Florent

Hi everyone !
My wife and I are new to this forum, and to this wonderful Tandem World. :-)
We just bought a beautiful CYFAC carbon road bike (manufactured in 2005).
What a pleasure to ride it, we absolutely love that feeling !
The only drawback of this machine is the braking system: 2 Campagnolo Record rim brakes are installed, front and rear.
Our region is only made of quite hilly roads: average 5-7%, up to 12% climbs and descents. Our first descent was quite scary, as we needed several hundred meters to stop the bike, and the rims heated so much that the rear tire started grinding the frame.
5-min stops are now required quite frequently for cooling the rims at each descent.

So now, my plan is to go "hybrid" braking:
Front brake will be on disc, ideally hydraulic, but must be compatible with the Campagnolo Record cable braking system and levers. TRP HY/RD associated with Shimano Saint disc, Ø203mm could do the job. I'll need a new fork with IS mount, a new compatible wheel, and 700x28c tire (Continental GP5000). Rear brake: unfortunately I must keep the current rim brake as the frame doesn't have any disc mount. The only upgrade will be to change the wheel for a more rigid one, and reduce the tire width from 700x28c to 700x25c, to add some more clearance with the frame.

This upgrade raises some questions:

1. Can I expect any improvement in the braking efficiency by switching only the front brake to that disc configuration, and keeping rear brake "as is" ?
2. Will the TRP HY/RD handle the abuse, on long term ? Or should I simply switch to a more rugged mechanical system (TRP Spyre) ?
3. The tire confiuguration will be quite uncommon: 700x28c front, and 700x25c rear. Is there any drawback to this (apart from aesthetics) ?
4. Just in case... do you know of any good solution to convert a rim brake system to disc on a carbon frame ? (apart from modifying the frame itself :-) )

Thanks !
Best, Florent

bwebel

You do not mention what kind of rims you are using, which may matter a lot with regard to the braking that you have on the record brakes. Assuming a quality aluminum braking surface, housing, and pads, I have not experienced a significant difference between the record brakes and mechanical discs in terms of dry braking power. The discs probably will, however, have better heat management, which is what you are running into here. So I imagine the overall braking would be better with the front disc. And is the record rear a single pivot? Might not hurt to change to a dual privot caliper as well. Will not help with the heat, but might let you cycle the brake on and off a little more which could let it cool. Something else to consider is a deep section rim. A deep section rim has a lot more surface area that would move heat away from the brakes and cool faster than a box section rim.

I have taken the Spyre on Alpine descents, and been fairly happy with them. Have used the HY/RD, but not for serious descending. I do not find a huge difference between the two in regular use. I've had a TRP rep tell me that the HY/RDs have no problem with heat build up, but, personally, I'd probably put the Spyres on, There can't be much fluid in the HY/RDs and it just seems that you would boil it pretty quickly. I've looked for finned brake pads for these brakes, but haven't been successful at finding any.

No problem running 28 front and 25 rear, though you might find the front disc works well enough to avoid the problem with the rear brake.

You'd need to modify the frame to get a rear disc...might be worth checking with Cyvac. Calfee is going to do it for our carbon tandem. Not cheap, but cheaper than a new tandem.

Where are you riding? I'm assuming France given the Cyfac brand?

Florent

Thanks bwebel for the comprehensive reply !

Yes we live and ride in the center of France, in Auvergne (Limagne fault). Not really called a mountainous region because our old volcanoes have been eroded by time, but there is no flat road out there ! :-)
And you, where do you ride ?
Until now, the wheels installed on the bike were Easton Orion II, with aluminium low profile rims (22mm deep). They are being replaced by a custom-assembled pair of wheels from ASTERION: hope RS4 hubs + DTSwiss RR411 rim (rear) and DTSwiss RR421 rim (front), all with 32 CX-Ray spokes. I questioned ASTERION about deep profile rims: they didn't know of any with more than 24 spokes holes, and all were carbon: definitely not ideal for heat management, energy dissipation and stiffness. The Campagnolo Record rear caliper is single pivot, so yes, I will definitely move to a more recent double-pivot caliper ! I'll be digging for one. :-)

