# Are disc brakes necessary?



## Speedbump

I'm starting to shop for a tandem. I was hoping to find a good used one, but they seem to be hard to find.

One question I have is about brakes. I've been told that disc brakes are almost a necessity. We do live in a fairly hilly area, so I'm inclined to believe it, but I wanted a few opinions. Finding a tandem is enough of a challenge. Finding one with disc brakes seems near impossible. Do I need to suck it up and buy new or can I buy a used one w/o disc brakes?

How feasible is it to add disc brakes? New fork, new wheelset? How much $$$?

Thanks


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## California L33

Some tandems come with a drum 'descending' brake. If you live in a hilly area you'll probably either want disc brakes, or rim brakes AND a drum brake. If you count on rim brakes alone you can overheat the rims and cause blowouts- very bad when you're having a hard time controlling your speed anyway. I'm no tandem expert, but as I understand it, when there's a drum, the stoker controls it, the captain controls the rim brakes. The drum is generally used as a 'drag brake' to keep speed from becoming excessive on descents.


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## CleavesF

disc brakes aren't too pricey assuming you stick to the mechanical road ones BB5/BB7

shouldn't cost more than 100 a set. Hydraulic is for MTB and usually are pretty pricey as well in terms of maintenance. 

Mech disc and drum FTW.


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## Speedbump

I'm not so worried about the cost of the brakes themselves, I assumed it would require a whole new wheelset, possibly a fork, and the frame may not even be capable of mounting the caliper in the rear. I thought it could get expensive quickly.

I thought bigger rotors are a good idea too, not the standard 160mm.


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## California L33

Speedbump said:


> I'm not so worried about the cost of the brakes themselves, I assumed it would require a whole new wheelset, possibly a fork, and the frame may not even be capable of mounting the caliper in the rear. I thought it could get expensive quickly.
> 
> I thought bigger rotors are a good idea too, not the standard 160mm.


Careful about going bigger than standard with discs. Your wheel fork combo must be able to take the additional torque large discs can generate. There are several threads over on Mountain Bike Review. 

Here's more info on drum brakes if you consider that route-

http://www.precisiontandems.com/arai.htm


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## sometimerider

This is second hand info.

A club member recently did some tandem tours in Europe. They have rim brakes plus a drum brake; they had no trouble on the descents.

(Edit: I should have mentioned that these were fully supported tours - so they weren't carrying significant extra loads.)

Those with just disc brakes were overheating the discs and warping them. Not so good.


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## Velonautic

*Define hilly*

We live on the SF peninsula and ride the coastal range weekly with a set of XTR V brakes only. I have considered adding a drag brake if we do more loaded touring. I think it depends on your team weight as well. We are about 290 with a half days worth of supplies. IMHO find a decent bike that fits and try it out before going to crazy. if your nervous add the drag brake, almost all decent tandems can accommodate one of these.

Along the same lines spend your money on good tires. I have never had a blowout related to heat but tires on a tandem do wear fast.


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## dir-t

Our tandem mtb has v-brakes and a drum brake and we find that to be adequate for our rides which do include hills. 

For example, we (300 lb team) descended a continuous 4 mile long dirt road/trail while pulling our BOB trailer loaded with about 40lbs of gear with no problem. It was a steep enough that we had the drum on and feathered the v-brakes for almost all of the descent. The series or rolling hills that followed also caused no problems.

We've also descended (unloaded) some fairly hairy steep ATV roads without blowing tubes etc.

I'm sure the drum brake has been key and I have talked to an ex-tandem mtb racer who says he and his wife were burning through brake pads (v-brakes) every 2 rides before moving up to discs.


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## ziscwg

just to reiterate

Yes,
disk brakes are necessary. Your bike could be unsafe without them****

You gotta love thread dredge Tuesday. All sorts of posts come out of the closet of history



****If you are going 40 mph, downhill, and it's raining


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## Lelandjt

Not only are discs non mandatory for tandems but there's only one disc (Santana's 10" Bengal) speficically designed for tandems and several (Avid) that specifically say they shouldn't be used on tandems.


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## Texico

I know this is a thread dredge, but...



Lelandjt said:


> Not only are discs non mandatory for tandems but there's only one disc (Santana's 10" Bengal) speficically designed for tandems and several (Avid) that specifically say they shouldn't be used on tandems.


I just looked in to this, because there are quite a few tandems coming stock with Avid BB7's now. There is nothing from SRAM/Avid saying that BB7's or others are not compatibly with tandems. In fact, they seem to be the preferred brake caliper now by many manufacturers when paired with 200/203mm rotors.


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## Trek_5200

Texico said:


> I know this is a thread dredge, but...
> 
> 
> 
> I just looked in to this, because there are quite a few tandems coming stock with Avid BB7's now. There is nothing from SRAM/Avid saying that BB7's or others are not compatibly with tandems. In fact, they seem to be the preferred brake caliper now by many manufacturers when paired with 200/203mm rotors.


I'll probably get shot for saying this, but i'd go with Shimano. Everthing I've heard/read point to them being the standard. My own experience is limited to Shimano disc and they seem to work well. i do think they make sense on tandems.


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## Lelandjt

Texico said:


> I know this is a thread dredge, but...
> 
> 
> 
> I just looked in to this, because there are quite a few tandems coming stock with Avid BB7's now. There is nothing from SRAM/Avid saying that BB7's or others are not compatibly with tandems. In fact, they seem to be the preferred brake caliper now by many manufacturers when paired with 200/203mm rotors.


Ask Avid. They'll tell you not to use them on a tandem. They are aware that the plastic bushings and dials will melt. A little forum searching will bring up stories as well. The TRP Spyre is the current popular tandem brake and it passed all our heat testing but as a rear brake on a tandem the spring is a little soft and the leverage a little high. It's got a long stroke and mushy feel with that long cable. Still, unless you buy Santana's Bengal (tandem specific leverage and spring rate) it's the best option going.

Shimano Ice Tech rotors have melted both in our testing and in real world use on big descents. Search the Bikeforum tandem page for stories of squeezing the aluminum out coming down big mountains.


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## jnbrown

We have had three tandems over a period of 35 years. None of them have had disc brakes. Our current Calfee is setup to have disc on the rear but I have never felt a need to install one. Dura Ace caliper brakes have been fine.


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