Smooooth

Which hub should I run-polished aluminum finish? I have a chris king front hub.

Is there any other choice other than arai drum brake?

Where is the best place to order the brake, cables, etc. ?

Thanks for your help

TandemGeek

Yes and no.

You're a 310lb team which falls on the left hand side of the bell curve for tandem team weight. Therefore, the need for the drum brake is somewhat questionable UNLESS you:
A. are doing a lot of long, steep, technical descents and like to keep your speed in check...
B. plan to do loaded touring or will be pulling a trailer in hilly terrain... or
C. are otherwise not inclined to make spirited descents and don't want to risk overheating your rims.

Assuming one or more of the above apply, then an Arai drum brake is the only "true" drag brake for those applications.

However, if you'd just like to have a rear brake with a bit more heat capacity than a rim brake for the occasional steep hill that makes you feel as though you're pressing your luck with rim brakes, a 203mm Avid BB Road mechanical disc brake hooked up to your right front brake lever as the primary rear brake may be the ticket. That's what we and many other teams have migrated to who have found that a dedicated drag brake just isn't needed; however, still find ourselves on descents where we know weve pushed against the edge of our dual rim brake's performance envelope. There are a few tricks to getting them set-up correctly, then there is the break-in time, and they do require a bit more attention than your rim brakes relative to keeping the pads properly adjusted for heavy-duty users. However, at least for us, they have been a vast improvement over rear rim brakes or any other combination of rim and drum brakes... noting we're a 285lb team that likes to bomb the descents.


That depends on what you ultimately decide to go with for a rear brake and/or supplemental brake. Your Co-Motion has 145mm rear spacing so there are several options. At the high end, Chris King will sell you a disc compatible rear hub, but doesn't offer one that is threaded for the Arai drum brake. Phil wood also offers a disc hub, but it's rather massive: just not their niche IMHO. However, their threaded hubs are fine for the Arai and will also accept a thread-on disc rotor adapter. Although, be mindful that any of the thread-on disc adapters are a bear to get off once you've been using the rear disc. In the mid-range, the
White Industries hubs are very nice and come in both threaded and disc mount versions and there is of course the threaded Shimano HF08 hubs. I believe the DT/Swiss hubs are all black these days so that doesn't fit your spec. I'm sure I'm missing a few, but those are the big names in tandem hubs.


I'd check with Mark Johnson at PrecisionTandems.com, Mel Kornbluh at TandemsEast.com, Rich Shapiro at GTGtandems.com, or perhaps even the folks at the Bicycle Outfitter in Los Altos, CA. Mark will most likely have what you need, particularly if you're considering the disc set-up ILO rim + drum. Mark and the others will all have the drum brake components and you can sometimes score a barely used Arai drum brake on Ebay for not a lot of dough.

Smooooth

Tandem Geek:

As usual a very thorough answer to my question. I talked to Chris at Bicycle Outfitters and he is really against the disc set up b/c of the finiky, touchy set up and bending rotors by knocking into things...

I ride mountain bikes with disc brakes and know how to deal with them. The problem is that my frame is not set up for disc I would prefer to do a disc on the rear. The frame does have a drum brake attachment on the rear stay.

I bomb the hills, very fast decender. My stoker is the exact opposite, this is why I am trying to find out a braking solution that will allow me to keep the bike at the compromise speed. That speed requires a lot more braking than I am accustomed to using. I am worried that I will over heat the rim and have a front tire blow out. As you know there is no way of surviving that one without a spill. A spill would set us back significantly.

This evening we decended 2000 ft from the mid mountain point of Mt. Diablo here in Walnut Creek. I kept the bike going at the compromise speed which required quite a bit of braking. Probably on the brakes 70% of the time. I let off and re-apply to get some cooling. We did stop about 1/2 way down so that I could feel the rim. It was warm-hot, but no where near burning temp. I could easily keep my finger on the rim.

