jacks1071

I think the standard V2 would be more than enough - the vented ones look killer though!!

Krenovian

An interesting point to consider when it comes to disc caliper adjustment and installation: https://www.blackmtncycles.com/2012/10/more-tension.html
Shimano has an in line brake cable adjuster, part # CM-CB70, to allow for adjustment without having to work with the cable attachment at the caliper. They show it as part of their cyclcocross disc setup: https://www.fuchs-movesa.ch/tradepro/...Chart_2012.pdf

Krenovian

CX75 now also listed on ProBikeSupply and JensonUSA. Looks like they must have started arriving in the shops last week.

PMK

Interesting read, in regards to the concerns about no barrel adjuster on the caliper, riders need to realize that if there is a cable adjuster on the brake system, it is possible to obtain more lever feel but in reality have the disc not contacting the brake pad but actually using the caliper housing as friction material. The inline adjuster is good for setting initial cable runs or making a minor cable adjustment over time. True adjustment of the brakes needs to happen at the wheel.

PK

DubT

Dean, you are an innovator, why not run tubular tires and your current rim brakes. Here is what Joe Young, a wheel builder says about tubulars.

Joe Young Wheels


First, I am not trying to sell anyone on riding tubular tires and rims. I have noticed that most of the information and comments on the web and in the cycling press about tubular wheels is negative, so I am thinking someone needs to be an advocate. Most see them as a relic from the past but the pros don't think so. Due to the interest of the pros and serious riders in tubular wheels for cross racing, there are more tire choices available now.


When I started riding bikes, clinchers were unsafe at any speed. This was before the "hook bead rim" appeared; the flat side rim would only take about 60 to 70 psi before the tire popped off the rim, or, worse, came off in a corner. Tubulars were what serious riders considered. So we learned the skills from the Euros to make them work and they worked extremely well. Everyone had at least one spare tire that was stretched and had a bit of glue for a spare. Back in the very early days when the rims were wood and the tires were bigger (the roads were not paved) the tires were formed in a figure 8 and riders put their arms through and wore them on their backs - sometimes two or 3 at a time as there were no trains or support cars.


We never had a problem with the tires coming off the rims as long as there was enough air in the tires. I have seen beginners show up at races with no glue on the tires and the tires stayed on. (I am NOT recommending this unless you are into the jackass thing)


One of the superior attributes of the tubular design is that the air pressure energy in the tires goes down into the rim toward the center of the wheel, holding the tire on the rim. In the clincher, the energy goes into the rim side walls trying to pull the rim apart.


This is also an advantage as the tubular tires will tolerate more air pressure. Track tires use 160 to 180 psi. To my knowledge clinchers are still not allowed on the track. No one needs that much pressure unless the paved surface is very smooth.


Another superior fact about tubular tires is that they are perfectly round so transitioning into and out of corners is smoother. This is one reason the industry is trying clincher designs to be more like tubular tires (tubeless and the new 23mm theory). If you think about it, neither design will really work like a tubular because the tire is not perfectly round and the air pressure still goes to the side instead of toward the center of the wheel. You can make the rim wider but it is still not perfectly round.


If you want a tubular ride just get a tubular. Nothing in nature seeks to be a square but always seeks a circle. The best rim designs are not square but a combination of circles and triangles. The circle and triangle is much stronger. The circle matches the tire where it joins the rim. The triangle at the top of the rim where the spokes join the rim for stability. There is no reason for the profile of the rim to be more than 30 mm. More profile just makes the rim heaver. In my experience aero rims and spokes are all smoke and mirrors.


The tubular rim is much simpler than the clincher. Therefore the rim can be lighter and should cost less. Check out the weight of the carbon rims. The lightest are tubular. Otherwise why pay the price of carbon if it isn't lighter than aluminum? I think one of the best tubular rim design is the Velocity Escape and Pro Elite. Again, the triangle and circle.


Okay now to the negatives. You have to deal with the messy process of gluing the tire on. You can take it to the dealer but they probably have never seen one. Much of the lore of cycling is learning some simple skills. The bicycle and most other industries have taken simplicity away, but Grant Petersen at Rivendell has been telling us that for years - much better than I can.


