grindr82

I have a cannondale caadx 5 stock set up....it has tektro CR710 Cantilever brakes,
what would it take to convert from cantilever brake system to disc brakes?

hueyhoolihan

i will admit right off that there are many more people on this forum that know more about this than me, and a lot of them are regulars on the framebuilders forum, but...

IMO, engineers have had to redesign frames and forks to safely tolerate braking forces on the side of the fork and rear triangle that the calipers are mounted on, making a non disc brake design fundamentally unsafe for use with disk brakes. (not that i am the type to respect that type of argument, mind you)

forks can be swapped without too much fuss if you have enough money, but rear triangles present a bit more difficulty, i think...

no1mad 

Off the top of my head: new fork, wheel, hub, rotor, pad, cable, lever. That's for the front. You lack the tab on the rear, which means a custom fabrication/modification.

But you really should ask this in the Mechanics forum...or sell it and get one that has discs.

SuperDave

You could compromise and just do the front - far easier from an engineering standpoint. I'm doing that with my hybrid, at a cost of about $650 for carbon fork, custom wheel & brake....you can plan on this process costing as much as you paid for the whole bike if you want to do both ends. I can only justify it because I was replacing all that stuff anyways.

tarwheel 

Better options would be to: (1) replace the stock brake pads with Koolstop Salmons; (2) buy a new frame.

fietsbob

Yup, if the frame and Fork does not have the fittings on it, to bolt the disc caliper onto,

N+1 Shop for a disc brake equipped second bike ..

TurbineBlade

Get a new frame, upgrade your pads for the CR720, or install higher leverage cantilevers (like oryx or shorties), or go even higher leverage with v-brakes.

Since this is in the commuting forum, I'm assuming this is the type of riding you do. Disc brakes are fine, but you should have more than aqequate braking from any of these other brakes without having to upgrade to discs. Discs have their disadvantages too.

AdamDZ

If your frame and fork don't have mounts for disc brakes then you will need a new frame and a new fork. You will likely need new wheels as well, or rebuild your wheels with hubs that can take disc rotors, so you might as well buy/build a new bike at this point.

ThermionicScott 

I'd convert the bike to money and then convert the money into a disc-equipped bike.

AdamDZ

grindr82

@ Turbineblade,My bike is primarily used for commuting I had no idea it would be so detailed to add disc brakes, but Im glad to know what some of the options are at this point. I have found the Felt F65 equipped with disc brakes...Is Felt a good company?

As for improving my existing brakes I have found this set of particular interest....

TRP Eurox Magnesium Cantilever Cross Bicycle Brake Set

Monster Pete

Any decent set of cantilever brakes should give more than sufficient braking force when set up properly. Once you begin to lift the rear wheel and/or skid the front wheel, you've reached the maximum useful braking force and any extra is effectively wasted as it can't be used. If you really want a bike with disc brakes, I'd support ThermionicScott's approach.

TurbineBlade

That set sounds expensive -- Magnesium? I mean, go for it if you like that kind of thing. For cantilevers (my choice) there's basically low profile and wide profile. Well, medium too, but there's not as much emphasis on these for some reason. As a rule, the wide ones are lower power, higher pad movement. The low profiles are higher power, less pad movement.

I prefer the look of high profile cantilevers (like tektro cr720s, etc.) but in practice I don't like their low power and sometimes they interfere with my racks and stuff. If you ride in the mud, they're great because the pads retract really far from the rim and allow crap to build up with brake rub. That said, I usually run tektro oryx because they're cheap and work extremely well. I also don't ride cross or into too much mud, lol.

Once caveat -- if you use flat, mountain brake levers tektro oryx work VERY well. I highly recommend them for that lever pairing. If you use drop bars, not so much. The combined power is just too high to get good braking with drop bar road brake levers and oryx, or any other low profile canti. If you use drop bars, for for the wide profile brakes. Otherwise I find that I have to raise the yoke REALLY high to reduce the power into a good braking set-up, which is hard to do on some frames.

Actually, I almost can't ride a bike anymore unless it has mountain short pull brake levers with some type of low-profile cantilever brake (like oryx). I just find that match to provide excellent braking for whatever reason.

spare_wheel

$120 nashbar disc fork (made in same factory as winwood fork)
~$60-70 for avid bb7 (multiple places online)
~$60 for joytech weinnman 700c 6 bolt wheel (amazon)

total cost $250.

wheel upgrade:

open pro wheel with deore/xt hub: $120-150

(i personally run hydraulics and 1600 gm xc "disc only" wheels)

Ultraspontane

Bad idea. Don't do it.

SuperDave

At least we agree on the brakes. I'd actually be all over that Nashbar fork if it was disc-only.

OP just mentioned his interest in cantis that cost $350 per wheel. I'm thinking sheer cost is a low priority here.

no1mad 

$350 per wheel?!? For cantis??

Andy_K 

I put a front disc brake on my Kona Jake by getting a steel Civia Bryant fork to replace the steel fork it came with. It was a great upgrade. I already had the wheel and brake. It helps that the Bryant fork matches my frame perfectly.

grindr82

OP here...cost is definitely a factor in either decision. I am just curious about making changes to my existing bike...but as I am learning its very costly to do major conversions....so if I want disc brakes, Ill have to buy a bike with disc brakes in the future

My interest in the magnesium brake set is purely because of a recommendation I received and based on information I read online, I am open to suggestions for improving my stopping ability by any safe method

Andy_K 

There's a sticky thread in the cx forum about cantilever setup. It's very helpful. If you want to go the easy way, try either mini V brakes or V brakes with Travel Agents. The latter option isn't quite as easy, but it's more fender friendly.

SuperDave

The large numbers I threw out for my own disc conversion are a unique case - I'm rebuilding my sole form of transportation, and I wish the end result to not only carry me for at least the next decade and many thousands of miles, but to look very good while doing it. Furthermore, I am more than a little neurotic about having things exactly the way I want them; otherwise I'd just have bought a new Jamis Coda Elite and be done with it.

The numbers spare_wheel mentioned above are a more realistic idea.

If your sole goal is to improve braking performance, simply switch to the Koolstop salmon pads which are so (rightly) favored here and anywhere people talk about bikes. On my bike (OEM Avid Single Digit 5's), that inexpensive addition gave me brakes which not only modulate nicely with one finger, but have sufficient power to completely overwhelm the wheels should I wish to be a movie action hero and also change flatspotted tires frequently. The only advantages of disc brakes on the street is their relative immunity to wet conditions given that they're not on the rim where you'd splash them through puddles, and no wear on the rim itself which should prolong the life of your wheels.

They are otherwise heavier, more expensive and more sensitive to proper adjustment. Were you talking about a mountain bike, the math would be different.