Front Vs. Rear braking questions
Perusing this forum, it appears to be fairly standard procedure to install disc brakes on the rear of a tandem and keep cantilevers of some sort on the front. Why not the disc in front, and canti's in the back?
From what I understand, the majority of braking force comes from the front of a vehicle whether it is a bike or a car. Seeing as how it seems near impossible to lock up the front wheel and jackknife or endo on a tandem, wouldn't you want as much braking force up front as possible, as opposed to the rear?
My stoker and I just purchased our second tandem, a Santana Sovereign. Loving it so far! It came with a rear mounted drag brake, which I like as a parking brake at stoplights and on long extended descents it is a nice feature given we are in Colorado and love climbing rides. However, the weight on the thing is pretty ridiculous, I don't like the extra cable sticking out of my right drop, and considering how rarely it is actually utilized it seems like a waste.
The brakes are pretty decent, but it would be nice to have more bite, overall force, and modulation, especially when riding in group situations. It seems to me, the most effective and perhaps economical solution to increasing overall braking performance would be to remove the drag brake, and install a disc in the front of the bike. This would require rebuilding the front wheel, and replacing the fork with something with a disc mount. Our Santana has a mount for the drag brake, but it doesn't appear anything for disc mounting on the rear, so I am assuming a disc in the back is not feasible?
Anyone suggestions on improving braking performance, and what to do with the drag brake? I almost took it off the other day but couldn't figure out how to detach it from the HUB! Advice for this if I decided to remove drag brake? Do I have to insert a spacer of some sort to take up the extra space on the 160mm axle?
Ours is a late 90s Co-Motion with V brakes. Had an Arai drum brake on the rear but needed is so rarely I removed it. I've never locked up either the front or rear wheel. I don't know if I could. As you are probably aware, the rear brake on a tandem is far more effective than on a single bike. So, I'm not sure where the "better" brake should go. I've not looked into it but I've assumed that converting a tandem to disc brakes would be quite expensive. Probably better to buy one that was designed to have them. Let us know how this goes for you.
I have looked into retrofitting disk onto my CoMotion Speedster. I talked with CoMotion and the front is easy, new fork and rim that is disk compatible. For the rear I would have to ship the bike out to them to have the mounts for the disk added to the frame. They recommend doing the front only to have that extra braking force. I currently do not have the drag brake installed since we don’t ride many steep long hills near me, but if I head to the mountains I will reinstall it. Drag brake is needed on long descents to keep the rims from overheating.
For me the cost of a disk up front is a new fork, rim and the disk brake and parts.
Cost for disc conversion in the front would also be considerable: New fork, hub, rebuild wheel, disc brake components. I work in a shop which helps but still, is it worth all this rebuilding, cost, and hassle for the performance a disc would offer over the cantilevers.
My second thought was simply upgrading the cantilever brakes to a better set. There are a lot of canti's out there marketed as Cyclocross brakes, many of which look quite nice. Anybody have any experience with the newer crop of cross canti's on a tandem?
Been riding as a duo since 1974.
Our first tandem, a French Follis, came with an Atom drum brake. We had spoke 'eating issues' and removed it; replaced it with 2 back-to-back calipers that worked just fine.
Our next 4 tandems, all built to our specs, had no 3rd brake and we have utilized anything from Mafac cantis, U-brake (in the rear), Scott brakes, V-brakes and now on our Zona we have Dura Ace caliper front and Tektro Mini-V rear.
Have ridden in 30-some states and done lotsa climbing: hills and mountains (up to 9,200') with some twisty/steep/fast (50+ mph) descents and so far have survived them all.
However, much of it is in braking technique and equipment that you feel comfortable with.
Yes, have ridden a prototype tandem several years ago with discs front and rear. Hitting the brakes hard in a 30+ mph descent was, to say the least, a heart/tandem stopping experience. A real revelation bordering on scary/dangerous.
Have never felt the necessity for that type of stopping power.
However we all have our own tolerance levels.
Just our input.
Pedal on TWOgether!
