UnfilteredDregs

Shimano doubles down...



"There has been a lot of speculation since Shimano first announced a new brake mount specific to road, but little in the way of details. Ironically coming on April 1st in Japan, Shimano is finally showing their hand and introducing two new hydraulic road disc brakes built specifically for the Flat Mount fitment. Announced along with a new 10 speed Tiagra group and WH-RX010 road disc wheelset, the new BR-RS505 and BR-RS805 disc brakes are non-series components at the 105 and Ultegra level respectively.

We have a feeling we’ll be learning more about these new brakes come Sea Otter, but the preliminary details are after the break…"



Beneficial to both the frame and the caliper design, Flat Mount uses an all new caliper that bolts up from the bottom instead of through the top like most calipers. On the rear brake that results in a true “Flat Mount” with the caliper sitting directly on the chainstay. Caliper mounting bolts are inserted through the bottom of the chainstay and thread into the caliper making a very tidy rear triangle of the frame. While the mounting and shape of the caliper changes, the brakes still use one-way bleeding with a bleed nipple at the highest point in the caliper’s hydraulic workings.



Due to the fact that the caliper bolts up through the bottom, the front brake will still need an adapter which is then bolted to the back side of the fork leg. Shimano tells us that you can still use additional adapters to run larger rotors while the brakes are capable of running 140mm.





Visually, there is little difference between the BR-RS505 (105 level) and BR-RS805 (Utlegra Level), other than the finish. We wouldn’t be surprised to find that there is more to it beneath the surface though. Both calipers will use new brake pads which are not mountain bike compatible, likely meant for much higher heat applications.



Completing the RS-505 level hydraulic system is the new ST-RS505 hydraulic/mechanical shift lever which brings Shimano’s hydraulic road performance down to the most affordable level yet. Compatible with either of the new Flat Mount disc calipers or even previous Shimano hydraulic road calipers, the 11 speed mechanical shift lever with Vivid Indexing includes reach and free stroke adjustments as well.



As promised, frames equipped with the new Flat Mount standard will still be able to run standard road brake calipers with one of the Shimano adapters. That means frames will be backwards compatible, but the new Flat Mount brakes will not be since they can only be mounted to frames with the Flat Mount provisions.



Along with the ST-RS505 brake levers, the RS505 system includes a new 105 level Centerlock hubset to facilitate custom wheel builds that are 11 speed road disc compatible.



The Flat Mount brakes will continue to use the current Shimano Centerlock rotors with the SM-RT81 and SM-RT99 Freeza rotors available down to 140mm.

We’ll update the story as pricing and weights become available."

Dave Mayer

Boring. When I am hauling 50 pounds of camping gear down steep grades on tour, I may be interested in disks.

Wonder how much extra weight has to be added to the frame for the mounts? Plus extra for the brake calipers.... I have looked over a few disk-compatible road bikes at our local shops. Despite expensive carbon frames and high-end components, they are heavy pigs.

BTW: Year to date I've ridden 80 days on carbon rims. Using rim brakes - in the rain. Despite some major descents (my main route drops 500 vertical feet in 5 blocks), I've had no problems.

bt

fugly and un-needed.

lolz

cale

It's exciting to see this innovation in bike braking take place for road bikes. I like the sleek caliper shape and the hydraulic system suggests that the modulation and self-centering aspects of the brakes will be up to snuff too.

If you're counting grams, like the poster above, I doubt you'll be impressed with these brakes. But entry level racers (as soon as they get the go ahead) are going to enjoy better braking and I think it will make for better racing. Another group that will benefit are commuters, a growing segment among alternative forms of transportation. I think they will benefit from the instantaneous application of the brakes in wet and muddy conditions. It is confidence inspiring when there's no waiting for the brakes to grab.

Thanks for posting the announcement.

Lazyass

bt

self centering?

I don't think so.

pads retracting equally doesn't equate to "self centering".

cale

Why don't you add something positive?

svtmike

Your main route must be up and down Filbert Street in San Francisco.

UnfilteredDregs

I can see you two in a room together...and a bucket of squealout.

UnfilteredDregs

Sigh...this is getting so boring. Hydraulic disc brakes are self centering, they maintain the pad to rotor gap as the pads wear down.

Next.

RJM

lolz


I hope they are better than my xt brakes on my mountain bike, which squeal almost every ride.

bt

false.

if the caliper isn't centered, you unscrew the mounting bolts and center it over the rotor.

the pads may retract the same amount equal to the previous protrusion cycle, but that isn't self centering.

UnfilteredDregs

If the caliper isn't aligned to clear the rotor the brakes haven't been installed correctly.

Hydraulic systems maintain the pad to rotor gap, otherwise known in the common parlance when speaking of hydraulic disc brakes as "self-centering."

but..you'd argue the semantics because..that's you. take it up with Lennard Zinn, I'm sure your opinion would carry great weight.

Kinda like parkways & driveways genius.

Stucky

Yawn...

Boiy, that crap looks heavy! Looks like what it mounts to must be beefed-up and heavy, too.....