One major negative is that if you puncture a tubular you have to learn a major skill: how to repair it (or else you have to toss it)! But enter the magical tire sealant. Like the tubeless tires which are difficult to deal with if you have a flat, you can use the same sealant for a tubular tire. The TUFO tire has had a sealant for years. They also have a tape that can replace the glue. People ask, “Can I depend on the tape in the summer or can I do Crit racing with the tape?” In fact, you can. We are finding that to remove the tire from the rim, you need to leave a 10mm gap to fit a tire lever to pry the tire off. It is that strong of a bond.


Enjoy your ride.
Joe

TandemGeek

Tubbies are fine for tandems, so long as:

A. You don't use them on rides that put high heat loads into rim-brake equipped tandems; or
B. You use them on a tandem with dual discs, noting that Rolf worked with Co-Motion to develope a dual-disc / tandem-specific tubular wheelset a few years back for this very purpose.

Again, tandems put heat loads into rims that far exceed what are experienced on single bikes, and those heat loads can and have caused the glue to release and tubular tires to roll-off rims... some with serious consequences.

From the archives, a previous thread on tubulars with secondary links to other anecdotal information: https://www.bikeforums.net/showthread...dem-experience

photogravity

It seems to me that one commonality in the tire blow-offs I read about is that almost everyone is running quite narrow tires - usually 23-28mm. I know that if you get a puncture on a very narrow tire, the air escapes very quickly since there is very little air volume compared to a larger, wider tire. It would be interesting to see how many blow-offs occur with larger tires, when using similar rims on similar terrain. At least anecdotally, it seems larger tires tend not to have as many blow-offs.

DubT

I ran tubular tires on our Santana back in the 90's for several years, full disc on the rear and Zipp deep dish wheel on the front. Never had a problem, however we live in Illinois.

I am currently running the HED 3 tubular on the front of our Calfee and really like the way it looks, handles and carves through the air. This wheel has the aluminum braking surface. I have been using TUFO tape to mount all of my tubulars for the past few years and wonder how the tape would holdup in extreme heat conditions. It might not have the same issues as glue. Since we do not have any major downhills I will probably not find out.

Wayne

Mike Ayling

For a different opinion have a look at the Thorn site.

These are touring tandems running 26" X 1.75 and wider tyres and they swear by XT V brakes on ceramic coated rims which are well regarded by touring cyclists.

Thorn recommend hard braking to reduce speed then allowing the bike to run then repeat hard braking as mentioned by the original poster.

They will not fit a front disc brake because they say that their forks are designed with some flex for a comfortable ride and the forces exerted by the disc brake would destroy the fork.

You can have a disc drag brake which I think is hydraulic.

They have some unconventional ideas but as I said the bikes are well regarded in the touring community.

I suggest that you surf the site with one of your favourite alcoholic beverages at hand as the sales pitch gets a bit heavy at times!

Mike

Ritterview

Avid has a new alloy center rotor, it promotes as heat shedding. Competitive Cyclist claims there is a 200 mm size, but that doesn't show at the Avid site. You'd think 200 mm rotor would be in the offing.


HSX Rotor




Utilizing cross-drilled technology, the lightweight two-piece HSX series stays cooler when your run heats up, offers enhanced wet-weather performance and takes braking to a whole new level of smooth.
Available in 140/160/180mm

photogravity

Before you know it, they'll have disc rotors as large as 559mm and 622mm.

photogravity

Interestingly enough, the method on the Thorn site and that you mention here is what I use on hills with my tandems. While one of my tandems has a drum drag brake, I've never felt the need to use it. Also, despite tandems having enough weight for a rear brake to be effective compared to a half bike, I tend to use the front brake more than the rear brake.

Team Fab

The Burnaby Velodrome allows clinchers. In fact their riding school bikes are all on clinchers.

