Go Back  Bike Forums > Bike Forums > Touring
Reload this Page >

Disc Brakes - What do I need to know?

Notices
Touring Have a dream to ride a bike across your state, across the country, or around the world? Self-contained or fully supported? Trade ideas, adventures, and more in our bicycle touring forum.

Disc Brakes - What do I need to know?

Old 04-14-11, 07:35 PM
  #1  
Accordion
Senior Member
Thread Starter
 
Join Date: Oct 2007
Location: Orange County - SoCal
Posts: 1,480

Bikes: 2011 Cannondale CAAD10

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Disc Brakes - What do I need to know?

I have a 2011 Novara Safari that is prepped for disc brakes. I can see from the front hub that there are six openings to accept the disc brake and I can also see that there are two holes on a mounting plate molded into the left side of the front fork.

I want to put a front disc brake on only. No rear needed. The front does 80% of the stopping anyway so this is the one I need.

I looked at some options - Avid Brakes....looks like I can get a plate and mechanism for $50.

My questions - what do the sizes mean? 160mm 170mm 185mm, etc. Can I use whatever I want on the Safari? What about mechanical versus hydraulic. I assume hydraulic uses some type of oil or water to apply the pressure whereas mechanical just means you squeeze the brake lever and it closes the brake.

Any help is appreciated. I'm pretty new at disc brakes!
Accordion is offline  
Old 04-14-11, 07:58 PM
  #2  
Cyclesafe
Senior Member
 
Join Date: May 2006
Location: San Diego
Posts: 1,435

Bikes: IF steel deluxe 29er tourer

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Both work, but mechanicals can usually be repaired on the road and are preferred while touring for that reason. Rotors are available in various sizes; the bigger the better stopping power, but any would probably work OK. I have 203's, but for a 250 lb total load, they're overkill. Look at stock bikes to make your choice.
Cyclesafe is offline  
Old 04-14-11, 08:00 PM
  #3  
Cyclebum
Senior Member
 
Cyclebum's Avatar
 
Join Date: Jan 2007
Location: NE Tx
Posts: 2,766

Bikes: Tour Easy, Linear USS, Lightening Thunderbolt, custom DF, Raleigh hybrid, Felt time trial

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Interesting that you say you want only front disc. I've pondered this option as being the most practical way to minimize rim wear without the weight and complications of disc for both wheels. There was a recent long discussion about that here.

As disc put more stress on the wheel, might be a negative if only on the front and used exclusively for most of the stopping. Don't know about that.

I concluded that for the type of touring I do, discs would needlessly complicate my life. But, if I were to head out
for remote areas, especially where rain and mud were common, like east Asia, I'd certainly give the combo you question serious consideration. Or, if I anticipated riding extensively in mountaneous areas with long, steep downhills.
Cyclebum is offline  
Old 04-14-11, 08:14 PM
  #4  
sstorkel
Senior Member
 
Join Date: Apr 2008
Posts: 5,428

Bikes: Cervelo RS, Specialized Stumpjumper FSR Pro, Schwinn Typhoon, Nashbar touring, custom steel MTB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 1 Time in 1 Post
160mm, 185mm, 210mm etc. are generally the diameter of the rotor. Larger rotors dissipate heat better and, in theory, provide more stopping power. They also exert more force on the forks, so there's usually a maximum size that the bike is designed to accept. My guess would be that the Safari is designed to use 160mm brake rotors.

Hydraulic brakes are generally regarded as having better modulation than mechanical disc brakes. They may also require less lever effort than a mechanical brake. The downsides to hydraulics (a.k.a. "hydros") are increased cost, possibility of damage (ex: a nick in the brake line can allow the fluid to drain out, rendering the brakes useless), and more complex maintenance. Mechanical disc brakes are generally cheaper than hydros, less likely to fail, and easier to maintain.

I've got Avid BB7 brakes on my touring and commuter bikes and Magura Marta hydros on my mountain bike. The Magura Martas are the best braking system I've ever used on a bicycle... and complete over-kill for anything other than mountain biking. BB7s are a nice upgrade over rim brakes, especially when it rains. Like all Avid brakes, they tend to make quite a bit of noise. On tour, I felt like I was tweaking the adjustment every couple of days to keep them from squealing. BB7s are cheap enough that I wouldn't consider buying the slightly less adjustable BB5s.
sstorkel is offline  
Old 04-14-11, 08:53 PM
  #5  
Accordion
Senior Member
Thread Starter
 
Join Date: Oct 2007
Location: Orange County - SoCal
Posts: 1,480

Bikes: 2011 Cannondale CAAD10

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Thank you very much for all the advice.

