carsonau said:
Hi Lelandjt, thank you for your quick respond.
If I go with 1, will I need some kind of adapters to move the calipers further out? Any particular brand you would recommend? Would you recommend trying to bleed it anyway?
Those Avid Elixir R have great reviews, will you take them over Shimano XT? Is 5.1 fluid a bad idea compare to mineral oil?
Thanks again!
Cars
Well, first off.......don't base your judgement on just one review. Read a few dozen. Many times, a fix is posted in the review itself, if the writer found it. For the most part, they're fine for XC and light downhill use, depending on what you mean by "downhill fast" you may just be pushing them too hard.
A good bleed might help. Shimano's factory bleed isn't exactly stellar, so pick on your shop wrench to do a proper job of it.
Larger rotors, yeah. I would just go larger in the front, though. Going downhill, most of the braking power is in the front, and too much brake in the rear with the back end unweighted will cause skidding. Not only does that cause some lack of control, it's bad for the trail. Yes, you will need an adapter, the caliper will need to be mounted out further to accomodate the larger rotor. Try to get a round rotor, like one from Hope. I don't mind wavy rotors, but you lose contact area. Even just switching to the same size rotor using a round brake path can make a difference. You're probably limited to a centerlock rotor, though, so get what you can that fits.
Avid over XT.......I'm still up in the air about that one. I like the Avid design, and they seem fine for general use, but I think you'd have the same issue as you do now. They're an XC brake, not designed for downhilling. XT's would be the better choice, if you want to go that route. Still an XC brake, but more power. Lots of modulation though, and some people don't like that. Mostly guys coming off Hayes with their on-off feel. Actually, that's one place you might want to look. Hayes Strokers seem to be pretty good, and might fit your needs better than either the Elixrs or XT's. They're the ones who pretty much wrote the book on downhill brakes. Not too expensive, either, I saw them the other day for $100 per wheel, you just need to buy the adapters for your fork and frame. Again, the centerlock rotor thing. You won't be able to use aftermarket rotors, unless they specifically make one for your hubs. Not a big deal, for the most part rotors are interchageable. As long as the diameter matches what your brakes take, you're fine.
DOT vs mineral oil. Age old debate. What it comes down to is DOT has a higher boiling point, so theoretically less fade as the brakes get hot. Downside is it's caustic, harmful to the environment (big deal for me, since I do biking advocacy. Nothing will shut down a trail faster than a puddle of poisonous fluid spotted by the forestry guy you're walking the trail with). Mineral oil boils at a lower point, so theoretically fades faster, but the Magura Gustav was one of the top downhill brakes, and it used mineral oil. Take that with a grain of salt. It's also safer to work with, safe for the environment, and in a pinch, you can use unscented, chemical free baby oil as an emergency backup. I wouldn't suggest leaving it in there, get the proper stuff as soon as you can.
