Bike Gremlin

Talking about FLAT land commuting here.

matimeo

All I know is that after 1.5 winters in Portland the rims are almost a gonner and I've gone through almost two sets of brake pads.

A little concerned about the 130mm spacing on the rear hub. I didn't even realize that wasn't standard for rear disc wheels. As for switching to Sram shifters, I can't imagine I won't be able to adjust. A good friend uses them and likes them, and I actually prefer the ergonomics to Shimano. Not really willing to pay 300 more for Ultegra.

Route 66

If you had asked me a month ago about talking you out of getting a bike with disc brakes, I would have given it a shot because my new bike with disc brakes was squealing like a greased pig every time I tried to stop. I pulled the pads and sanded them and did the same with the discs themselves. None of that worked and I was having a serious case of buyers remorse. Then I thought I give THIS stuff a try, and it totally took care of my problem. I'm at the point now where I'm as please as can be with my disc brakes and I'm so glad I have them on my new bike.

TGT1

you got my curiosity up so I got the calipers out and measured the face to face rear dropout dimension on mine.

It's 130mm., but I could spring it out to 135 with nothing more than fairly light hand pressure.

dynaryder

I had an earlier model of that bike. Was my fav until it got stolen. Wish they still sold just frames so I could have another one and get rid of some of the parts in my bins.

Not sure what the rear spacing on mine was,I thought it was 132.5. I did have to spread the rear dropouts a bit to get the (aftermarket,135)wheel in,but it was no big deal. The stock wheels aren't crap,so I wouldn't even sweat this. Plus,discs are starting to become more popular on road bikes,so 130mm disc hubs and wheels may become more commonplace.

Just curious,did you check? Did you feel the brake tracks to see if they were concave,or check the rim with calipers? You can't always tell just by looking at them.

Do you clean and lube your rim brake calipers? They need it to. I run a free bike clinic and have wrenched well over 1k bikes. Pretty much every week I see a bike with rim brakes,usually V's,that has an issue with dragging because gunk has gotten into the arm pivots and slows the arm from fully retracting. BTW,I also see people with rim brakes all the time that have issues with noise;squeaky brakes aren't just limited to discs.

I switched to discs after my V brakes packed up with snow and I glanced off the side of a car. Never had an issue with discs,even riding through blizzards and freezing rain. My pads also last longer,I have to adjust the brakes less frequently,and I don't have to worry about the rims being perfectly true.

Bike Gremlin

The wheels had grooves like a wear indicator. No difference between the front (used for 99% of braking) and the rear. No wear I could tell.

I clean brakes about once a year.

About disc brakes: I would NEVER bother with hydraulics. Do mechanical ones work OK? And how do calipers stand to salt? I've repaired, and seen corroded beyond repair, numerous motorcycle brake caliper pistons, due to winter riding. Red rubber grease helps a bit (What is Red Rubber Grease, such as Castrol and Girling, why and how it is used for hydraulic brakes, clutch and suspension lubrication. Technical information and selected applications.), but it's a bother to apply, then clean, then reapply... Guess mechanical don't have those problems?

Bike Gremlin

Some flaws of discs (the rest is all pro - better in the snow etc...):

Disc brake assemblies are heavier than rim brakes, and are generally more expensive.
Disc brakes require a hub built to accept the disc. Front hubs designed for discs often move the left hub's flange inward to make room for the disc, which causes the wheel to be dished. A dished wheel is laterally weaker when forced to the non-disc side. Other hubs use conventional flange spacing and provide a wheel without dish, but require a less common wide-spaced fork.
A rim brake works directly on the rim and the attached tyre; a disc brake applies a potentially large torque moment at the hub. The latter has two main disadvantages:

1. The torque moment must be transmitted to the tyre through the wheel components: flanges, spokes, nipples, and rim spoke bed. Engineering for this moment inevitably leads to a heavier wheel.
2. A front disc brake places a bending moment on the fork between the caliper anchor points and the tip of the dropout. In order to counter this moment and to support the anchor points and weight of the caliper, the fork must be thicker and heavier.[SUP][28][/SUP]

The heavier fork and wheels compound the weight disadvantage of the brake assembly itself.
Disc brakes are sensitive to lateral play or "slop", so careful manufacture and adjustment is required. Hub bearing wear is an issue with disc brakes.

Since about 2003, riders have reported a dangerous problem using disc brakes: under hard braking, the front wheel comes out from the dropouts. The problem occurs where the brake pads and dropouts are aligned so the brake reaction force tends to eject the wheel from the dropout. Under repeated hard braking, the axle moves in the dropout in a way that unscrews the quick release. Riders should make sure the skewers are properly tightened before riding.[SUP][30][/SUP][SUP][31][/SUP] Forks that use different brake/dropout orientations or through-axles are not subject to this problem.

spare_wheel

I find hydraulics to be more reliable and less trouble to maintain than any other brake.

spare_wheel

That wikipedia quote reads like steel is real anti-carbon fiber propaganda. Hilarious.

All of the so-called problems brought up were mitigated ages ago (disc-specific forks, lawyer tabs, disc wheels have less rotational mass with no dish problems). Hydraulic disc brakes are the de facto standard for mtbs due to their merits. And it's just a matter of time before hydraulics are the default for road bikes.

alan s 

Hydraulic discs are the best. Low maintenance (replacing pads takes 5 minutes), no adjustment required and the stopping power is unparalleled. When BD comes out with a Ti commuter-worthy drop bar bike with hydraulics, I'll be first in line.

alan s 

That was so last decade. Even then, it was an exaggeration.

Bike Gremlin

That is good to know.

