[iRider]

Hi Guys, Please excuse me for dropping in here on a scintillating conversation that Trick Stuff may have stock and it may even be cheap but i suffered a bit of a head banger last week and I have searched high and low for an answer which isn't coming. Maybe your guys could please help.

I have a new set of MT7 Racelines, I crashed after about 3 hours of use and the lever went to the bar. After much headache ( read bleed, bleed again) I decided it must be a problem in the MC so i pulled it apart.. Sure enough the 10.5mm Master Cylinder main seal sheared right through, resulting in a sealed system with no lever pressure.

I mailed Magura and prayed, sure enough they came back an said it wasn't a warranty as the system isn't leaking and they don't sell rebuild kits, so its a 100EUR lever to fix a 1 dollar seal.

Would anyone know if there a possibility to source just the seal anywhere, I searched and searched but cannot find anything. I found a number of piston kits but i cant be sure the seal lip is correct or dimensions are the same.

Apologies again if its been answered, which would be awesome.

Thanks.

I would take it to the local bearing/seal shop and see if they can find it in their catalogs. I highly doubt it is specific for Magura.
If it is, find some business with the seal manufacturing machine: https://www.skf.com/group/products/industrial-seals/machined-seals/skf-seal-jet-dd-system

 

[Sandwich]

Hi Guys, Please excuse me for dropping in here on a scintillating conversation that Trick Stuff may have stock and it may even be cheap but i suffered a bit of a head banger last week and I have searched high and low for an answer which isn't coming. Maybe your guys could please help.

I have a new set of MT7 Racelines, I crashed after about 3 hours of use and the lever went to the bar. After much headache ( read bleed, bleed again) I decided it must be a problem in the MC so i pulled it apart.. Sure enough the 10.5mm Master Cylinder main seal sheared right through, resulting in a sealed system with no lever pressure.

I mailed Magura and prayed, sure enough they came back an said it wasn't a warranty as the system isn't leaking and they don't sell rebuild kits, so its a 100EUR lever to fix a 1 dollar seal.

Would anyone know if there a possibility to source just the seal anywhere, I searched and searched but cannot find anything. I found a number of piston kits but i cant be sure the seal lip is correct or dimensions are the same.

Apologies again if its been answered, which would be awesome.

Thanks.

If you cannot find a replacement, and can confirm that an mt5 seal will fit an mt7, then I have a broken MC that you can pull parts from. I’m not sure where you are or if shipping will be crazy expensive, but I will never use it.

if I ever do need a new lever or MC, I intend on grabbing a set of m4100 levers and seeing how that does. That’s something you could try of finding a seal doesn’t work. No servo wave and metal.

 

[Andeh]

Last Saturday I had a crash where my bars spun and pulled the hose out of my MT7 MC. I put a fresh olive on and rebled the system. It seemed ok at first, but today I noticed a ton of oil leaking out onto the hose and the lever pulling to the bar. I gave the hose nut 1 more rotation (it felt just a hair loose when I checked it) so that it feels similar to my rear hose and rebled it. It feels fine in the garage now, and I'll try to ride again soon to check, but I'm definitely wary now, and wondering if its possible I did more damage. I looked top and bottom and don't see any cracks. Anything else I should check if the problem continues?

Worst case, my buddy's got a set of nearly new Code RSCs he said he'll give me, but I'm not sure the rear hose is long enough, and they'd need a bleed. Can I use the thicker Magura HC rotors with Codes?

 

[Cummo]

If you cannot find a replacement, and can confirm that an mt5 seal will fit an mt7, then I have a broken MC that you can pull parts from. I’m not sure where you are or if shipping will be crazy expensive, but I will never use it.

if I ever do need a new lever or MC, I intend on grabbing a set of m4100 levers and seeing how that does. That’s something you could try of finding a seal doesn’t work. No servo wave and metal.

Hi Sandwich, Thanks so very much for your kind offer, I did manage to find a used MT5 ( here in Germany) which indeed does have the same piston as the MT7, luckily the fellow didn't need the piston so was happy to let it go. Thanks again.

 

[Cummo]

I would take it to the local bearing/seal shop and see if they can find it in their catalogs. I highly doubt it is specific for Magura.
If it is, find some business with the seal manufacturing machine: https://www.skf.com/group/products/industrial-seals/machined-seals/skf-seal-jet-dd-system

Thanks so much for the advice iRider, it's a little tough for me. I am and Australian living in germany and not speaking the language and finding this type of outlet is quite the challenge.

