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Birzman Disc Brake Piston Pusher

3
£54.99

VERDICT:

3
10
Great idea that unfortunately is not delivered on by this tool in a reliable manner
Feels premium
Didn't work for most callipers
Difficult to get in place
Won't push four pistons squarely
Price
Weight: 
213g

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The Birzman Disc Brake Piston Pusher is designed to make the maintenance chore of replacing disc brake pads easier by pushing the pistons back into the calliper. Unfortunately, it fails to achieve those aims in a meaningful and replicable manner.

When replacing disc brake pads, it is essential to first clean inside the calliper to remove any mud or road contamination from around the piston edge, and then push the pads fully back into the calliper ready to accept the new pads. As you use your disc brake and the pads wear, over time the pistons don't retract back as fully as they had. This is an automatic adjustment feature, which means that you can use your pads from new all the way down to replacement, without ever needing to make any adjustments yourself.

The tried and trusted way to get your pistons pushed back into the calliper is to use a 10mm (or so) ring spanner or plastic tyre lever, carefully centring the closed end of the spanner or lever on the centre of the piston and leveraging against the side of the calliper to slowly push the piston back. Another option is a large flat-bladed screwdriver inserted between the worn pads, allowing the screwdriver to push back against a large surface area that you don't care about damaging.

You can buy specific flat tools from the likes of Park Tool and others that will push back pistons in a similar, more-couth fashion. But with care, the ring spanner or tyre lever method is perfectly acceptable and will cause no harm to your calliper.

Regardless of your chosen method, it's critical to thoroughly clean around the piston, so you aren't pushing muck back inside past the seal and into the chamber with the hydraulic fluid. Best suggestions for removing baked-on build-up include using a very fine bottle brush, or a section of cotton string soaked in alcohol and sawed back and forth around the piston while clamping two £1 coins.

The Birzman Disc Brake Piston Pusher seeks to do this job in an even more couth fashion than any sort of other hand tool. By applying force evenly to both pistons at the same time, it slowly pushes them back into the calliper using a handscrew mechanism that applies pressure to both pistons evenly. This means that if one piston is slightly stuck, both will be pushed back without having to chase back and forth between the free and recalcitrant pistons.

In theory this is an excellent idea, but in practice it doesn't work in a consistent manner.

Firstly, there's the issue of clearance. On a number of bikes I found it quite challenging to get the tool inserted cleanly between the pistons in a way that allowed the tool to push back squarely against them. This could be down to either calliper design, where there is a small key to guide new pads in place, or where there is a disc brake mount in the way, particularly in the case of rear callipers bolted closely into the frame. To be fair, in the instructions Birzman notes that for bottom-loading callipers the calliper will almost certainly need to be removed in order to gain clearance. For top-loading callipers it's generally easier to find a way to get the tool in between the pistons.

Secondly, Birzman states that this tool is suitable for four-pot callipers. Again, nice idea, but there is no way that this 23mm-wide tool can push back squarely against all four pistons at once.

Recently I tested the piston release tool from R3Pro, which I have had success in using not only to release stuck pistons, but also to push back a stuck or final piston in a four-pot calliper with care, using a thin, flat-bladed screwdriver.

Finally, even if you can get the tool cleanly inserted between two pistons, the force against the pistons does not end up being applied squarely, resulting in at least one if not both pistons going in slightly askew and almost certainly binding.

I thought this might be down to user error and tried many different combinations of calliper, angle and amount of pressure. I only managed to get one calliper with known-working-well pistons to retract back cleanly.

> Everything you need to know about disc brakes

A scour of internet forums threw up a few similar comments, where purchasers found the tool didn't manage to work as promised. To be fair to Birzman, there were a number of glowing recommendations where it did work.

