Nerding out on Brakes shall we? Not another tech deraliment

notthatbryan
Posts
435
Joined
3/8/2023
Location
Acworth, GA, USA
3/17/2025 9:57am
I see Maguras being the primary brake for most guys ridiing trials. I'm definitely generalizing but for a group that needs powerful brakes they seem to...

I see Maguras being the primary brake for most guys ridiing trials. I'm definitely generalizing but for a group that needs powerful brakes they seem to gravitate to them. Or is it more technique? I know little about trials riding skills. 

ex-ballz wrote:

Do they ever go faster than 2MPH? Very fine control of wheel slip is likely the key ingredient here, not strength or performance under duress.

Plus it's a holdover from the good old days of HS33 hydro rim brakes and ground braking tracks. Magura was the king of the hill for trials brakes long before disc brakes became a thing in MTB.

3
JVP
Posts
233
Joined
4/20/2016
Location
Bellingham, WA, USA
3/17/2025 10:00am
yzedf wrote:

Free returns with Prime for 30 days. Easy enough to figure out in that time frame. 

Fake pads will ruin your rotors in a handful of rides. I learned this the hard way, cut short a big Whistler day for me and ended out being an expensive mistake. Buying a full set of pads and rotors in Whistler isn't fun. Chains and pads are pretty much guaranteed to be fakes on Amazon/Ebay/Alibaba/Walmart/Temu/etc, especially if they're listed at <50% MSRP. 

If informed Vital posters are making this mistake, just how many average weekend warriors are ruining their shit with all these fakes? The scale of Amazon is so huge it's hard to believe, all the counterfeits lumped into the co-mingled inventory is a massive problem for the industry.

4
3/17/2025 10:11am

I've always been wary of buying anything bike-related on Amazon. The only thing I do buy is tools because of how seldom I use them although their tolerances aren't amazing. 

On the topic of pads, has anyone here tried sintered Koolstop pads? They are significantly cheaper than Shimano pads/Galfers/other big brands. 

3
Primoz
Posts
4680
Joined
8/1/2009
Location
SI
3/17/2025 10:30am

Speaking of plastic guns and Magura MC issues, I'm wondering how much it has to do with the design. Would having a Shimano/Sram/etc.-esque master cylinder with maybe also more bracing to the bar and less protrusion overall make things better for Magura?

1
3/17/2025 11:25am
I see Maguras being the primary brake for most guys ridiing trials. I'm definitely generalizing but for a group that needs powerful brakes they seem to...

I see Maguras being the primary brake for most guys ridiing trials. I'm definitely generalizing but for a group that needs powerful brakes they seem to gravitate to them. Or is it more technique? I know little about trials riding skills. 

ex-ballz wrote:

Do they ever go faster than 2MPH? Very fine control of wheel slip is likely the key ingredient here, not strength or performance under duress.

Plus it's a holdover from the good old days of HS33 hydro rim brakes and ground braking tracks. Magura was the king of the hill for...

Plus it's a holdover from the good old days of HS33 hydro rim brakes and ground braking tracks. Magura was the king of the hill for trials brakes long before disc brakes became a thing in MTB.

Yup the hydro rim brakes were the best thing back when disc brakes didn't have the raw torque to hold a wheel locked, and Madura were one of the few companies to make trials-specific brakes. Maybe they still do? But I dont think sram or shimano really put any effort in to the trials market

3
Evil96
Posts
875
Joined
8/21/2014
Location
Portogruaro, VE, IT
3/17/2025 11:47am
DServy wrote:
Current Magura mt5/7 race pad cost for one set of pads on Jenson screenshotted below. Sure you can find them cheeper online elsewhere, but if the...

Current Magura mt5/7 race pad cost for one set of pads on Jenson screenshotted below. Sure you can find them cheeper online elsewhere, but if the MSRP is $60 USD(!) a pad then that's what they go for at things like local bike shops and such. And yeah you could get them cheeper online, but that doesn't always work in the "heat of the moment" if you're on a big trip or need them yesterday.

