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Disc brakes on road bikes...

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Apr 8, 2012
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Just a reminder; I'm only 500 or so miles south of you so we're pretty much riding in the same weather. Consider different rotors. These new RT-900 by design are going to louder in the wet than most. But they shouldn't be as bad as you describe if broken in right. Even the RT-99 are much quieter. I've been using Sram/Avid Centerline X since they were released a few years ago. I can make them squak, but only in the wet on technical singletrack under very hard breaking. Otherwise completely silent in all-weather on the road, probably the quietest rotors I've ever used. In the Summer months I actually switch to Ashima ARO-8 rotors.
 
Jun 30, 2012
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Excellent point about the rotors. Any noise is likely exacerbated by the big resonating heat-sink fins in the Shimano rotors. I have some others on the spare wheels I might try.

I cleaned the pads on a flat whetstone. They were certainly black and grungy, but a couple of seconds of light rubbing brought back the sparkle. But the dirt didn't seem ingrained at all. I also noticed on one pad a noticeable scoring line, as if maybe a small rock had been lodged in the discs in one of the slots (ironically designed to assist with self cleaning). No sign of the rock now, but maybe it kind of clogged everything up somehow.
 
Jun 30, 2012
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So, here's an update.

Cleaned pads, and replaced the rotor with a different model. Still a Shimano with an alloy carrier, but without the fins and laminated structure of the Dura-ace version. I cleaned the rotor with isopropyl alcohol. I bedded in the brakes as suggested, with a dozen short sharp stops at the start of my ride. The performance increased noticeably over the first 4 or 5 stops, and by the end of 12 stops it was excellent and seemingly as good as it was going to get.

The ride in to work was fairly dry and no issues at all. A bit of rain on the way home and wet roads meant a bit of noise returned on initial application of the wet brakes, but nothing that would really be bothersome.

The ride in this morning was properly wet, with water running across the road in many spots, and at times heavy rain. Observations:

1) The new rotors collect MUCH less muck from the roads, and the issue of debris snagging and rubbing on the rotors is essentially eliminated. It's gone from near-constant to only-occasional. This is a huge win. It was driving me nuts. I think the big fins on the DA rotors were collecting muck and flinging it onto the braking surface or direct into the calipers. The brakes had no chance of self clearing. It's now much better. Note to self: Save the finned rotors for the summer.

2) The squealing in the wet has been reduced, but not eliminated. Eventually, by the time I was in town, the stops were getting pretty noisy. Earlier in the ride the noise was less prevalent and would stop after a second or two as the brakes presumably warmed up and dried out. But by the end, they were fully saturated and consistently noisy (I don't have any "hard" stops in the second half of my commute to get them warm).

3) The brakes continue to work well, but the initial bite in the wet is still a bit lacking compared to my expectations. Don't get me wrong, they do stop well.
 
Apr 8, 2012
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If you only cleaned the rotors with alcohol and didn't use the sandpaper first like I instructed then you didn't pull off a true bedding in process. The whole point of this is to start with fresh pads and rotors to 'bed in' pad material into the surface of the rotors before you start wet riding. Glad you see a difference with the rotor swap, but you're always going to squck in the wet if you don't bed in properly from the beginning. Meanwhile, I rode this weekend in the wet, not a single chirp from my brakes. ...How that be, winky?
 
Jun 30, 2012
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The rotors were new. They supply them out of the box unsuitable for use? (They do with motorcycle tyres, so I'd not be surprised).

I'd also be interested in why my very first few rides, a month ago, which were with brand new pads and rotors, and were in the dry, didn't result in the transfer of the necessary material to the rotors.
 
Apr 8, 2012
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Yeah, new is good. Well, I'm gonna throw my hands up about your incessant squealing in the wet. It's more apt to happen in wet riding but not that much. Maybe try Sram Centerline X like what I ride. The silence is deafening!
 
Jun 30, 2012
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Yep, I'll try different rotors, for sure. That 1/2 my annoyance is gone is a good start. Thanks for all the advice.
 
