Weight Weenies

please , do not discuss here " i love rim brakes" , "i love disc"

not my intention

who gone with a disc frame ?

in cross or road , both.

tips, problems, issues, pics ....

please, fellas, let's do a good thread

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I run discs on my CX frame. They are just Avid BB5s though which aren't anything exceptional. I think that disc is nice for everyday use but they are a work in progress. . Like mountain riders, us roadies need to be able to one finger brake, and the BB5s definitely cant do that. I haven't tried any of the new hydraulic options and I won't buy any until Hope makes a hydraulic road setup. They are the only hydraulic discs that I trust offroad and I would like to maintain that when I'm riding on pavement, and especially during cross season.

All in all, road disc is still in its infancy. I would give it a couple more seasons, simply so more manufacturers can have time to do some real R&D. I have a feeling the next couple years will prove to be monumental for hydraulic road disc designs.

please, can you explain ( although you have a cross bike ) a real road use of mech Avid ?

issues ? quality ?

I have them on my commuter bike (BMC Alpenchallenge).

Pro:
- no cable adjustments needed (hydraulic)
- Maintenance free. During rainy autumn/spring weeks with a lot of dirt on the road I could wear out my V-brakes pads in one week. With the disk brakes, I managed 4000 km's before wearing out my pads
- Far better stopping power in wet conditions

Contra:
- there always seems to be a slight noise-rubbing, certainly on wet/dirty roads
- Very sensitive to wheel alignment. Wouldn't be the first time after a puncture that I have to re-insert the wheel a few times before it spins freely.

Would I put them on my racing rig ? Yes, but only on my bad weather one. The advantages in dry weather, certainly in the region where I live in, are almost non-existent. I only see benefits on wet roads.

I have Avid BB7 on my Boardman CX Pro. Actually, I think they work surprisingly well. Powerful with ok modulation. I would like to try a set of hydro brakes, though.
Upside is that I can use my 29" enve XC wheels on the CX bike.

I have bb7s on my daily commuter (Habanero ti frame, whisky 7 fork) which I also use sometimes for CX. I am very happy with them. I find that they don't slam me to a halt with one finger like they do on my mountain bikes, but the power, modulation, wet-weather performance, and pad life are fantastic. I will definitely be getting a disc frame for my next road bike (especially with carbon braking surfaces). I would be interested in trying hydros too, though can't complain about the performance of the bb7s.

The main downsides I see are weight, limited hub (or wheel) and lacing options, trickier to mount fenders (in general). Hydros prob make the weight less of a difference. I find on the whole that I need to adjust these less (for wear) than mini-v or cantis that came before.

After a winter on (road) BB7 and Avid Shorty 6s, the WW calipers on carbon tubs feel sketchy. No full disc road bike for me though.

Currently have a Gen 2 Volagi Liscio, and had another couple of road disc bikes before that.

I'm no racer, but they are netter for my riding, esp when it rains.

-Robin- wrote:Contra:
- there always seems to be a slight noise-rubbing, certainly on wet/dirty roads
- Very sensitive to wheel alignment. Wouldn't be the first time after a puncture that I have to re-insert the wheel a few times before it spins freely.

I hope this is in the spirit of the thread - not meant to be critical, just curious.

I rented a cross bike with discs last winter and rode a bit on the pavement in Death Valley area of California. It was kind of dusty in that area, but not "dirty" and I didn't ride on trails or gravel roads.

I had kind of chronic, quiet rubbing/rasping/scraping sound coming from the brakes. Quiet - more like a hiss, but definitely audible. The wheels were spinning freely, so I don't think they were adjusted too close. I'd never used disc brakes before so I really didn't know how to adjust this sound out of them. I figured out how to adjust them, yes, but it seemed to me that at reasonable clearance/brake throw, this sound would pop up regularly. I found that I could get rid of it temporarily by just hitting the brakes. I figured that the sound was made by dust between the pads and the disc, and braking cleaned them temporarily.