Conclusion

Owning a bike servicing business, piston pushing is one of the most common tasks I have to perform in the workshop when replacing customers' brake pads. So when I saw the Birzman Disc Brake Piston Pusher, I was keen to get my hands on it and see if it could make what can become a time-consuming and frustrating job much easier and quicker. Unfortunately, the reality did not deliver on the promise, and therefore I cannot recommend this tool.

 

• As a matter of course when a product scores below average, we put our findings to the manufacturer to give them the right to reply.

Birzman says: "All of our products have of course been carefully tested on as wide a range of bikes/frames/parts as we could get our hands on during research and development stage, and we would only state the compatibility of a product if it has proven to work over various trials. It is our responsibility as the manufacturer to ensure the effectiveness of the product after all.

"At the same time, we are aware that due to the diverse specifications of bikes available on the market, there are inevitably limitations, mentioned by the reviewer, to the product when it comes to certain frame/brake designs where the product may not perform as well."

Birzman also says it will be releasing a new Double Ended Piston Pusher, due around September: 

35 mm end for 4-piston callipers e.g. models from Shimano®/SRAM®/TRP®/Hope®

15 mm end for 2-piston callipers and callipers with unique structures e.g. Magura® MT5/7s

Verdict

Great idea that unfortunately is not delivered on by this tool in a reliable manner

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road.cc test report

Make and model: Birzman Disc Brake Piston Pusher

Size tested: One size

Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

The product is designed for people wanting to replace their disc brake pads.

Birzman says: "Like a piston press, but doubled.

"Simultaneously presses pistons back into the calliper with parallel and symmetrically moving panels, the Disc Brake Piston Pusher is a handy tool that prepares the calliper for brake pad replacements."

Tell us some more about the technical aspects of the product?

Birzman lists these features:

Compatible with two- and four-piston brake callipers with an opening wider than 23mm.

Material

Aluminium 6061 / Alloy Steel

Size

Ø23 x 121mm

Weight

220g

Rate the product for quality of construction:
 
8/10

The quality of construction is extremely high, with fine tolerances and a lovely feel in the hand.

Rate the product for performance:
 
2/10

The performance is poor, as I only managed to push back a single pair of pistons cleanly.

Rate the product for durability:
 
8/10

The build quality does feel premium and I have no doubt that if it worked it would give many years of solid service.

Rate the product for value:
 
2/10

Given that the tool didn't work for most callipers tried, the price of £54.99 is exceedingly high.

Tell us how the product performed overall when used for its designed purpose

It does not achieve its designed purpose most of the time.

Tell us what you particularly liked about the product

The build quality.

Tell us what you particularly disliked about the product

The fact that it doesn't work for most callipers.

How does the price compare to that of similar products in the market, including ones recently tested on road.cc?

Compared with the Park Tool or other equivalent hand tools which I know work exceedingly well at this job and cost a fraction of the price, it is extremely expensive.

Did you enjoy using the product? Yes

Would you consider buying the product? No

Would you recommend the product to a friend? No

Use this box to explain your overall score

Given the tool only managed to push back one set of pistons cleanly, I cannot recommend it, and rate it accordingly.

Overall rating: 3/10

About the tester

Age: 47  Height: 183cm  Weight: 77kg

I usually ride: Sonder Camino Gravelaxe  My best bike is: Nah bro that's it

I've been riding for: Over 20 years  I ride: A few times a week  I would class myself as: Expert

I regularly do the following types of riding: cyclo cross, general fitness riding, mtb, G-R-A-V-E-L

Living in the Highlands, Mike is constantly finding innovative and usually cold/wet ways to accelerate the degradation of cycling kit. At his happiest in a warm workshop holding an anodised tool of high repute, Mike's been taking bikes apart and (mostly) putting them back together for forty years. With a day job in global IT (he's not completely sure what that means either) and having run a boutique cycle service business on the side for a decade, bikes are his escape into the practical and life-changing for his customers.

Add new comment

62 comments

Avatar
Steve K | 8 months ago
1 like

Absolutely soaking wet commute this morning.  My disc brakes were squealing like mad when braking.  Annoying, but I still prefer noisily stopping to silently carrying on!