I see that PricePoint has some 2010 Avid BB7s for $44 in 160mm size. Those seem to be perfect for my needs.

Quick question: Can I use the stock brake lever and cables I have? I realize that I may need to get longer brake cables but with my understanding of mechanical brakes any lever should work fine.

Thanks again!
Accordion is offline  
Old 04-14-11, 10:09 PM
  #6  
gorshkov
Senior Member
 
Join Date: Apr 2009
Posts: 293
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I've got a Raleigh Sojourn with BB5s (160mm front, 140mm rear), and I've been fairly happy with them, though I don't think that they significantly outperform cantis except in wet weather.

My two cents would be to put the same kind of brakes on front and rear. That way you only need to carry one set of spare pads.

You need to be careful of lever compatibility. MOST mechanical disks have the same cable pull as V-brakes, but Avid has started making versions of the BB5 and BB7 that use a shorter cable pull to make them compatible with standard road levers. If your bike has V-brakes now, you should get the standard brakes. If it has cantilevers now, you should get the road-compatible version.
gorshkov is offline  
Old 04-15-11, 12:43 AM
  #7  
NoReg
Banned
 
Join Date: Aug 2005
Posts: 5,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times in 1 Post
The set-up I was considering was the bb7 MTB front only with a 2 finger lever on the tops, and cantis all around opporated with road levers. So that would be three brakes total. The idea was:

1) improve the braking performance, having come back at the time from a long tour with lots of brake problems,

2) get levers on tops and drops, not a big deal but not bad either, like the cross levers.

3) Get more redundency for my near tandem loads. Tandems use three brakes.

I bought some of the parts, but never went through with it. I didn't want to compromise the ride of the front fork.
NoReg is offline  
Old 04-15-11, 01:57 AM
  #8  
seeker333
-
 
seeker333's Avatar
 
Join Date: Feb 2004
Posts: 3,865

Bikes: yes!

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 281 Post(s)
Liked 38 Times in 36 Posts
Originally Posted by Accordion View Post
I see that PricePoint has some 2010 Avid BB7s for $44 in 160mm size... Can I use the stock brake lever and cables I have?
PP is a good source for inexpensive parts. I've been buying from them for over a decade now, they've never disappointed me. The $45 160mm 2010 model is the one you want.

https://www.pricepoint.com/detail/187...t_Rer-2010.htm

The mtb BB7s are compatible with all mtb (mechanical, i.e. cable) levers, including your stock levers.

I didn't look, but odds are your fork will only accept the 160mm disc, which will work fine for your application. The curvature of the fork prevents larger diameters from having adequate clearance. You need a fork with straight legs (suspension) for the bigger discs.

You will need new housing and brake cable. Cutting and finishing conventional brake housing properly is a little complicated. You want to cut it cleanly without crushing it, then you have to file the end flat so it seats properly. Go to Park Tools and research this topic.

Jagwire ripcord aka Nashbar mech disc brake cable can be cut easily, with no filing required, due to it's kevlar construction (no steel). I buy it when it's on sale for ~5 bucks. I discovered this product several years ago, shortly after I perfected a procedure for cutting and filing conventional brake housing with common tools.

https://www.nashbar.com/bikes/Product...1_10000_202417

The new cable run may be a little tricky. Plastic tie straps might help.

Last edited by seeker333; 04-15-11 at 02:18 AM.
seeker333 is offline  
Old 04-15-11, 09:35 AM
  #9  
PamolaPat
Member
 
Join Date: Jul 2010
Location: Boston, MA
Posts: 38

Bikes: Soma Smoothie ES running SRAM Rival

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I upgraded to BB7s on the front end of my commuter and it has been totally worth it. I used the Jagwire product from Nashbar which seeker333 mentions. It's a great product and very worthwhile...the first time you ride in the rain you'll know it was worth it! I cut my cable housings with a Dremel tool using a carbide disc bit, which works perfectly. However, there are steel strands in this housing. Not a problem for the Dremel though.
PamolaPat is offline  
Old 04-15-11, 09:55 AM
  #10  
sstorkel
Senior Member
 