You'd think we were riding mountainous hairpin switchbacks at 200MPH, instead of 17 lb. bicycles at 20MPH...... Gee...how did we manage to stop for the last 50 years? I've lived with coaster brakes; I've lived with steel rims with rim brakes; alloy wheels with dual-pivots is all the brakes I'll ever need....

bgav

Don't knock hydro road-disc til you try it...

datlas 

Just wondering...

Psimet2001 

More accurately - they compensate for pad wear.

This is what made disc brakes even remotely viable for cyclocross. With the mechanical setups the pads would wear too quickly on muddy courses and the pads wouldn't compensate like they do on hydraulic meaning that the pads just got further and further from the rotor leaving the racers without any brakes within a lap or two.

Timely post. I was about to pickup a set of road hydraulic Di2 for my latest show/demo bike. Guess I'll wait. Better hit soon or else I'll just end up on SRAM wireless/Hydraulic disc road group when it's finally available later in the year.

Psimet2001 

My cross bike complete with SRAM CX1 hydraulic disc weighs in at 16 lbs.

Disc overkill? Absolutely. As a wheelbuilder - gotta say I prefer how disc brake wheel fare, but I can always build a lighter rim brake wheel of course.

I guess I understand the hesitation, but here's the basics - you can't fight it. The whole industry is going disc. I can't fight it and I am in the industry. So - get used to it. Also: riding disc on the road, even at human speeds, is actually a LOT of fun. A whole helluva lot more fun than I thought it would be. More control overall.

Needed? No, but then again we really didn't need to change from the old school canti's either. I mean they stopped us. Same with Friction shifting....it shifted.... etc.

Stucky

It may be where the industry's going (and I have no quarrel for MTB and CX, BTW)- but it's not where a lot of consumers (like myself) want to go- which tells me it will likely be a passing fad; like suspension forks for roadbikes a-la 1992.

Personally, my next bike will have downtube shifters (Whether friction or indexed, I don't care). As the industry is pushing electronic shifting and discs and such other BS., I'm wanting to return to the simple basics. Can't predict the future, but I've often been a good indicator of (in other spheres of endeavor) of what the market will do in a few years. Sometimes I'm ahead of my time; other times, I just represent a solid niche. We shall see; but just going by what i see on these forums, I'm not sensing an overall warm reception of discs by the mid and high-end road bike market. The industry's trying to dictate to the market, rather than serving it. That's not good for the industry. That often signals a major change in players.

lkngro

This isn't a "good" or "bad" thing that disc brakes are becoming more popular. It's just preference. If you want something lighter, go with calipers. If you want more braking control/power, go with discs. Shimano is just adding to the available options for people who prefer discs and attempting to make it as good as a product as possible.

cale

Sometime ago, the "industry" pushed for helmet safety. A lot of people pushed back, including many if not most at BF. You'll get too hot! It will make you slower climbing (aerodynamics?). You look ugly wearing one. Driven by consumer interest in safety (cars were already getting much safer), national helmet awareness campaigns and local regulations regarding the use of helmets by children drove helmet popularity to the point where the bicycling elite, could no longer ignore the trend. If the helmet trend is temporary, it is having a good long run.

This really isn't so different than the trend towards road bikes with disc brakes. Consumers understand what it means to purchase safety features and that sort of thing remains important in the purchase of any transportation vehicle. Even one used primarily for recreational purposes. Besides, they are really fun to use. After an initial adjustment to their feel, the rider will enjoy greater confidence which translates into more enjoyable downhill rides and confidence in traffic, just to name a couple places riders gain some benefit.

Psimet2001 

In a few years there will be a niche segment where hand builders and custom guys like us will harken back to the old vintage caliper brakes and what was old will be new again.

If you're set on being a Luddite/retro grouch then I bought a bike shop last year that is simply full of stuff you'd love to buy from me. It's like taking a trip down memory lane with each shelf.....but it's all still there for a reason. While it may be simple, durable and elegant: no one wants to buy it.

As for suspension forks on road in 92 - no....disc is nothing even remotely like that. There are production frames already on the floor made by most of the industry's largest manufacturers. All of the component OEMs have focused on developing top tier disc components and the UCI is voting on disc use in road. It is already legal for road and Crit use in USA Cycling events. I lived through top end road racing in 92 and couldn't tell you 2 or even 3 real major production road bikes that had them. They were more of an oddity. Like drop in bars. Or power cranks. Nothing more.

Stucky

Bad analogy- as helmets offer some actual benefit; and did not require the adoption of new standards in bike frames and components. Conversely, how many cycling accidents are caused because of inadequate braking? I'd bet very, very few. In-fact, I'd guess that more are caused by over-zealous use of brakes/grabbing too much in panic situations....and such incidents will actually increase if discs become common [So next, they'll probably start putting anti-lock brake systems on bikes! -Where does it end? All to solve a problem which doesn't exist for 98% of road cyclists; just to stimulate sales.)

cale

You start off by saying it is a bad analogy and then claim that disc brakes off no benefits. I've had enough of responding to posters that adamantly state that there are no benefits. Look, if you want to stay with your existing system, that's fine. But you do nothing but stir up trouble with this denial of benefits. Go on then, tell me again how no benefits exist.

Psimet2001 

.....and shifting wasn't a "problem" when we had friction shift, downtube shifters and 5 gear freewheels. Resistance to change is normal.