|   Hydraulic discs pros&cons | tbone
Jul 9, 2002 9:47 PM | | I am far from an expert on bicycles. But I was wondering if these hydraulic disc brakes I see on bikes are an advantage over the old cable-operated ones? Just curious; like I said I barely know the difference between a Huffy and a Volkswagen. |
| Disc | Wrenchhead
Jul 10, 2002 1:19 PM | | First off, cable operated mechanical disc brakes for bicycles were first available from Avid and Hayed in the year 2000. Hope introduced their full hydraulic disc brake and then came Formula, Hayes, Magura and Shimano Deore XT. in the early 90's. If you read others posts, you will discover pros and cons for both options. Personally I feel the that mechanical discs are all around more economical, equal in quality to some, and better than most hydro's. |
| Disc | Cassius
Jul 10, 2002 10:08 PM | | Thanks for the answer! Mountain bikes have always been interesting to me, especially now with the ultra-light alloys and tecno innovations. I hear they can take a direct hit on a boulder at 20mph and suffer no damage. I personally only have a 1 spd. balloon tire bike. The way things are going, these mountain bikes will soon be available with anti-lock! LOL
Cassius |
| Much like rim brakes | Jaybo
Jul 11, 2002 7:41 AM | | I have used XTR rim brakes for years. I'm finally coming around to the idea of using disc brakes. I know, where have I been? I have also used Magura rim brakes. I must admit, I like the Magura's a touch better but not much. I have ridden disc brakes: XT, Hope, and Avid. I'm sure I like hydro's a touch better, but the race is very close for me. Oh, almost forgot, don't believe the hype that hydro's cannot get contaminated by water and mud. I live in rainville. I have talked to shops that say Magura's particulary can get contaminated by water. Only in the west side of Oregon. *L* |
| Sorry, no way water or mud can contaminate a hydro... | AndyH
Jul 11, 2002 9:45 AM | | ...brake line UNLESS there is a leak in the system.
Sure, water on the rims of a Magura rim brake system will decrease the braking force...is that what you're referring to? |
| actually, hydros are not completely impervious to contamination | Louie
Jul 11, 2002 11:51 AM | | Granted, they (hydros) stay a helluva lot cleaner (inside) than cable operated brake systems when it comes to nasty conditions... however the seals on the calipers are not 100% water/mud/grime proof. You may in fact never experience it, but given enough time, water, and mud it is in fact possible to have the system contaminated and/or have a piston sieze up. Basically it's the piston seals that can eventually be a problem -- they work really really good but they aren't 100% sealed. Most people won't ever encounter that happening... if you are living in a place that is really wet and slimy the majority of the year and riding a lot year round it is likely that one day you will experience a contaminated hydro system. |
| Water & mud contaminated my hydros | Spar¡cus
Jul 11, 2002 11:57 AM | | Not in the brake line, but the muck caused one of my Hayes pistons to sieze in the bore. The popularly held idea that hydraulic brakes are impervious to contamination is a myth.
I'm not trying to pick on hydraulic brakes. Many people like them better than cable systems and for the most part hydro systems are well designed and function well. Just want to set the record straight. Hydraulic brake systems are not without their own weaknesses, some of which are shared with cable operated brakes and some of which are unique to the use of fluid as an actuation medium.
--Spary |
| Agreed, sorry guys I wasn't even considering the piston... | AndyH
Jul 11, 2002 12:54 PM | | ..or piston seals. Brain-fart....doh! |
| I dont agree | m00ch
Jul 11, 2002 7:01 PM | | When you say contamination. Do you mean contaminating the brake fluid or the pads. Because if you can get dirt and gunk between your seal you will also get fluid out your seals and you have a whole set of new problems. The fluid has much more pressure than the water that is trying to get in.
Maybe I am wrong but I ddoubt that you can contaminate the fluid by out side means unless something is really wrong.
And you can more easily get dirt inside the workings of a cable actuated brake.
I agree that you could seize up a piston if moisture gets past the dust seals and the bike is left to sit
Please show me proof if I am wrong |
| We're saying the same thing | Spar¡cus
Jul 11, 2002 8:49 PM | | Is a siezed piston on a hydraulic brake proof?
--Spary |
| IEver bleed the brakes of a car a few years old | Lowlypawn
Jul 14, 2002 8:35 AM | | Ever bleed the brakes of a car a few years old?
What color is the fluid? 99.9% of the time it's gunky gray to black. It ain't that way out of the bottle. It's mostly form water getting dissolved into the fluid (so I was told). Also depends on the fluid, the different DOT(1-4) have different moisture absorbing qualities. I think hydraulics are probably more reliable but more difficult to service when needed. Just my .02. |
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