Magura disc brake bleeding

[Browser]

Hi all, the Magura MT Sport disc brakes on my 'bent have always slightly disappointed me with their stopping power, or lack of it. I replaced the Avid BB7 mechanical disc brakes which were on the bike when I got it with a set of Magura MT Sport. As I recall I went up to 180mm disc front and kept the 160mm rear. No real power, spongy-feeling lever. Tried several bleeds myself, couldn't make them better. Went up to 200mm front and 180mm rear discs, still felt weak. Took them to two different local cycle shops (I'm on the South Lincolnshire/North Cambridgeshire border) still the same, finally got them roughly acceptable by a third shop in Peterborough but the lever feel still made me think there was air left in them.
Is there a definitive guide for how to bleed these effectively, do the levers flex as they are polymer rather than metal and does it make any difference that I've bought a third-party bleed kit rather than a Magura one??

 

[si_c]

Not familiar with the MT Sport brakes, but a third party bleed kit should work as well as the Magura kit, perhaps not as easy to use, but as effective.

I've always found plastic levers to flex substantially more than metal ones, but it depends on whether they are reinforced or not, if it's a fibreglass and resin mix then it should be fine, but you can check that by placing something behind the lever at the handlebar fitting to stop it moving (dowel or similar) and then flexing the lever itself to see how much it moves.

Otherwise has pumping the lever repeatedly improved the feel of the brakes? Usually that's a quick indicator of whether it needs another bleed or not, if it doesn't improve then they could just be poor brakes, in which case perhaps consider replacing with Shimano? Basic MT200s with 180mm disc at the front stops my not inconsiderable bulk at speed on an MTB so should be more than adequate for a recumbent.

 

[Yellow Saddle]

Hi all, the Magura MT Sport disc brakes on my 'bent have always slightly disappointed me with their stopping power, or lack of it. I replaced the Avid BB7 mechanical disc brakes which were on the bike when I got it with a set of Magura MT Sport. As I recall I went up to 180mm disc front and kept the 160mm rear. No real power, spongy-feeling lever. Tried several bleeds myself, couldn't make them better. Went up to 200mm front and 180mm rear discs, still felt weak. Took them to two different local cycle shops (I'm on the South Lincolnshire/North Cambridgeshire border) still the same, finally got them roughly acceptable by a third shop in Peterborough but the lever feel still made me think there was air left in them.
Is there a definitive guide for how to bleed these effectively, do the levers flex as they are polymer rather than metal and does it make any difference that I've bought a third-party bleed kit rather than a Magura one??

Mechanical disc brakes are crap.
The disc size has NOTHING to do with stopping force (not power).
Spongy feel is subjective. To know whether there is air in the sytem or not, pump the brake. It it feels harder with pumping, there is air in there.
"Weak" is subjective. Take the disc diameter outof iyour diagnosis and focus on the symptoms. Don 't pre-diagnose the problem.
Brakes don't care where you live.
Describe the lever feel and don't be tempted to diagnose. Just focus on the symptoms.
Judge the flex or yourself. Bring them up to contact point, pull harder and see how much they give under your given pressure. All materials flex.
Bleed kits don't come in Catholic, Jewish, Happy Clappy or Islam. If it is bled, it is blem.

 

[Browser]

I've checked again and I really need to try and remember the components I've fotted to my bike, as the brake levers are alloy not composite like I'd said!
Yes, squeezing the levers several times does firm up the 'feel', I'm 100% convinced there is still air in the hoses or calipers but am reluctant to try bleeding again lest I should make them worse. I'll research online and watch videos on YouTube then give myself a kick up the jacksie and give it another go.

 

[Yellow Saddle]

I've checked again and I really need to try and remember the components I've fotted to my bike, as the brake levers are alloy not composite like I'd said!
Yes, squeezing the levers several times does firm up the 'feel', I'm 100% convinced there is still air in the hoses or calipers but am reluctant to try bleeding again lest I should make them worse. I'll research online and watch videos on YouTube then give myself a kick up the jacksie and give it another go.

OK, if bfrakes "pump uup" with repeated strokes of the lever, it is an indicator of air in the system and a bleed is required. However, approach the test with some precision. Let the bike rest for ten minutes or so. Now stand over the bike, focus and give it two or three pulls on a lever. Did it get harder? Yes/No.

If you are unsure, wait a few minutes before tyring again.

Bleeding brakes is easy. There are plenty of Youtube videos to show you how it is done. It's a skill that will pay off.

 

[almostvegancyclist]

I think I know what you mean about the spongey feeling. I have Tektro on the left and Magura MT8 on the right. I bled them both with the same Aliexpress kit and the lever feel is very different. Tektro and Shimano feel very similar in that they both come to a clean stop as the pads grab the rotor. Magura feels like there's more modulation even after the pads grab the rotor. But I don't find that braking is weaker. The lever material doesn't have anything to do with braking power. Nor should which bleed kit you've used. It should absolutely be more powerful than mechanical.

 

[Yellow Saddle]

I think I know what you mean about the spongey feeling. I have Tektro on the left and Magura MT8 on the right. I bled them both with the same Aliexpress kit and the lever feel is very different. Tektro and Shimano feel very similar in that they both come to a clean stop as the pads grab the rotor. Magura feels like there's more modulation even after the pads grab the rotor. But I don't find that braking is weaker. The lever material doesn't have anything to do with braking power. Nor should which bleed kit you've used. It should absolutely be more powerful than mechanical.

Front and back brakes feel very different when squeezing hard. Because of the long flexible hose going to the back, that brake feels more spongy or as you say, the lever feel is different. This has nothing to do with brand or lever type.

Within brands, there are several levels of sophistication. Some can adjust the distance the lever travels before making contact - the so-called bite point. Others have that and lever distance from handlebar adjustment.

 

[almostvegancyclist]

Front and back brakes feel very different when squeezing hard. Because of the long flexible hose going to the back, that brake feels more spongy or as you say, the lever feel is different. This has nothing to do with brand or lever type.

Sure, front and rear brakes can feel different but I'm comparing front magura to front tektro that it replaced, or shimanos that I tried, both front and right. Magura definitely has a distinctive lever feel, at least mine does. But that shouldn't affect braking power.

 

[Browser]

I've had a look at the Magura video online and will have another bleeding session (and it might be a bleedin' session depending upon how well it goes!! 😁). Assessing it this morning on the way here giving the lever a couple of quick tugs before braking definitely makes it bite earlier but it still lacks brake force. It's a little bit like old steel wheels which rubber brake blocks used to be when it rained, you could feel the blocks contact the rim but no matter how much you squeezed it didn't brake any harder.
For anyone losing the will to live over this thread I will update you when I've had a play 😉😁