Rudy and Kay/zonatandem
I may be completely missing something but what I perceive is that with a 700 C front and rear wheel that has a machined braking surface you have, in effect 2 large diameter discs. If you use good caliper brakes with good pads and use them correctly you should have excellent brakes. The only issue that people have talked about is the possibility of overheating on a long descent and blowing up a tire. I believe this is why people have used drum/drag brakes in the past. My opinion is that for most teams good wheels with good caliper brakes provide good stopping power.
Here in the flat lands of Illinois that is all we need. Now if you are using carbon rims you probably need disc brakes in order to keep from overheating and melting the carbon rims. Wheelbuilder.com was going to quote a pair of wheels with Enve rims for us but insisted that I use a disc on the rear to keep from melting the carbon rim. I ended up with Bontrager tandem wheels and Ultegra calipers with Kool stop Salmon pads. Our brakes work great.
Had a Cannondale that we retro-fitted an early cable actuated hyd. disc master. Lot's of work, this was way back when. worked so well that when Avid came uo with the BB-7, we had a fork made for that app. the best stopping power one could ask for, highly recomended. We miss our front disc. We used to try and be the first down the hill, didn't matter how technical or steep the downhill was, and loved beating all the half bikes. Our technique has changed quite a bit, age and smarts got the best of us.
Last edited by mkane77g; 06-03-11 at 05:23 PM.
Reason: pic added
I believe that you can buy a kit from Mark Johnson of Precision Tandems to convert your drag brake to a disc brake. We had a drag brake on two previous tandems but only used them for steep long descents and parking. We now have a rear Avid disc and linear brakes on the front. The rear disc stops better than any other brake that we have had, especially in the rain. I use the rear disc for most of our stopping unless it is a quick stop, from a faster speed or on a hill. One advantage to not having a disc on front is if you remove you front wheel often to haul the tandem the wheel is a little more tedious to put back on the bike. There is not much clearance between the rotor and the pads although if I bought a new tandem today I would get disc brakes for both wheels.
I find it is a little easer to remove and install the wheel on our tandem with a front disk. No straddle cable to disconnect and reconnect. Most of the time it doesn’t matter to me if I’m riding the tandem with disks or cantilevers. In the rain the disk is nice. I like the disk a little better but wouldn’t put a disk on the front unless I wanted or needed to change the fork anyway.
Originally Posted by tandem rider
I'll add one more thing. These BB7's were using on our tandem cannot lock up the wheel at speed unless the roads very bumpy. The hyd. dics in the pic could. Way more stopping power. To take full advantage of this kind of power, it must be mounted in the front.
For the Hydraulic disc? what kind of Levers were you using? I saw something on Velonews the other day. I think it was made by TRP but is essentially a master cylinder that mounts under your stem spacers on the steerer tube where the brake hanger would normally go. Allows you to use standard road levers with hydraulic discs. Super cool, is there another way?
Like DubT, we use Ultegra calipers (with Mavic CXP 33 wheels) and they have worked great in Seattle and other rides in Washington where we sometimes encounter hills and rain. We do do not do extended high speed runs down the mountains so the calipers have been sufficient.
Originally Posted by DubT
I don't know if things have changed since we purchased our tandem 4 years ago but at that time most tandems came with v-brakes, although an adapter was required to use them with brifters. It seems some folks like to outfit their bikes for the worst case scenario, thinking, for example, maybe I'll want to do some nice mountain rides or tour with heavy panniers so maybe I should get a drum brake or some form of extra stopping power. As
zonatandem mentions, many riders have decended long steep mountain roads with caliper brakes and their knowledgeable use. If we ever end up on a long steep decent I'll just be overly cautious and check rim temp if I am concerned. We have no plans for such a ride.
Disc brakes have their own shortcomings. I like the simplicity and effectiveness, for us, of the calipers.
We used road levers with one of those booster/cable pull gismos. This was way back when, long before anyone had disc's on the front. Old motorcycle roadracer here.
Originally Posted by HorsCO