Adventure Cycling Association Forum

Bicycle Travel => Gear Talk => Topic started by: dknapp on February 06, 2006, 03:39:27 pm

 
Title: Importance of Disk Brakes?
Post by: dknapp on February 06, 2006, 03:39:27 pm
I am looking to buy a new touring bike in the $800-1300 dollar range.  The Trek 520 looks good, but I am not happy with the shifters or brakes.  My wife has done some touring in hilly areas (we live in Virginia) and says brake/rim overheating on long downhills is a real problem.  So, do I opt for something like the Gary Fisher Utopia, with disks, or stick to the Trek?  I have not yet decided on the trailer vs. pannier question either, but I guess if I go with disks I am also voting for the trailer, as none of the disk brake bikes I have seen have the mountings for panniers.  Or is there an alternative for bikes without braze ons?

Title: Importance of Disk Brakes?
Post by: bikeman on February 06, 2006, 06:55:21 pm
If your on pavement all the time then you can use panniers or BOB trailer.
OldManMountain.com has pannier racks with clamps for MTN bikes and others that don't have brackets for panniers.
Keep in mind that carrying loaded panniers will put a lot of stress on your wheels so your bike choice must have heavy duty wheels. High-end panniers (Ortlieb) plus racks cost $300 to $400 USD. A standard rear rack may not fit around the rear disk brake caliper so verify the fit before buying the rack if you have disk brakes. Old man mountain has racks that get around the rear disk caliper problem.

If you chose a trailer there's less stress on the bike and wheels so the bike and wheels aren't so critical. I pull a 2 wheel trailer (Burley Nomad) using standard 32 spoke wheels and haven't had any problems.  I think the BOB trailer cost around $275 and the Burley Nomads about $250. I traded my BOB trailer in when I bought the Burley Nomad. I won't go into all the reasons why I traded it in but one was the weight limit of 40-45Lbs for the BOB versus 100Lbs for the Burley. You gotta be crazy to haul 100lbs around but I can if I must.

I have also used panniers and old man mountain racks over my disk brakes when on un-paved roads. I had to upgrade to heavy duty wheels that cost me $300 more than std wheels. When I get back on paved roads I have my trailer shipped to me and I switch back to my Burley Nomad trailer because the bike handling is so much easier and I can carry more gear, weight with a lot less stress on the bike and wheels.

Hope my opinion helps.  Good luck.

Regards: Clyde
The journey is my destination.
Title: Importance of Disk Brakes?
Post by: cyclesafe on February 07, 2006, 01:44:22 am
Although mechanical disks are best, IMHO, V brakes, as found on the TREK 520, are perfectly adequate for most touring situations (where there isn't any mud clogging the brakes and rims).  The only brakes out there that are sometimes not suitable for touring are the caliper brakes found on road bikes.  This is because there isn't adequate braking power while going down steep descents when loaded.  

However, the wheels that you get with the 520 are not so great.  I watched several 520's fall apart on the Southern Tier last year.  Also, I greatly prefer STI shifters to bar-end shifters.

Although the Utopia has mechanical disks, the rest of the componentry, including the wheels, is marginal.  The straight bars offer limited hand positions, an issue which can be only somewhat addressed with bar ends.  In addition, the bike's frame geometry is more like a mountain bike, which after many hours in the saddle will not be as comfortable as a touring bike.  Also you will not be as aerodynamic.

You should definitely test ride any bike for several hours before buying.  My prediction is that you'll want to get off the "Utopia" as soon as possible.

Before you make a final decision, also check out the Cannondale T2000 (msrp $1600).  It has a more suitable mix of components for touring.  A fallback would be the Cannondate T800 (msrp $1300).

http://www.cannondale.com/bikes/06/CUSA/model-6TR2.html

If you add up the weight and cost of racks and panniers and keep in mind that 2/3's of breakdowns while touring are attributable to racks, panniers, and rear wheels, you will conclude that a BOB trailer is lighter, cheaper, and less of a problem for rear wheels than traditional panniers.  Also, the BOB bag is waterproof.

