Advertise on Bikeforums.net



User Tag List

Results 1 to 13 of 13

Thread: Drag Brake

  1. #1
    Captain - 2nd in Command djsincla's Avatar
    Join Date
    Nov 2004
    Location
    Redondo Beach, CA
    Posts
    158
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Drag Brake

    I just upgraded my Tandem and I have yet to install a drag brake. On my previous Tandems, I used drum brakes -

    Is it practical to use a disc brake as a drag brake or should I stick to the drum brake?

    Thanks

  2. #2
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,154
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    If you truly need a drag brake use the Arai drum brake.

    Some of the older disc brakes from Hope that used big and beefy rotors, pads, and calipers were adequate as "light duty" drag brakes but they had their limitations. Current disc brakes could also support "light duty" use as a drag brake, but that's about it and in doing so you'll run the risk of warping the rotors and perhaps damaging some caliper parts if you overheat the system.

  3. #3
    All or nothing
    Join Date
    Dec 2006
    Location
    Davis, CA
    My Bikes
    Bike Friday PR Pro, Santana Arriva, Bike Friday Tandem Travler XL
    Posts
    12
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TandemGeek
    If you truly need a drag brake use the Arai drum brake.

    Some of the older disc brakes from Hope that used big and beefy rotors, pads, and calipers were adequate as "light duty" drag brakes but they had their limitations. Current disc brakes could also support "light duty" use as a drag brake, but that's about it and in doing so you'll run the risk of warping the rotors and perhaps damaging some caliper parts if you overheat the system.
    I am in the early stages of considering to upgrade from my 1996 Santana Arriva and 2001 Bike Friday Tandem Traveler (considering carbon -- yikes), and have been investigating disk brakes, trying to understand tandem advances in the last 5-10 years. Both of my tandems have the Arai drum brake.

    I have the impression many folks now-a-days use only one or two disk brakes and skip the drum brake, even for loaded touring in the mountains. I understand the benefits to be:
    (1) weight of disk brake is less than the weight of drum brake
    (2) braking performance (stopping power and heat dissapation) of disks is superior to performance of V-brakes, cantilevers, or sidepulls, so much so that one doesn't need a drum brake (assuming your hands don't get too tired holding the brake levers for 10-mile descents.

    I think the only downside to not having a drum brake is that the captain can't relax with the drum brake engaged because the disk brake must be continuously modulated for braking.

    Based on my understanding, one could skip the drum, use one or two disks, and from what I've heard/read, it seems like one only needs a single disk brake and folks usually put it on the back (likely on the back because the lightest carbon forks can't take a disk?).

    One more thought... I think Santana uses a 10-inch rotor (maybe one of their exclusive products?) but I think everybody else uses an 8-inch rotor. A 10-inch may have more braking capacity but it seems like the rest of the world is getting by fine with the 8-inch unit?

    Tandem geek(s) and gurus, is my analysis correct?

    Don

  4. #4
    Captain - 2nd in Command djsincla's Avatar
    Join Date
    Nov 2004
    Location
    Redondo Beach, CA
    Posts
    158
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Arai

    Appreciate for the feedback -

    Both of my previous Santanas were V-Brake with an Arai drum brake.

    I now have the sweet 16 wheelset and just wanted to make sure I considered all options.

    I do like a drag brake to assist on desents and to keep the bike "locked" when stationary.

    Thanks.

  5. #5
    Senior Member
    Join Date
    Jan 2005
    Posts
    841
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    On the triple we have V-brakes and drum brake. On the tandem we have calipers in the front and V-brakes plus disk brake on the back (8" rotor). Our team weight on the triple is 500 lbs, bike and gear included. On the tandem our weight is 350 lbs, again bike and gear included. We do fine with this setup down the sierras of central California on both bikes; but we do not do loaded touring.

    We use the disc brake as a drag brake. Earlier today we went up to 4-5K ft. elevation and there was snow on the road. Some of the turns we had to do at <10 mph. Having the option of the drag brake during the long descent came really handy especially with frozen fingers.

    The drum brake is beter to shave off speed than de disc brake but it is heavier.