 As for bleeding Magura, just say no. Their levers require so much damn gymnastics to get all the air out of, and woe to you if need to swap pads without a brake bleeding kit on hand because you'll probably blow the master cylinder or accidentally get air into the lever. I know there are people who can make them work, but with my tiny monkey brain and skills I much rather have bleed fittings with screw on threads then the bargain basement syringes you get in a Magura bleed kit.

And I've been a hater of SRAM dot brakes for a long time, but they have really changed my mind with the mavens as they have tended to hold a bleed better than any brake I've used. Also, every brake on the planet should have the "bleeding edge" connector on the caliper, it's just that good.
 

Screenshot 2025-03-17 at 6.37.29%E2%80%AFAM

i mean it might help that i had mt7 for 4 years, i did pads swap in the parking lot at the bike park plenty of times, a cup with a little bit of oil, clean piston, push in, fresh pads, always tidy with no air and adjusted in minutes, ready to go, i really don't see the problem, same as shimano with the difference those will have air all the times inside no matter what.

as per the bleeding, yes, knowing where the bleeding holes and master access holes are inside the lever help a ton to know where to orientate the lever while bleeding, instead of following the magura official procedure, but then again, just like for every brake, there's always tips and tricks.

so far i believe the fastest and easiest brake to bleed that doesn't require any extra work is any of the hopes with that car/moto style bleeding system, a tad messy but 100% effective in minutes. Perhaps the only one easier are the Impossible to get Intends.

also, impressed to see the mrp in the us, pretty wild!

2
1
TEAMROBOT
Posts
1579
Joined
9/2/2009
Location
Los Angeles, CA, USA
Fantasy
3/17/2025 12:24pm
Primoz wrote:
Speaking of plastic guns and Magura MC issues, I'm wondering how much it has to do with the design. Would having a Shimano/Sram/etc.-esque master cylinder with...

Speaking of plastic guns and Magura MC issues, I'm wondering how much it has to do with the design. Would having a Shimano/Sram/etc.-esque master cylinder with maybe also more bracing to the bar and less protrusion overall make things better for Magura?

I'm just an idiot, not an ME, but I've been wondering the same thing about Magura master cylinders. Every design needs to be built around the material you're using, i.e. a house should look different if it's made of wood or made of concrete, and a frame should look different if it's made of steel or aluminum. If the Magura MC's break so often, maybe it's not the material, it's just the design. To use another example from this thread, a Glock is a hell of a lot blockier than a Beretta because they're designed around different material properties. Maybe Magura needs to use more material. The material itself is super light, so it doesn't seems like it add a substantial amount of weight. And if the tiny wood screws they use keep pulling out of the plastic or stripping the inside of the lever body... maybe bigger screws or deeper threads? Doesn't seem like rocket science. But again, I'm just an idiot.

1
Primoz
Posts
4680
Joined
8/1/2009
Location
SI
3/17/2025 12:30pm

Wood screws are actually a very good choice for the material - the softer it is, the more bracing you need against the material, thus deeper threads. The finer they are, the easier it will be to strip them.

Bigger screws maybe, inserts would help, but would be expensive (I think Magura's masters are straight plastic with nothing else added? Including a straight plastic master cylinder bore?). My thinking was that a more Sram/Shimano-esque master would be closer to the bar so an impact would apply less bending torque, force, etc., to the bar interface vs. their current, fairly long and completely perpendicular-to-the-bar master cylinder. With a lever long enough anything will break.

2
Nobble
Posts
228
Joined
9/24/2010
Location
Lakewood, CO, USA
3/17/2025 12:37pm
Primoz wrote:
Speaking of plastic guns and Magura MC issues, I'm wondering how much it has to do with the design. Would having a Shimano/Sram/etc.-esque master cylinder with...

Speaking of plastic guns and Magura MC issues, I'm wondering how much it has to do with the design. Would having a Shimano/Sram/etc.-esque master cylinder with maybe also more bracing to the bar and less protrusion overall make things better for Magura?