 

[Cummo]

@Cummo
Cheaper levers from Magura are likely to have the same seal or you could get Shimano levers. Deore are cheap and/but disposable

Thanks Happymtb.fr but i really liked the Magura, I had just installed the HC3 and really like them so i wanted to keep the system the same. Thanks again.

 

[slyfink]

At one point there were some questions about aftermarket brake pads. Here's an article that adds some data points: https://nsmb.com/articles/oem-alternative-brake-pads-one-month-later/

 

[maxyedor]

Last Saturday I had a crash where my bars spun and pulled the hose out of my MT7 MC. I put a fresh olive on and rebled the system. It seemed ok at first, but today I noticed a ton of oil leaking out onto the hose and the lever pulling to the bar. I gave the hose nut 1 more rotation (it felt just a hair loose when I checked it) so that it feels similar to my rear hose and rebled it. It feels fine in the garage now, and I'll try to ride again soon to check, but I'm definitely wary now, and wondering if its possible I did more damage. I looked top and bottom and don't see any cracks. Anything else I should check if the problem continues?

Worst case, my buddy's got a set of nearly new Code RSCs he said he'll give me, but I'm not sure the rear hose is long enough, and they'd need a bleed. Can I use the thicker Magura HC rotors with Codes?

The Magura crush olives do seem to take more torque on the nut than you'd think, honestly they should consider a slightly softer material for them. You're probably 100% fine, pulling the hose out shouldn't damage anything as long as the barrel nut stayed put.

Rubber-band/velcro strap the lever to the bar overnight if you're worried, any leaks will show themselves if pressure is applied for that long.

 

[Blackhat]

I've got some questions about the Formula R1.

The calculations show R1’s to be some of the weakest brakes available, with a total leverage of just 23.8 (based on a rough 91/14 lever measurement). Yet they have a reputation as a powerful brake, with reviews suggesting they’re one of the few XC brakes that can hang at a bike park, and that they’re suitable for enduro riding. My own experience is that they are at least equal to the SRAM branded Elixir equivalents I have that rate a 38.1 leverage ratio (72/9 lever).

Is there some factor that we’re missing? Maybe it’s perception related to the squishy feeling SRAM tends to have? Maybe I’m failing at my bleeds and the formula’s just haven’t gotten significant air in them? Is there a discussion between Page 8 (how far I've gotten) and 55 of this thread that sheds some light?

The idea that leverage ratios are directly related to stopping power is attractive to my enginerd side, but something isn't adding up for me. I'll go back to combing the thread now. Sorry to post before reading everything, but it's a lot to take in without voicing some thoughts.

 

[Happymtb.fr]

@Blackhat
You are only considering the hydraulic leverage, there is also the mechanical leverage to consider coming from the lever geometry and sometimes some sort of linkage

 

[Blackhat]

@Blackhat
You are only considering the hydraulic leverage, there is also the mechanical leverage to consider coming from the lever geometry and sometimes some sort of linkage

Don’t know what part of my post gave you that impression, but I definitely considered it, mentioned the lever measurements in the post, and gave leverage results in line with the results of other brakes that included mechanical leverage.

Anyway, I found some calipers so I could take official measurements for the spreadsheet since neither lever is documented.

Elixir/SRAM pivot to finger = 73 mm

Elixir/SRAM pivot to piston = 9 mm

Formula R1 pivot to finger = 89 mm

Formula R1 pivot to piston = 14.5 mm

 

[Happymtb.fr]

Don’t know what part of my post gave you that impression

My bad! I will blame the post ride beer...

I didn't crush the numbers. How does it look like when combining the mechanical and hydraulic leverages?

 

[Blackhat]

Elixir
Hydraulic leverage - 4.9
Mechanical leverage - 8.1
Total leverage - 39.6

Formula R1
Hydraulic leverage - 3.7
Mechanical leverage- 6.1
Total leverage- 22.5

So Elixir has almost double the leverage of the R1.

 

[Boozzz]

Elixir
Hydraulic leverage - 4.9
Mechanical leverage - 8.1
Total leverage - 39.6

Formula R1
Hydraulic leverage - 3.7
Mechanical leverage- 6.1
Total leverage- 22.5

So Elixir has almost double the leverage of the R1.

That would make the Elixir as powerful as the Trickstuff Direttissima, leverage wise. Time to dig up those old Elixirs Or, maybe that pivot to cam measurement is a bit off.

