Modulation and power (V-brakes vs. Cantis)
 

I am thinking of upgrading the old school shimano (circa 1990) cantis on my tandem.

I am considering both V-brakes or Canits. Not equipped for disc.

I know you need Travel Agents for the V-brakes.

Whatever option I chose will have the cartridge style pads (going to run Swiss Stop Green), so that is one variable gone.

Questions are:

How is the modulation of the V-brakes with the travel agents? I would like for the brakes to be precise in this aspect. I trail break a little bit, and like to progressively ease off the brakes through the apex.

Is the power of the V-brakes much greater than Cantis?


Main reasons for ditching my brakes:
- Post style pads, and old brake system leaves much to be desired in the adjustment department. Very hard to ditch the noise. Also, it doesn't seem like the angle of force for the pad/rim is consistent through the brake's range-of-motion.
- Play on the posts. The brakes can move around quite a bit on the posts when wiggling them.

For V-brakes I am considering the Avid Single Digit Ultimate

For Canti's I am still up in the air. I was thinking just the standard Shimano BR550s would be good. I think the wide anlge of my canti's makes more sense, but I think the play and pad adjustment is what make them suffer.

Here's what they look like now (sorry hard to see):

http://farm3.static.flickr.com/2092/...c26b9a3a_o.jpg

BTW....

Any recommendations for Canti's or V's are appreciated as well :)

I cant speak specifically to the Travel agents but just recently added Single Digit 7s and Kool Stop Salmon pads to my Santana Rio along with Speed Dial Levers. The bike currently has a flat bar so my V-Brake levers and the SD7s work superbly. I would like to go to a road bar and brifters so I will follow this thread.

I am running Avid Single Digit 5's with travel agents off Shimano 105 STI levers. The modulation and control is fine, but I am far from satisfied. I hate the pad wear (Avid 20R pads; seem too soft a compound), and I would like to get rid of the travel agents. I actually think canti's might be better, but have to figure out the center hanger issue.

I haven't spent much time on this, as my butt has had priority, but it is interesting to hear that someone with Canti's wants what I have...

I have found on mountainbikes that Good V brakes are significantly better than Good canti's. V brakes have more leverage, lower profile and are easier to adjust (generally speaking). They also have the advantage on the more advanced designs of being able to approach the rim in a parallel fashion. I currently only have one bike with cantis and that is my cross bike. I have found much better V brake performance by changing to conventional style brake pads with significantly more rubber rather than the thin cartridge type pads. I found the cartridge pads to wear fast and really chew up your rims when they got very hot. For either brake style, pads make a huge difference to performance.
V brakes also are better for avoiding the dreaded carbon fork shudder as the cable is not rigidly fixed to the frame.

I dont know if it directly translates to a tandem but I test rode several tandems with front V brakes and the stopping power was very good but not as good as the XTR V brakes on my mountain bike with proper V brake levers.

I find I get really good wear out of these Azteks

http://www.zensurweb.com/bikes/aztek.jpg

We have a '90 C'dale that I switched from barends to STI. In the process went to V brakes. Chose Travel agents with Avid Single Didgit 7's with Avid CW2 pads. Could not be happier...great modulation (I trail brake quite a bit as well) and serious stopping power when needed here in the mountains. I would do it again without hesitation. We are a 300 +/-pound team.

Bill J.

v brakes
 

Following the advice of folks on the forum and Jack at Tandems Ltd, we changed out the Tektro Mini-V brakes on our Burley Rumba for a set of Avid Single Digit-7 brakes with the travel agents. The Burley uses Shimano "Sora" brake/shift levers.

I feel that the travel agents are a "Rube Goldberg" solution, but I have to admit that everything works really well. We did have a bit of hassle bending the rear-rack strap around to fit the travel agents.

The bicycle stops well and the modulation is great - but remember, I have never used cantilevers so I can't compare them. We changed brakes because the mini-Vs never felt right and it was annoying to have to completely re-adjust the front brake whenever we wanted to remove the front wheel (i.e. a car trip with the tandem required 4 brake adjustments).

Going from Mini-Vs to regular v-brakes with travel agents is one thing but I would think that the improvement would be a lot less if you're switching out a set of decent cantilevers.

-Ken

We have these brakes on our Rodriguez tandem (well, this is not actually a photo of our tandem but a photo from www.rodcycle.com):

http://www.rodbikes.com/articles/gra...igsqueeze3.gif


http://www.rodbikes.com/articles/gra...igsqueeze2.gif


I'm not sure, but I believe that ours is the first of their tandems to get these brakes. We have nearly 1000 miles on them so far and I couldn't be more pleased. They are powerful, easy to adjust, and don't squeal.

anyone running these:

http://us.st12.yimg.com/us.st.yimg.c...d_2006_4368465

I'm narrowing it down.