My next mod on the bike is some fusion 700 deep v rims, for added strength, and better heat dissipation. I have dura-ace 9 brakes and will upgrade to dura ace 10 - better strength and clamping force. I believe the braking power is adequate - just don't want to have a blow out. Maybe I can use heavier tubes or something which will mitagate such an occurence.

Currently running 28 conti 4 season, slime tube, kevlar tire liner.

My stoker is getting better and better about the decending. As you know we are a new team and the trust thing is built over miles of safe, fun rides.

If we decided to pull a trailer, the drum or disc would be a must.

Thanks again for any input

TandemGeek

I wonder what it is about the Bay Area that causes a simple disc brake on a road bike to be so problematic, whereas those of us using them in the Southeast mountains of North Georgia, Eastern Tennessee, and Western North Carolina have no such problems? Seriously, I can't ever recall bending a rotor on my road or even off-road tandems... despite more than our fair share of off-road crashes that have clearly put the rotors up against mother nature's out croppings and such. As for finicky set-up, all I've eve done to my Avid is to add a compression spring to preload the brake cable which improved brake lever feel (by eliminating slack) and eliminated rotor drag by making sure the caliper's pads were always returned to a fully-open position. Well, that and I believe the S&S cable splitter sitting 1/2 way down the brake cable run may also mitigate some of the slop in an unbroken, 6' long brake cable. I've stuck these compression springs to most all of our friends disc-equipped tandems... and there are quite a few of them: no disc brake related problems to speak of in several years.

Regardless, you'll need to take your cues from other tandem teams as to the threshold for rim brake performance on your local mountains. I've cooked my rear Deep-V rims enough to make them hot to the touch -- which was precipitated by heavy outgassing and brake fade -- but without any dire consequences. Before adopting a full-time rear disc I made a point of biasing my brake usage front to back so that each rim / brake would get a chance to cool off vs. applying both brakes simultaneously. I also was mindful of using the front brake as much as the rear so as not to over use the rear... something that I think many cyclists and tandem teams in particular may be prone to do.

As for your set up, the 28mm tires should afford you better heat capacity vs. the 23mm and 25mm tires that we run. However, I would expect that the slime tube and kevlar tire liner's will contribute to increased tire heating from friction -- emembering that the "brake" heat we are all concerned with doesn't only come from the friction between the brake pads and rim, but from the friction between the tire and the road -- so I am inlined to ask if they are really needed or if you're just applying the old "belt and suspenders" to prevent potential tire flats

Anyway, you'll have to decide if the drum brake will afford you piece of mind: no one can really tell you that you don't need one without spending a lot of time riding with you and observing how you use your brakes and the type of descents you're encountering.

I still remain a big fan of the rear disc brakes and even went so far to have one of our tandems that already had an old Hope mechanical disc drag brake retrofitted to accommodate the Avid. It was money well spent. I only mention this because I seem to recall that your '04 Co-Motion was a Supremo (steel) which makes it a prime candidate for a retrofit.

In closing, hear everyone out on their experiences and be attentive to your brake performance on those regular mountain descents. Although we've never experienced one, in talking or reading the accounts of those who have had brake-induced heat failures, heavy brake usage to the point where the brake pads begin to outgas, glaze, and generate both audible and tactile signs in advance of brake fade... and that's when rim heating really soars.

cornucopia72

Plus one.

We started with a couple of V brakes plus a drum brake. Several years later we replaced the drum with a disc and the front V brake wioth an Ultegra caliper. About half a year ago we got rid of the V brake in the back.

We are relatively close to the bay area and have done Mt. Diablo a couple of times. Even though that last section before the sumit gives us vertigo going down and cramps going up, we can handle the descent just fine with a caliper in the front and a disc in the back. We are a 300 lbs team but the first time we did it with the original setup we were more like 325 lbs.

The only regret I have is taking so long to makes those changes.... It takes time to develop confidence on your equipment, on yourself and on your captain.