Avatar
BalladOfStruth replied to Steve K | 8 months ago
1 like

Is it just me that gets one initial squeal on the first stop in the wet, then pretty much nothing afterwards? I'd honestly say that on balance, I find rim brakes slightly noisier in the wet than disks. I ran Shimano GRX R800 on my commuter.

Avatar
ErnieC replied to BalladOfStruth | 8 months ago
0 likes
BalladOfStruth wrote:

Is it just me that gets one initial squeal on the first stop in the wet, then pretty much nothing afterwards? I'd honestly say that on balance, I find rim brakes slightly noisier in the wet than disks. I ran Shimano GRX R800 on my commuter.

Ditto for me. 

Avatar
Steve K replied to BalladOfStruth | 8 months ago
2 likes

Mine kept squealing this morning, but it was very very wet.

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ktache | 8 months ago
0 likes

I might get one of these if they make the wider four piston version.

Avatar
wtjs | 8 months ago
4 likes

It's very simple: disc brakes have taken over because they're better. I had never ridden discs until I bought a gravel type bike in October 2019- it has TRP Spyre cable discs. Best general purpose bike I have ever had, and I'm in the Lakes now on a trip with a fairly heavy trailer. Fantastic braking, rims not wearing away.

Avatar
dave_t | 8 months ago
7 likes

I use a pair of old pads with the brake material removed, just put the pads in as normal, stick a flat blade screwdriver in between and twist, the pistons will be pushed back.

Avatar
Steve K | 8 months ago
3 likes

Can I just compliment you, Mike, on the use of the word "couth" (though maybe I'd have given extra credit if you'd said "couther" yes)

Avatar
Boopop | 8 months ago
1 like

That's a shame, pushing pistons back can be tedious. I spent an hour or so trying to get them back in my mechanic stand, then each time it was still rubbing. This tool would be great if it worked.

On the other hand I had to replace brake pads in Italy last month with the bike upside down and just bikepacking kit with me, and my attempt with plastic tyre levers worked first time! 😅

Avatar
wycombewheeler replied to Boopop | 8 months ago
1 like
Boopop wrote:

That's a shame, pushing pistons back can be tedious. I spent an hour or so trying to get them back in my mechanic stand, then each time it was still rubbing. This tool would be great if it worked.

On the other hand I had to replace brake pads in Italy last month with the bike upside down and just bikepacking kit with me, and my attempt with plastic tyre levers worked first time! 😅

I've always used plastic tyre levers, i did buy a piston pusher but it didn't fit (too wide for my calipers). I think the important thing is to clean the pistons (with the correct brake fluid) before pushing them back in.

Avatar
ooblyboo replied to wycombewheeler | 8 months ago
0 likes

I have always used plastic tyre levers and had no problems when replacing pads but recently my local mechanic warned me only to use them with the old pads still inserted. Apparently he finds that if you don't you can crack the pistons if they are too badly stuck. Not sure if this tool would help in that regard or not.

Avatar
Fignon's ghost replied to ooblyboo | 8 months ago
1 like

I prefer to use my plastic tyre levers....to do just that.
There's more room in my kit bag for more important items than say, a rotor truing tool or a piston popper. I can instead pack a delicious pastie or loaf of bread. And a packet of minstrels. All because I don't need to pack mineral oil too.
You see, I'm very grateful to my simple and very effective rim brakes for being completely and utterly maintenance free. Every day...

You guys are bonkers!
Ditch those disks.

Avatar
KiwiMike replied to Fignon's ghost | 8 months ago
8 likes

I love rim brakes. I get to charge customers for new housing, cables, noodles, pads, and eventually rims too. The more they ride, the more often these things need replacing. 

Disc brakes just don't need as much work, mile for mile. Swap pads now and then, quicker and easier than on rim brakes. A 10min bleed every 4-5 years for mineral systems. So yeah, bring back rim brakes, your local mechanic thanks you!