So you are quite experienced with the TRP Spyres. How often do you need to offset the pads to compensate for wear ? I heard a lot about TRP HY/RD bad quality pads that need replacement for reliability and longevity. Do the TRP Spyre face the same issues ? Could you give me a rough estimate of how much Calfee charges you for the rear disc brake mod ? It would be an option if we cannot manage safe stops in descent.
By the way, do you have any picture of your tandem bike ? :-)

Thanks again for your valuable advice, much appreciated !
Best, Florent

Leisesturm

I don't know ... it just seems to me that a lot of work and money are going to be expended trying to bring a bike from 2005 into the 21st Century. I have to think that tandem was perfectly safe in 2005. It's safe now. If not, sell it. Get a different bike that works better without all the modification. Those skinny tires won't stop any better with 203mm discs. The limit of braking is at the contact patch. That's why the full carbon road racers STILL use dual pivot sidepulls. 28mm is not enough of a contact patch increase to bother. Seriously, if fresh brake pads (Kool Stop Salmon), compressionless brake housing for the rear run at least. And maybe, some dual pivot sidepulls just because. If that can't do it. I wouldn't bother.

Florent

Thanks Leisesturm !
I understand your point and would totally agree if we talked about classic bikes. On my road bike, I wouldn't mix two parts from two different groupsets, wouldn't put a "mechanical-to-hydraulic" brake converter, wouldn't do any mod to my frame for the sake of "mechanical purity". In the tandem world, such a thing called standardization doesn't exist, it's all about reuse, DIY and hacks seem to be a mindset because tandem-specific parts just don't exist. I'm okay with that.
Also, new tandem bikes are virtually nonexistant in the todays market. Before buying this bike, we looked for a brand new one. We met local manufacturers, called big brands, dealers... with the current situation on bike components, tandems are the least priority of those big brands. Local manufacturers need 2 years for any custom-build, just to get their components orders fulfilled by the big Shim, Campa and SRAM companies. When you look for a good road tandem bike in France, seeking the second-hand market is not an option. Plus, it's environmentally friendly. :-)

Also this 2005 tandem design is still almost the same in 2022 at CYFAC. And honestly, it's a gem :-). Maybe the steering pivot standard would change, maybe the group would be 2x11s instead of 3x10s, maybe the calipers would fit direct-mounts... but except from that, 2022 base designs for tandems at CYFAC are manufactured the same way as they were in 2005 and still use a pair of rim brakes. Discs are optional. As you say, tandems were already safe in 2005. The problem is not the age of the bike, the problem is me choosing a different destination for its use. The first owner lived in a flat area where rim brakes were more than sufficient, we live in the hills where they aren't. But we bought this oldie at 1/3 of the price with a mileage of 1500km only. It spent its whole life decorating the bicycle store of its owner, it is just brand new. We could have bought it too times, we wouldn't be close enough to the price of this exact brand new tandem, which gives me some room for "hacks" while keeping into our expected budget. So, I'm pretty sure that it's not a risky operation to plan even for the heaviest frame mods. If we need a seat+chain stay replacement, it will still be cheaper and quicker to do it than to buy a new bike.

Your point regarding the limiting parameters of braking is interesting ! The thing is, for the moment I'm far from exerting enough braking torque to stop the wheels when pulling both brakes, which makes me think that I could gain some braking power before finding a limit in the wheel-to-ground grip force. In fact, I'm deliberately looking for this limit: once I find it, I'll be sure that my braking system is correctly dimensioned.
But the real safety problem here is less the braking torque than my inability to evacuate the heat accumulated into the rims during a long descent. If the problem was braking power, I could just solve it by driving smoothly/slowly in descent. But driving smoothly means braking all the time, which causes the rims to overheat. That's why the front disc brake sounded pretty to me, but I don't know... Sure, if I gain some brake authority, that will be fine, but the real plan here is improving the heat management.

Anyway, I'm really glad that you shared your vision, thanks !
Best, Florent

robakun

perhaps adding a rear drum brake somehow and have the brake actuated by the stoker may solve issues since i dont think a dual pull option exists with more modern brifters?

conspiratemus1

How heavy are the two of you together?

Leisesturm

Strap one of these on your Stoker. I'd do it if we had mountains here ...