  6. #6
    Senior Member zonatandem's Avatar
    Join Date
    Dec 2003
    Location
    Tucson, AZ
    My Bikes
    ariZona carbon fiber tandem & single
    Posts
    10,037
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    A drum brake is a true 'drag brake', use a barcon mounted on stoker bar, set it and forget it (?) on long/steep descents. And it works great as a parking brake too.
    Having said that, we use a D/A caliper on front and Mini-Tektro V brake on rear. Plenty braking for us, but we are a sub-250 lb tandem duo. Have descended many mountains (as high as 9200+ feet) without drum/disc brakes.
    Don Aumann: considering carbon tandem? Do it! We've got an ariZona c/f tandem with 13,000 miles on the odo. Have also ridden Calfee c/f 2-seater.
    Ride comfort/weight are great!

    Pedal on TWOgether!
    Rudy and Kay/zonatandem

  7. #7
    Dr.Deltron
    Guest
    A DRAG BRAKE???

    You're on a descent! Pedal for all it's worth! And brake before the sharp corners.
    .
    .
    .
    Oops. Sorry, I ride a tandem recumbent trike!

    (I don't need no stinking drag brake!)

  8. #8
    Captain - 2nd in Command djsincla's Avatar
    Join Date
    Nov 2004
    Location
    Redondo Beach, CA
    Posts
    158
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Stoker Speed Limits

    I have stoker speed limits! I do like the recumbant trikes but we also like to travel with the bike and ours fits in two standard 21"x21"x10" suit cases.

  9. #9
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,154
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Don Aumann
    I have the impression many folks now-a-days use only one or two disk brakes and skip the drum brake, even for loaded touring in the mountains.
    In the big scheme of things, dual discs on road tandems are still fairly rare, the notable exceptions being Cannondale's RT, a few custom spec'd tandems, and the Raleigh Coupe. To the best of my knowledge, Avid still recommends only their 203mm rotor be used on tandems but the Raleigh comes with a 180mm rotor. Go figure. While the newer disc systems are excellent, and while there are even some reports from teams that have toured the world with dual hydraulic discs without any problems, I'm not sure dual-discs have been fully embraced for use by the heaviest teams, teams that do loading touring, or other high drag-brake-demand users. The most common configuration is the front rim brake with rear primary disc, which is very popular with the go-fast and wanna-be go-fast teams that want to have the latest and greatest gear on their tandems and who either have no need for a drum or appreciate having the added safety margin vis-a-vis the rear disc instead of only rim brakes. The Arai drum remains the only true drag brake.


    Quote Originally Posted by Don Aumann
    I understand the benefits to be:
    (1) weight of disk brake is less than the weight of drum brake There is a slight weight reduction with the discs, e.g., less than 1lb of static weight compared to a non-shaved Arai
    (2) braking performance (stopping power and heat dissapation) of disks is superior to performance of V-brakes, cantilevers, or sidepulls, so much so that one doesn't need a drum brake (assuming your hands don't get too tired holding the brake levers for 10-mile descents). Discs definitely have more heat capacity than rim brakes and properly adjusted, fully bedded-in discs -- at least based on my experience -- can exert far more brake energy than calipers and cantilevers; the jury's still out on the comparison with V-brakes. However, the difference is probably neglible for the average cyclist. An Arai drum remains the only true drag brake that can without hesistation be recommended for use by all teams and that can prudently be used with a set-and-forget friction shifter to reduce brake demand on rim brakes during long descents

    Quote Originally Posted by Don Aumann
    I think the only downside to not having a drum brake is that the captain can't relax with the drum brake engaged because the disk brake must be continuously modulated for braking.
    ...and disc brakes take more frequent care and attention to set-up, break-in, use, adjustment, and pad replacement.

    Quote Originally Posted by Don Aumann
    Based on my understanding, one could skip the drum, use one or two disks, and from what I've heard/read, it seems like one only needs a single disk brake and folks usually put it on the back (likely on the back because the lightest carbon forks can't take a disk?).
    A well-informed decision regarding brakes would depend on your team weight, intended use, mechanical skills, and riding style. However, for the average team, a rear disc is a very effective choice. Front discs haven't been popular primarily due to the added complexity and cost, i.e., it takes a special fork, special hub, and requires compromises on wheel construction, i.e., an asymetrical front wheel with steep spoke bracing angles to accommodate the rotor installation. The latter can be partially mitigated by using an off-set rim designed for use with front disc wheels, such as those offered by Ritchey and Velocity. For the rear, I.S. mounts are a fairly easy add-on and there are a number of ways to mount a rotor to a hub, to include thread-on adapters that work with the same hubs used for an Arai drum. Tandem rear wheel spacing is already fairly generous and off-set for a supplemental hub-mounted brake making the addition of a accommodations for a rear disc rather easy for the builders.

