JohnJ80

It's almost a positive feedback loop with the right components. In an underdamped system, if it is hit with the right input, it can set up into oscillation or a slowly decaying oscillation. That, in fact, is what happened to my bike when I swapped out my Gunnar steel fork for an Enve carbon one. The Enve carbon cross fork was much more compliant but that also meant the fork blades would move fore and aft more and do it with less latency (i.e move faster). When I put that fork on, the whole thing was so dangerous and the chatter so strong and growing in magnitude, that I had to stop with the rear brake only. When I looked at it more closely, it was one of those "palm to the forehead" moments. Adding the v-brake instantly stopped the problem and permanently - not the slightest bit of chatter or oscillation ever.

So, yeah, similar to the bump stock but a little different. I don't know if it could have been stopped in my case by fiddling with making the cable length shorter without eliminating it, but with systems like this it depends on the frequency and amplitude of the input. If you break the whole feedback loop by removing the cable length entirely from the loop, it's a certainty that you won't have that problem any more.

Most bikes with cantilever brakes are of older design so they are going to have a shorter head tube than a cross bike or a gravel bike would today. So that is probably helpful in not having the problem be as bad or as widespread because cable lengths between brakes and headset tend to be shorter. In current bikes were the head tubes are getting longer (even longer than the custom one on my bike for my size), with disc brakes - and in looking at the mechanical case again - the cable is managed similarly to how it is on a v-brake and is decoupled from the cable length because the cable connections essential both start and terminate on the brake and are not affected by the fork blades moving. I would presume it's the same with hydraulic brakes too.

Anyhow, with the Paul's Components Minimoto v-brakes on the front and the Paul's canti's on the back, the braking performance was superb.

robow

I have three cyclecross bikes, two carbon fiber, one titanium, and all have carbon fiber forks on them. All have had a cable hanger in place when using canti brakes and none of given me any difficulties once the hanger was used. I have also run a Soma steel fork on the titanium one when touring and using a front rack, again without difficulties. I do know there are combinations of frames and forks out there where it is very difficult to remedy but so far I've been lucky.

djb

Ya, my bike has c.f. fork, and a fairly tall head tube, and the doohickey clearly works, I'm a hard front braker at times, really hard, and never a hint of problem.
neat to know how a v brake clears it up.

Tourist in MSN

I have not had that problem on a touring bike where the fork was pretty stiff.

And on one of my bikes I used a fork crown mounted hanger that completely negates that long distance from the hanger to the straddle cable yoke as shown in the photo. Sorry the photo is a bit busy with the wiring for the dyno powered headlamp, taillamp and USB charger, plus wiring for a wired computer. But the hanger is there, you will figure it out.

JohnJ80

A lot of forks - especially carbon ones, it's not possible to mount a hanger on the fork crown. My Enve cross fork is a good example. Ritchey cantilever cross forks are another example.

djb

Again, very interesting. Thanks

MassiveD

Basically you are only going to get the geometry from the levers that you have. And there is also geometry in the fork, how wide set the blades are, and how stiff.

I don't personally prefer the Vs with travel agent option because it is a little klugie, and at the end of the day you have just converting the Vs into something with canti effectiveness. You can't add a travel agent and end up with the powerful geometry of a V brake set-up as on an MTB.

These days you also can't assume a factory knows what is best on your bike when it comes to cantis.

I did go the route of upgrading to Paul brakes when I had a particularly bad tour. But the result was identical to the junkers I replaced - some hideous stamped steel shimano brakes, shrouded in plastic, as the geometry was almost exactly the same on the Pauls.

The one system that will super charge your front brake with cantis is to find some Peterson self energizing brakes off ebay. They work like cantis, but once you touch the rims the bike's energy cranks in to really grab the rims. Modulation is not fabulous, but they will stop a truck. They basically got taken off the market as too dangerous for front wheels, and you don't want the resulting sets where only the rear wheel is SE. First, brakes that can throw you over the handlebars (as if) are just what I want on a loaded touring bike, they stop a heavy load and with bags, there is no risk of going over. But the real answer is to use regular brake blocks. DO NOT FIT SALMON COOL STOPS on SEs. These things work great with regular rubber, or I used to have sintered blocks on a Canondale. With really sticky rubber the rubber grabs, then the SE grabs as well, one or the other is a good deal, and I really like SEs.

djb

Ive mentioned this before, but in my limited experience with v brakes, I find them to a lot more "ON" or "OFF" compared to cantis. I really like my cantis with the softer pads unloaded and when braking really hard and late, that the modulation is nice at the far end of the braking application.
My mtb with v brakes, good shimano ones I think from about 20 years ago on a Comp mtb from that time, are more grabby at that crucial point of heavy braking.
I know its only one example, but I can say from having lots of experience braking hard on motorcycles and having a pretty good feel for maximum braking, my cantis with salmon kool stops work really well, and I have a lot of confidence doing hard and modulated front braking going into corners fast.

and on a side note, I also feel exactly the same way about my BB7 disc brakes on my Troll. When loaded up, I can brake good and hard, and they modulate well on a heavy bike.

Doug64

Travel Agents work well with v-brakes. My wife wanted V-brakes, and really likes them. Travel Agents works with STI shifters. She has over 20,000 miles on this pair of Travel Agents without any problems. They do stop better than my cantis, but my cantis also provide more than adequate stopping power.

fietsbob

But, last I looked QBP ran out, and won't be shipping any more 'travel agents' to your drealers..