Apr 20, 2009
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Try backing off the tension on your through axles. Over tightening can create some interesting and unexpected results. They can generate a lot more force than a QR, so play with that. They are not going fall out. Nice pics though... gotta love a quality Ti setup. BTW, Is that the Nanaimo ferry?
 
I just skimmed through the issues here so I'm sure I missed plenty, but noisy disc brakes are usually from vibration, and wet makes it worse so its a balance of alignment.

EDIT: I took a few things off of my post after reading a bit more.

Thisthread is from last fall so hopefully winky got it figured out!
 
Re:

VeloFidelis said:
Try backing off the tension on your through axles. Over tightening can create some interesting and unexpected results. They can generate a lot more force than a QR, so play with that. They are not going fall out. Nice pics though... gotta love a quality Ti setup. BTW, Is that the Nanaimo ferry?
That seems like it would lead to more noise to me. I certainly haven't seen every dropout, but the setups that I am familiar with have a "mechanical stop": The axle caps stop against the inside face of the dropout, and the skewer stops against the outside. Sure you can stand on it or get a big cheater bar to really torque it, but by hand, I don't think that you can over tighten them. Besides, the rotor is mounted to the hub either via centerlock or six bolt, its not mounted to the axle so even if you crush the axle caps, the rotors should be unaffected. On the other hand, if the skewer is slightly loose, the hub/rotor might move slightly.

EDIT: This thread popped into my head on my way home from the trail head so I tried a little experiment. My brakes don't make any squeals. I loosened the skewer/axle (Fox fork/Fox axle) about 15 mm...not very much. I got up to about 20 mph and then grabbed a hand full of lever and the brakes squealed. So at least in my application backing the axle tension off wasn't good.
 
Re:

King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
When I read that yesterday I had two thoughts going through my head: how did his (right) leg get to the rear rotor, and what else could cause that gash? In the comments someone blamed the through axle, but unless its some crazy thing I've never seen, I can't see that causing a gash like that. Its U23 so a video might be hard to find.
 
Re:

King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
The obvious comment is that the pros arent likely to be riding sub 2k bikes....average punters are, and so far there is little or no evidence of which I am aware of discs causing injuries among the general populace.

For the pros, different story. Both high profile cases involves crashes with other riders. Crashes for pros are a daily occupational hazard with, I believe, most riders crashing about 3 times in every GT.

I have to say that this latest incident sounds compelling.
 
Re: Re:

jmdirt said:
King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
When I read that yesterday I had two thoughts going through my head: how did his (right) leg get to the rear rotor, and what else could cause that gash? In the comments someone blamed the through axle, but unless its some crazy thing I've never seen, I can't see that causing a gash like that. Its U23 so a video might be hard to find.
I don't understand why your first question came up, his right leg below the knee is the most likely part of him to come into contact with the rear rotor. Of course he'd have to be very close and I would have thought that to get a cut like that his leg would also have had to touch the spokes (which makes you question whether both riders would stay upright) and there doesn't appear to be any other injury, but in terms of possibility this type of injury it a lot more likely than the others blamed on discs.

What else could cause it? I'm drawing a blank on that if it happened as described.
 
Re: Re:

macbindle said:
King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
The obvious comment is that the pros arent likely to be riding sub 2k bikes....average punters are, and so far there is little or no evidence of which I am aware of discs causing injuries among the general populace.

For the pros, different story. Both high profile cases involves crashes with other riders. Crashes for pros are a daily occupational hazard with, I believe, most riders crashing about 3 times in every GT.

I have to say that this latest incident sounds compelling.
The two things weren't meant to be connected.

I haven't seen any evidence of discs causing injuries where the person/someone wasn't at fault for general riding. There have been a few crashes in my club with discs involved and I've not been told of any disc-related injuries either and nothing seems to have popped up in local racing so far.
 
Remember, the WT pros are riding in groups and racing nearly 365 days of the year. Amateur club riders dont get anywhere near that. I'd guess that I am probably in the top 5% of cyclists nationally when it comes to mileage, but I haven't ridden in a group since may 18th. The pros are doing it all the time, so the opportunities for a disc related incident seem higher to me.