Avatar
lio replied to KiwiMike | 8 months ago
3 likes

Sorry could you repeat that I couldn't hear you over the constant rubbing of disc break pads.

Seems no matter how many times I take the bike back to the smug mecanic in the shop he can't fix it either.  It's alway 1 puddle away from that foresaking rub, rub, rub sound.

Avatar
KiwiMike replied to lio | 8 months ago
5 likes

Find a better mechanic mate. Sorted. 

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Rendel Harris replied to KiwiMike | 8 months ago
0 likes
KiwiMike wrote:

A 10min bleed every 4-5 years for mineral systems. 

What make of brake is this that only needs bleeding every five years? We have three out of six bikes with discs, so I'm hardly an anti, but the longest any of them go without needing a bleed is eighteen months.

You've also left out the need to straighten warped rotors in your "discs are so much easier" eulogy, something I spend quite a few hours on every year! Additionally disc pads need replacing much more frequently than blocks and at a greater cost each time, I reckon we spend at least twice as much annually on pads and bleeding for the disc bikes as we do on parts for the rim brakes, and in forty years I've never worn a brake track out before the hub or the rim has worn out; the longest a rim brake wheel has lasted me has been about 20,000 kms before some bugger nicked the bike.

Avatar
mark1a replied to Rendel Harris | 8 months ago
2 likes
Rendel Harris wrote:
KiwiMike wrote:

A 10min bleed every 4-5 years for mineral systems. 

What make of brake is this that only needs bleeding every five years? We have three out of six bikes with discs, so I'm hardly an anti, but the longest any of them go without needing a bleed is eighteen months.

Mineral systems mentioned, so typically that would be Shimano. Systems that use a DOT hydraulic fluid (such as SRAM) need bleeding more frequently as the fluid is hygroscopic so it absorbs moisture, mineral oils are not and last much longer, at the expense of slightly lower performance at high temperatures. 

Avatar
Rendel Harris replied to mark1a | 8 months ago
0 likes

All three of ours are Shimano and use mineral oil, they still need bleeding round about once every 18 months. Admittedly they are mainly used in very traffic-heavy central London, so probably do a lot more work than some others, but I'd be really surprised if a system only needed bleeding once every five years unless the bike is really lightly used, as in below 2000 km per year.

Avatar
KiwiMike replied to Rendel Harris | 8 months ago
5 likes

I had a GT i-Drive with Shimano discs that I 100% know went eight years before being bled, and that was only because I was selling it. Of course it's all down to how often a bike is being ridden, the type of trail and climate. It's impossible to generalise, apart from mineral lasting way longer than DOT. 

Straightening rotors is only needed if you've been careless putting it down, racking it or have crashed, and the technique is easily learned.

I'll categorically state that you are 100% flat out wrong that disc pads 'need replacing much more frequently'. ***Riding the same bike over the same terrain, through the same filth*** - ie a fair apples-apples comparison - rim-brake block will wear far quicker than a disc pad. Sorry, zero correspondence will be entered into here, the entire world's experienced rider/mechanic population disagrees with you. 

And you're ignoring the massive performance benefits and rider equality (smaller/weaker/disabled hands etc) afforded by discs.

Finally, I've worn two MTB rear rims totally through on V-brakes. I have a cross-section of road bike rim on my desk, where a friend and customer collapsed it through wear riding around Hampshire lanes over a few years. He was a few rides away from a very nasty explosive failure of the rim, likely under hard braking. I own a dental caliper specifically to measure rim wear, and mfrs include wear indicators for safety reasons. I've destroyed a set of rim brake blocks in *one day* on an extremely steep and muddy 80km ride - but rode an entire Scottish winter of enduro trails (1300km) on one pair of sintered pads, on a 26kg eMTB. 

