Magura disc brake bleeding

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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.