Even so, if you took every rider crash from every WT race (or training) and consider that there have only been 2 high profile cases, it seems so staggeringly rare as to deserve being classed as a freak accident.

Whenever I've crashed, I've always cracked my nuts on the stem, but I dont see any calls for stems to be banned :D
 
Jun 3, 2019
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Just bought a city commuter and it has disc brakes. First bike I have ever owned that has disc. It seems good to me.
Is it cheaper to make disc than the calipers?
 
Re:

nevele neves said:
Just bought a city commuter and it has disc brakes. First bike I have ever owned that has disc. It seems good to me.
Is it cheaper to make disc than the calipers?
Very unlikely it's cheaper, but it's economies of scale so there will no doubt be a tipping point. I wouldn't be surprised if we see lower end (Sora, Tiagra, 105 type level) caliper brakes drop out of production within the next 10 years or so. The really cheap ones might stick around for a while.
 
Jun 3, 2019
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Re: Re:

King Boonen said:
nevele neves said:
Just bought a city commuter and it has disc brakes. First bike I have ever owned that has disc. It seems good to me.
Is it cheaper to make disc than the calipers?
Very unlikely it's cheaper, but it's economies of scale so there will no doubt be a tipping point. I wouldn't be surprised if we see lower end (Sora, Tiagra, 105 type level) caliper brakes drop out of production within the next 10 years or so. The really cheap ones might stick around for a while.
But there is a ton of lower end cycles being produced that have the disc's. Maybe they have the price down so far that it does not really make a difference to the bottom line profit.
 
Re: Re:

nevele neves said:
King Boonen said:
nevele neves said:
Just bought a city commuter and it has disc brakes. First bike I have ever owned that has disc. It seems good to me.
Is it cheaper to make disc than the calipers?
Very unlikely it's cheaper, but it's economies of scale so there will no doubt be a tipping point. I wouldn't be surprised if we see lower end (Sora, Tiagra, 105 type level) caliper brakes drop out of production within the next 10 years or so. The really cheap ones might stick around for a while.
But there is a ton of lower end cycles being produced that have the disc's. Maybe they have the price down so far that it does not really make a difference to the bottom line profit.
The cheapest of the cheap bikes are still rim brake. Even if we ignore those I think it's still likely cheaper to produce and equip rim brakes. As market saturation of discs at the "proper bike" low end becomes a reality it will shift, I just don't think it's there yet.
 
Re:

King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
Just bought the below for my 8 year old grand daughter...with Tektro wet discs..so yup, gonna be on bikes, most all, soon, for good or ill...GREAT bike, BTW...

https://www.clearybikes.com/products/meerkat-24-5-speed
 
Jun 3, 2019
237
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Re: Re:

Bustedknuckle said:
King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
Just bought the below for my 8 year old grand daughter...with Tektro wet discs..so yup, gonna be on bikes, most all, soon, for good or ill...GREAT bike, BTW...

https://www.clearybikes.com/products/meerkat-24-5-speed
Nice bike for a 8 year old.
Yes it does seem that all bikes are going to have a disc brake setup.
 
Re: Re:

Bustedknuckle said:
King Boonen said:
And the disc brake debate rumbles on:

http://www.cyclingnews.com/news/disc-brake-said-to-be-cause-of-serious-injury-at-paris-roubaix-espoirs/

With Shimano releasing Tiagra level hydraulic disc brakes I think that we are slowly getting to the point where rim brakes are going to disappear from lower end bikes. They may remain for higher end bikes, but with bulk frame production I can't see many brands persevering with rim brakes on sub 2k bikes for much longer.
Just bought the below for my 8 year old grand daughter...with Tektro wet discs..so yup, gonna be on bikes, most all, soon, for good or ill...GREAT bike, BTW...

https://www.clearybikes.com/products/meerkat-24-5-speed
Nice little bike! Interesting that they only make bikes for kids.
 

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