 

[MikeD]

Magura peoples...

Does anyone know if there's a one-finger lever blade available to fit these older MT4s?

 

[StiHacka]

Magura peoples...

Does anyone know if there's a one-finger lever blade available to fit these older MT4s?

View attachment 161032

These work great, and I mean GREAT, with Shimano levers.

 

[MikeD]

So did my Shimano calipers...till they didn't, lol.

I love the Shimanos above all brakes I've ever used, but the wandering bite point/failure I experienced makes me think I'll never use those levers again. Maybe Kidwoo has poisoned my brain.

(These would be going on this Canfield I'm hoping to get...)

 

[Inclag]

So did my Shimano calipers...till they didn't, lol.

I love the Shimanos above all brakes I've ever used, but the wandering bite point/failure I experienced makes me think I'll never use those levers again. Maybe Kidwoo has poisoned my brain.

(These would be going on this Canfield I'm hoping to get...)

You're brain isn't poisoned. Shimano levers last one year for me before they get worn, leaky, and require constant bleeding.

 

[MikeD]

I switched to TRPs and I'm happy with both the Quadiems and the Slates.

I just want something that works solidly, reliably, and simply. My days of having time to fiddle with stuff are over...

But I have these old Maguras I'd used on my hardtail for a while. Great brakes too; just prefer a shorter, rounder lever.

 

[Jm_]

The E-bike pads on my V4s are renewing my faith. Need to do some more testing, but having the "bite" of shimanos seems more the case.

 

[Blackhat]

That would make the Elixir as powerful as the Trickstuff Direttissima, leverage wise. Time to dig up those old Elixirs Or, maybe that pivot to cam measurement is a bit off.

Would welcome someone checking my work. If the numbers are accurate then they would be a good lever option for dot brakes.

There's more to a good brake than leverage obviously. Otherwise we could just make longer lever blades and call it good. My elixirs have a longer throw and tend to be squishy. And I hear the calipers don't handle heat well.

 

[Sandwich]

Would welcome someone checking my work. If the numbers are accurate then they would be a good lever option for dot brakes.

There's more to a good brake than leverage obviously. Otherwise we could just make longer lever blades and call it good. My elixirs have a longer throw and tend to be squishy. And I hear the calipers don't handle heat well.

Reminds me of old maguras. Lever blades as long as handlebars. Tons of power, but terribly brakes to use.

 

[Nick]

Have you got both your DH-R EVO's yet?

OK so my Evos have finally shipped. Stoked to try them next week.
The DHR Evo and new Trail Evo are both back in stock at trp.com in case anyone has been looking.

 

[Udi]

@Blackhat @Boozzz
Any significant errors usually come from incorrect MC piston diameters. Hard to get measurements for as it involves lever disassembly. I have removed the MC diameter value for the Elixir as it's incorrect, given the "taperbore" design which no one here has measured. The original value was a placeholder. I have left the other measurements in place, but you'll see the total leverage is now blank.

We have verified MC values for many modern brakes (eg. DRT, MT7, V4) thanks to kind members and manufacturers, however it's worth researching if this value is correct (or ideally measuring yourself) if you want to be 100% sure. Thanks for sharing measurements, hope that answers your question.

The calculations show R1’s to be some of the weakest brakes available

The R1 is a weak brake by modern standards, what you read may be old or XC / 26" related. I'd consider them dangerous on a modern DH / park bike and a poor choice for an Enduro bike (27.5" or 29"). The Elixir stops better than the R1 but has other issues (built by avid/sram, taperbore). Both are outdated brakes in many respects. At minimum on the R1 I'd change the caliper to T1 or RO. Where are you located?

 

[Andeh]

The last couple rides, my rear MT7 started suddenly deteriorating until it would randomly pull to the bar, despite being bled a week prior. I did a full bleed again, and didn't observe any bubbles (used a very large bottom syringe and probably pushed ~40cc worth of oil through the system). However, the oil was dark black, and I also noticed that half the caliper pistons are very sticky. The brake is a couple years old, and I'm the second owner.

I did some searching, and it doesn't look like there are any service kits or service manuals for replacing piston seals at both the caliper and MC. Is that correct? Basically, once they deteriorate to a certain point, they're done?

 

[Happymtb.fr]

@Andeh
You can try to push the piston out, then clean and regrease the seal. It might help...
Be sure to use the right grease, it is red rubber grease if I remember correctly. The info is somewhere in this giant thread.