TEAMROBOT wrote:
I'm just an idiot, not an ME, but I've been wondering the same thing about Magura master cylinders. Every design needs to be built around the...

I'm just an idiot, not an ME, but I've been wondering the same thing about Magura master cylinders. Every design needs to be built around the material you're using, i.e. a house should look different if it's made of wood or made of concrete, and a frame should look different if it's made of steel or aluminum. If the Magura MC's break so often, maybe it's not the material, it's just the design. To use another example from this thread, a Glock is a hell of a lot blockier than a Beretta because they're designed around different material properties. Maybe Magura needs to use more material. The material itself is super light, so it doesn't seems like it add a substantial amount of weight. And if the tiny wood screws they use keep pulling out of the plastic or stripping the inside of the lever body... maybe bigger screws or deeper threads? Doesn't seem like rocket science. But again, I'm just an idiot.

Funnly enough, Glock doesn’t use fiber reinforcement in their frames.


I just found that out when I went to look into what they’re made of. Allegedly it’s a proprietary polyamide blend.


I bet the surface finish requirement on the master cylinder is a constraint on what materials or fiber infill Magura can use. It’s also possible they have a massive sunk cost in injection molding tooling/equipment that drives them to continue the plastic levers.

1
Primoz
Posts
4680
Joined
8/1/2009
Location
SI
3/17/2025 12:53pm

Gustav is all new in design which means new tooling. And with high quantities of carbon fibres, tools will wear out fast.

If done correctly the bore can be smooth even with abrasive fibres in there. Might cause issues with the seals that have been mentioned in this thread too, but the surface of plastic parts can generally be fairly smooth even when fibres are used.

TEAMROBOT
Posts
1579
Joined
9/2/2009
Location
Los Angeles, CA, USA
Fantasy
3/17/2025 1:02pm
Nobble wrote:
Funnly enough, Glock doesn’t use fiber reinforcement in their frames.I just found that out when I went to look into what they’re made of. Allegedly it’s...

Funnly enough, Glock doesn’t use fiber reinforcement in their frames.


I just found that out when I went to look into what they’re made of. Allegedly it’s a proprietary polyamide blend.


I bet the surface finish requirement on the master cylinder is a constraint on what materials or fiber infill Magura can use. It’s also possible they have a massive sunk cost in injection molding tooling/equipment that drives them to continue the plastic levers.

That's all interesting, but to reiterate my question in a shorter form: why not add more material until it stops breaking?

AndehM
Posts
797
Joined
5/7/2018
Location
El Granada, CA, USA
Fantasy
3/17/2025 1:09pm

The fiber reinforced plastic Magura uses wouldn't handle tensile loads very well (compare to carbon fiber which has a fabric grid).  No surprise that it breaks so easily from minor crashes.  I had a set snap at the lever pivot on a trivial crash myself.

Back in the late 90s, I used to paintball a bunch, and had a gun that used a similar fiber reinforced plastic material for the grip/trigger frame.  I had it snap off at the mounting bolts to the receiver one cold morning.  I never saw that happen to any of the other brands that used aluminum for the grip/trigger frame.

As to why Magura uses it still, it's probably a combination of sunk cost and German-ness.

1
Eae903
Posts
466
Joined
10/20/2023
Location
Not Saying., WY, USA
Fantasy
3/17/2025 1:43pm
I see Maguras being the primary brake for most guys ridiing trials. I'm definitely generalizing but for a group that needs powerful brakes they seem to...

I see Maguras being the primary brake for most guys ridiing trials. I'm definitely generalizing but for a group that needs powerful brakes they seem to gravitate to them. Or is it more technique? I know little about trials riding skills. 