Join Date: Apr 2008
Posts: 5,428

Bikes: Cervelo RS, Specialized Stumpjumper FSR Pro, Schwinn Typhoon, Nashbar touring, custom steel MTB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by PamolaPat View Post
I cut my cable housings with a Dremel tool using a carbide disc bit, which works perfectly. However, there are steel strands in this housing. Not a problem for the Dremel though.
+1 on using a Dremel to cut housing. I've got an expensive Park housing cutter and it invariably ends up crushing the housing. Results are somewhat better if you cut the housing with a piece of cable inserted at the end, but I think the Dremel still does a better job.
sstorkel is offline  
Old 04-15-11, 10:03 AM
  #11  
ollyisk
Senior Member
 
Join Date: Feb 2007
Location: Kansas City, MO
Posts: 305
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
You may want to consider floating rotors for sanity's sake. I'm a bigger guy (I hover around 240ish) and I've had problems with rotors warping on me--I don't know if I was just laying my bike down on the rotors and them bending, or if they were overheating and warping, but I haven't changed my bike handling behavior, and I haven't had any issues since I upgraded to floating rotors. Typically speaking, floating rotors are lighter than regular rotors and more heat resistant (the inner spider is usually aluminum). However, they're also quite a bit more expensive.

I frequently had to adjust my brakes when I had the stock Avid rotors--I was constantly bending the rotor back into shape, or turning the dials on the caliper to get it so the rotor wasn't rubbing. Since I upgraded to Hope's Floating rotors, I've never had any issues with my rotor warping or rubbing on the brake pad, to me they were worth the $45/each (or whatever they're going for), because truing a disc rotor can be an f'ing nightmarish task if you don't know exactly what you're doing.
ollyisk is offline  
Old 04-15-11, 10:11 AM
  #12  
Accordion
Senior Member
Thread Starter
 
Join Date: Oct 2007
Location: Orange County - SoCal
Posts: 1,480

Bikes: 2011 Cannondale CAAD10

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Really appreciate all the advice.

My main reason for wanting to go disc on the front is the stock Safari V-brakes are really spongy to me. I'm used to my CAAD9 brakes and they are rock-solid.

I've adjusted these brakes from here to Kingdom Come and I'm tired of the spongy feeling still. I think it's the nature of the brakes - they are cheap.

Since this will be a commuter-type mini-tour bike I thought discs would be good but the stories above about constant adjustments with the Avid brakes are scaring me. The last thing I want it warped rotors or constant adjustments. I can't just purchase the same brakes my CAAD9 has because my Safari isn't drilled for them plus the fact that under load they may not be so great. I'm 190 and my CAAD9 is 17 pounds. My Safari with rack and rackbag is around 35 pounds!
Accordion is offline  
Old 04-15-11, 10:16 AM
  #13  
Seattle Forrest
Senior Member
 
Seattle Forrest's Avatar
 
Join Date: Mar 2010
Location: Seattle, WA
Posts: 21,842
Mentioned: 73 Post(s)
Tagged: 0 Thread(s)
Quoted: 14260 Post(s)
Liked 5,299 Times in 3,015 Posts
I love my disc brakes. They don't have any more power than the rim-pinchers on my road bike, under the best of conditions, but when it starts to rain sideways, the consistency of stopping power is really nice. You don't need to "wipe them down" or anything like that; you pull the lever, and the bike comes to a stop.

But you should seriously consider getting one for the rear wheel, too. I've noticed that the rear brake supplies more stopping power when I'm carrying a lot of heavy stuff in the panniers.

I have Avid BB7s on my cross bike. I need to adjust them more often than I think I should, but on the other hand, it takes about 20 to 30 seconds to adjust them on either wheel. Knock on wood, I've never had any mechanical problem with them.
Seattle Forrest is offline  
Old 04-15-11, 12:32 PM
  #14  
ollyisk
Senior Member
 
Join Date: Feb 2007
Location: Kansas City, MO
Posts: 305
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Don't be worried about adjustment! It's really not that hard.

There are lots of tutorials on "pain free disc brake adjustment" on the net, but I'm an idiot and didn't really bother to look around when I first got them. I had an epiphany one day and suddenly "got it." It hasn't been so bad since then, and I've honestly never even had to touch my brakes since I put the floating rotors on.

I used Ashima and Avid rotors before switching to Hope rotors (again, the Hopes are considerably more expensive). My experiences were like this: the Avids got bent out of shape rather quickly, but never too bad. I had to adjust my brake pads so I had very little braking power. I could never really tune them to the point where I felt confident with them. After that, I bought Ashima rotors because I thought sawblade rotors looked "cool," and they were really lightweight (and quite cheap). They came bent from shipping, and I could never get them right. It just got worse and worse, and one night after trying to true and tune them for an hour, I freaked out and just bent the hell out of them in a fit of adjustment rage. I got the hope rotors, and they've been perfect absolutely since day one. I haven't even had to use my disc truing fork once to prevent rubbing.