There is plenty written elsewhere about trailers versus panniers.

Good luck.

Title: Importance of Disk Brakes?
Post by: dknapp on February 07, 2006, 09:28:34 am
Good thoughts on the road vs. off-road.  I do plan to keep to the roads.  I also feel I am sort of at the higher end of the size range, at 6'3" and 215 lbs., so those wheels will already be stressed.
What is your bike with the disk brakes?

Title: Importance of Disk Brakes?
Post by: dknapp on February 07, 2006, 09:38:51 am
I agree about the bars.  I rode the Utopia for only about 10 minutes and could see that on a long ride I would have little choice on hand position.  I also really hated the shifters, which were in the way at all times and caused an unintended shift when I gripped the bars to speed up.  Is there that much difference between the Shimano 105 and the Ultegra components on the T2000 and T800?  From looking at the specs, Those items and the fork/wheels/tires are the main differences between the two bikes.  There is a big price difference.


Title: Importance of Disk Brakes?
Post by: DaveB on February 07, 2006, 11:27:45 am
Quote
The only brakes out there that are sometimes not suitable for touring are the caliper brakes found on road bikes.  This is because there isn't adequate braking power while going down steep descents when loaded.

That's really not correct.  Modern double pivot caliper brakes have plenty of power and excellent modulation at reasonable hand pressure.  

Their disadvantage is limited clearance for fat tires and/or fenders.  Even "long reach" calipers don't offer the clearance that V-brakes or cantilevers do.

This message was edited by DaveB on 2-7-06 @ 7:28 AM
Title: Importance of Disk Brakes?
Post by: cyclesafe on February 07, 2006, 12:00:00 pm
DaveB: Of course it depends on what sort of a load your're carrying/dragging and the hill you are descending.  Ultegra caliper brakes will not stop me (165 lbs), my bike (18 lbs), and my BOB (60 lbs) while going down a 10% grade.  Maybe nothing will...

I agree that the tire width and fender issues also rule out caliper brakes for a typical touring bike setup.  Another reason is that mud/dirt can more easily interfere with the function of calipers.

dknapp: The Ultegra STI shifters shift more crisply than the 105's and IMHO are worth spending more money for.  Same comment for the Schwalbe tires.  But, the fork on the T2000 is really not necessary for touring on pavement and won't make much difference if you go off-road.  Also, note that the T2000 doesn't come with pedals, so the price differential with the T800 is closer to $400 (plus tax).

Note that there is a XL T800 for sale in the classifieds here.  For a bike in good condition with panniers, $1200 could be a good deal.

You didn't ask, but my disk brake touring bike is at the bottom of this page...

http://www.co-motion.com/Amerc.html

My children are now going to have to be happy with junior college  ;p

Title: Importance of Disk Brakes?
Post by: dknapp on February 07, 2006, 12:19:04 pm
I was mostly concerned about long, controlled descents where the pads (seem to be mostly hard rubber) heat up to melting and also wear/heat the rims.  Some of the folks on last year's Bike Virginia ride in the Blue Ridge encountered big problems going slow.  My wife, who rode it without any appreciable extra load (other than her svelt self) on a Gary Fisher Nirvana, had trouble controlling her downhill speed due to brake fade.  I have already smashed my collarbone once in a header and would like to avoid brake fade in the middle of a 5-mile descent.  I am pretty sure any brake can handle the occasional stop, but a 10-minute glide is another thing.  I guess I am a bit gun shy about that collarbone incident and I am way older (58) now.

That Co-Motion is really sweet.  Some states have a good junior college program, hope your kids live in one of them.  After seeing your bike, I may have to check into that myself.  Or maybe a home equity loan...