We should talk about the difference between static friction and kinetic friction. Basically, all friction is calculated using the equation of F (or N) times Mu, f being force, either from weight (the normal force, how much the surface you are on is pushing back against you perpendicular to its surface) or how much force you are putting into the surface and Mu being a coefficient that is dependent on the two material that are rubbing against each other. There are two Mus for every combination, one for static friction the force preventing slipping, and kinetic friction, the force once there is slipping. The Mu value for kinetic friction is always lower than the Mu for static friction which means that there is always more force required to start something slipping, than it takes to keep it slipping. With trials, most of the time brakes are going to be operating in the static friction area, so less force is required to keep the wheels from slipping. Trials bikes use pretty small rotors compared to most mountain bikes, I would suspect mostly because weight is a much more important factor for trials than all out power. 

This is only looking at the forces between the pads and the rotor, so it doesn't cover every but of friction that keeps the wheels from moving, but it's a start. 

Basically, a powerful brake is a brake that delivers enough force to the rotor, that the maximum static friction between the tire and the dirt can't exert enough force to keep the tire rolling, locking up the wheel. Tons of variables there, once we start considering different rubber compunds and riding surfaces, so we focus more in on how much force the brake can put out at the Caliper, not to mention heat management and how that power is delivered (modulation). Understanding braking is a blend of classical mechanics, fluid mechanics, material sciences, and thermodynamics all at the same time. I love thinking about this but for most people, pull on lever to stop wheel from moving is good enough haha.

2
3/17/2025 1:43pm
Nobble wrote:
Funnly enough, Glock doesn’t use fiber reinforcement in their frames.I just found that out when I went to look into what they’re made of. Allegedly it’s...

Funnly enough, Glock doesn’t use fiber reinforcement in their frames.


I just found that out when I went to look into what they’re made of. Allegedly it’s a proprietary polyamide blend.


I bet the surface finish requirement on the master cylinder is a constraint on what materials or fiber infill Magura can use. It’s also possible they have a massive sunk cost in injection molding tooling/equipment that drives them to continue the plastic levers.

TEAMROBOT wrote:

That's all interesting, but to reiterate my question in a shorter form: why not add more material until it stops breaking?

because reducing weight is absolutely the most important thing on a bike and must be done AT ALL COSTS

4
Eae903
Posts
466
Joined
10/20/2023
Location
Not Saying., WY, USA
Fantasy
3/17/2025 1:44pm
Nobble wrote:
Funnly enough, Glock doesn’t use fiber reinforcement in their frames.I just found that out when I went to look into what they’re made of. Allegedly it’s...

Funnly enough, Glock doesn’t use fiber reinforcement in their frames.


I just found that out when I went to look into what they’re made of. Allegedly it’s a proprietary polyamide blend.


I bet the surface finish requirement on the master cylinder is a constraint on what materials or fiber infill Magura can use. It’s also possible they have a massive sunk cost in injection molding tooling/equipment that drives them to continue the plastic levers.

TEAMROBOT wrote:

That's all interesting, but to reiterate my question in a shorter form: why not add more material until it stops breaking?

That's a great question that I don't know the answer too. Maybe the cost, maybe weight, maybe it's a lot harder to mould. The only people who would know are magura 

1
notthatbryan
Posts
435
Joined
3/8/2023
Location
Acworth, GA, USA
3/18/2025 5:11am

Funny enough, I work for Glock Wink

1
Primoz
Posts
4680
Joined
8/1/2009
Location
SI
3/18/2025 12:15pm Edited Date/Time 3/18/2025 12:18pm
AndehM wrote:
The fiber reinforced plastic Magura uses wouldn't handle tensile loads very well (compare to carbon fiber which has a fabric grid).  No surprise that it breaks...

The fiber reinforced plastic Magura uses wouldn't handle tensile loads very well (compare to carbon fiber which has a fabric grid).  No surprise that it breaks so easily from minor crashes.  I had a set snap at the lever pivot on a trivial crash myself.

Back in the late 90s, I used to paintball a bunch, and had a gun that used a similar fiber reinforced plastic material for the grip/trigger frame.  I had it snap off at the mounting bolts to the receiver one cold morning.  I never saw that happen to any of the other brands that used aluminum for the grip/trigger frame.