Smooooth

Our bike is a Supremo and is steel. Is it possible to weld the bracket to the frame for disc brakes? Will require $2,000 ish with the new hub, wheel, brake, welding, paint...

The other option is to sell this one - got it on Craigslist with only 1,000 miles, for a great price and can recoop my investment + a few. Then get a new bike with all the stuff from the factory.

Here are the arguments for the new bike:

1) 172.5 cranks to 175
2) better fit for me, a little longer top tube
3) disc brake on rear
4) little lighter bike
5) less money in my pocket

New bike will take 12 weeks to get. Ride this one in the mean time.

Don't get me wrong - the Supremo is an awesome machine and we are enjoying it immensly.

Decisions, decisions. The new bike -robusta with all the bells and whistles.

Smooooth

Tandem geek:

I am actually running 23 mm conti 4 season now and will move those to one of my 1/2 bikes. Going with the 25 mm conti 4 season. Not sure the 28 mm tire will work with the cantelevier brakes. Just want a tough tire and don't want flats - that is why the slime tube and kevlar tire protector strip.

Would love to loose the extra weight. I can change flats easily, so maybe just use a regular tube and no protecotor strip.

TandemGeek

Yes, the disc mounts are a relatively easy add to a steel frame. I wouldn't think it should cost that much. Worst case assuming you're current hub won't accept a $25 thread-on adapter:

~$250-$350 for adding the I.S. disc brake mount, all inclusive (braze & paint)?? Co-Motion will have a price for it and others could also do the work, e.g., Steve Rex who is somewhere there on the left coast.

~$130 for Avid brake caliper, 203mm rotor & proper adapter.

~$235 for a White Ind. disc hub + spokes for a rear wheel rebuild on your existing rim. Up to $375 for a Chris King.

If you KNOW that you will be a committed tandem team spending lots of time on the bike, e.g., not a first time buyer where it's not known how well riding together will work out, upgrading an existing tandem is usually not cost effective vs. a total bike upgrade, particularly when the frame doesn't fit the way you'd like or when looking at major component upgrades. $575 for a new set of cranks + $500 - $800 for a new wheelset is a big chunk of change, and all of those other things -- never mind the disc upgrade -- will nickle and dime your budget to no end (I'm still looking for the end and haven't found it yet). Moreover, tandems depreciate like everything else so for a tandem that's a few years old, the costs of the upgrades represent a significantly higher percentage of the total bike's fair market value that may or may not be recouped in the second hand market once they are hung on an older frame.

Smooooth

We are enjoying the tandem riding. It is a great way for us to spend time together in a healthy way. We do not get the same close interaction on our single bikes. I know you know this, but we are definitely seeing and appreciating the benefits of tandem riding Thanks again for the input.

deanack

I have arai drum brake and woud like to convert to disc. Were can I get the thread-on adapter?

cornucopia72

Precision Tandems (MARK) for sure.

TandemGeek

...but do you have the I.S. disc brake tabs on your tandem's frame?

Xanti Andia

I am late to this party, but I have been advised on a drum brake in an S&S coupled tandem because disk rotors can easily be bent when the bike is packed in the suitcase.

Our drum is manned (womaned?) by the stoker with a brake lever, control on the descent was much appreciated behind.

deanack

I talked to Matt Assenmacher, he built my single back in 1981. He can add the I.S. to it and paint the area. I may just do it and have him repaint it at the same time.

Knubby

We have two older road tandems and only one has the Arai drum brake. We are slow hill decenters and wish our other bike had a drum brake too. Sounds like adding an drum brake is cost prohibitive. In our case, we're better off buying a new drum/disc equipped tandem instead of modifying the old one.

TandemGeek

FWIW, if I was a tandem dealer -- and I'm not -- I would NOT recommend discs to most clients. As a dealer, the last thing you want to deal with are customer issue's after the sale.

