scouse

I am in the research phase of selecting my first tandem.

How important is it do get a bike with disc brakes? Are they superior to regular rim brakes?

I have heard stories of disc brakes failing but these were relayed by sellers who didn't offer bikes with disc brakes. Are these stories true?

For example, I am looking at a new Cannondale. The Road 3 is about $600 cheaper than the Road 2. Although the R2 has nicer components all round, I am not really bothered about any of these (relative to the R3) other than the disc brakes (R3 has rim brakes).

Any input would be much appreciated! Thanks!

uspspro

Need = no
Want = depends

andydreisch

We have a Cannondale R2. I love the disk brakes if only because I don't have to worry about overheating the rims. We're a heavy team and typically carry gear on our rides. I've heard some frightening stories about rims overheating on long descents and I'm glad to not have to worry about that whatsoever.

Andy

merlinextraligh

Depends on team weight, and how you're going to use the bike. We went through this when were specing a new tandem for Everest Challenge. There are several posts on our blog discussing our decision to just use rim brakes, FWIW.

https://everestchallengex2.blogspot.com/

Rim brakes will give you all the stopping power you need. The issue is the potential for brake fade and possibly bblowing a tire from heat build up on the rim.

Personally, if you're not a heavy team, do not do loaded touring, and aren't planning on doing a lot of twisting descents, I would stick with rim brakes.

In racing the descents on EC, we hit 62 mph, and I never felt like the rim brakes were limiting our ability to descend fast, or slow appropriately for the turns.

In training we also did steeper, twistier descents, such as Brasstown Bald, and Hogpen in Georgia.

Coming down Brasstown, you need to go much slower, (some people who haven't have died coming down Brasstown.) Doing a slow controlled descent of Brasstown definitely caused the rim brakes to off gas.

If I was going to be doing a lot of descending like that, particularly if it was in a racing situation, I'd want a rear disc.

But short of that, I decided for us that the lower weight, and decreased complexity argued for no disc brake.

Another thing to consider, if the frame has the tabs to mount a disc, you can always add it later if you decide you need it.

cornucopia72

We ride on the sierras of central CA. We are a 300-310 lbs team. For us a rear disc brake is a must have... short of a drag/drum brake.

It is our opinion that a rear disc brake on a tandem is far superior to a rim brake.

Have been usin rear disc brake on tandem and triplet and only once they faded after a long steep descent on the tandem... we stopped, re-adjusted the brake a couple of clicks and continued on.

VaultGuru

Our first tandem (Burley Duet) came with v-brakes and a drum brake. The only time I ever used the drum brake was on the descent off Cadillac Mountain in Bar Harbor. Glad I had it, because the v-brakes alone would not have done the job. I built our new tandem with just Campagnolo skeleton rim brakes. Like Cornucopia, we ride the Sierra foothills a lot. With that setup, we did not feel comfortable with our ability to control our speed on technical descents. I replaced the rear rim brake with a Avid mechanical disc and love it. Lots of stopping power and no fade. Unless you live in, and ride in a flat state, you might want to consider a disc.
Cheers

pel

In my opinion do not think twice about it - get disc brakes front and back!
No comparison for emergency stopping power on a heavy tandem.

We bought a new Cannondale Mountain Tandem in April 2006 primarily because of the disc brakes. Never looked back.

Did a 6500km tour through Europe with a fully laden tandem pulling a Bob Yak. All up about 200Kg. Did three major passes Splugen, Albula (Switzerland - Alps) and Cole de la Schlugt (France) and long 30 km descents. Brakes (get mechanical) were superb. Got real hot but no concerns re tyres or anything else.

Brake adjustment and pad replacement is easy from the second time on.

merlinextraligh

Assuming you can lock the wheels, and modulate them short of locking, with rim brakes. Disc brakes will not make the bike stop any faster.

Our Dura Ace calipers easily have the power to lock up both wheels. Going to discs would not make the bike stop any faster.

The potential advantage is avoiding brake fading on prolonged descents, and ovrheated rims. But they are not going to give you any advantage in an emergency stop.

cornucopia72

How heavy was your rig (team plus gear) when you tested the above?

jgg3

Where are you (OP) located? Generally speaking, unless you are planning to tour, and the local area isn't very hilly, then you don't "need" discs.

merlinextraligh

right around 340lbs, plus 29lbs for the bike.

We've gone down 21% grades with it and had no trouble stopping, and hauled it down from 60mph plus speeds.

There isn't a problem with stopping it quickly. There can be an issue with repeated or prolonged braking on steep descents due to overheating issues.

Coming down Brasstown the pads were off gassing by the bottom, and we would have to stop if the descent was much longer.

I'm not saying that there are not reasons that a team may need disc brakes. I am saying stopping distance isn't one of them.

Old Army

Do you need disks? No. But when we purchased our Cannondale Street Tandem in 2007, I immediately replaced the rim brakes with MTB spec AVID BB7’s and upgraded the wheel set to a tandem specific disk brake compatible set. We used Avid full metal jackets on the fork and seat stay for reduced friction. The brakes feel nearly as good as the hydraulics on my single MTB. I have no worries about the brakes and big disks on a tandem bring the bling!
-Old Army

scouse

I am in Pittsburgh which is quite hilly but they are not big (long) hills. However, I am planning some long distance touring this summer. Tandems and touring are new to me so this may not pan out as I would like but you gotta start somewhere and I would really like to get a tandem I can keep (asking a lot I know...given that you never really know your bike until you have put at least a few hundred miles on).