The above new Shimano BR550

or these....

85mm Campy Veloce mini-V brakes (I prefer to NOT use travel agents)

http://i4.ebayimg.com/01/i/08/98/5b/d8_12.JPG

I agree - travel agents are suspicious, but for me they were the lesser of two evils. I couldn't fit calipers because I needed long reach calipers and those collided with the mounting points for the V brakes...

Those Campy Mini-Vs are gorgeous, but I'd be worried that they'd have the same issue as my old Tektro Mini-Vs did. Even though they require less cable pull than full sized Vs, you still have to adjust them to be a "micron" off the rim or the brake lever will bottom out. Even then, the braking performance is sub-par.

Then if you need to get the wheel on and off you have to actually pull out the hex-key and loosen the brake cable. It's not the worst problem in the world - but it gets really old really fast.

This is pure speculation as I've never used the Campy Mini-V.

Best of Luck.

-Ken

I was thinking if I went with the mini-V I would get the noodle with the barrel adjuster. That combined with the Campy lever release should let me get the 28mm tires out (I think).

I haven't quite figured out what V-brakes have that cantilevers don't. Because of their long arms V-brakes require more cable travel than is provided by road levers, so an adapter is needed to account for it. And what do you get? Are they really as powerful, easy to adjust, and trouble-free as cantilevers? When you go to mini-v's, you gain some on the cable travel issue but lose on braking power (or so it appears to me). Also, V-brake pads are thinner so don't last as long.

The brakes that I have are extremely adjustable. They can be set so that the posts are all the way in for maximum stiffness and moved up or down the arm so that the pads contact the rim straight-on. This results in a brake that needs little or no toe-in to eliminate squealing. Spring tension can be fine-set (not like the 3 hole positions on standard cantilevers) so that they can be centered easily. I know that they're pricey at $125 per wheel, but as of now I'm (obviously) sold on them.

My Santana Tandem came with Cantis stock and when adjusted well, they were "adequate" I switched to the Avid Single Digit 7s and can literally pick up the back wheel if I want to with the MTB tires on. I haven't tried it on the pavement with the Road tires but the performance difference is at least a factor of five! I was just looking for a performance gain as my wife and I are both larger riders (for now) and the terrain we like to ride includes some hills. I would go disk if the frame provided that option but it does not. The SD 7s with Koolstop Salmon pads is the closest to disk performance you can get in a V Brake IMHO. YMMV.

Well a couple things I can think of...

1) The Mech advantage is more constant through the pull, while cantilevers' diminish the more they are applied.

2) The (front) cable stop for the v-brake is on the brake and thus is a bit more "tied to" the fork during flexing. The cable stop for a canti is above the headset. The canti cable stop flexes more during application of the brakes and is less "tied to" the fork.

I like Cantis. Just weighing out the options. I want what will work the best, and provide the best feel. I might just go with the modern Shimano BR550 cantis.

Yes - that's a nice feature and it would probably help a whole lot.

No chance for dual-pivots?

They'd have to fit 28mm tires.

Not sure if they would provide enough power.

My Mavic SSC dual pivots provide scary stopping power on my single bike. However, not sure about on the tandem.

I was present at Crank 2 while a couple tested several bikes with different braking systems. Their feedback was pretty revealing:

• V-brakes are the weakest of the 3 they tried.
• Disc brakes tend to be noisy and wobbly while doing high speed braking (may be an installation issue as we haven't seen wobbly rotors yet on our Co-Motion).
• Dual-pivots were the best of the three due to stopping power and smoothness during high speed braking. They were also very silent as compared to discs.

Don't rule out dual-pivot systems yet, marco. If they fit, they might work for you, and shave a few grams to boot! :)

I run Avid shortys on my Cannondale tandem. They set up just like V brakes, but you dont to run the travel agents. They have worked well for me over the past 3 years.

Just looked, I don't have the holes in the fork crown or seat stay bridge. They are only drilled/tapped for fenders on the back sides (the holes don't go all the way through).

I think new cantis should be good.

Got the BR550s and Swiss Stop Green Pads.

I will report back.

Anyone using the Paul's neo-retro cantilevers? They say they're made to use with sti/ergo levers and have much better stopping power than the v-brakes w/travel agents. I'm not real confident with the Tektro mini v's on our tandem.