Colnago C59 disc brake

Discuss light weight issues concerning road bikes & parts.
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JKolmo
Posts: 384
Joined: Sat Feb 10, 2007 2:00 pm

by JKolmo

...and when thinking of it: For pro applications, what excuse can now be used when needing to rest your legs leaning against the service vehicle while the team mechanic performs the oh so important but time consuming brake adjustment?

RollingGoat
Shop Wrench
Posts: 284
Joined: Thu Feb 26, 2009 1:18 am
Location: Boston

by RollingGoat

bikewithnoname wrote:I just want someone to buy one, ride it (preferably in an alpine environment) and let us know how it goes. It could be the best thing that's happened to road bikes since the STI/Ergopower, or it might be entirely pointless :noidea:

Until someone gets inot the saddle it's all really just conjecture


How about the guy who owns this bike (quote taken from VelocipedeSalon): http://www.velocipedesalon.com/forum/f1 ... 23769.html
Tristan wrote:it rides like a road bike which fits me. I'd previously used a Salsa La Cruz but struggled to get the bars low enough and the long wheelbase always felt a bit lethargic on the road. The IF rides like a gentleman's road bike with great manors - given that this wasn't a race bike I asked for the feel to be slightly more stable and reassuring and Jesse nailed it.

Personally, it's great to see disc brakes finally making the limelight for CX and road use. There is still development to be done to make them more road-specific, but the BB-7s work fantastically well. Think full breaking power in pouring rain by using one finger, from the hoods. On a training ride the other night I rode away from a National Champion mtber on a 10% descent in the pissing rain - I thought I was taking it really easy and when we talked about it at the bottom Stu said he was on the limit and had a few moments trying to keep up. I've ridden with this guy hundreds of times in all weather conditions - the only difference this time was the discs. The primary use for this bike is wet-weather commuting so the discs were a shoe-in, although the bike does have mounts for long-reach callipers so I ever become a Luddite.


He also says elsewhere that the total weight gain from disks was 459 grams, using BB7s, DT 240 hubs, a wound up fork, and on a steel frame.
I'm so rubbish at this.

by Weenie


bikewithnoname
Posts: 994
Joined: Tue Sep 22, 2009 1:29 pm
Location: UK

by bikewithnoname

That is a very nice IF. :thumbup:

It doesn’t quite address my lingering doubt on discs though as it’s running cable disc brakes. My concern is specifically around the hydraulic set up, I would just like to be sure that when I head down the Galibier or the Agnel on a July afternoon that the hydraulic fluid doesn’t boil and I don’t find myself off the side of the mountain where only the Chamois should be!

That said one would assume colnago have tested the new C59 on this type of decent, at least I hope they have!
"We live in an age when unnecessary things are our only necessities." Oscar Wilde

Pegoretti Responsorium, Parlee Z5i, Donhou Commuter, 1946 MacLeans Featherweight L'Eroica!, 2x MTB 'dales

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LarsEjaas
Posts: 259
Joined: Sun Jan 21, 2007 10:52 am
Location: Aarhus, Denmark

by LarsEjaas

If you ask me, disc brakes on roadbikes are the solution to a problem that doesn't really exist.

But hey: I would like to try it anyway, maybe it would be nice to have in the rain, when riding full carbon wheels (really the only time when I really feel I would need a little more braking power).

Colnago's are as stylish as ever: Even with discs 8)

bones
Posts: 414
Joined: Sun Aug 23, 2009 10:38 am

by bones

MichaelB wrote:
The 2011 Kona Honky Inc that I ride has a road specific fork in that the A2C height is ~370mm.

There is also a disc fork made by Evo in Taiwan that can be bought from SJS Cycles in UK. There are others as well.



Are you sure about this? I called Kona last year and IIRC they said that their fork length (A2C) on the Honky was around 390+. I don't recall it being 370mm, and it isn't published on their online geometry chart. Are you sure it is 370mm? :?:

Thanks for the tip on the carbon disc road fork at SJS cycles. Unfortunately, they are currently out of stock. They said that demand has been unexpectedly high for this item and they didn't order enough of these. They also weren't aware of any other aftermarket carbon road forks w/ disc tabs.

So, it really appears to be not many choices out there for a decent carbon road fork with disc tabs.
:(

airwise
Posts: 1049
Joined: Tue Jul 27, 2010 8:31 pm

by airwise

bikewithnoname wrote:That is a very nice IF. :thumbup:

It doesn’t quite address my lingering doubt on discs though as it’s running cable disc brakes. My concern is specifically around the hydraulic set up, I would just like to be sure that when I head down the Galibier or the Agnel on a July afternoon that the hydraulic fluid doesn’t boil and I don’t find myself off the side of the mountain where only the Chamois should be!


It won't. And the latter is far more likely to happen when your tyre explodes from what I see on a regular basis.