For me the V-brakes do the job still. Both cheaper and lighter. And no need to change oil, bleed brakes. I'm fed up with that on the motorcycle. Not too much trouble, but still - I prefer good old cables. If this commuter doesn't get stolen soon, I'll see how long my rims will last. My guess is 5 years minimum. Them being like 10 to 15 euros for the whole wheel (rim alone costing about half the price).

winston63 

+1

I was pretty suspicious of disk brakes, but I love the stopping power, particularly in wet conditions.

Just thought I'd note that I don't have any problems with SRAM double tap. I'm running SRAM Apex on my touring bike and Shimano 105s on my cross but I have no problems making the mental switch when I change bikes. I thought that would give me fits, but it turns out that it's not a big deal at all for me. YMMV of course!

matimeo

Currently I run 105 on my winter bike and Nashbar Microshift on my fair-weather bike. They have different mechanisms for shifting and I don't even have to think when I shift between the two bikes. I'm optimistically hoping that the switch would be no problem, but I should probably ride on some Sram just to make sure.

Still not for sure on the titanium frame. I like the idea, but BD has some aluminum frames with equally nice components or better for less money. There's something alluring about the titanium though...

Really the bottom line is I want a cross bike with disc brakes, so I don't have a lot of options in my price range (read, Bikesdirect). I also really am only considering aluminum or titanium since longevity in a very wet climate (with minimal maintenance) is desired.

winston63 

For me, the biggest difference is in the feel of the shifting. Shimano is very smooth, takes only a light touch to shift. At least on my bike, the SRAM shifting is a bit stiffer, but with an incredibly crisp and precise feel. There's a very solid "click" when gearing up or down and it's quite different than the smooth feel of the 105s.

I don't actually have a preference though - when I ride the Kona I marvel at the smoothness of the 105s, when I ride the AWOL I marvel at how crisp the shifting is - I kind of like both!

spare_wheel

Absolutely agree that V-brakes or even road brakes are a good option if weather and rim wear are not an issue. (The rims on my dry weather road bike last forever!) However, many disc brakes use mineral oil which does not degrade like DOT oil and can be run without being bled for a very, very long time in an un-compromised system. I personally have gone about 6 years without a bleed and would have gone longer if I had not found some shimano 775s for $50 online.

alathIN

Matimeo, I have been looking at a Salsa Vaya II but now you've got me looking at this bike as a possible alternative.
Just one reservation - what about brazeons? I do not see a lot of options for mounting a rear rack or other commuter/tourer gear (maybe it's just my crappy screen at work?)

TGT1

It has rear rack and fender brazeons.
The top rear brazeons came plugged with Ti bolts even.
Bottom ones on the dropouts are threaded


One of the reasons I bought one.

The Ti and CF road bikes don't have any.

No rack on it now, but I wanted something I could put one on for touring if I ever decided to do that.

dynaryder

Bike hydos are different than motorcycle hydros. As spare_wheel said,many are mineral oil which doesn't absorb water like DOT. Also,bike systems don't have the large(comparatively speaking) reservoirs that motos have,so there's less chance for air and water to get into the system. Many bike shops hang bikes with hydros upside-down from the ceiling;you would never do that with a motorcycle.

My Safari has been through every winter since I got it in '06. Zero issues.

Blah,blah,dishing,weight,oh my! All the MTBers beating their bikes up on trails with dished wheels,yet somehow they don't fall apart after every ride. And while I prefer a lighter bike,you're talking less than a pound difference between a disc and non-disc bike. Most of which is in places where it's not going to be an issue.

Sorry,but everything you posted there is nitpicking,and pretty much non-issue in the real world.

That crap needs to die out. Seriously,I've never had any issues with QR's on the front of my disc bikes. I have had many bikes come into my clinic with loose QR's because people not using them properly is a common issue.

You know what has happened though? Once forgot to reconnect the front brake on a V equipped bike after installing the wheel. Caught it before I went more than a couple feet,but this is impossible to do with a disc bike. Also have never had to loosen the brakes on a disc bike to get them open.

Do it! Rides much better than aluminum,completely impervious to corrosion,and won't get scratched no matter what you lock it to.

Bike Gremlin

So mechanical or hydraulc - which are more salt corrosion resistant? Less expensive to maintain?

dynaryder

For corrosion resistance,I'd say about even. Mechs have cables that need attention,hydros have seals. As for cost to maintain,I'd say also about even. You'll wind up replacing cables about as often as you'll need to bleed hydros and maybe replace the seals. Hydros may be a touch more,but then you don't have to adjust for pad/cable wear,so what's your time worth?

wolfchild

I've used both and they all needed maintenance when use a everyday on roads with a lot of salt. The best preventative maintenance that you can do is to rinse all the salt out regularly every few days...Hydros are more powerful then BB7's...Mechanicals also require frequent pad adjustments, hydros are self adjusting...

matimeo

I ordered the bike today when I saw last night that they had 61cm size in stock. I never thought I'd spend that much on a bike, but I didn't want to go down in quality and I couldn't stomach the thought of buying a lesser bike for the same money at the bike shop. It has what I want at a great deal. Just hoping I don't have trouble finding replacement wheels in the future (due to the 130mm rear spacing). Looking forward to disc brakes through this winter. I'll only have to ride it every day for 5 years or so before it pays for itself.

Thanks for talking me into everyone!

matimeo

TGT1- Does it look like a traditional rack will fit around the disc brakes or would it take a disc-specific model?

TGT1

It looks like you'd have to put some kind of spacer on the left side if the rack is less than 24" from frame mounting bolts (seat tube end) to where the struts attach to the rack.

That's pretty long and makes for a structurally unsound angle on the strut. I don't think I've ever seen a rack like that.

It will need a disc specific model or some customization.

I have access to TIG and tube bending equipment so I'm not worried about it when the time comes to throw a rack on.
I might even invest in some Ti tubing and go the full monte when the time comes to do it. :-)