Shimano's VariableBitePoint®️ brakes

I'm always baffled by this as i've never ever experienced it, despite having owned dozens of sets of Shimanos in the last 20 years.

You and I are amongst the gods @weeksy.

I've experienced it, but a thorough bleed and ensuring there is no air in the master cylinder reservoir fixed it.

I've also never experienced it, I'm assuming it doesn't affect power but will the bite point move enough for the lever to hit the bar?

I have one that does it and one that doesn't, on the same bike. It's a bit annoying and I've put up with it for the last 7 years. Might put something else on it 1 day when I've got some spare cash!

@dc1988 that's pretty much it, yes.

You and I are amongst the gods @weeksy.

Never experienced it here either @scotroutes, but maybe it's because we (obviously just me) are not among the cycling gods that we haven't experienced it 😋

I've had it on both of my shimano sets and found it was much worse if you used one of those hanging storage hooks. Also appeared more frequently if bike transported on it's side in the boot more than 20 mins.

Both indicators of air in the system.

You and I are amongst the gods @weeksy.

I’m not amongst the gods but I do follow the whole laborious tappity tap on the brake lines, flickety flick of the lever for however long the gods deem appropriate before I am blessed with no more air bubbles in the bleeding cup of truth.

had the variable bite point once after a bleed, bled them again properly and the brake was back to normal.

I did 1 and 2 combined to be sure. Fixed the problem. 😉

I assume you've done a bleed using a syringe to push fluid up from the caliper to the funnel at the lever OP? And moved the lever in and out while squeezing to get extra bits of air out?

If that hassn't worked, you've got a lemon - and personally I'd replace it with a different Shimano unit.

I honestly haven't had the VBP for years and my MTBs are all Shimano.

Also, I don't know if this is still the case - but it used to seem that the more basic Shimano units (Deore, Zee) might get VBR less often than the SLX and XT.

Do you have to do a full bleed?

Pop the wheel off, push the pistons in and then remount and apply the brakes to re-set everything. Pushes any air at the top back into the m/c... has worked for me with Hope and SRAM. Plus, not storing bikes vertically or on their sides.

I’ve had it on both of my shimano sets and found it was much worse if you used one of those hanging storage hooks. Also appeared more frequently if bike transported on it’s side in the boot more than 20 mins.

Symptom of air in the master cylinder reservoir. They need to be bled properly so the reservoir is full of fluid, without any air.

It’s definitely a well/badly bled issue.
However, the same process of bleeding has given me both perfect, and squidgy brakes at different times.

I have resorted to using the technique I saw Steve Peats mechanic use, which is a complete fluid drain from the lower calliper end, then pump new oil back up through to reservoir screwed into bleed port of master cylinder. Any bubbles are forced out the top and brakes become solid again.

Wastes quite a bit of fluid, but works.

Across the 10 bikes in our house, all with shimano brakes, I’ve done quite a lot of bleeding. Some have never needed it, some need it a lot.

Also, the bikes that get used a lot, never get the seal ‘microleak’ issue, as the seals stay well oiled. The ones that get used infrequently, ALWAYS get it after a year or so.

I plan to try a ‘Shigura’ setup soon to see if they’re as good as people suggest.

Hope E4 caliper with RX4 mineral oil seals, and shimano lever is an option.

Also, the bikes that get used a lot, never get the seal ‘microleak’ issue, as the seals stay well oiled. The ones that get used infrequently, ALWAYS get it after a year or so.

I just came across my first set of leaky Shimano calipers in some Tiagras on a secondhand bike, there might be something in your theory about regular use.

I plan to try a ‘Shigura’ setup soon to see if they’re as good as people suggest.

I had a quick go on my friend's Shigura's - they were by some margin the most abruptly powerful (aka grabby) brakes I've ever used.

He loves the feel, I much prefer the standard Shimano feel. I wonder if they're all like that though.

Hope E4 caliper with RX4 mineral oil seals, and shimano lever is an option.

The Shimano levers are the source of the variable bite point. They are slightly tricky to bleed, plus the ServoWave mechanism magnifies the effect of air in the system.

A good bleed is not hard. Get the fill cup and watch the you tube video.

Crack on and it’ll only take you and hour or so.

Bought a bike with a set of Saints on it, first Shimano brakes I’ve had in years. In a shocking turn of events, both have standard Shimano VBP 😆

Bled them, after scouring the internet on the various ‘insider’ ways to get the perfect bleed, bled them again, and again & generally wasted many hours of time trying to get them right. Might as well have resorted to voodoo dances & rituals 🙄

Gave up, fitted my spare Code RSC’s, for which I had to even split the hose due to stupid internal routing, put it back together, gave the lever a squeeze & it was rock solid. No more worrying about brakes.

Bled them, after scouring the internet on the various ‘insider’ ways to get the perfect bleed

Bleed instructions are on the Shimano website.

A good bleed is not hard. Get the fill cup and watch the you tube video.

Crack on and it’ll only take you and hour or so.

The words of a none believer. I envy the fact you've never dealt with a duff set of Shimano brakes.

Bought a bike with a set of Saints on it, first Shimano brakes I’ve had in years. In a shocking turn of events, both have standard Shimano VBP 😆

My first experience on it was with Saints. Fitted to a DH bike and taken straight to the Alps. I spent every night bleeding the bastards, wondering what I was doing wrong. This was nearly 10 years ago and the breaks are still the same and people are having the same issues.