Ross200

"Braking all the time" will also overheat disc brakes. 17 year old Campy brake pads may not be helping the matter. New KoolStop pads and compressionless housing might be a helpful upgrade on dual pivot calipers along with a re-evaluation of tandem braking technique.

A hub mounted drum drag brake is most likely the best solution for "braking all the time". Rodriguez and others have installed both rim and hub disc brakes on tandem forks in the past.

Welcome to tandemonium!

Chilepines

You'll see mixed opinions on HY/RD brakes, but mine is only negative. I had them on a gravel bike and they were impossible to get them working properly. The brake stops fine, nearly as well as true hydraulic, but the lever bottoms out to get that braking. There is an after-market part that is supposed to solve this, but it did not for me - on SRAM road brifters. I ended up dumping the brifters and going to hydraulic and now I can stop!
I converted our old tandem to hydraulic disc front and rear from rim brakes by changing the fork, and then coming up with a hack to mount a rear caliper to a rack mount using this adapter. I'm sure a lot of folks will think this is a crazy setup but it works!
I totally get the sentiment that you should just stick with rim brakes, but I'll never ride a tandem with rim brakes again after a harrowing descent in the rain.

bwebel

We are in the Washington DC area, but my wife is from the Lot and we are back there often. Not quite the climbing in Auvergne, but not flat.

I don't know that I have a good feel for the pad replacement interval on the spyres. I am constantly tinkering, and have more than one tandem, so it just gets kind of absorbed in the (perhaps too much?) time I spend in my bike room. The pad type will matter, the first TRPs seemed to go fairly quickly, but there are some compounds out there for Ebikes and they would probably last longer.

I think I'd really try something deeper than the RR411, I'm surprised something aluminum in the 30mm deep range couldn't be found. If you do the math, it's a lot more surface area to radiate heat. The Rolf tandem wheels might be something to think about, but I know the paired spoke design might not be the best depending on your riding. I'd also think about a Chukker/Dyad combo from https://www.velocityusa.com/product/rims#models-tab though I recognize those are probably not quite as racey as what you have in mind.

The only pic I have is this one of our older Cannondale, not quite ready to ride, that is in France. We have two Comotions and a Calfee in the US. I think I'm going to bring one of the nicer bikes over, so if you know anybody in France looking for an entry level tandem, let me know.

Alcanbrad

Our first tandem is a late '90's Santana with cantilever brakes. When we moved to a hilly region, we were not comfortable with the stopping power of the brakes (we are heavy team). I added a drum brake and it instantly gave us excellent braking control AND performance on the descents. Its a good option for a tandem. Drum brakes require a torque arm that attaches to the chain stay where most of the drums braking power is transferred to the chain stay (just as a disc brake transfers braking force to the stay). I believe you said your bike is a carbon frame. If you are considering a drum brake, I would contact the frame manufacturer and ask if your frame can handle that setup or what it would take.

Our second tandem came with the TRP Spyres. We quickly gained confidence and liked the braking performance of disc brakes on a tandem. As the brake pads wore down, I had to adjust the pads which is very easy, however, the pads are adjusted via threaded posts held in position with loctite. After a few adjustments the effectiveness of the loctite was pretty much zero and I found that I was putting the bike in the work stand and adjusting the brakes every couple of rides as the brakes would go out of adjustment. Adding more loctite helped, but only until it's effectiveness declined after a couple of adjustments. I think that the HY/RD version of the Spyres solve this by providing the self adjusting characteristic of hydraulic brakes (I don't have any direct experience with the HY/RD and don't know if the self adjusting characteristic is as good as hydraulic brakes, others can comment). Our (3rd) tandem (travel/trail) has Avid BB7 brakes which I feel are not as refined as the Spyres, they are easily adjustable as the pads wear and they hold that adjustment reliably so overall I am very satisfied with them.

We upgraded our bike with the Spyres to SRAM Red with hydraulic brakes. Although we had some major drive train issues with the upgrade (several other threads on the forum), after straightening those issues out we find the performance and feel of the hydraulic brakes to be superior.