Title: Importance of Disk Brakes?
Post by: cyclesafe on February 07, 2006, 12:37:37 pm
Maybe better brake pads is the answer.  The link below reviews a huge number of pads, most of which can be purchased on line.

http://www.mtbr.com/reviews/Brake_Pad/



Title: Importance of Disk Brakes?
Post by: Dan_E_Boye on February 08, 2006, 01:07:25 am
I like disc brakes.  I have a Burley Canto recumbent and one reason I chose it was the disc brakes.  Last spring I rode from Sisters, OR to Eugene, OR over Makinzie pass and I spent a lot of time on my brakes.  I weighed about 215 at the time and I was pulling a nomad trailer.  The brakes were screeching something awful but I never felt like I was unable to stop.  The stopping power between disc brakes and ordinary brakes is amazing in my experience.

This message was edited by Dan_E_Boye on 2-7-06 @ 9:08 PM
Title: Importance of Disk Brakes?
Post by: RussellSeaton on February 08, 2006, 12:39:33 pm
If you don't like the wonderful bar end shifters on the Trek 520 you can have the bike shop put on less reliable STI shifters and Travel Agent adapter.  The Trek 520 retails for $1100 so you have some budget to change the shifters and still be in your price range.  The brakes are also fine.  Old time cantilever brakes and new fangled V brakes and even older centerpull or side pull caliper brakes have served many tourists for many years.  Less complicated and more reliable than disk brakes.  You do not want complicated brakes on loaded tours.  You want simple and reliable.  Adventure Cycling had an article discussing disk brakes on touring bikes.

http://www.adventurecycling.org/resources/touring_brakes.pdf

Disk brakes overheat and warp the disk if kept on constantly.  Just like you can melt a brake pad if you keep it rubbing constantly on a descent.  Tandems do not use disk brakes for additional braking on mountain descents.  They use drum brakes.  Drum brakes are designed for drag braking.  Constant rubbing the whole way down the mountain.  Disk brakes cannot do this.  Rubber brake pads cannot do this either.  Tandems can easily weigh 400 pounds so they test brakes very well.  Even disk brakes in your car are not designed for constant braking all the way down a mountain.

If you are overheating the brakes or rims on descents, you are using poor braking technique.  The best way to brake on a mountain descent is to sit up and catch all the wind you can.  Let the bike coast up to a high speed or until you are close to a sharp turn.  Then apply the brakes HARD, VERY HARD.  Come to a stop.  Then let the bike coast up to speed again until you have to brake again.  This will take a bit of distance and time.  The brakes and rims will cool down just fine in this time and be ready to go when you need them again.  Do not keep the brakes rubbing constantly.  You can get away with this poor braking technique on short hills, not miles long mountains.  I know a tandem that rode Bicycle Tour of Colorado using caliper brakes only.  No drum brake.  They made it just fine but they are very experienced riders.

Not sure why the stock wheels on the Trek 520 would not be fine.  They have Shimano LX hubs with 36 spokes and Trek brand rims.  My stock 1991 Trek 520 wheels with Shimano DX hubs and 36 spokes and Trek brand Matrix rims are still in use today after many thousands of loaded tour miles and many more thousands of non loaded miles.  Never broke a spoke on these wheels.  I did break the entire front wheel in an "accident".  The wheels climbed and descended the Dolomites, Alps, and Rockies.  But then me, bike, panniers are only about 270 pounds.

Title: Importance of Disk Brakes?
Post by: scott.laughlin on February 08, 2006, 05:11:49 pm
CoMotion used to build a half bike using tendem components.  If it's still available it might fit accept a drag brake.  That certainly solved our overheating problem on a tamdem with twice the weight you mentioned.  

Title: Importance of Disk Brakes?
Post by: dknapp on February 08, 2006, 05:25:36 pm
Thanks very much for the info.  For sure I am new at this stuff and have never even read anything on the techniques to be used for those specialized locations like, gulp, big downhills (why is everyone worried about going up, that is the less dangerous part).  Thanks also to the person who posted the brake pad review web site. Now, if I could only find about a half a dozen different bikes that folks have suggested and ride each one for a week or so to try them out....