I have had the wandering bite poiunt on a few sets.

I found the technique used in this video worked the best

Seen Marshy’s bleed technique posted on here a while back and gave it a try. Works for me:

https://m.youtube.com/watch?v=piWBVDh1pTE

Ha! Great minds etc…

I’m aware that a good bleed should sort the issue, but that's only achievable by the gods and not mere mortals.

No it's not, I was going to quote the above easy bleed, but it's been done 😀 literally takes 30minutes tops to do a bike like that, even if you're not exactly mechanically minded.

I've had Shimano brakes for over 10 years from non-series long lever thingies to XTR M9100 and also GRX and Ultegra hydraulics and never had this. Then again I generally use shimano rotors and OE pads, I did use UberBike Race Matrix for a while, but they went downhill in feel and power and switched back to Shimano Resins on everything.

I’m always baffled by this as i’ve never ever experienced it, despite having owned dozens of sets of Shimanos in the last 20 years.

Me too 🤔

No it’s not, I was going to quote the above easy bleed, but it’s been done 😀 literally takes 30minutes tops to do a bike like that, even if you’re not exactly mechanically minded.

Or it doesn't, which is the big problem here. Bleeding should consistently be a doddle and shouldn't be that mess of a process where you're letting oil piss out of the bleed hole (not even using the nipple). I've warrantied Shimanos for this, I've also had brand new brakes suffering from VBP and most recently I've swapped by TRP levers for XTs. One is fine the other is being an absolute **** to sort out (tbf not varying in Shimano style, just not bleeding nicely) even after using the Marshy method. By contrast, when the setup was full TRP, you would've had to have gone out of your way to bleed them badly.

shouldn’t be that mess of a process where you’re letting oil piss out of the bleed hole

Why on earth would you want to do that?

Bleeding should consistently be a doddle

This is what it boils down to in my opinion. This Shimano problem is so widely reported that I think they should already have looked at why and sorted it.

Why on earth would you want to do that?

It’s the method employed in the Marshy video above. Marshy is probably responsible for the scarcity of Shimano brake fluid a year or so ago

😂

The way I bleed them is to screw the funnel into the master cylinder and put fluid in that, then connect a syringe to the caliper and draw fluid out until the syringe is full, then reverse the direction and use the syringe to force the fluid back through the system. Then close the bleeder and you should have a good solid lever. Then repeatedly squeeze and release the lever to get any remaining air bubbles out of the reservoir. It's a good idea to adjust the lever position a bit to make sure the bubbles can float up to the transfer port and up into the funnel. It does not waste fluid and seems to work fine. Key thing is to make sure you have all the air out of the reservoir.

I use two syringes, one attached either end. Start by pushing fluid in the caliper until it's coming out clean at the lever. If it's really manky, this is where you might want to empty the top syringe and half fill with clean fluid.

Tie the lever off and then squeeze and suck at the caliper to remove all air from the caliper.

Release the lever and push fluid in at the caliper to push air out of the lines into the reservoir. Tie the lever off, remove caliper syringe and refit bleed nipple.

Release the lever and now push and suck the lever syringe to remove any air from the master cylinder reservoir.

It's quick and clean while using minimal fluid. You just need to think about what you're trying to achieve.

I solved this by buying a set of hope e4 and v4.

The Shimano brakes have been shunted on a bike that gets ridden with my 3 year old sitting on it.

Not braking very much and never braking hard has solved the problem.

The hopes haven't been problem free, but they haven't suddenly and alarming had a different and unexpected amount of power for a given squeeze.

QWERTY before you go and spend big on new Magura parts could I recommend you try Putoline 2.5 shock oil. It is also mineral oil but slightly thinner than the Shimano variant. This allows the air trapped to be purged easier from the system. Cost of a 1lt bottle around £10
Been running this in my Shimano XT and Saints for over a year both locally and on a trip to the Alps with zero problems and with zero bite point issues.

I agree that a bleed should be simple and easily repeatable by 5he average home mechanic. I’ve had lots of Shimano brakes over the years (Deore, XT, SLX, Saint and Zee) and they’ve nearly all suffered from it at one point or another. You shouldn’t have to buy special expensive after market fluid or spend an hour to bleed them.

I'm going to have to plant my flag in the baffled camp here. Yes, I sometimes have to give my brakes a pump after they've been stored vertically, but even the cheaty 'bleed' where I just add some fluid at the lever and give everything a tap and a pump has always worked well for me, MTB or road, MTB being easier. It's fundamentally pretty simple - push fluid at the lever which pushed the piston at the other end - only air in the system or a pretty big leak can affect this badly.

Swings and roundabouts - I've recently started using SRAM, which does seem to be more solid six months after my initial bleed, but I did manage to peel some paint off an inconsequential workshop stool doing that (more complex) bleed!

lardman
Free Member

It’s definitely a well/badly bled issue.

I reckon it is. But, like with some other brakes, the amount of problems people have is ridiculous and definitely a problem with the brake. Bleeding is 100% a solved problem, it shouldn't be hard at all. Maybe if it was a side effect of some peformance-adding bit of design that'd be OK, but it doesn't seem to be. So basically a brake that causes this much hassle bleeding, is a bad brake.

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.