As others have said, there are trade-offs to upgrading an older tandem. It comes down to the cost and effort required. My recommendation would be to seriously consider a drum brake if your frame can accommodate one and get new brake pads if yours are more than a couple years old. Koolstop offers good options and high performance. A drum brake will allow you to keep everything on your bike as it was originally designed and you will find that it offers good braking performance with very little to no maintenance futzing.

Paul J

Your thought of moving to a disc compatible fork sounds like a good idea. If you were to do that, could you move the front brake to the rear by changing the pads and cutting and re-threading the mounting post? I was thinking that the campy brakes were dual-pivot on the front and single on the rear. As a aside, we have the Spyre's on our Co-motion and have had good luck with them. We have about 5,000 miles with only the front pads being replaced with the rears now needing replacement. Se live in Pennsylvania with hilly conditions but most decent being less than a mile.

CaliTexan

Another data point: we rode a similar vintage Bilenky and wanted to upgrade the brakes, as well as moving to Di2 shifting and a few other improvements. In the end, we concluded it was more efficient to buy a new bike.

The Di2 has been great. We opted for TRP Spyke brakes and have been happy with them. I originally spec’d the Hy/Rd, but was persuaded that the increased complexity (on a travel bike with S&S connectors) was probably not worth the marginal benefit. No complaints yet about the durability of the TRP metallic pads after 6,000 miles.

Chilepines

Another option for adding a disc brake to a caliper brake bike. A little goofy looking but I've seen it work.
https://www.chasertech.com/disc-brake.html

daywood 

My tandem is considerably older than yours and also has caliper brakes. I’ve tried a lot of things to improve their stopping power: brake booster, dual calipers on the rear, many different pad compounds. The thing I did that helped me the most was using the brake pads that Kool-Stop makes for e-bikes. The description for them said something like “made for the higher speed and greater weight of e-bikes.” I said hmmm. They are the ones with grey compound pads in metal carriers. YMMV but they made a big difference for me. I’ve even put them on a couple of my other bikes and liked them there, too.

merlinextraligh

Our Co-Motion Java tandem came with mechanical Spyres. The braking was not adequate for us on the steep descents in the Appalachian mountains.

We upgraded to the Trp/hybrids and while they aren’t as strong as a pure hydraulic system the braking improved substantially.

There is a problem with the levers bottoming out. Careful adjustment and compression less housing help with that. Also there’s a hack you can do to help with the cable pull, by slotting the actuator arm with a hacksaw. We did it with the mechanical spyres and it helped.

I don’t actually remember if the same hack works on the hybrids, but we didn’t find it necessary in the hybrids anyway.

merlinextraligh

I would be sceptical of using a rear disc adapter on a carbon frame that was not designed for discs.

the rear disc brake puts different forces in different places on the rear triangle. When we spec’d our Calfee Dragonfly so it could use either a caliper or disc on the rear, Calfee added a brace on the rear triangle to deal with the twisting forces resulting from the disc.

Im pretty sure if you wanted to add a disc to the rear, a carbon repair outfit could modify the rear triangle for a disc mount as well as reinforce the rear triangle

Carbonfiberboy 

There are many fairly deep rims out there, for instance the Kinlin XR31T Rim Brake Rim, 31mm deep, and come in 32H. Deep rims make a huge difference, not so much in the weight, but in heat dissipation. Pads make a difference. Only run Swissstop BXP pads.

mtseymour

[/QUOTE]
So now, my plan is to go "hybrid" braking:
Front brake will be on disc, ideally hydraulic, but must be compatible with the Campagnolo Record cable braking system and levers. TRP HY/RD associated with Shimano Saint disc, Ø203mm could do the job. I'll need a new fork with IS mount, a new compatible wheel, and 700x28c tire (Continental GP5000). Rear brake: unfortunately I must keep the current rim brake as the frame doesn't have any disc mount. The only upgrade will be to change the wheel for a more rigid one, and reduce the tire width from 700x28c to 700x25c, to add some more clearance with the frame.