Title: Importance of Disk Brakes?
Post by: cyclesafe on February 08, 2006, 09:01:24 pm
Russell, what happens if you're up to a high speed or about to enter a curve and you can't slow down, much less stop?  You crash, that's what.

Modern STI shifters and mechanical (not hydraulic) disk brakes are plenty reliable for touring.  I stand corrected that the TREK 520 wheels have indeed been improved for 2006, but its msrp has been increased to $1239.99.  The 520 is probably equivalent to the T800 except for the latter's 105 STI shifters.    

Title: Importance of Disk Brakes?
Post by: biker_james on February 09, 2006, 08:23:52 am
My wife and I ride Cannondale T800's and have found them to be great bikes. I think the "unreliability" of STI shifters is a bit out of date-maybe the first one's were, but not now. Our bikes came with Tiagra shifters, which we used for over 5 years, but we did decide to replace them this year (basically since we got a good deal on Ultegra's). They were not shifting as crisp, and skipping the odd shift, but certainly not crippling our riding.
Brakes-our came with V-brakes and travel agents, which has turned out to be a very simple and easy to use system. But, all things being equal, I would probably take cable actuated disc brakes over the V brakes. Down steep hills loaded, especially in the rain, it would be nice to have a little more stopping power, and require less hand force to get it. I wouldn't be worried about maintenance, as they are still relatively simple. On a touring bike it seems that they would be nearly indestructable-hidden behind panniers from any harm. My worst wipe-out when loaded, I noticed that the panniers were a little scuffed, as were the end of the handlebars-nothing else on the bike even touched the pavement. Wish I had been so lucky.

Title: Importance of Disk Brakes?
Post by: RussellSeaton on February 09, 2006, 05:00:21 pm
"Russell, what happens if you're up to a high speed or about to enter a curve and you can't slow down, much less stop?  You crash, that's what."


Proper descending technique never gets you to high speeds you cannot stop from.  Think of driving a car in winter or rain.  Prudent drivers go slower than normal because they know the road is slick.  They stay off the accelerator so they never go too fast.  Same with descending a mountain.  Maybe 20 mph is as high as you can safely go.  When you get to 20 mph, put on the brakes hard and come to an almost complete stop.  Then let the bike coast back up to 20 mph and repeat.  Don't let your speed get too high in the first place.  "An ounce of prevention is worth more than a pound of cure."

I've been on a few brevets where STI shifters failed.  They worked fine until they stopped working.  They are probably reliable enough I suppose.  If they came on a bike, I probably would not replace them.  If they did not come on a bike, I probably would not get them.  I'm fairly indifferent to STI.

As for disk brakes, I see no benefit to them for road touring.  Old style cantilever brakes or new V brakes work well.  They do slow you down and they do stop you.  Even in the rain.  I descended Red Mountain pass from Ouray to Silverton in the rain.  I have more than a few miles of mountain descents as confirmation they are up to the task of slowing me down and stopping me.

Title: Importance of Disk Brakes?
Post by: dknapp on February 09, 2006, 05:23:42 pm
I spoke to my wife about what her experience was in last year's Bike Virginia, which was pretty much all hills/mountains.  The organizer's instructions to the riders was to alternate front and rear usage so that each brake could have a chance to cool a bit before use.  Of course, only the rider would know what technique was used, but it is good to know that there are alternatives to what I had planned, which was to pretty much just drag evenly over the whole distance.

As for the drum brakes, those went out on cars for several very good reasons and I really cannot see them as an improvement over disks on bikes, at least if the disks are well designed.  Once drums heat up it seems to me that they would stay heated longer due to their larger mass, would be harder to maintain than disks, and add more weight to the wheel and bike, which, when you are already humping a 'bent uphill is not something you need.

I am leaning to the T800/T2000, but have not yet found one to look at.  The person with the T800 never responded to my e-mail, and I would have had to pay shipping across the U.S.

After short trips on two different tandem recumbents, the whole concept of hitching yourself to a stoker is not very appealing either, but that is a different thread. :)