Bicycle Mechanics - Mechanical or Hydraulic discs for road bike?

Having fought bent rims all my life, I'm interested in building a road bike with disc brakes. I have either carbon or aluminum frames that I can weld the mounting bits to. Alternately, I can buy a frame with disc mounts already there.

I would prefer to build rather than buy because all the disc-brake road bikes I see (Specialized Sirrus, Giant OCR Touring, Cannondale Cyclocross Disc, etc.) either have low-spoke-count road wheels or 700c by 28mm mixed-use wheels. I specifically want 36-spoke (or more) wheels with a 20mm-wide deep-V rim profile. No production bike with disc brakes offers this, and the LBS is unlikely to swap out on what I want.

Now the question: I can buy a hub-disc-rotor set for mechanical discs significantly cheaper than I can buy the same set for hydraulic discs. I understand that for mountain bikers, who decend continuously, the hydraulics are more reliable and preferred. Would there be any significant safety or functional difference on a road bike? For purposes of this question, assume 6" discs.

Thanks for your patience with my repeated questions.. I appreciate the responses I get and have become significantly more bicycle-educated by reading them.

avid mechs... bb7

Mechanical brakes tend to be less exspensive. They are easier to set up for feel, Avids are, they are the only mechanical brake to get right now. The other issue would be that if you use STI, or even drop brake levers, you will pretty much have to use a mechanical brake. Formula makes a cable to hydraulic mastercylinder for their tandem brake but it is a pain compared to a lot of straight mechanical or hydraulic setups.

Avids are, they are the only mechanical brake to get right now. The other issue would be that if you use STI, or even drop brake levers, you will pretty much have to use a mechanical brake.

Bless ya, Rev. - I hadn't thought of the drop brake lever issue.. That makes the question moot - Mechanicals are the way to go!

Why are Avids superior to others? I can buy Shimano Deore for a song.. Is there something wrong with Shimano?

Thanks!

It is not so much that they are bad inherrently. Rather, the Avid system has a great deal more refinement and reliability than the competitors do. They are the closest you will get to the hydraulic feel without being hydraulic.
I thought about making a set of non-sti drop levers a while back, but I decided there would be little advantage for road use to have hydro. It would be better, and I will never go back to mech on my mtb, but the difference in the road application is much more slight. There is not nearly as much grit and muck that can foul a cable system as there would be on a trail.

The Shimano is OK but the Avids are gold. They are easy to set up, easy to adjust . You can play with feel and lever pull, a great brake. Avid also has one meant to work with the pull of a road lever so you don't need a travel agent to change the ratio.

Avid has a road specific disc brake. The ball bearing system in avid's and the easy adjustments are pretty good, they're the only ones I've felt that comes close to hydraulics.

Just out of curiosity, how do you "weld" brake tabs onto a carbon frame?

Why are Avids superior to others? I can buy Shimano Deore for a song.. Is there something wrong with Shimano?Thanks!

I've not ridden the Shimanos, but I have a set of the Avids on my Salsa. They are awesome - tons of power, and nearly maintenance free. They are as good as the Avid mechanicals for mountain bikes. I had a set of the mtb version for my mountain bike, but ended up with hydros. The Avids were great, but in the mtb environment, the cables would get mucked up quicker. The sealed hydros solve this problem.

Anywho, I don't think you can go wrong with the Avid mechanicals.

http://www.bikegreenecounty.com/bac/Salsa.jpg

I have used the Avid road mechanical disc brakes on my road bike ( well, it's a cyclocross frame ) for over 4000 miles and they have been perfectly reliable. I use Ultegra STI levers.
I was under the impression that no other mechanical disc brake system besides the Avid road disc was designed to work with road-style levers. If there are others I would be interested to know about them. I did note the previous posting about the hydraulics above.

[QUOTE=bac]I've not ridden the Shimanos, but I have a set of the Avids on my Salsa. They are awesome - tons of power, and nearly maintenance free. They are as good as the Avid mechanicals for mountain bikes. I had a set of the mtb version for my mountain bike, but ended up with hydros. The Avids were great, but in the mtb environment, the cables would get mucked up quicker. The sealed hydros solve this problem.

Anywho, I don't think you can go wrong with the Avid mechanicals.

That Salsa is beautiful. What material is the fork made out of ? Your picture popped up right as I submitted my previous post.

Just out of curiosity, how do you "weld" brake tabs onto a carbon frame?

No welding with carbon - One can braze to carbon steel, TIG weld to Chrome-molly, and MIG weld to aluminum (but only with care). To go carbon, the manufacturer would have had to do it during the molding process. I'm not a welder, so don't quote me on the above, but I'm relatively confident that I'm right.

Avid also has one meant to work with the pull of a road lever so you don't need a travel agent to change the ratio.

Might you know the model of the Avid road model? Thanks.

I've not ridden the Shimanos, but I have a set of the Avids on my Salsa.

What model Avids did you choose to work with your existing road levers?

Thanks.

As far as I know there is only one model, and it is called the Avid road mechanical disc brake. Look at the Avid ( now a division of SRAM ) website. The brake assembly actually has a nameplate on it that says Avid Road.

No welding with carbon - One can braze to carbon steel, TIG weld to Chrome-molly, and MIG weld to aluminum (but only with care). To go carbon, the manufacturer would have had to do it during the molding process. I'm not a welder, so don't quote me on the above, but I'm relatively confident that I'm right.