 

[Blackhat]

Any significant errors usually come from incorrect MC piston diameters. Hard to get measurements for as it involves lever disassembly. I have removed the MC diameter value for the Elixir as it's incorrect, given the "taperbore" design which no one here has measured.

Just bought a cheap extra elixir to try pairing with the R1 caliper. But if it hasn't been measured a tear town will come first. Worst case I break it and learn something. Though "taperbore" does not sound like a simple thing to measure.

The R1 is a weak brake by modern standards, what you read may be old... Where are you located?

The reviews were indeed old and I figured recent brakes had progressed, but it just seemed a bit crazy to see such wildly different viewpoints. Especially since elixirs date to a similar era. I'm not actually here to figure out whether to use the R1 or the Elixir but to try to use my experience with those brakes to understand what I'm looking for. I'm located in east Tennessee, and have recently decided it sounds more fun to be a mountain biker than a roadie who mountain bikes. Which explains the R1 and Elixir ownership.

Anyway, moved some stuff around to run both on the same bike to get a better comparison. Elixirs were markedly better head to head. Someone in a colorful mood could say the R1's were a gentle suggestion rather than a brake. So apparently my subjective impressions should be firmly ignored unless there is some sort of science behind it for now. Caliper pictures will be more trustworthy.

 

[Boozzz]

The last couple rides, my rear MT7 started suddenly deteriorating until it would randomly pull to the bar, despite being bled a week prior. I did a full bleed again, and didn't observe any bubbles (used a very large bottom syringe and probably pushed ~40cc worth of oil through the system). However, the oil was dark black, and I also noticed that half the caliper pistons are very sticky. The brake is a couple years old, and I'm the second owner.

I did some searching, and it doesn't look like there are any service kits or service manuals for replacing piston seals at both the caliper and MC. Is that correct? Basically, once they deteriorate to a certain point, they're done?

Nope, no official service kits for Magura unfortunately. Like Shimano, it's replace lever and/or caliper. Or measure and find o-rings yourself. However, sticky pistons should be a relatively easy fix. Squeezing them out (hold back the pistons that move easitly, and be sure not to squeeze them out too far!), spraying them with silicone spray and pushing them back in a few times usually does the trick. Otherwise you can do as @Happymtb.fr says, squeeze the piston out entirely and regrease with red rubber or silicone grease.

As for the black fluid, I had a similar question a while back, fluid of my MT5's completely black at the lever end. It's because the non-anodized lever piston moving in the bore, which contaminates the oil. My fresh oil turned black within a few months. Not much you can do about that, except refresh the oil once in a while.

 

[iRider]

Anyway, moved some stuff around to run both on the same bike to get a better comparison. Elixirs were markedly better head to head. Someone in a colorful mood could say the R1's were a gentle suggestion rather than a brake. So apparently my subjective impressions should be firmly ignored unless there is some sort of science behind it for now. Caliper pictures will be more trustworthy.

Did you consider the type of pads and the disc rotor as well? I use Swiss Stop and Trickstuff pads with the R1 and R1R and they offer more than enough power with 200/180 mm (F/R) rotors for an enduro bike. Longest descents I have done with those were about 1000 m of elevation in one go and they were only minimally affected by heat.

 

[Blackhat]

@iRider

There’s definitely some pad difference to be explored. Rotor was the same though. If that’s your experience then I’ll take another look and try to get all the variables reasonably controlled. How much do you weigh?

 

[iRider]

@iRider

There’s definitely some pad difference to be explored. Rotor was the same though. If that’s your experience then I’ll take another look and try to get all the variables reasonably controlled. How much do you weigh?

About 70-75 kg ready to ride with everything included. FWIW: I ride 26" wheels.
If I switch to new pads I also clean the rotors with brake cleaner and then thoroughly bed the new pads in.

 

[chuffer]

More MT7 stuff...

I am having trouble getting the pistons in my MT7 calipers to actuate in balance. The outboard side pistons are moving more than the inboard pistons. They are so out of balance that when I try to center the rotor in the pads, the rotor touches the caliper before I can get the pads centered. The imbalance is getting worse as the pads wear, obviously - I think.

Calipers are less than a year old and haven't seen a ton of abuse (They are on their second set of pads, which are still nearly new).

I tried doing the recentering exercise shown on the Magura youtube and also tried cleaning and light lube on the cylinders. Bleed seems rock solid - the engagement point on the Shimano lever is rock hard and consistent...so far...