To be fair though, lots of people use Avid and Ashima rotors and claim to not have issues. My personal experience wasn't so sweet. Paying $90 for two rotors that have essentially been maintenance free since day 1 is absolutely the price of admission for me.

Don't skimp on rotors--if they're cheap, there's a reason for it.
ollyisk is offline  
Old 04-15-11, 01:23 PM
  #15  
sstorkel
Senior Member
 
Join Date: Apr 2008
Posts: 5,428

Bikes: Cervelo RS, Specialized Stumpjumper FSR Pro, Schwinn Typhoon, Nashbar touring, custom steel MTB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by ollyisk View Post
I used Ashima and Avid rotors before switching to Hope rotors (again, the Hopes are considerably more expensive). My experiences were like this: the Avids got bent out of shape rather quickly, but never too bad.
Agree with this. My Avid BB7 rotors always seem to be slightly tweaked, which does compromise stopping power a bit. Not enough to be a huge issue, but it does contribute to their endless scraping and squealing...
sstorkel is offline  
Old 04-15-11, 01:38 PM
  #16  
fietsbob
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,599

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,315 Times in 826 Posts
I'd reccomend the pairing of Front and rear discs ..
True , weight G shifts forward, when braking, to a stop.

but a lot of rear rims wear thin from speed control , without coming to a full stop,
dragging the rear brake on the rim..

Galfer discs are thicker than Avids, but cost significantly more ..

Its particularly true when the rear hub is using a 4 bolt disc.
fietsbob is offline  
Old 04-15-11, 03:06 PM
  #17  
positron
Senior Member
 
Join Date: Mar 2007
Posts: 1,268
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I use avid BB7 (road version) with tektro aero levers. Ive never had an issue with bent rotors (on my touring bike, but I used to bend rotors on the MTB on occaision)

I also nearly never adjust the brakes. maybe once every two months i click the pads in one click. if that.

highly recommended for the ~75 bucks it cost for the set.
positron is offline  
Old 04-16-11, 03:54 PM
  #18  
marmot
Senior Member
 
marmot's Avatar
 
Join Date: Oct 2005
Location: Ottawa
Posts: 439

Bikes: Kona Dew Drop, Specialized Expedition Sport

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by sstorkel View Post
Agree with this. My Avid BB7 rotors always seem to be slightly tweaked, which does compromise stopping power a bit. Not enough to be a huge issue, but it does contribute to their endless scraping and squealing...
I have BB7s on my main bike, and they are notably quiet. They make a barely perceptable whispery hiss, and occasionally a very quiet "moan" just as the stop is completed. They only have a couple hundred miles on them, though, but so far there's no hint of scraping or squealing. They are MUCH quieter than the rim brakes on my other bike, and far more effective.
marmot is offline  
Old 04-16-11, 06:41 PM
  #19  
sstorkel
Senior Member
 
Join Date: Apr 2008
Posts: 5,428

Bikes: Cervelo RS, Specialized Stumpjumper FSR Pro, Schwinn Typhoon, Nashbar touring, custom steel MTB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by marmot View Post
I have BB7s on my main bike, and they are notably quiet. They make a barely perceptable whispery hiss, and occasionally a very quiet "moan" just as the stop is completed. They only have a couple hundred miles on them, though, but so far there's no hint of scraping or squealing. They are MUCH quieter than the rim brakes on my other bike, and far more effective.
Just wait! Eventually, you'll drop the bike and bend the brake rotor ever so slightly, or the pads will get a bit glazed, or the calipers will go out of alignment and then you'll be treated to the scraping, squeaking, squealing, and turkey warbling that seems endemic to Avid brake products...
sstorkel is offline  
Old 04-17-11, 09:56 PM
  #20  
NoReg
Banned
 
Join Date: Aug 2005
Posts: 5,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times in 1 Post
I don't know if it is an issue, but I found some old Jobst thread and he mentioned that front wheels are more likely to collapse than rear ones. He was saying how the old idea of using 40 in the rear and 32 in the front was all backwards as almost all wheel collapses are in the front wheel. Which does raise the point of whether the front wheel dish is a good idea.
NoReg is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cyber.snow
Touring
75
04-17-17 11:38 AM
str
Touring
220
10-13-16 09:56 PM
xlDooM
Mountain Biking
18
12-08-12 04:11 AM
PeregrineA1
Touring
7
09-27-11 10:24 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.