This upgrade raises some questions:

1. Can I expect any improvement in the braking efficiency by switching only the front brake to that disc configuration, and keeping rear brake "as is" ?
2. Will the TRP HY/RD handle the abuse, on long term ? Or should I simply switch to a more rugged mechanical system (TRP Spyre) ?
3. The tire confiuguration will be quite uncommon: 700x28c front, and 700x25c rear. Is there any drawback to this (apart from aesthetics) ?
4. Just in case... do you know of any good solution to convert a rim brake system to disc on a carbon frame ? (apart from modifying the frame itself :-) )

[/QUOTE]
We routinely ride 5-7% hills and have done descents of 12%. Our team weight is 330lbs. Since we like to ride reasonably fast with good safety margin, we use reliable, powerful brakes. Coming from a mtn bike background, I found that mechanical disc brakes like the Avid BB7 and Spyre were hard to adjust and too weak. The TRP HY/RD is a significant upgrade and reasonably safe for steep descents. It's not less "rugged" than the Spyre, and is the minimum configuration if you ride 5-12% hills.

Your brake options depend on your budget. The cheapest option is to use a front TRP HY/RD with 180mm rotor and rear rim brake. This assumes that your disc fork can handle a 180mm rotor and tandem weight. The CoLab Cross is a great option if your frame can handle a tapered steerer (1-1/8 to 1-1/2).

A more expensive option is to modify your carbon frame. In case you don't know, it's easy (and reasonably affordable) to substantially modify your carbon frame with a good builder. In contrast, steel and aluminum frames are difficult to repair or modify. For example, Calfee recently modified our Tetra frame to increase tire clearance to 32mm, change the rear axle from 145mm QR to 148-12 thru axle, and moved the 203mm disc mount from the seatstay to the chainstay for a cleaner setup. The quality was top notch and well worth the expense. Filament and Carbon Bike Repair Ltd are closer to Frane and can give you quotes for various frame upgrades.

Wider tires are better. 700x32 front and rear will improve comfort without sacrificing speed.

Btw, we're using Shimano XT 8120 4-piston hydraulic brakes front and rear.

Chris_W

I've tried most of the mechanical disc brake options out there, and Paul Klampers are by far the best IME. They even sell a Campy-specific version, which might be good for the OP.

Campy rear brakes are sometimes single pivot deigns to save weight, make sure you have the dual-pivot version. In addition, Shimano brakes often have the most rigid arms/pivots, so I'd install one of those on the rear.

You might need to experiment with rotor size. I initially used a 200 mm rotor with a tandem-rated carbon fork, which should have been fine, but the fork juddered pretty badly even under moderate-strength braking. I dropped the rotor size to 180 mm and there is no more shuddering even under hard braking. I was shocked by how big the difference was. Brand and model of rotor was identical (Shimano XT).

longpete

Combine disc and rimbrakes against heat. Disc brake hub and rimbrake rim. On a road frame maybe impossible. Unless you mount a flat bar. Widest possible tyres. 22cm disks: ask if your frame and fork can manage that. 22 bends sooner than 20 and 18. Dual piston diskbrakes have most of the time larger brake pads. And your body can also help breaking.(legs wide, sit upright, open jacket etc.

Msteven 

Regarding the TRP HY/RD: These will fail in the event that you have to drag brake on a long descent. These do not have enough mass to dissipate the heat before the caliper body expands and presses on the cylinder, effectively failing in the clamped position, so at least you don't have an open brake situation.

ferengii

We have reservations for a self-contained (fully loaded panniers) September cyclotour in the Dordogne area (Sarlat and surrounding area). Using Komoot, we see that our planned rides have numerous 10-12% climbs and descents. We have a 7-year old Co-motion Equator (Speedster with a Rohloff hub) with TRP Spyre mechanical brakes and have had issues with brakes overheating on our rides in the Colorado front range - on 8% declines with no load. I recently installed the TRP HY/RD brake on the front and upgraded the 203mm rotor to a Shimano Ice Tech rotor. The rear brake is still a TRP mechanical. If we’re careful on the descents (balancing dragging, stopping to let the brakes cool down), we are fine. I’m concerned about the steeper descents in France, but am hoping that we can get by with our new set up. I’ve been very impressed with our new stopping power and am optimistic that it will suffice for our trip. I hope we’re not being foolish!

scycheng

We have done a fair amount of credit card touring in Provence and surrounding areas. Other than getting on and coming off the plateau, it's not that hilly. I have a cantilever brake in the front and a TRP Spyre in the back. Never had braking problems though I do let the bike run if the roads are clear.