While I'm a strong advocate of the discs, just as I'm an advocate of S&S couplers, I recognize that they are what I'd characterize as "enthusiast" items that may not be appropriate for the average tandem buyer. Both options demand a certain degree of mechanican aptitude relative to maintenance and use. Lacking that mechanical aptitude, the average tandem buyer -- or a high-maintenance enthusiast -- will likely have questions that need to be addressed and will direct those to their dealer, often times in the form of a complaint that has already been shared with others. Both of those things are bad for business.

So, yes, I would agree with the mechanic at Bicycle Outfitters... disc brakes can be a PIA, particularly if you sold a lot of tandems fitted with a Formula disc to a lot of average tandem buyers. Similarly, the same would be true of the Avid's which aren't "perfect" out of the box and that will occasionally need some informed maintenance. And, as for travel, if you didn't have the fore thought to take some care in protecting your disc rotors when packing an S&S tandem I would also expect the rotors to be bent and wouldn't be surprized if there was some other related damage to the frame pieces or components they were pressed up against in the luggage.

Again, certain options just aren't appropriate for the average tandem team due to their complexity. The same is true of certain, lightweight or high-performance options that were originally designed for competitive applications which when fitted to the average tandem merely become something a dealer must address in the future.

cgallagh

Our Roadster has the V-brake front, Avid disc rear set-up. When I bought the bike from it's former owner it had less than 100 miles on it and the brakes were in need of adjustment. I carefully readjusted both brakes and now they work perfectly. We descend quickly but my stoker starts squeeking at about 40-45. I have Rolf Vigor wheels and have never had the front wheel get more than just a little warm. I had Avid Mtn brakes on our former Raleigh Coupe front and back. They also required a little care in the initial break in but I had no problems in the several thousand miles we rode it. Many of those spent screaming down hills. We are 300-305 combined on the bike depending on dinner.

As for going down Diablo I can only say it can be dangerous. I have not yet ridden it but have driven it many times as it is my primary hang gliding site. We always drive very slowly and use extra caution when going around blind corners. As with anything there are drivers and cyclists that do not and many times I have been all the way over on the right and barely avoided mishaps with cars and bikes. My friend is a captain at the local fire station that services Diablo. He has had to scrape many bikers off the pavement after some serious mishaps. Take care on the Devil and use the brakes wisely.

Smooooth

TG:
Yes, I knew that was what Chris from bicycle outfitters meant when he said he did not like discs. His next sentence was full of the call back adjustments and complaints from the average riders.

For us that know how to work on our bikes, the disc set up seems to be one of the best braking solutions.

CGallagh:
It will be nice to meet you guys at the time trial next Saturday. We are still a very new team and I am really enjoying the experience. We took a ride up Mt. Diablo (mid mountain only - 2200 ft.) on Wednesday and our standing and climbing is coming along. It was significantly smoother than any time before. It just keeps getting better.

ftsoft

Just wondering about maintenance on the avid rear disc. We only have about 350 miles on the bike so far and are pretty light at 260 lbs. So far the brake has been flawless, but we haven't really done any hair aising descents (we live in Ohio). What sort of things should I be watching for with the rear disc? Thanks.

TandemGeek

You'll just want to periodically check the pads for wear... either by making note of increased lever travel or by checking the brake pad spacing / wear at the rotor. When adjusting for wear, be sure to adjust both the inner (fixed) and outer (actuating) pads. If you forget or are a bit late-to-need on adjusting the inner pad you may hear a metallic sound when you apply the brake: this is the rotor brushing up against the caliper body.

That's about it. We have a couple thousand miles on our Avid's original pads, a few of which were some pretty hard braking from mountain rides in North Georgia, North Carolina and Eastern Tennessee. I have a spare set of pads on hand, but so far so good.

ftsoft

OK. Thanks. I think I'll check out this adjustment so I know what I'm looking for.

Retro Grouch 

Nope. Adding an Arai drum isn't a big deal at all. The key is if you have a tandem rear hub that's threaded on the non-drive side to accept the drum. Everything else just bolts on.

Disc brakes are different.