Just because you lack the maintenance skills and analytical approach to understanding brake system wear and cost doesn't mean rim brakes are better. 

Avatar
Rendel Harris replied to KiwiMike | 8 months ago
4 likes
KiwiMike wrote:

 Just because you lack the maintenance skills and analytical approach to understanding brake system wear and cost doesn't mean rim brakes are better.

Nowhere have I said that rim brakes are "better" - if I believed that why, as I stated above, does half our garage have discs? - I simply politely and reasonably pointed out some drawbacks to discs that you didn't mention. I'm not clear as to why you think that warrants such rudeness; you ought to remember the dignity of your office as apparent spokesperson for "the entire world's experienced rider/mechanic population".

Avatar
IanEdward replied to KiwiMike | 8 months ago
1 like
Quote:

Straightening rotors is only needed if you've been careless putting it down, racking it or have crashed, and the technique is easily learned.

Nope. Rotors can warp just from heat, I've fitted new pads and rotors, gone out to bed them in (a 'maintenance' task nobody every mentions for disc brakes) and they've come back warped enough to catch the pads.

 

Avatar
kamoshika replied to Rendel Harris | 8 months ago
5 likes

I've got Shimano disc brakes on my Bullitt cargo bike that haven't needed bleeding once in the almost ten years I've had it. I've changed the rotors a handful of times and the pads once or twice a year, but aside from that they've been maintenance free. I don't do massive distances on it, but ride it almost every day, and being a cargo bike it's often carrying a load.

Avatar
Fignon's ghost replied to KiwiMike | 8 months ago
0 likes

Every single cyclist that I know who wear discs MOAN about their performance. Everyone. Thing is. I never intrude. Never offer advice. I don't think it's my place to do so. IMO. They are, mostly, dedicated followers of fashion.

On here is different.

I find it difficult to believe any cycle mechanic doesn't profit more from disc system work versus the humble rim brake.

I've over 30 years fixing bikes and know how tricky disc systems can be. And to get back to point. I don't need to carry all the sos kit should the disc system FAIL, WARP or STICK.

Avatar
KiwiMike replied to Fignon's ghost | 8 months ago
7 likes

Are you serious? I mean, really? You think every cyclist should be on rim brakes because every cyclist you know is a fashionista (ie you look down on them) who moans about discs?

Here's a counterpoint: in the real world where I live, everyone on discs - and I include pretty much all my customers here - prefers them over rim brakes for power, all-weather performance (ie SAFETY) and lower maintenance. Yes, they are aware that if not set up using OEM pads, or if contaminated, they can be noisy. And if they aren't moderately careful, rotors might need a 30-second truing. These are compromises people are happy to accept in return for massive benefits  

Pro tip: if your mechanic can't stop your discs squealing, *find a better mechanic*.

And what's a 'SOS kit' for disc brakes? I ride enduro trails almost daily. I don't carry a single item of brake-related kit, because in 30 years riding discs, I've not had a single brake-related failure mid-ride. I *have* worn out new rim brake pads in a single ride (42 Traverse, North Island NZ, winter, Shimano Exage 300 canti pads), had brake cables freeze solid, seen sticks destroy canti arms, etc etc. Do you carry a rim brake SOS kit? Yeah?

The only place I see people following fashion is on here, where it's fashionable to make out that discs are forced on a gullible population by The Man. 

Avatar
IanEdward replied to KiwiMike | 8 months ago
2 likes
Quote:

Pro tip: if your mechanic can't stop your discs squealing, *find a better mechanic*.

Nope. Disc brakes squeal, not always, not for everyone (I'm hugely jealous of those who don't experience it) but they can squeal, especially in the wet.

Manufacturers have admitted it, I've had different mechanics in different shops admit there is nothing they can do about it, and as a competent home mechanic who can keep discs running sweet and quiet in the dry, I've yet to figure out how to keep them running sweet and quiet in the wet. It's why I still won't use discs even on gravel or CX, I'll take the downsides of rims brakes for a (literally) quiet life.

For what it's worth I think it's something to do with extended bedding in, my MTB discs eventually quietened down after being absolutely cooked by the sort of prolonged braking my road or gravel bike will never experience.

Avatar
KiwiMike replied to IanEdward | 8 months ago
1 like

Repairing thousands of bikes over the years, I can only recall one where I could not silence noise, even with new pads and rotors. It was a no-brand dirt-cheap set, that seemed to have in-built resonators, not helped at all by the loosely-fitting fork stanchions and headset/wheel bearings. Every other bike I have vanquished squealing brakes from by cleaning calipers, lubing pistons, replacing pads and either sanding, burning off or replacing rotors. Also facing mounts to be 100% square does wonders for noise and rotor rubbing.  And yes a proper really-hot bedding-in process does wonders. I suspect many bike shops don't bother with the multiple hard sprints needed to do this properly, or don't buy a Cyclon or Bonas bedding-in machine. 

I'm not discounting that many struggle to silence discs. Just saying that if you follow process, it's almost always successful. 

Avatar
IanEdward replied to KiwiMike | 8 months ago
0 likes

Yeah, I'd be interested to find a shop with a bedding in machine.

I don't brake hard enough or often enough on my gravel or road bikes to properly burnish the rotors I think, which means they work great in the dry but howl in the wet. The MTB brakes are OK but they get an occasional roasting on some steep local trails.

I think bedding in machines should be standard issue in shops now, but do they cause tyre wear?

Avatar
mark1a replied to IanEdward | 8 months ago
0 likes
IanEdward wrote:

I think bedding in machines should be standard issue in shops now, but do they cause tyre wear?

I wouldn't have thought so, I've just investigated the CyclOn SBR, it spins the wheel at 25km/h and you brake without locking up for 15-20 seconds, repeat 3-4 times. I very briefly considered that I really needed one in my life, but then quickly came back to the reality that I don't change brake pads & discs that frequently at all, and I could just carry on doing what I do now which is ride up to the end of my road and and return under braking several times.  

Avatar
Fignon's ghost replied to IanEdward | 8 months ago
0 likes

IMO. The point is. If you're well experienced at cycle repairs/general maintenance and enjoy/need extensive use of your bike. You'll be motivated and in a strong position to manage disc brake issues.
However, for the majority of cyclists. It is a casual and less essential leisure activity. It'll also mean they're likely to be less inclined to know how to solve the dreaded stick, squeal or squawk of disc brake issues.
My concern is that those who do have a bad experience using their disc brake bicycle may not be encouraged to continue with that experience. Primarily due to an over engineered brake system that is not necessary for casual riding around local cycle lanes, parks and tow paths.

We are supposed to encourage more and more people take up cycling. For the many benefits it brings. So, when the disc brake lot pipe up in their defence. Just think of those people who will have dropped their bicycle into the deep, dark recesses of their shed or garage. All because manufacturers have stopped adding rim brakes to almost all bicycles.
By way of encouragement. The cycling community needs to consider the wider implications of disc brake experience amongst the "General" population.
There is no doubt in my mind. People are put off from cycling because of the common problems introduced by the disc brake.

Avatar
HoldingOn replied to Fignon's ghost | 8 months ago
1 like

My first commuter bike (two years ago) had rim brakes and they annoyed me. No matter how much i "tweaked" them, I couldn't get them to sit clear of the rim & be close enough to actually press onto the wheels when I needed them.

When I "abused" that bike to being beyond feasible repairs (abused was the bike shop term) I replaced it and sought disc brakes (mechanial not hydraulic). Been much happier with them. I find them so much easier to "tweak". Pads are a little fiddly to replace, but so were the rim pads. I have had some pads squeal, but I am happy to ignore it if it means I am not cycling against the brakes!

Definitely not put off by disc brakes and find the maintenance much easier.

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