    Quote Originally Posted by Don Aumann
    One more thought... I think Santana uses a 10-inch rotor (maybe one of their exclusive products?) but I think everybody else uses an 8-inch rotor. A 10-inch may have more braking capacity but it seems like the rest of the world is getting by fine with the 8-inch unit?
    Santana always strives to one-up and the 10" + Winzip caliper is just another example. Whether it's 160mm rear spacing with superwide spindles & a unique front derailleur mount, or 1.25" steerers/ headtubes/ headsets, and now mega-range 10 speed, Santana's are always somewhat different than the rest. 203mm rotors have worked well for most teams and I'm sure the 10" rotors from Santana will also work for most average teams. There was a time when Santana was working with Galfer on a 10" disc rotor and they were never able to get the things to pass the high-heat / recovery testing without warping issues. Santana's new supplier evidently found a way pass this obstacle.

    Bottom Line: Front caliper / rear disc is a very good default for tandem enthusiasts who will encounter challenging terrain. Given Cannondale's apparent success with dual discs for the past three production model years, other builders like Co-Motion will continue to offer them as an option. If at some point marketing data suggests that the dual discs become a discriminator, then stock tandem models from the speciality houses may show up in the market place. Again, for many teams, discs can be a solution looking for a problem that carry with them added costs and complexity which may or may not provide an equivalent improvement in safety or performance. However, at the end of the day, the no-brainer for teams that will put very high braking demands on their tandem will remain rim brakes with an Arai drum. If cost and complexity aren't an issue, then a front disc could be added to this configuration and I suspect at some point some ingenious individual will patent a new rear drum that incorporates a replaceable outer rotor to give cyclists the best of both worlds. As to whether such a brake would ever be economically feasible to produce and market, it would take some deep pockets to pull that one off.

  10. #10
    Captain - 2nd in Command djsincla's Avatar
    Join Date
    Nov 2004
    Location
    Redondo Beach, CA
    Posts
    158
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Thanks!

    Appreciate the feedback. I think I will stick with the Arai Drum Brake.

  11. #11
    rebmeM roineS JanMM's Avatar
    Join Date
    Jan 2006
    Location
    Indiana
    My Bikes
    RANS V3, RANS V-Rex, RANS Screamer
    Posts
    11,668
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Wouldn't hesitate to put a drum brake on our KHS Tandemania Comp if the need arose. The rear hub is already left-side threaded for a drum brake while a disc brake would require a new wheel and adapter on the stays.

  12. #12
    Elite Rider Hermes's Avatar
    Join Date
    Oct 2006
    Location
    San Francisco Bay Area
    My Bikes
    Too Many
    Posts
    8,441
    Mentioned
    33 Post(s)
    Tagged
    0 Thread(s)
    For this type of decision, I suggest calling the manufacturer, not the LBS, and talk with someone knowledgeable about your bike and what can be realistically done. Because tandems are limited production equipment, the specialty manufacturers are easily approachable with questions about their equipment and welcome customer contact.

    Here is an article written by Bll McCready, President of Santana in 2003 about disc brakes. http://www.sudibe.de/articles/billondiscbrakes.html It may be dated, but I provide it so that you can better frame the issue, ask the right questions and make a choice.

    From personal experience, we have the Winzip 10 inch disc brake with Avid rim front brake on our Santana. I can stop the bike easily with the rear break alone or use it on long descents without fade. Previously, I had rim breaks and a drum brake, used as a drag break, and it worked okay for slowing down the tandem to keep the wheels from overheating.

  13. #13
    hors category TandemGeek's Avatar
    Join Date
    Jan 2002
    Posts
    7,154
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by lordoftherings
    Here is an article written by Bll McCready, President of Santana in 2003 about disc brakes. http://www.sudibe.de/articles/billondiscbrakes.html It may be dated, but I provide it so that you can better frame the issue, ask the right questions and make a choice.
    I'd say that's it's interesting, but that's about it. Despite all the hand wringing and, while being long on theory and words, at the end of the day and in real-world use the Avid disc brakes (and earlier Hope mechanicals used by folks like myself) do not fail as predicted and the much touted Formula was a horrible product that failed many times, was difficult to maintain, and generally didn't work very well for many owners.

    Bill's a great guy with a wealth of knowlege who writes as well as anyone I know -- and I've known and had lively discussions with Bill many years -- but technical objectivity is not his strong suit. Good to hear you're Winzip 10 is working well.
    Last edited by TandemGeek; 12-18-06 at 01:02 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •