Disc brake options / using mountain bike disc brakes

[bazzawill]

So I want to go with hydraulic disc brakes. Eventually when SRAM release hydro etaps and I can afford to replace my drive train that's how I would like to go but in the mean time I was am looking at my options. Road drifters are so damn expensive so I was thinking of using bar end shifters and mountain bike brakes. Any one have experience with such a combination, thoughts, other ideas.

 

[LMT]

TRP Spyre's are the way to go, I think a few of us on here have the Spyre's fitted. Go with a 160 rotor on the front and 140 on the back. Be advised though that the 140 rotor on the back is very tight against the frame. You may (as I did) need to file away about 1 mm from the weld in order for the rotor to spin without interference.

Another thing I would say having done a few thousand K's on them is to buy the sintered brake pads. The organic pads for me burnt out way too quickly after about 2500kms. And the riding I do is not aggressve.

 

[ratz]

So I want to go with hydraulic disc brakes. Eventually when SRAM release hydro etaps

Building on Lee's thought if you want hydraulic and e-tap now; then go with TRP "HY/RD" and E-tap; the TRP HY/RD is a hyrdo operated by a cable the cylinder is at the brake and they are very nice; and cheaper and less maintenance than the full on hydro stuff. IF we had built our aero wheels with Disc hubs that's what I would be running with our E-tap setup. Next set of wheels will be disc. I personally right now am not sure running a hydro brake cable under the boom clamp would be a good idea; there's not enough clearance to not pinch the cable.

 

[Bryan Schlinkmann]

Hi friends!

I'm finally starting to dream up my first Vendetta V20 build. I'm doing a search for threads on disc brake options which led me to this one. Since the last post was 2+ years ago, is there any new articles or threads on hydraulic disc brake recommendations for the V20? Still TRD HY/RD's? Still 140mm rear, 160mm front rotors?

I CAN'T WAIT to rejoin the Cruzbike tribe again at some point soon once I have the $$$ for my V... Thanks!

 

[Mathew Fy]

I’m happy with SRAM’s hydraulic brifter. It works flawlessly. Unfortunately, getting the brake line through the frame to the rear requires cutting reconnecting. I think the sizes you mentioned are correct.

 

[RojoRacing]

There's no cable to hydro setup that feels almost as good as full hydro, anyone who claims as much doesn't no the true feel of good hydro brakes.

Yeah you can't go wrong with sram hydro road brifters. I have 22 speed HRD(hydro brakes, cable shifting) on the V20 and Etap HRD on the Trek. The etap HRD is supposed to be a better update but honestly I'd give them a solid 8 but the 22hrd setup on the V20 I'd give a 10 out of 10.

 

[Rampa]

I would think the cable/hydro might have a bit more "boil" problem, as there is much less fluid in them, and it's only right there in the calliper.

 

[RojoRacing]

Only in the most extreme conditions could you ever boils brake fluid on a bicycle and I guarantee there ain't any recumbent rider crazy enough in the mountain to do it even with a cable setup.

 

[benphyr]

Only in the most extreme conditions could you ever boils brake fluid on a bicycle and I guarantee there ain't any recumbent rider crazy enough in the mountain to do it even with a cable setup.

Agreed. Rojo knows. And common sense agrees.

Max heat (energy) generated from braking a Cruzbike is limited by in absolute worst case scenario I doubt that we could get
Energy of stopping from top speed - momentum based on (I doubt that we could get): -400lbs of rider+ bike+touring setup, and 70km/h top speeds, and
Energy of slowing stopping to counteract gravity potential energy of largest hill we go down
Meanwhile some heat is being dissipated by convection of air past brake rotor
Only once: fluid/rotor/assembly will have cooled somewhat before next hill especially if next hill is same size highest hill.

Limit for Racing motorcycle:
Energy of stopping from top speed: momentum based on racing motorcycle weight heavier and easily 200km/h speeds (speed is squared function! so has an increasingly greater impact)
Energy of slowing/stopping to counteract gravity potential energy of largest hill - very small factor for the motorcycle
Repeated over and over in close succession not allowing as much heat dissipation before the next brake use,

I would think we have many orders of magnitude safety margin compared to anything that boils brake fluid.

And another more common sense thing. Brake fluid lines are small, there is not going to be a whole lot of difference in convection or conduction dissipation of heat away from the caliper between a cable/hydraulic system as compared with a full hydraulic system.

(And Rojo said no recumbent rider is crazy enough to in the mountain to do it and he is the craziest in the mountain recumbent rider!)

Whew! We're all safe.

 

[RojoRacing]

How often do you here people worrying about their dura ace brakes on quality alloy rims failing from hard use? Yes it happens, hell it happened to me on the V20 but it a rare mention at best. Caliper brakes have been great for a long time especially in the time before carbon rims. Then years later comes along disc brakes, this never before seen black box tech(oh yeah I forgot cars, motorcycles and Mtb's) and everyone start worrying if they can hand the severe conditions of stopping a bicycle that isn't even falling off a mountain at 20% grades. Disc brakes are in every way better than rim brakes so unless you're looking for a solution because you just melted half your $60 rim brake pads to the side of your carbon rims you ain't no business worrying about if disc brakes can handle your use.

Not ranting at anyone here, you asked honest good question, I'm just expressing my humor on the subject.

 

[RojoRacing]

In motorcycle racing we have a track call road America, I forgot which state. But there are so many 160-200mph straitaways with 40-50mph corners at the end that you need a whole box of brake pads for the weekend. You literally change brake pads after each 45 min practice session because if you try and go two session in a row you'll experience brake fad from loss of pad compound. Even then we don't worry about the fluid expanding.

Also I like sram because they use proper DOT brake fluid and I can use my motul racing fluid from my racing days.

 

[Mathew Fy]

Go to 6 min. 55 sec. of this video where Jason enters a 15 mph curve at 48 mph. Have the sound up so you can hear the aggressive braking. It's exciting.

 

[Rampa]

That is actually why Shimano didn't release hydraulic road discs until they had developed their Ice rotors with extra fins. Road bikes generally produce way more heat than mountain bikes because of the speeds.

It is probably not much of an issue these days, especially for knowledgable riders.

 

[Rampa]

Regarding the specific cable/hydro brakes mentioned in this thread, they seem engineered for it.

"TRP tests its Hy/Rd cable actuated hydraulic brakes to the point where rotors get red hot. With a substantial metal body, the calipers act as an effective heat sink.
The company has also developed an insulating brake piston that helps to protect the brake fluid from heat transfer, a solution also used by SRAM in its brake calipers."

Read more at https://www.cyclingweekly.com/news/...ing-to-worry-about-310878#11efRU0pIxfFH2iQ.99

 

[RojoRacing]

That is actually why Shimano didn't release hydraulic road discs until they had developed their Ice rotors with extra fins. Road bikes generally produce way more heat than mountain bikes because of the speeds.

It is probably not much of an issue these days, especially for knowledgable riders.

Bwahahaha I'm sorry but I can't help but laugh at that marketing excuse. Trust me mtbs are way harder on brakes then road bikes by a fare large margin. Assuming you're actually riding the mtb the way it was intended and not just on paths and fire roads.

 

[Suz]

Disc brakes are in every way better than rim brakes

So Rojo and crew, serious question, why does it take a longer distance to brake with discs as opposed to calipers? I’ve always ridden with calipers until the S40 and I feel like the discs don’t react as well, feel spongy, and it takes more distance to brake with the discs. So I’m not sold yet. Is this an adjustment issue or inherent to discs?
Thx

 

[RojoRacing]

So Rojo and crew, serious question, why does it take a longer distance to brake with discs as opposed to calipers? I’ve always ridden with calipers until the S40 and I feel like the discs don’t react as well, feel spongy, and it takes more distance to brake with the discs. So I’m not sold yet. Is this an adjustment issue or inherent to discs?
Thx

your setup must be crap in one way or another. Also if it's a brand new disc brake setup it'll need several dozen hard braking actions before the pads and rotors really start to get along aka bedding in.

pictures of your setup could help us see if something looks amiss

 

[super slim]

So Rojo and crew, serious question, why does it take a longer distance to brake with discs as opposed to calipers? I’ve always ridden with calipers until the S40 and I feel like the discs don’t react as well, feel spongy, and it takes more distance to brake with the discs. So I’m not sold yet. Is this an adjustment issue or inherent to discs?
Thx

My experience is the disc brakes (if adjusted correctly!) are FAR superior to road rim brakes, and even side pull MTB rim brakes, especially in the wet!!!

The rear rim brakes and rims NEED to be cleaned regularly, if riding in wet conditions, as LOTS of grime gets thrown up by the front wheel!!

If it is a Avid BB5 with 22 mm circular disc pads, these are VERY hard to adjust so parallel to the disc, with 1/3 gap between the inboard FIXED pad, and 2/3 gap to the Moving outboard pad!
If it is a Avid BB7 with 31*19 mm rectangular disc pads, these are EASY to adjust so parallel to the disc, with 1/3 gap between the inboard FIXED pad, and 2/3 gap to the Moving outboard pad!

 

[bladderhead]

Suz must have made a mistake setting them up. When I first got disk brakes I was shocked by how well they worked. If that bike had been a DF I would have put myself over the bars. The first disk brakes I had on the Silvio were no good at all. That was because of a mess-up by me. The ones I have now stop me.

 

[Suz]

your setup must be crap in one way or another. Also if it's a brand new disc brake setup it'll need several dozen hard braking actions before the pads and rotors really start to get along aka bedding in.

pictures of your setup could help us see if something looks amiss

I haven’t done any hard braking. I’ll try that. The brakes are smooth just slow. Thx.