Like I said this was a quiet sound, but noticeable and kind of bugged me. Is this just the way it is with discs? I would imagine that this sort of thing would be meaningless on a trail - lost in the background noise. But I wonder if it's just something that one would have to accept because of one's preference for disc performance on roads?

Disc rub is The bane of discs, until they figure out a way to fully retract pads far enough away from the rotor and still have minimal lever throw when pulling them, people will be irritated no end. Its acceptable on mtbs because of the background trail noise but on the road......

Mind you the new TRP cable disc brake sounds promising in that both pads retract from the rotor unlike the current cable 'gold std' Avid Bb7...... so I guess this drawback will eventually be overcome.

corky wrote:Disc rub is The bane of discs, until they figure out a way to fully retract pads far enough away from the rotor and still have minimal lever throw when pulling them, people will be irritated no end. Its acceptable on mtbs because of the background trail noise but on the road......

Mind you the new TRP cable disc brake sounds promising in that both pads retract from the rotor unlike the current cable 'gold std' Avid Bb7...... so I guess this drawback will eventually be overcome.

I love discs, but I'm open-minded enough to know that Shimano, Avid, SRAM, etc have to listen to complaints like this so they can improve their products.

corky has a good point. A lot of disc brakes don't have alot of adjustability so that you can put the pads far away from the rotor. On my old road bike with caliper brakes, I actually like my brake pads kinda far away from the rim so I don't get brake rub when the rim is slightly out of true. On disc brakes, the rotor doesn't really go out of true unless you bang it against something. So, your rotor tends to be pretty dang straight. Soooo, it really doesn't matter as much to have the disc brake pads really far out from the rotor on disc brake systems. However, there is a ton of fiddling around on discs to get the brake pads adjusted just right.

While I am a huge proponent of disc brakes on road bikes, I think corky has a great point. Manufacturers need to do better on the mechanical disc systems so that people like myself can put their brake pads further out from the rotor, but still have the ability to only squeeze the brake lever a little bit to get the brake pads to hit the rotor.

BTW. I still love discs!

I want to like disc brakes, the idea sounds good, and looks good on paper, it works on cars, and motorcycles. Interestingly, this tech hasn't gone through the rigorous testing of the pro riders like electronic shifting. So it will take few years, and tons of patents from the 3 major component players before the dust settles.

I dunno. I have never had chronic disc rubbing / noise issues in the road. Every now and then (every other ride or so) it might happen that something gets stuck in there or the pads don't fully retract, in which case there is scraping sound but hitting the brakes fixes it. I will say that I don't run the pads super close, though. Agree that it'd be nice to have disc setup that can engage with less lever throw, but I don't run out of throw before calipers are fully clenched.

metanoize wrote:I want to like disc brakes, the idea sounds good, and looks good on paper, it works on cars, and motorcycles. Interestingly, this tech hasn't gone through the rigorous testing of the pro riders like electronic shifting. So it will take few years, and tons of patents from the 3 major component players before the dust settles.

Disc brakes have been used in mtb pro cycling for many years. Sure there will be tweaks in the technology for road setup, but the basics are certainly more established tech than electronic drivetrains.

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I have discs on my CX bike and think they're great for that application, and of course for MTB.

For road, though, I really don't see the point. I find even the crappy Red brakes on my race bike to be more than powerful enough, and DA brakes are 1-finger stoppie powerful. Maybe I have strong hands, but really, discs on a road bike seem like a solution to a problem that doesn't exist. Front wheels won't be able to be radially laced with discs, and I'm not sure rims can get much lighter than the new light carbon tubulars by forgoing the brake track. Getting them lighter than rim brakes seems unlikely, and in the world of people who replace the bolts on their garmin mounts with Ti to save .6g, 50g will be prohibitive.

Unless you ride in the rain often, I just can't see the advantage.