Ideas?

I'd really like to use these calipers. Other than this current issue the brakes are fantastic.

 

[Happymtb.fr]

@chuffer
Check what I wrote and what @Boozzz wrote a few posts earlier

 

[chuffer]

@chuffer
Check what I wrote and what @Boozzz wrote a few posts earlier

The "recentering exercise" I mentioned is the as what @Boozzz talks about. I tried that, but it didn't seem to fix the issue. All cylinders move, but the outboard side seems to consistently move more.

I guess I could try popping the pistons out and greasing them, but how hard is it to get them back in the cylinders? The "top" edges of the cylinders look pretty sharp - perfect for nicking an o-ring while pressing the piston back in...

 

[Happymtb.fr]

@chuffer
You can either squeeze the pistons out (both sides) as far as you dare, clean them and push them back. For the cleaning part, don't hesitate to also use some mechanical action either with a small stiff paint brush or a little piece of cloth, etc... push the pistons back in and repeat a few times. Once you're done with the cleaning, regrease the pistons, massage them in and out full stroke a few times before cleaning off the excess grease.

The other option is to pop out the pistons, clean them and the gasket, regrease, massage and clean off the excess. The pistons are easy to push back in from what I remember.
Popping them out will make the cleaning easier but will imply bleeding...

 

[Nick]

OK so my Evos have finally shipped. Stoked to try them next week.
The DHR Evo and new Trail Evo are both back in stock at trp.com in case anyone has been looking.

Time to put these together and get a test ride.

Edit: set was easy to trim lines and install without needing to bleed, which is good as TRP bleed port is larger size threaded nip than the formula I have laying around, and larger than a shimano cup too. Just topped off with a few drops and levers feel great. Rotors feel heavy compared to the saints coming off. Fit and finish are very nice, nothing fancy, 1- bolt split perch, integrated lever adjust knob, and no perceivable MC/lever flex in my scientific garage testing.

 

[canadmos]

My right Shimano XT m8000 brake lever appears to be slowly leaking fluid. Haven't figured out where from though.

Has anyone rebuilt these before or should I just start the quest of finding a new lever?

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[6thElement]

My right Shimano XT m8000 brake lever appears to be slowly leaking fluid. Haven't figured out where from though.

Probably the caliper

 

[StiHacka]

My right Shimano XT m8000 brake lever appears to be slowly leaking fluid. Haven't figured out where from though.

Has anyone rebuilt these before or should I just start the quest of finding a new lever?

Just get a pair of Saint levers to impress the ladies, like many of us do.

 

[Bsanick]

Hello from the Brecon Beacons in Wales. I thought I would post some pictures of the finished and tested for 3 weeks combination of my Sram Guide RS lever and new Hope E4 Caliper. The spreadsheet proved to be very helpful in the decision to try this with a theoretical 13% hydraulic advantage. My concern over piston retraction proved to be groundless in fact I believe it is better than that of the Guide pistons. The modulation for which both systems are well known has been retained I’m pleased to say. The improvement in lever force is noticeable.
Installation was simple unbolt the old and bolt on the new. As a bonus the Sram banjo fitted directly on the E4 so no need to make up any bespoke connections.
Bleeding was a doddle I just used one syringe on top, I have done this twice now because I have fitted some extravagant blue “bling” bore caps along with a blue decal to match up with the frame highlights.
I cannot say I really needed better brakes but the Guide Caliper was damaged around the pad retaining pin and needed new pads anyway, it was slightly used when I bought it cheap and needed the known master cylinder piston problem attended to, I bough one of the alloy replacement piston on eBay and it made a very good brake. I have been using a 203mm Hope semi floating disc up front and a Sram DB5 with 180mm centreline rear for some time now this is as big as can be fitted at the back. Neither disc makes any noise.
I must confess to a slight obsession with improving the brakes, I live a mile from the start of a climb up to The Gospel Pass this is the highest metalled road In Wales. The lanes are narrow and convoluted with several hills over 20%. I weigh in at over 17 stone and the bike is

electrified. This is the only way I would be able to climb up our lovely mountains. All up weight is err - too much! I have old discs which are probably fine but nearly black. It’s not really about stopping power but about easy comfortable control without aching hands and forearms and with no concerns that the disc will overheat and fail.
I am also 74, with a heart problem, falling off or crashing is not an option to be trifled with, or that’s how I justify the expense anyway!