It's not on their website... any more ... will they order another batch from their supplier?

not in the loop call them on the phone & ask..

The inline version was discontinued and never returned , at all ..

but cable disc calipers being in long & short pull made them unneeded..





...

robow

fietsbob, thanks for the heads up. As everything is moving towards disc brakes, parts for V's and canti's are going to be harder to find. If I used travel agents, I would be tempted to pick up a spare pair.

fietsbob

My 1 V Brake bike a BF Tikit 349 - 16" wheels I've gone from a 2 to 3 finger hand lever and found that made my braking nicer

straight bar lever .. I had to shift my grip to reach the shorter hand-levar .. which was harder to pull ..
as the way a V brake works , greater MA on the wheel requires a low MA to pull more cable from the lever,

so a 4 finger V pull lever regains some of that lost leverage ..



....

Tourist in MSN

Oops, I said something stupid here, edited it out later.

Unlikely that you would need to replace them. But, I just might be tempted to get a spare in case I buy a bike that I want to convert to V brakes if I see a cheap one at a swap meet.

veganbikes

Just FYI both Cane Creek and Tektro make long pull drop bar brake levers so you could use linear pull or v-brakes without a travel agent. You can also get Gevenalle levers with your shifters on them too. Get a nice set of linear pull brakes, good pads and good cables and housing you will get great stopping power. Sure it won't be hydro discs but it will be pretty darn good. That is what I have on my commuter bike, Deore brakes with dual compound Kool Stop pad inserts with in this case Avid Speed Dial 7 levers. The only thing I need to change is the cables and housing (it is just a hair short on the new Moloko Bars) so I can maximize things but the braking isn't bad.

Goofball

Travel agent +v-brake = good

fietsbob

Maybe crowd fund the money needed to convince QBP to order a production run renewal ..

Cash talks...

Tourist in MSN

No need for that, there are chinese copies being made, ordered one (to have as a spare in case I buy another bike) on Ebay yesterday.
https://www.ebay.com/itm/1pcs-Black-Bicycle-Folding-Bike-V-Brake-Adapter-Converter-to-Caliper-Brake/273706014859

I saw some red ones on Ebay too, they were not offered in red before.

Doug64

I had one spare TA, but I picked up another one last night. Demand has allowed dealers to jack-up the prices. The TAs I bought when I put my wife's bike together cost $18. The one I got last night was almost double that!

fietsbob

The originals were chinese too, Taiwan ROC is a Go to manufacturing source for the Bike business now

QPB uses them for most of what they sell .. can't beat the cost and quality combined ...

robow

Veganbike, those long pull levers only work if you are not using brifters. With brifters you need the travel agents for longer v's, but not mini v's.

seeker333

You solved the problem in your opening paragraph. Vee brakes simply work better than fussy cantilever brakes. Bike folks have argued this issue for years. Three or four years ago even Surly gave up on cantis and began selling their LHT Complete (and Cross-Check Complete) with V brakes, which was easy for them since they already used bar-end shifters. All Surly had to do was convert from a traditional short-cable-pull drop bar brake lever to a long-pull lever compatible with V brakes (Tektro RL520 or the prettier Cane Creek clone), and spec a V brake. Avid SD7 is my favorite V brake, highly effective, reliable, inexpensive and lightweight - some versions sold with Mg arms / Ti hardware, it has been made/sold continuously for 20 years now.

Since you obviously want to continue using brifters, in addition to trying different brake pads you could also try different canti brake calipers. Tektro has a couple which were both speced on LHT in the past. TA short-to-long cable pull adapters do work but they have a hidden fault - bike cables (brake and especially gear) do not last as long when used in a tight bending radius. Finally, although you seem to have avoided it, a fork crown-mounted cable stop will usually eliminate the somewhat common front canti brake chatter/shudder phenomenon.

Of course most readers will wonder why anyone still uses rim brakes. Surly started selling disc-braked versions of the LHT in 2012, and obviously nearly the whole bike industry has abandoned rim brakes for disc brakes - the only holdout being road/racing bikes. Over at Trek's road bike page I counted 17 of 23 bikes with disc brakes, or about 75%.

fietsbob

not entirely abandoned them , but in the price point Enthousiast types visiting this site are willing to pay

they can have frames ready to fit disc brakes .. which will cost more ,

that work well

if low cost is primary , you will still see rim brakes. specified..

fietsbob

An example of Hydraulic Rim Brakes made in Germany .. they work reliably and service free after initial set up...

rhm

Another way to improve existing cantilever brakes is a doodah called a "power hanger." Originally marketed by SunTour, I think Tektro makes one now. It's a small (4 cm?) Aluminum V that mounts to the hole in the fork crown. The cable and housing run from the brake lever to the Power Hanger, eliminating the need for a fixed hanger on the headset. It does away with all the flex in the steerer tube etc, fixing brake shudder etc. Costs about $15 per brake, well worth the cost.

edit: sometimes I wrote "power lever" where I should have written "power hanger." Sorry about that... .

JohnJ80

Presuming your fork has a hole in the crown. Most carbon fiber cantilever forks do not. That’s one of the big reasons I wound up using a v-brake on the front anyhow.