Anyone done this? One brake is feeling spongy, more lever travel than usual. I was quoted $25/per brake to bleed them at the bike shop. That's probably reasonable, but I want to do it myself. I picked up some clear, .170"id tubing, and a liter of Pentosin 7.1. I don't have a bike stand, I'll try clamping it in my Work Mate table.
Piece of cake. Helps to have two people and being in a bike stand is a bonus but you can figure another way to lift the rear tire so the little reservoir is level and keep the bike stable. You do it just like a car. One person puts pressure on the brake lever, the other opens/shuts the bleed valve and the fluid runs out the tube. As to the Pentosin - did you get this because you know it's compatible? I have always bought the $$$ Shimano mineral oil from fears of compatibility but have been waiting for someone to establish a cheaper alternative. What's the word on that?
I planned to level the reservoir partly by rotating it on the handlebar. I guess I'll see how that goes. I'm expecting to do it solo, I'll use the same type tube and bottle on the caliper like I do on cars, only smaller. I should be able to reach the rear caliper.
I found instructions online, Pentosin 7 was mentioned as an upgrade to Shimano fluid several times. $15/liter at NAPA, sounds like a good deal to me. I have a liter of Pentosin 11, but the instructions cautioned against using this synthetic version of Pentosin. How much $ is the Shimano fluid? I usually run a liberal amount through on cars to be sure I get it clean, I'll probably never go through a liter on my bike.
I planned to level the reservoir partly by rotating it on the handlebar. I guess I'll see how that goes. I'm expecting to do it solo, I'll use the same type tube and bottle on the caliper like I do on cars, only smaller. I should be able to reach the rear caliper.
I found instructions online, Pentosin 7 was mentioned as an upgrade to Shimano fluid several times.
Sounds like you've got it under control. Get the pads way out of the way. Rotors you can clean with alcohol, but the pads are ruined if any fluid gets on them.
The Shimano fluid is something like $15 for a 2oz bottle - enough to thoroughly flush both brakes but annoyingly expensive. I have not looked around to see if anyone's found a substitute but I'm hoping so by now. I have the original 4-piston calipers that were their first generation so I've been buying the overpriced crap for a lot of years. They still work flawlessly despite a fair bit of racing - including 8 24 hour races over the years.
Yeah, Shimano uses mineral oil - thus their ability to specify that you use their brand. Mineral oil would need some additives to handle the extreme heat, moisture resistance, etc of a brake application and who knows what compatibility to Shimano's caliper seals, brake lines and such is needed. Other brands use ordinary brake fluid available for 1/100th the price.
Endurance bike racing is popular and there are a lot of races. There are the ordinary 24hr ones I do, and some insane ones like the Trans Rocky types that last for days. You start at 12 noon, at 7:30pm you are not allowed on the course without lights, and they end at 12 noon the next day. You can enter them as a solo (insane), dual team (ouch), and a team of 4 (slightly less ouch). I've done a few as dual and a few as 4 man. The 2am hallucinations are amazing.
They work ok, but good hydros are much less maintenance. Avid pads wear out faster than Hayes pads in my experience.
I'm running at least one Hayes brake that I bought in 1999; their very first generation. It has been flushed a couple of times, but it's never had a seal replaced or anything like that.
I have the hayes stroker rides on my new bike and I have to say they work much better than the juicy 5's on my friends bike. Those things just felt too mooshy for me. So far I haven't had to do any maintenance on my brakes but its still too new to tell.
Mechanical brakes? You mean like go backwards about 70 years in technology? Meh.
I don't know what has happened to bring mech brakes back in, but I noted that after the original Shimano hydro disc brakes, each succeeding generation of them got cheaper to make and bulkier. My 4 piston calipers are a study in simple and highly developed design. The proof is in the 6200 miles and 5 years of exclusively offroad use. These things are spot on and I suspect they were so overengineered as a first generation that Shimano immediately started reducing costs as the concept was proven and they knew competition would enter. I'm still on the original rear rotor which shows little wear. The front was shattered in a head on collision with a dirt bike (long story, but he got the short end of the stick).
I've heard great things about the mechanicals and a couple buddies have switched.
Avid mechanicals have no modulation compared to hydros.
I run XTR hydros and they are great.
Avid mechanicals were popular for awhile when people were making the switch to disc brakes but they are def. a solid step below in performance. Nothing wrong with them, they just are not hydros.
Avid mechanicals have no modulation compared to hydros.
I run XTR hydros and they are great.
Avid mechanicals were popular for awhile when people were making the switch to disc brakes but they are def. a solid step below in performance. Nothing wrong with them, they just are not hydros.
That has not been my experience. I have ridden XTR hydros for a year or two. They needed constant attention in terms of adjustment and pad replacement, (they wore out quick in muddy conditions). They were constantly rubbing one side or another. My wifes bike still has these and I am always tuneing them, (just replaced a pad set last pm).
On my mulispeed XC, I set up the avid mechanical disk. I have yet to replace the pads after a lot of miles. I have yet to even need to adjust them, and will never need to bleed cause' they are on cables. Another awesome thing about the avids is the ability to adjust either pad independantly so you can customize the feel and eliminate the rubs.
Pop a hydro line out in the middle of nowhere...you have no brakes, and I have yet to learn of a fix. Breaking a cable is a very rare occurance.
So the mechanicals didn't wear out quick in muddy conditions? What would be the difference?
Rubbing pads are annoying. The mechanical Shimanos on my wife's bike seem to retract better, the disposable retract springs on my XTR hydros don't seem to do as well. For centering, I picked up some .001" and .005" thick washers to space the disk and/or caliper assembly. I have the same brand hubs on my commuter/snow wheels and my skinny slick wheels, but somehow they don't quite center the same.
Pads I subpose...I have had better luck with the avid pads that came stock with the avid brakes. Also the fact the the XTR's are pretty much always rubbing in one way or another makes the pads wear constantly, (as in a little bit for every revolution).
I have yet to see significant wear before they squeal so bad I can't stand it and replace them. I'm running metal pads, not organic, I think the organics wear faster. I've tried sanding my pads down to get fresh material, and cleaning the rotors, but they still squeal 'till I get fresh pads. I thought the sanded pads were the reason for my increased lever travel, but the new pads didn't change that.
