Disc Brake Concern
 

I am in the middle of deciding which disc setup to go with. I have three options:

• Avid BB7
• XT hydraulic (I have everything but the rear hose)
• or keep using the Hayes disc setup that was on my Kona Blast (mechanical)

I just want the pros and cons of each. I replaced the mechanicals Hayes with XT hydraulics as soon as I purchased the Blast. I was having the XT hyd put on my Dummy but the cool jagwire braided hoses didn't work. I admitt I wanted to ride my Dummy desparately that's why the Hayes are on it now, but I can't help feeling the XT's would be better. Any suggestions would be great.

Hydraulics are IMHO overkill for anything but downhill racing. Too complex to maintain and repair. I replaced my Hayes MX1 with Avid BB7 and I like them: they can be adjusted with better precision and are more powerful than the Hayes brakes. Me, my bike and my commuter cargo are around 240lbs and BB7 will lock my wheels if I squeeze too hard.

If you're gonna haul tons of stuff on your BD the hydros may give you an edge but you'd probably want a larger rotors. I don't know what's the max rotor size Big Dummy frame and fork can handle. Since you already have them...

A.

BB7's are great. I've got a spare set, but nothing to put them on to at the moment.
I've had XT hydraulics... very nice, very smooth feeling, once bled properly, they were no maintenance other than pads.

I have heard the bb7s are easier to keep aligned than the haynes, the XT m775? are nice brakes though... you will have to bleed them every year or so... but it would be much easier to bring your big dummy to a halt since there is better modulation. If you had anything other than a large big dummy i would say stick with the mechanicals.

Having used both, I'd say XT hydraulic brakes are noticeably lower maintenance than cable disks.

There are also more effective in the winter.

BB7s are good. But XTs are better, and they (M775s) are what's on my commuting MTB.

Most downhill bikes these days use something more substantial, like M810s.

I'll agree with AdamDZ that the hydros are a bit overkill, but they're indeed good brakes and hydros aren't as maintenance heavy as some would make believe. Key is to do a yearly flush/bleed since the fluid does retain water. You certainly don't need bigger than 160mm rotors, I'll disagree with him there. You do however want to be sure to use XT rotors if you go that route as the swept area of the discs is specific to XT.

That said, BB7's are the gold standard of mechanical, and parts and service are available anywhere.

I switched from hayes to bb7s, basically because the hayes were driving me batty with squealing. I did get that mostly tamed with the bb7s, though I do wonder if I could finally win that war with different rotors.

No experience w/ hydros. I'd be open to them for sure. Do they cost a lot different?

Huh? A yearly flush?

I have an 05 Kona Caldera I bought in Sept 04 (the first week they came out). It came stock with Hayes HFX-9 hydros. I put 3850 miles in all conditions year round on them. Once, while riding a downed tree, I had to bail, jumped off, and it pulled my front brake plunger, which was attached to the lever, out. I was able to force it back in, but this messed up the little plunger (I think it's actually a piston). That was probably in 05 or 06. That front brake lasted until Nov 09 when the plunger finally stuck inside the master cylinder. Mind you, it was my fault that this happened to begin with, and I knew since the day it happened it was on borrowed time. Now, I've got about 4200 miles on the Caldera with the original back brake and a new front.

I replaced the front pads on the original brake once. That is the only maintenance I ever did. I never, not once, bled or flushed the brakes - in 5 1/2 years. And, the new brake came pre-bled so I didn't even have to mess with it when I installed it.

I have read on other forums that other hydro-brakes have more problems (non-Hayes). For example, one person I read said every time his bike was turned upside down, air would get into the line and he'd have to bleed them. I think he had Avid Juicy somethings.

Re squealing: I have never had a squealing issue. Neither on my Caldera, nor my Trance X2 which has Hayes hydros as well.

A few variables are gonna determine when you have to flush hydro brakes... they will have to be flushed eventually though since no system seals perfectly.

Agreed. They will need to be flushed eventually. My point was that even one who was advocating that they're not as maintenance intense as some might think, in my opinion and experience, was exaggerating the amount of maintenance required.

Compared to mechanical brakes... i would say they are a bit more labour if a problem arises but that is relative... in absolute terms they're all low maintenance

Disc Brake FAQ

Depends on the problem. I've found changing pads easier (the one time I've had to do it) with my hydro-discs than mechanical rim brakes. Adjusting reach is just as easy with either setup. As pads wear on rim brakes they have to be adjusted. As pads wear on hydros, mine automatically adjust. Replacing hydros with a whole new setup is easier (no cable lengths to adjust). A rebuild is probably more labor intensive due to the bleed process.

People grossly overstate the maintenance required on hydros..... I'm not going to speculate why.

BB7s and 180mm rotors work just fine on my Big Dummy.

^Totally agree. Obviously any of them will be good enough, since most people get around fine with rim brakes.

+1 for BB7 disc - I have switched out all my hydros on all my bikes for Avid BB7. The ease of set up and they just plain work. cheap too. pad replacement and realignment is a breeze for me.
Easy to swap between bikes just need a new cable for the rear.
I got the 180mm rotor on the front of my nice mountain bike with 5+" of travel front and rear- it works even better.

I would get BB7s because you're in great falls, and I've heard of problems with the XTs in cold weather.

Hi. My bike is currently in the shop getting a couple of repairs done and have taken the opportunity to put a BB7 setup, with speed dial levers and Goodrich cabling, on the bike. I'm replacing a Hayes Stroker Ryde system that I cared for and kept nice and clean for over a year.

Unfortunately the Hayes Strokers levers started sticking. The rear lever started sticking at 7500 miles and the front about 1000 later. On analysis the system seamed oil tight with no weeping so the problem was with the hydraulic levers. I priced up overhauling them myself and the price of the spares required to totally overhaul the levers was not acceptable to me. Neither was the amount of work required to repair and then bleed them (I used to work on Flight Simulators and I know how yucky working with hydraulic systems can be...I just didn't warm to the idea....even on a smaller scale). I can manage a mechanical system and the spares seem cheaper to.

Being a high mileage rider I need systems that I can maintain and fix myself. After a bit of research it seemed to me that keeping on top of a mechanical breaking system is an easier option i.e. less hassle, than maintaining an hydraulic.

Shimano Hydros came stock on my Seek1. It is my wet weather and deep snow bike, so it doesn't see too many miles, but I love them, and haven't had to touch them in two years.

I've used the HMX and the BB7, never tried the hydro; too much coin for me.

I will never use HMX again, and will never forsake BB7. For there to be any more power and modulation in my brakes would be dangerous.