Yeah but you said, "I have either carbon or aluminum frames that I can weld the mounting bits to."

pull of a road lever so you don't need a travel agent to change the ratio.

OK, Rev. - I'll bite - what is a travel agent and where does one find such? The Avids seem to be a superior solution, but at $170 per bike (with no levers), they aren't cheap! I can get the Shimano Deore set (including two: hubs, discs, and caliper sets) NEW for under $100. Unless travel agents go for an arm and a leg, the Shimano still seems like the better buy..

Yeah but you said, "I have either carbon or aluminum frames that I can weld the mounting bits to."

My oops - I meant carbon steel or aluminum.. Mind got ahead of the typing fingers..

the avids are 170per pair? Where are you seeing this? I know with my BB7 i payed 64.95.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42331&item=7138526241&rd=1&ssPageName=WDVW
Super deal. IDe buy that kind of fast

the avids are 170per pair? Where are you seeing this? I know with my BB7 i payed 64.95.

I got about the same price but as I read the advertisement, I thought the price was per brake (not per pair). Did I read it wrong? If I read the ad wrong, the e-Bay guy who wants $125 for his pair must have the same misconception.

The extra $$ was for shipping.

Well from that auction its only 7.95 for shipping, ide say its a steal.

OK - Assuming I go with the Avid road calipers, can I use them with any 6" rotor (like the Shimano Deore)? If not, what do Avid rotors go for? Finally, is the rotor mount pattern standardized so that I can add Avid rotors to Shimano hubs? I'll quit asking questions after these - I promise!

any rotors will do

well im not totally sure since i try to avoid shimano stuff. BUt some of their hubs use "centerlock" which is their own little wal of mounting disc rotors. TO use these avids you require a a hub and rotor with a 6 bolt pattern. 6 bolt is very easy to find. Some shimano hubs have the 6 bolt pattern so just take a look at yours, it should be evident.

If you buy them "in the box" they will come with an ISO mount rotor. But you can use them with any 6" rotor.

The $170 sounds like front and rear not each to me

A Travel agent is a pulley gadget used to change the ratio of pull* on a linear pull (v-brake)brake so it will work with a road lever. You can use one on a disc brake for the same purpose.

*I hope I don't have this backwards, it is bedtime: Road levers and old canti brake levers pull the cable a short distance but with a lot of force, linear pull levers pull the cable a greater distance but with less force(Which is increased by the long arm of a linear brake) You need something, like a travel agent) to move more cable and reduce force or you end up with a brake that is really strong and starts working about the time the lever touches the bar. This goes for most mechanical disk brakes as well because they were intended to work with a linear compatible lever.

[QUOTE=FarHorizon]Having fought bent rims all my life, I'm interested in building a road bike with disc brakes.
.

Now the question: I can buy a hub-disc-rotor set for mechanical discs significantly cheaper than I can buy the same set for hydraulic discs. I understand that for mountain bikers, who decend continuously, the hydraulics are more reliable and preferred. Would there be any significant safety or functional difference on a road bike? For purposes of this question, assume 6" discs.

QUOTE]


The Airborne Ti Carpe Diem has the mechanical (Avids) disc brake option. The CD is promoted as their Cyclocross/light Touring/Audax frame. The frame-set comes with a rugged carbon (780 gram) fork designed to handle discs. It runs around $1400 but sometimes they run specials.

When I built-up mine, I went to V's because I didn't want the drag penalty of the ATB hubs nor the extra rotating mass.

I've never had bent rims, but I do use 6" Avid mechanicals on my ATB. My new ATB came with Shimano hydraulics, but I got the bike shop to buy them back so I could use my old Avids from my hardtail. I've ridden in Moab with the Avids and I typically spend 6-weeks/yr riding single-track and forest service roads in the N. Georgia and Tennessee mountains. I can't imagin Avids not suitable for down-hill or anything else. Some of the hills I run down extend over 5 miles and are very steep in sections.

If I were into moderate to heavy touring, then I'd put Avids on the front.

Al

I'd go with the Avid mechs..

My Sirrus disc has the Deore-level Shimano mechs., and I've had a lot of issues in the past with the brakes (scored rear rotor almost right off the bat (the pad was OK): replaced...bad cable (which might have not been Shimano's fault, although the caliper might have damaged it--don't know for sure)..replaced.
They've also needed quite a bit of adjustment and rotor truing until recently.

They can--unless in very good tune--squeal like pigs!! And, they are also quite grabby, especially in the rear; you can put yourself into a skid easily if you are not careful!

Avids, on the other hand, seem to run quietly once they're broken in (and it only takes a few stops!).
They modulate well and show signs of staying in adjustment very well. (These are mounted on my Stumpy in place of the Shimano hydros spec'd. on the bike--those showed many of the same problems the Shimano mechs. do!)

If I wanted to put disc brakes onto my road bike, does that mean that I need to change out the fork? I read the install documentation on the AVIDs, which specify that different hubs for the wheels need to be used, but did not exactly specify the types of forks needed. (I did, however, notice that the pictures show mounting points that don't exist on my fork and seat stays).

Mel

(I did, however, notice that the pictures show mounting points that don't exist on my fork and seat stays).

Mel
You'll need to swap some parts to run discs, and even then I'm not convinced that many of the adapters will work on a road frame.