After a year of riding our slick-tire-equipped Burley Rock & Roll we got at an amazing price, my wife and I are thinking seriously of upgrading. Ideally, we'd get an S&S road tandem for traveling (but not touring). The other thing that is near the top of our list is disc brakes (mechanical of course). After having felt the searing heat from our rims after one long descent, we both thought this would be a very good idea. I know, a drum drag brake could also substitute, but there is something to be said about the control of going from no brakes, to hard braking, to no brakes again. It's fun! I'd want these front and rear: the front will be doing as much braking as the rear. I just don't want to be paranoid about a tire coming off!
So, after looking at the common brand name bikes (comotion, santana, cannondale), I have not found this combination. It's couplers or it's disc brakes, but not both. Why not? Is there a compatibility issue? I'd consider building up something from a frame and fork. Is there something else I should be looking at? Thanks!
Larry
The BikeForums Team
-adv-
This is an archived thread, you can find the full version of this thread, with images, links and more content here.
So, after looking at the common brand name bikes (comotion, santana, cannondale), I have not found this combination. It's couplers or it's disc brakes, but not both. Why not? Is there a compatibility issue? I'd consider building up something from a frame and fork. Is there something else I should be looking at? Thanks!
There aren't any compatibility issues between couplers and discs. At present, the only "major" brand name tandem builder to offer dual discs as standard equipment is Cannondale who, coincidently, only sells aluminum tandems. While it is possible to build an S&S equipped aluminum tandem, it is highly impractical and to my knowledge only Santana has offered the S&S coupler option on aluminum tandems. Other tandem builders "can" build S&S equipped aluminum frames but have no interest given the impracticality of aluminum as a travel tandem frame material vs. the more suitable steel, titanium or even composite frame materials. Moreover, S&S couplings (or other custom frame fabrication features) are not something that the mass producers like Cannondale, Trek, Burley, KHS, Raleigh, etc... offer.
As for other tandem builders who offer optional dual discs on their road tandems as well as S&S couplers, it's a small list that includes (but may not be limited to): daVinci, Erickson, Bushnell, Steve Rex, AriZona, and Santana (but only if you beg). Co-Motion will sell you an S&S equipped tandem with an Avid rear disc as the primary brake but does not offer a dual disc option. However, someone like Dennis Bushnell, Steve Rex, or Bob Davis at AriZona tandems can build you a disc-compatible front fork for your Co-Motion. You can probably assume that you'll void your Co-Motion's warranty by doing so, but that's only a guess.
As for the practicality of the dual disc equipped road tandems, the folks who own them seem to like them a lot. However, dual discs aren't for everyone. IMHO, heavier teams and teams who prefer to descend with lots of brake control at present are still better off with an Arai drum drag brake vs. the dual discs.
Brian
We've got an S&S coupled tandem MTB equipped with Avid mechanical discs, and have had no problems at all. I'm not sure a front disc is suitable on a road tandem though.
thepurplepirate
We have a front disc on our Roland and will never go back to rim brakes on any of our future bikes. Discs and Rim brakes are incomparable.
larrydj
Thanks for all your inputs. My search continues, but I may have to start with a rim brake equipped S&S frame, and add discs later, if the frame accepts them.
On a related topic, the real reason I wanted discs is to avoid the overheating rims syndrome when doing a long descent. I don't want a tire coming off when doing a fast descent! Are there wheel designs that are less prone to this than others? For instance do the Aerospoke rims heat up less due to the larger mass of the rim? (On the other hand, carbon fiber is an insulator, it may not distribute the rim heat). Any thoughts, or am I just paranoid?
SDS
Aerospoke no longer makes tandem wheels. All the CF/alu rims that I know of depend on a bond at the interface, and as a general rule the bonding material (high-tech word for glue) melts, and then bad things can happen. The current HED trispoke was sold by Specialized, and they did not warrant the wheel for tandem use for that reason. Many people used it anyway, and I recall hearing that a few people had some kind of problem because they melted the bond.
One person who used an Aerospoke with an Arai drum brake melted the CF thermoplastic around the hub. While the hub was threaded for a drum brake, apparently this was never properly tested, at least not to the extremes generated by one user.
I like my Aerospoke tandem wheels a whole lot, but if I was going to the mountains I would fit a disk, or wire-spoke wheels and a disk or drum brake. I believe nearly all stokers, when presented with the issues and the options, would pick an Arai drum brake. I believe the difference is about a pound, and the Arai has a long history of doing well. I think I might be willing to go with the Santana/Formula disk, which is STI compatible, even though customers have had some complaints, mostly having to do with maintenance.
Cannondale is using disks on both ends now with no rim brakes (?), so I think I am being unreasonably conservative. It would be fun to get Bill McCready to buy a C'dale with disks so he could demonstrate that it would (?) fail his brake test protocol (I like Bill's test. he only uses one brake, on a steep hill).
I think the best rim for keeping tire temperatures down with rim brakes would be a high-profile, all-aluminum rim.
On a related topic, I have considered a total loss, water-spray cooling system for the rims. I think this is nuts and would weigh more than other braking systems.
Addendum:
With the Cantilevers v. V-brakes v. disk thread back to the top, I found that one poster with a 2004 dual disk Cannondale tandem reports melting parts on the Avid disks. It's probably a sure thing that the brakes would fail Santana's brake test protocol.
TandemGeek
Are there wheel designs that are less prone to this than others?
It has been my experience that Deep section rims like the Velocity Deep-V, Mavic CXP33, and the like with larger wind-swept surface areas are more efficient as heat sinks than non-aero box section rims.