Thanks for all the insight!

Interesting comment about the stopping power being same with rims as discs (emergency context). Both my single DF bikes have rim brakes (as does my recumbent) so I have no prior experience.

zonatandem

Need or want?
Hey if you 'feel' safer (mentally) with discs get 'em. If not, don't.
Over 220,000 miles on tandems so far. Tandemed at over 9,200 ft elevation. Have done long/steep/twisting descents off mountains. NEVER had an overheating problem. Much has to do in 'how' you brake.
Have used the old Mafac cantilevers ('70s and '80s), U-brakes, Self-energizing and V-brakes.
Have test ridden tandems with discs . . . they are fine. We are happy with Dura Ace front caliper and Tektro Mini-V rear brake on our current Zona tandem.
All brakes can have their own issues . .
Have ridden tandems with discs . . . and there are all sorts of brands/quality/ discs out there.
So please yourself and get what you feel comfortable with.
Just our input/experience.
Pedal on TWOgether!
Rudy and Kay/zonatandem

cornucopia72

To us, peace of mind of using the disc brake is worth every extra gr and then some...

Coming down into Orvieto, Italy, It is rainning buckets. Total rig wt. is under 400 lbs. Apply front rim brake full force, bike continues on like nothing happened. Apply rear disc brake and the bike slows down instantly to a safe speed to take a turn.

uspspro

In the rain, an initial application of the brakes will usually result in not much, until the water is shed (and the rim gets warm). Usually I apply light braking before the full application (which also requires much more force than in the dry). Granted discs are much better in the rain, my rim brakes have served me OK on a couple wet, twisty descents. My hands were tired after, but I was actually surprised that the brakes worked as well as they did.

EDIT: Pads are Swiss Stop Green High Performance Compound

oldacura

Disc brakes are not a "need" item. Under the right circumstances (long steep descent with lots of switchbacks), I'm sure that an inexperienced rider could overheat brakes - rim or disc. If you overheat a rim brake, you risk blowing a tire off. If you overheat a disc, it will fade. Under worst case conditions you might need both a rim and a hub brake on the rear wheel.

Disc -vs- rim is more of a preference than a need.

Old Army

Another consideration is the strength of the front fork. While tandem front forks are beefed up for tandem use, they may not be up to the task of disks. Generally, they wont have the disk mounting bosses if that is the case, but an unknowing LBS may be tempted to "upgrade" the bike to a disk compatible fork designed for a single (which is asking for trouble). So go with a frame made for disks if you think you will ever upgrade from V brakes.

-Old Army

brewer45

Malkin and I are a 325 lb casual team (about 2k miles per year), and avoid long steep whenever possible. We've had 1) rim brakes only, 2) rim brakes and drag brake, 3) disk front and rear. With rim brakes, we found the drag brake to be very useful. When we got our new bike with disks front and rear, I thought that we may have made a mistake. I don't think that any more. Although the disks require more fussing to maintain and adjust, we simply like them. It's probably completely irrational and not supported by good science, but I (captain) feel more confident with the disks.

Good luck with your decision and welcome!

Cheers!

andydreisch

I wonder if someone can chime in on the impact disc brakes (may) have on spokes given that the braking force occurs in a small area near the hub rather than being applied on the circumference of the wheel. I can't help but think that there wouldn't be some sheering-type forces applied to the spokes with disc brakes.

I haven't experienced any issues but we've got only 2500 miles so far.

Andy

specbill

' Born and raised near Carnegie/Bridgevile...rim brakes will get it done around Pittsburgh. We live in the southern Sierra now..we use rims brakes here too. We're a 310 team, not agressive riders but do plenty of miles and hills around here on our C'dale. Our next tandem will have rim brakes as well.
It is like zonatandem says...it is all about what makes you feel safer/comfortable. Good luck on your choice of tandem and Welcome!

Bill J

tandem rider

We have used an Avid disc since 03 and the spokes seem to last longer since we got the disc. Tandem wheels seem to be better than 10 years ago so I don't know if it is the wheels or the disc brake.
Sheldon

pel

Can someone tell me why disc brakes require a strengthened (relative to rim brakes) front fork if the disc brakes do not excert significantly more force in a full on emergency stop?

The Cannondale has to have the Fatty front fork - and I've seen it bend in a fully laden fast hard stop. A standard fork presumably could not take that kind of stress safely.

On long steep descents we had to alternate front and rear braking at times with 7 to 15 second intervals. But definately no fading.

tandem rider

The force is at the bottom of the fork with a disc while the rim brake puts the force at the top of the fork.
Sheldon

pel

Hey this is getting a bit technical for me (where are the boffins to sort this out) but rim or disc, as I understand it, what stops the bike is the wheel slowing relative to the frame ie front fork for front brakes.

So either way the force is excerted where the wheels joins the frame - Yes??