As to why Magura uses it still, it's probably a combination of sunk cost and German-ness.

Most users probably don't have any issues. The few that do sooner or later buy Shimano levers.

As to why not add more material, it's not the material itself, it's also what you do with it. You don't have aluminium bearing races, but it's fine for frames. You have to take care of the design and adapt it to the material you're using.

Mounting a structural plastic part to the bars is HAAAAAARD. Unless you want 10 mm screws either side of your bars and a 50 mm high master cylinder that is 100 mm long. Then it would probably work fine.

1
FaahkEet
Posts
100
Joined
3/12/2023
Location
Falls Church, VA, USA
3/21/2025 9:19am

I'm using A4 calipers with HardHeaded Ram sintered pads and TrickStuff Dachle HD front/HS2 rotor rear, only noisy when wet and great stopping power.

See no need for the Hayes D rotors, except to just try them out maybe at some point. 

3/22/2025 8:49am

My experience has been that Hayes rotors howl at a lower pitch than some, but just as loudly (when wet with metallic pads).

2
3/22/2025 1:30pm

Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)

I swapped out the pads to shimano metal(non finned) and Galfer Wave rotors (223 and 203) - ensured perfect alignment and equal piston movement to hit at the same time
Bedded them in via normal process on a hill i live on(like i do with every other bed in process)

Initially the brakes Grabbed really hard But after a couple of trails the perfomance fell off and was bad vibration, the Hummmm sound and could feel it through the bars - they still worked and didnt have that contamination feel or sound.(both front and rear)

checked pads, rotors and caliper and no oil or anything - went for anther ride and same performance, strong to start but heavy braking and vibration and performance falls off at same time

theres no oil from pistons or leaking etc 2 very high end botique shops(1 ex WC mechanic)  checked them and they couldnt find an issue.

the pads and the rotors look perfect - it's so weird, they go fine but under heavy braking they vibrate and the performance falls off each time

1
3/22/2025 1:40pm
Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)I swapped...

Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)

I swapped out the pads to shimano metal(non finned) and Galfer Wave rotors (223 and 203) - ensured perfect alignment and equal piston movement to hit at the same time
Bedded them in via normal process on a hill i live on(like i do with every other bed in process)

Initially the brakes Grabbed really hard But after a couple of trails the perfomance fell off and was bad vibration, the Hummmm sound and could feel it through the bars - they still worked and didnt have that contamination feel or sound.(both front and rear)

checked pads, rotors and caliper and no oil or anything - went for anther ride and same performance, strong to start but heavy braking and vibration and performance falls off at same time

theres no oil from pistons or leaking etc 2 very high end botique shops(1 ex WC mechanic)  checked them and they couldnt find an issue.

the pads and the rotors look perfect - it's so weird, they go fine but under heavy braking they vibrate and the performance falls off each time

Yeah that's pretty strange, a couple of questions-

Are front and rear equally bad?

Were the rotors new?

Are they bled with brand new fluid?

What frame/fork is it?

 

1
3/22/2025 2:03pm

Yeah that's pretty strange, a couple of questions-

Are front and rear equally bad?

Were the rotors new?

Are they bled with brand new fluid?

What frame/fork is it?

 

Yes, front seems worse but i assume from more braking load.

Everything brand new, I did a lever bleed only before i changed them out and to push piston back due to 2mm rotors.(used a brand new tyre lever)

latest Canyon torque CF with a fox 38.

Everything was clean and ensured Calipers were tight. 

1
Eae903
Posts
466
Joined
10/20/2023
Location
Not Saying., WY, USA
Fantasy
3/22/2025 3:07pm
Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)I swapped...

Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)

I swapped out the pads to shimano metal(non finned) and Galfer Wave rotors (223 and 203) - ensured perfect alignment and equal piston movement to hit at the same time
Bedded them in via normal process on a hill i live on(like i do with every other bed in process)

Initially the brakes Grabbed really hard But after a couple of trails the perfomance fell off and was bad vibration, the Hummmm sound and could feel it through the bars - they still worked and didnt have that contamination feel or sound.(both front and rear)

checked pads, rotors and caliper and no oil or anything - went for anther ride and same performance, strong to start but heavy braking and vibration and performance falls off at same time

theres no oil from pistons or leaking etc 2 very high end botique shops(1 ex WC mechanic)  checked them and they couldnt find an issue.

the pads and the rotors look perfect - it's so weird, they go fine but under heavy braking they vibrate and the performance falls off each time

Looking through this, I have to ask if your rotors are center lock or if they are 6 bolt, and what they are torqued too? Chasing vibrations is a pain, but torque is a good place to start. Same thing with the caliper fixing bolts but I don't usually think they would be the issue. Resurfacing the pads and the rotor could also help, if they came out of the factories not as flat as they could be. 

3
Finkill
Posts
239
Joined
9/2/2015
Location
GB
3/22/2025 3:09pm

I would second the suggestion to resurface the pads and rotor. 

2
3/22/2025 3:13pm Edited Date/Time 3/22/2025 3:19pm
Finkill wrote:

I would second the suggestion to resurface the pads and rotor. 

I have tried this, I've even tried new pads and rotors(same) - Because I bought lots of these from a shop going under so have many years worth of Wave rotors.

6-bolt rotors, Torqued to Galfer spec which i believe is 4NM for the Wave's.
I use Wave rotors With Mavens with Zero issues.

1
sethimus
Posts
954
Joined
9/20/2014
Location
CH
3/22/2025 3:52pm
Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)I swapped...

Question for the nerds, I dont have trouble with Brakes, generally ever But i picked up a bike with 4 piston XT m8120's(brand new bike)

I swapped out the pads to shimano metal(non finned) and Galfer Wave rotors (223 and 203) - ensured perfect alignment and equal piston movement to hit at the same time
Bedded them in via normal process on a hill i live on(like i do with every other bed in process)

Initially the brakes Grabbed really hard But after a couple of trails the perfomance fell off and was bad vibration, the Hummmm sound and could feel it through the bars - they still worked and didnt have that contamination feel or sound.(both front and rear)

checked pads, rotors and caliper and no oil or anything - went for anther ride and same performance, strong to start but heavy braking and vibration and performance falls off at same time

theres no oil from pistons or leaking etc 2 very high end botique shops(1 ex WC mechanic)  checked them and they couldnt find an issue.

the pads and the rotors look perfect - it's so weird, they go fine but under heavy braking they vibrate and the performance falls off each time

switch to galfer pads, i had the same problem with finned shimano metal pads on m8120 with sharkfin discs. 

2
yzedf
Posts
283
Joined
1/27/2015
Location
Hebron, CT, USA
Fantasy
3/22/2025 5:16pm

Putoline HPX R 2.5 weight seems to be a popular fix in Europe for weird bleed related issues. 

3/23/2025 6:07am

Interesting review from Dale Stone on Hope T4V4, i'd say i agree with everything said:

 

5
Finkill
Posts
239
Joined
9/2/2015
Location
GB
3/23/2025 6:19am

I liked his description of the power delivery being about position through the lever travel, rather than force applied to the lever. Great way to describe the feeling. Overall agree with the review, love my V4s 

2
Evil96
Posts
875
Joined
8/21/2014
Location
Portogruaro, VE, IT
3/23/2025 11:19am

Interesting review from Dale Stone on Hope T4V4, i'd say i agree with everything said:

 

only one things is effectively wrong, the inconsistent bleeding is user error, just by looking at the membrane you can easily understand how you should roll it to not trap any air, and the opposite has been done, but agree on the rest, even if even the Hope statement that there's no difference between the normal hose and the braided one is bullshit, the latter is way stiffer and gives a much firmer bite point.

 

1

Post a reply to: Nerding out on Brakes shall we? Not another tech deraliment

The Latest