Not enough stopping power with cantilevers - try V-brakes?

[NeezyDeezy]

Hi everyone, thanks so much for your help so far in getting my bike up and running.

I have a trek 820 mountain bike with an amped bikes front hub kit. I am not getting enough stopping power, and I was wondering if it would be worth it to try to convert to a V-brake on the front. If I do this, can I continue to use the specialized lever with the auto-cutoff that came with the ampedbikes kit? If so, can anyone recommend a really awesome v-brake?

Thanks!
Nate

 

[dogman dan]

I find the cheeziest wallmart v brakes better than cantilevers. They simply get more leverage. But at least get some similar to those on a slightly better bike, anything not punched out of sheet tin.

 

[deardancer3]

I had an old trek 830 with Shimano cantilevers, they worked pretty good after I learned how to adjust them.

here is the bible on that, written of course by the late great Sheldon Brown;


http://www.sheldonbrown.com/canti-trad.html

http://www.sheldonbrown.com/cantilever-geometry.html

I do remember spending lots of time keeping them adjusted.

From sheldon brown (may he rest in peace)

With modern cantilevers, they permit 5-way adjustment. Older cantilevers, such as the classic Mafacs didn't have any provision for yaw angle (toe-in) adjustment, but most cantilevers made since the 1970s have provided all 5 types of adjustability.

Sometimes it is difficult to get all 5 adjustments set at once, and to get the eyebolt tight enough without twisting it out of position. It helps if you remove the nut from the eyebolt and lubricate the threads.

Probably the best way to adjust the shoes is to use the Shimano technique:


Set the adjusting barrel 2-3 mm from fully closed.
Set the link-wire so that the guide line on its button lines up with the cable. If you're using a traditional yoke instead of a link wire, set the respective lengths of the main cable and transverse cable appropriately.
With the cantis in their relaxed position, adjust the brake shoes so they're touching the rims.
Close down the adjusting barrel. This should allow the brake shoes to withdraw just enough to clear the rim.
Threaded-stud brake shoes with plain washers generally offer height and pitch angle adjustability but little else. For this reason, they are not commonly used with cantilever brakes.
Threaded-stud brake shoes with spherical (domed) washers do allow for all angle adjustments. There are two convex washers, which go inside and outside the arm, and two matching concave washers that mate with the convex ones.

Usually, the concave washers are two different thicknesses, so you can select two different "extensions" depending on whether you put the thick or thin concave washer on the inside.

 

[Toshi]

with all respect to sheldon brown i think he's wrong. v-brakes are the superior design, imo. any old v-brake should work: get the cheapest tektro and go to town...

 

[docnjoj]

Um.............With respect to the learned Doctor and all others, dual front discs rule! Of course you need either a tadpole trike or 2 actual front discs! I believe Toshi has those on his 3-wheeler motorsykle!
Sorry for the impertinence! (sp?)
otherDoc

 

[Tiberius]

.... convert to a V-brake on the front. If I do this, can I continue to use the specialized lever with the auto-cutoff that came with the ampedbikes kit?

Possibly not, unless it was intended for V brakes. The cable travel on V brakes is slightly longer than with older types, so the levers are not generally interchangeable.

If you use a non V brake lever with V brakes, you will get a larger movement at the lever. You may be able to set it up it so that it works, but it will be tricky and need constant adjustment.

On the other hand, properly set up rim brakes (V or not V) can work really well. The reason people go to disc brakes is not for extra stopping power - its just for fashion or for special cases such as MTBs plugging through mud.

Nick

 

[docnjoj]

And stopping in rain!
otherDoc

 

[dogman dan]

No argument disk is better than any rim brake.

The amped bike kit brake levers may be part of the problem when used with cantilevers. I bet they are matched for the more common nowdays, v brakes. Fortunately when they designed v brakes, the brake posts on the frame are the same as cantilevers, so they interchange well, after some sorting out of the cables than no longer go to the center pull at the ends. Your local bikeshop may have some v brakes around, from somebodies bike that upgraded, or look for em on garage sale bikes for less than 20 bucks. And of course, easy to find on ebay from hopefully not stolen parted out bikes.

 

[deardancer3]

As mentioned by the Dogman and by Sheldon Brown, mis matched V brake handles on Cantilever brakes will always give marginal, at best, stopping power.

So if your bike worked good before the ebike kit add on, and you changed brake handles- then got marginal braking; be very suspect of the mismatched brake handlse. (Cyclone has the same thing)

If this is the case and the rear brakes are still original, swap front and rear brake cables, do a short ride and do some front brake testing.

Since 2/3 your braking power comes from the front, you can then make decisons based on the above.

I am about to go buy a bike this week - a great used chrome moly Mtn bike that fits a small friend very well, 24" wheels, but this discussion does remind me of the hours working on cantilever brakes. One can make them work quite well, but just changing pads becomes a major endeavor. Now giving 2nd thoughts about the cantilever braked bike.

 

[Drunkskunk]

I say put your original brake handles back on and ditch the silly ebrake handles.
Unless you are an idiot, you will remember to let go of the throttle when applying the brake.