Carbonfiberboy 

SJS Cycles has 700c Rigida Grizzly CSS (carbide) rims here:
https://www.sjscycles.co.uk/rigida-gr...ack-prod18886/

This is a 610g, 622 X 19 rim, but lacks the ability of the 520g Deep-V to carry the heat away from the brake track. Obviously any rim generates the same amount of heat for the same amount of stopping force. These rims won't wear like standard rims, but they may not keep your tires on any better, either. Still, they look to be heavy enough for a tandem rim and might be a good choice for people like me, who go through a lot of rims but put on an additional drum or disc brake for the mountains.

Bostic

I have the 160 and 140 HSX rotors on my Volagi single bike and have climbed up all the local really horrible steep climbs (Regnart 19%, Bohlman & On Orbit 19-22%). With metallic pads they squealed like crazy and I don't ride the brakes down descents. I recently switched to organic pads and want to see if they still are that noisy. I'd also like to try the HS1 and compare.

We've done Regnart on the Tadem and with the G3 cleansweep rotors the descent was silent.

2frmMI

We descended Ventoux (and some other steep ones) this last June with Avid BB7, Avid metal pads, and a new XT ICE disk with no problems. In fact whereas in past major descents we have noticed in real time the fade that results from pad wear, no such fade with this combo. The disc brake is used as a drag (stoker controlled with bar end) while our caliper rim brake is controlled by the captain to feather speeds as necessary. We are probably intermediate in our tolerance for speed on descents like Ventoux, neither creeping nor flying. I attribute most of this newfound happiness with the disc on big descents to the XT ICE and its ability to dissipate heat. In the past we heated the BB7 to the point of smoking, but not melting the adjusters, thank goodness. Team weight ca. 310 this summer (damn those croissants!).

gracehowler

I would like to know how the organics work for you, we had same noise complaint on our tandem with bb7, switched to organics and so far I'm impressed, quiet and stop just as well, it will be a season before I can report on wear.
R&J

Tom Spohn

We switched to organic bb7 also due to noise. I expected some reducton in braking power, but was surprised to find they stop as well as the noisy metallic ones and are silent.

PMK

From my experience with metal vs organics. Over time the organics, even semi-metallics tend to polish the disc surface. This is when performance degrade and shuddering would occur.

Also, in the wet, the metal pads work better.

The real question to ask is how much brake do you need, and are you willing to learn how to properly align and adjust the brakes, plus clean when needed to keep performance up and squeals down.

PK

2frmMI

We had no noise issues with metallic, other than the occasional "ringing" from too-close pad adjustment. Loooooong and repeated drag sessions with nothing more than expected/accepted sound. But then, noise was never the issue for us before we switched to metallic and ICE, either. Don't get why this is such a problem in this thread. Maybe I'm just lucky.

rdtompki

Disc brake threads usually elicit comments regarding the maintainability (or lack thereof) of disc brakes. Maybe they require a bit more than V-brakes, but with any practice you can loosen the holding bolts, reset the caliper location with the inner pad, clamp with the outer pad, tighten bolts and back pads off in max 3-4 minutes. Assuming the rotor is true the result lever travel, brake feel and performance (assuming clean rotor and good pads) should be excellent. Noise seems to be hit or miss, but our Shimano ICE with metallic pads (not Avid) is quiet.

Bent In El Paso

+1

I find alignment and adjustment of the BB7 disc brakes to be very easy and fast. It is an adjustment easy to make on the road if needed. I think most folks that own these brakes don't take the time to read the owner's manual on installation, set-up, and maintenance.

swc7916

This is interesting. The stainless/aluminum/stainless sandwich has been used for years in high-end cookware (see All-Clad.) I understand aluminum's superior ability to conduct heat, but the heat has to go somewhere or the rotor will continue to heat up - where does it go? I can see that the heat would be more quickly transferred from the surface and would help with intermittant braking, but I don't see how it works with continuous braking - as in a drag brake.

Just a thought: Instead of using a stainless/aluminum/stainless sandwich, what about an all-aluminum rotor with a ceramic coating only at the braking surface?

rdtompki

I think the Al spider has a lot to do with heat transfer to the hub, which has a fair amount of beef. The Avid HSX rotor, while using what looks like a convention steel braking surface, also uses an Al spider.

swc7916

Don't the "non-ICE" rotors use the same spider? Besides, the 6 contact points don't seem big enough to transmit all that much heat.