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Re: SRAM Hydraulic Disk Brakes

Posted: Tue Nov 13, 2012 12:57 am
by dereksmalls
BeeBee30 wrote:Damn those levers are ugly :shock:


I don't think they're that bad to be honest. So how would you design them?

Re: SRAM Hydraulic Disk Brakes

Posted: Tue Nov 13, 2012 2:09 am
by bobbyOCR
deltree wrote:SRAM trying to go forwards with hydraulic brakes when they should be looking at electronic shifting. Sure it makes sense for CX. But hydraulic brakes on road bikes are bad news.


Why?

And Why?

I still prefer mechanical groupsets. I think SRAM are still on the ball.

I will agree to a large extent with your second statement. There is a very limited calling for hydraulic brakes on the road. Rim or disc. The only advantage I can think of is discs being used to advance rim design. Some improved profiles and weights may be possible, but this is offset by the disc brake, of course.

Long descents may also be a good area for hydraulics.

I think those hydro levers look heinous. I hope they improve them.

Re: SRAM Hydraulic Disk Brakes

Posted: Tue Nov 13, 2012 2:09 am
by Weenie

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Re: SRAM Hydraulic Disk Brakes

Posted: Tue Nov 13, 2012 2:57 am
by yourdaguy
Can't see a better way to package a master cylinder in road levers unless you integrate them in the bars and that would be a bad idea. As far as hydraulic shifting goes, it seems like the weight penalty would not equal the benefits which I mainly see as less sensitivity to dirt and grime. The front shifting on a double would be easy to implement but the rear might end up being kind of complicated. Although it would be way easier for SRAM to implement since they are starting with a pull ratio that is constant across the rear der.

Re: SRAM Hydraulic Disk Brakes

Posted: Tue Nov 13, 2012 8:32 am
by BeeBee30
dereksmalls wrote:
BeeBee30 wrote:Damn those levers are ugly :shock:


I don't think they're that bad to be honest. So how would you design them?


I'm not saying I could do any better but the fact remains they are ugly, surely they could have made them a tad more streamlined, also I'm wondering how they are gonna feel honking out of the saddle?

Re: SRAM Hydraulic Disk Brakes

Posted: Tue Nov 13, 2012 9:21 am
by thisisatest
Hydro shifting doesn't have to be heavier. Acros system is about 150g lighter than XTR, I think.
Levers do look ugly. Would look less ugly if there was some visual separation between the traditional part of the lever body and its growth. It could pass for a bad Photoshop job as it is.

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 6:16 am
by johnsaysthisnow
if hydraulic brakes are sort of the answer to a question nobody was asking (for road anyway. for cx, I can see its usefulness), then hydraulic shifting is DEFINITELY the answer to a question nobody was asking. Other than it being new and shiny technology, is there any mechanical or performance benefit to hydraulic shifting over mechanical? Better modulation on your shifts? :roll:

Also, wasn't one of the main drawbacks for road disc the type of braking encountered? Aside from the other pros/cons of disc implementation on road bikes, isn't a major concern SPECIFICALLY long mountain descents, with respect to heat buildup/dissipation and brake failure?

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 6:52 am
by yourdaguy
Rim brakes have a greater problem with heat buildup on long descents because they can blow the tire off the rim. This is especially true on tandems and that is why many road tandems have for years had a rear disc brake (usually a 203mm rotor) and the newest ones have 10 inch rotors.

I think the advantages of hydraulic shifting would be that they almost wouldn't care about dirt/grime, etc. You could go an entire season without maintenance issues. Also, shifts could be easier since there would not need to be a spring to work against because the master cylinder position would be reflected in the slave cylinder position and the mechanism would only have to hold the place. All the power up or down could be from your finger. This could make front shifting especially easy because current designs use strong spring tension. This also means that you would have to push in a shift from the big ring to the small ring while current designs you just trip a release and the strong spring that you pulled against to shift up now shifts down for you so the levers would be more like Campy where you have a push on both sides.

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 7:07 am
by dereksmalls
johnsaysthisnow wrote: Also, wasn't one of the main drawbacks for road disc the type of braking encountered? Aside from the other pros/cons of disc implementation on road bikes, isn't a major concern SPECIFICALLY long mountain descents, with respect to heat buildup/dissipation and brake failure?


Was the same thing said about disc brakes on MTBs?

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 7:31 am
by johnsaysthisnow
yes/no. MTB braking (typically) is less sustained than road braking of something like a long technical descent.

And yeah, true, disc brakes are used for applications like tandems where heat buildup on the rim is more critical, but those have been mechanical discs. Hydraulic discs still introduce the same problem of heat management, just at a new position.

Re: hydraulic shifting - I mean, I guess those are pros to hydraulic shifting? Personally, those are just non-issues.

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 3:58 pm
by yourdaguy
My 2004 Santana tandem has had hydraulic disc from the factory and I think it has been an option from Santana since the 90's. Santana has a master cylinder that works on cable pull so I have Ultegra levers but the rear has a short cable to a master cylinder on the down tuber that is hydraulic the rest of the way back.

If you think MTB use brakes less then you need to go to a ski resort in the Summer and try 4000 feet of vertical with a 40 lb 7 inch travel bike and see how much heat you put in the brakes. Also, road bikes on long descents get a lot of cooling as the air moves past the disc at 30 MPH or so.

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 8:27 pm
by MichaelB
To see the hyd shifting integrated as well would be interesting.

After recently having tried the new Red on a bike (test review for an Aussie forum), I'm impressed in how well it worked, so I'm even more keen to go full hyd discs on my roadie (currently running TRP Parabox).

So why isn't there more info out there ?

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 8:34 pm
by prendrefeu
johnsaysthisnow wrote:then hydraulic shifting is DEFINITELY the answer to a question nobody was asking. Other than it being new and shiny technology, is there any mechanical or performance benefit to hydraulic shifting over mechanical? Better modulation on your shifts?


Read this on the ACROS system, then get back to us.
http://www.bicycling.com/mountainbikeco ... t-acros-ge

Nevermind the cost - ACROS is a small company and currently all of their components are CNC'd individually at their facilities in Germany. Should a company such as SRAM pick up hydraulic shifting, expect to see the costs go way, way, way down.

Re: SRAM Hydraulic Disk Brakes

Posted: Wed Nov 14, 2012 10:50 pm
by austke
Cant wait for hydraulic disc brakes. Almost all modes of transport run this brake set up, why? Because it is better overall, thats what believe.
Both MTB and roadies are capable of the same descents (grade and or distance).
I dont think the SRAM set up is ugly. Nor can I compare to much until other makers jump onboard.

Re: SRAM Hydraulic Disk Brakes

Posted: Thu Nov 15, 2012 3:09 am
by yourdaguy
SRAM should buy ACROS! That is so much better and lighter than electric shifting and should be way more reliable. The main concern was busting a cable but I run hydraulic brakes at much higher pressure and they never brake so I would expect this system to work for 3 years without any maintenance. Then change the fluid and go for another 3 years.

Re: SRAM Hydraulic Disk Brakes

Posted: Thu Nov 15, 2012 3:09 am
by Weenie

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Re: SRAM Hydraulic Disk Brakes

Posted: Thu Nov 15, 2012 3:15 am
by Dustin
gospastic wrote:Image

Whose bike is that? Wondering why Zipp logos on bar/ stem are taped over.