|   Magura question for Mike T | jimbo2k
Jul 22, 2003 6:49 PM | | I have had Maggies for a couple of years, and on a couple of bikes, and have never been happy with their performance. They always seem to have less stopping power than a decent set of V type rim brakes. Now the front brake on my sugar is so bad i find my self leaving the bike home and riding the rim brake #2 bike instead. Today, while trying to improve the performance I noticed a problem that i have not seen any reference to before.
For a static test,when I grab front brake hard, initially, i get good a good ammount of lever and it feels just like the rear, but if i hold hard tension on the lever it starts to sink slowly toward the handle bar. In a car we used to call this master cylynder bypass, but I didnt think this was possible in a bike brake. I kept expecting to see magura blood all over the place but no leaks anywhere. The rear does not do this. These are 2001 Louise brakes. Jimi at Magura has replaced both levers for leak problems, so this front lever is brand new. I am real sorry that i got a disc specific fork, or I'd chuck them for a pair of XTR Vees. Help me out here. Jim |
| Magura answer for jimbo. | Mike T.
Jul 22, 2003 7:08 PM | | How unfortunate that you're having problems and can't get to the bottom of them.
Today, while trying to improve the performance I noticed a problem that i have not seen any reference to before.
For a static test,when I grab front brake hard, initially, i get good a good ammount of lever and it feels just like the rear, but if i hold hard tension on the lever it starts to sink slowly toward the handle bar. In a car we used to call this master cylynder bypass, but I didnt think this was possible in a bike brake. I kept expecting to see magura blood all over the place but no leaks anywhere.
This problem has been mentioned many times before on a variety of hydraulic brakes. Why wouldn't it be possible in a bike brake? Why just in a car? A master cylinder is a master cylinder whether it's on a bike or a car. It's just a seal on a piston inside a vessel.
If the seal has a nick in it, or for some reason it doesn't conform to the inside of the cylinder bore then it will travel through the fluid rather than push it.
If this happens then there is no way an external leak will be visible.
Whether you change the brakes for Vs is up to you but as you have already found, Magura is quite willing to help with matters like this. It comes under their extensive leak warranty.
Mike T. (mcm # 717) |
| re: Magura question for Mike T | bradd
Jul 23, 2003 9:52 AM | | i had the same problem with a louise '02 lever that jimi had sent me to put on an '01 louise caliper.
when the "leak" formed, he replaced the lever again. apparently, they used a plastic piston in earlier models, but went to an aluminum one after several developed the problem you describe.
just contact jimi. he should take care of you.
-bradd |
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