeding and set-up process.

it is also really easy, or atleast should be, to bleed a brake properly

It should be, but everyone who’s ever bled brakes will have a horror story. Making light weight brakes means minimizing the size of everything and that will make them trickier to bleed.

Again, its more complicated than that, and it shouldn’t be.

here’s a quote from the designer of the red panda kit copied from the PB comments:

My name is Andrey, I’m from Red Panda Components.

Thank you for your feedback, it’s very important for us.

Need to say about our product and problems it actually solves. In short, the Lobster seals out dirt, dust and water (IP65). Every time you push the lever, the piston takes along some contaminations. Dirt particles settle between the piston cuffs and the cylinder walls and scratch them over time, which is the common cause of oil leaks. Leaking levers => degrading braking power, inconsistent brake feel et cetera. The Lobster drastically expands the lifespan of the lever hydraulic, saving your time&money, and contrary to what was said on PB, it is definitely NOT a magic pill for the bite point.

here’s a quote from the designer of the red panda kit copied from the PB comments

Their marketing bullshit then?