 

[Takemehome]

You could also go with regen braking.
Since I did, I almost never use my brakes. ( I use them only under 5 mph )

 

[heathyoung]

Can you use cantilevered brake handles on V brakes? Or bad idea?

 

[dogman dan]

You can, it's not as bad as the other way around, but I beliver the v brake handles have a longer cable pull length I think. So they may need to be run a bit tighter to get the pads to press hard. On a bike I am doing it on, I have had no problems, but I can't have a lot of slack which means I have to keep the wheel nice and straight or it will rub the rim a lot.

 

[gwhy!]

If I had the choice, which I did I went for hydraulic rim brakes over a hydraulic disk brakes and always will, as was said up the thread disk brakes come into there own in muddy or very very wet conditions. For pure stopping power rims brakes are the best if correctly setup but do require constant maintenance to keep them in tiptop form. The rims of the wheel also play a big part into how well a rim brake works to help improve the stopping power of rim brakes there are a couple of things you can try without spending any money ( i.e a very light grind of the wheel rim of try lightly rubbing a block of tar around the rim ) Tar works really well but don't go to mad with it as the brakes can end up sticking on.

 

[monster]

what about thoses coaster brakes you find on all cheap chinese ebikes?

 

[Gregte]

I say put your original brake handles back on and ditch the silly ebrake handles.
Unless you are an idiot, you will remember to let go of the throttle when applying the brake.

I don't know about the kit that the OP is using but some ebike motor/controller kits use regenerative braking (mine does) and the switch on the brake levers is what activates it.

The regen braking does a remarkable job of slowing the bike, to the point I almost never need to apply any brake force at all other than just enough to activate the switches in the brake levers.

The switches are also a very convenient way to deactivate the cruise control in my ebike kit which is required if you want to sop the bike. It is not intuitive to press another button to deactivate cruise when applying brakes for stopping.

 

[NeezyDeezy]

Thanks so much to everyone who offered their advice on this. I put v-brakes on and had the bike shop adjust them for really high mechanical advantage. I've had 6+ bikes and I've never had stopping power like this. Fully loaded, going 20+, I can lock up a wheel to a dangerous degree. Love these things.

 

[mikebikerad]

Some hydralic disk brakes are terrible, hayes sole for example, caused me to loop out doing a wheelie through town. the hydraulic reservoir was leaking due to bad seals and I didn't have any rear brake to grab while going of the back. V-brakes or great because they are very easy to adjust and much cheaper to maintain then hydraulic disks. But you can ride a disk brake wheel when you taco the rim and still need to get home.

 

[docnjoj]

Onr interesting caveat about disc brakes is that they get HOT! More that once I have accidentally touched one of my front rotors with my bare leg! Got the scars to prove it. But they (the discs, not my legs) really stop great!
otherDoc

 

[Patriot]

Canti's can give good stopping power. Alot depends on how well they are set up, and the quality of pads you are using. Generally though, V-brakes will provide better leverage for stopping power.

The Tektro V-brake I installed on my Ebike for the rear wheel, actually stops the bike better than the Promax disc brake on the front. Funny how that is.

 

[docnjoj]

I'll tell U, the Avid 7 mechanicals on my new trike will stand me on my nose at 15 mph. I can lock the tires at any speed if I choose! Luckily I know how to brake and hate flat spots on new tires! There is a 3rd disc in the rear used as a parking brake, but if I ever carry 50 kilos in the back I may hook it up to a brake lever. Generally tadpoles dont use a rear brake!
otherDoc

 

[EVnewbie]

I have found that correct setup with Koolstop "salmon" pads make a great brake, be it canti or V-brake.
That being said, I use Avid BB7 mechanical disc brakes on my mountain bike. Ever ride in sand? Yes, it makes rim brakes into a lethal thing called rim eaters. Luckily I moved from Florida in the last 10 days back to the dirt of Kansas. My recumbent runs rim brakes but my MEKS 20" suspension fork has disc mounts so I'll be switching to a disc front brake pretty soon.
Think of the strain on a back rim with a X5 hub motor, offset spokes with the 7-speed freewheel and a brake wearing away the sides. My back rim on my recumbent is a Mavic T520 and if the side walls get too thin, it shows a colored line to warn you to replace the rim.
My ebike build will use disc brakes to allow better stopping power in the rain, less stress on the rim from pad wear and I can pick whatever size rim I want without worrying about the rear brake pads not hitting the rim.

 

[ngocthach1130]

I prefer disc brake for the progressive stopping. The v-brake i had before had too much mechanical advantage and easily lock up the wheel. At the same time a lot of dirt and grime get stuck on the rim and slowly wears it down. At one time i noticed a huge gouge on the rim where a chunk of metal had embedded itself in the brake shoe

 

[yoyoman]

Have v-brakes improved greatly since 1998? My Avid v-brakes from 1998 are still going strong, and I'm considering a new set to replace the noname v-brakes/levers on my 2008 Diamondback Outlook.

Hmm, or should I buy disc brakes for the Schwinn and move the Avids to the Diamondback?