MichaelB
Posts: 405
Joined: Tue Apr 22, 2008 4:31 am

by MichaelB

bones wrote:
MichaelB wrote:
The 2011 Kona Honky Inc that I ride has a road specific fork in that the A2C height is ~370mm.

There is also a disc fork made by Evo in Taiwan that can be bought from SJS Cycles in UK. There are others as well.



Are you sure about this? I called Kona last year and IIRC they said that their fork length (A2C) on the Honky was around 390+. I don't recall it being 370mm, and it isn't published on their online geometry chart. Are you sure it is 370mm? :?:



Hi Bones.

That is a very definite YES. The 2010 and 2012 models run the more CX based 390mm versions, but for some reason, the 2011 model (mine) came with the 370mm fork, and also had some other geometry changes to the frame such as shorter chainstay's.

The 2012 model went back to the 2010 spec.

Why ? I have no idea.

Epic-o
Posts: 621
Joined: Tue Nov 20, 2007 7:18 pm

by Epic-o

jsinclair wrote:I'm not pro-disc or anything, but anyone that thinks the aero penalty incurred is going to be even noticeable is kidding themselves. Wearing just one shoe cover would most likely more than compensate. All this aero talk is ridiculous.


Have you got any data to back up this or you are just talking without knowledge?

dereksmalls
Posts: 1975
Joined: Tue Aug 02, 2011 9:20 pm
Location: New Zealand

by dereksmalls

RollingGoatHow about the guy who owns this bike (quote taken from VelocipedeSalon): http://www.velocipedesalon.com/forum/f1 ... 23769.html" onclick="window.open(this.href);return false;
[quote="Tristan wrote:
He also says elsewhere that the total weight gain from disks was 459 grams, using BB7s, DT 240 hubs, a wound up fork, and on a steel frame.


That's Tristan from Wheelworks here in Wellington, New Zealand - awesome, awesome mechanic and amazing wheelebuilder. He knows his shit.

He actually posts on here every now and then from memory in the wheelbuilding threads.

bones
Posts: 414
Joined: Sun Aug 23, 2009 10:38 am

by bones

MichaelB wrote:
bones wrote:
MichaelB wrote:
The 2011 Kona Honky Inc that I ride has a road specific fork in that the A2C height is ~370mm.

There is also a disc fork made by Evo in Taiwan that can be bought from SJS Cycles in UK. There are others as well.



Are you sure about this? I called Kona last year and IIRC they said that their fork length (A2C) on the Honky was around 390+. I don't recall it being 370mm, and it isn't published on their online geometry chart. Are you sure it is 370mm? :?:



Hi Bones.

That is a very definite YES. The 2010 and 2012 models run the more CX based 390mm versions, but for some reason, the 2011 model (mine) came with the 370mm fork, and also had some other geometry changes to the frame such as shorter chainstay's.

The 2012 model went back to the 2010 spec.

Why ? I have no idea.




Sweet. Who makes the Kona fork? I want to get one. Are you sure the 2011 Honky Inc model is a 370mm A2C? Was that a published spec? Or measured?

jsinclair
Posts: 396
Joined: Sat Aug 27, 2011 3:26 am
Location: Sydney, Australia

by jsinclair

Epic-o wrote:
jsinclair wrote:I'm not pro-disc or anything, but anyone that thinks the aero penalty incurred is going to be even noticeable is kidding themselves. Wearing just one shoe cover would most likely more than compensate. All this aero talk is ridiculous.


Have you got any data to back up this or you are just talking without knowledge?


Only a couple of years of Aeronautical Engineering at university, which i moved out of into architecture, so no i don't have the degree.

Of course i don't have the data, but neither does anybody else which is precisely my point.

You hear someone like Phil White of Cervelo say things like "It doesn't look good" (referring to disc brakes in the tunnel) but then fail to back it up with any sort of proof. So essentially his statement is worthless hyperbole, as is basically everything else their marketing dept comes up with. Ill bet the moment they release an S6 with discs, that quote will be long forgotten, and they will be calling it the fastest frame in the world again.


By moving to discs you are able to clean up the fork crown area, and move the callipers and such down into an area that is probably pretty disturbed anyway due to the hub and spokes. So looking at just the front there is maybe a small loss in efficiency, but its too hard to tell without hard data. As for the back, the placement of the disc there would already be in such disturbed airflow that after accounting for the removal and clean up of the top of the seat stays, could even result in a small gain in aerodynamics. Now if you were to fully internalise cables with the hydraulic discs, as opposed to a conventional cabled setup, then there is a further gain to discs. So overall, with the small loss at the front, and the potentially small gain at the rear, the overall difference would likely be quite small, especially when compared to the overall drag of a pedalling human being atop a bicycle (not just the idealised bicycle).


Then take one shoe, quite outboard and in its own, probably mostly undisturbed airflow. Cover it up/smooth it out and you might make some nice cheap gains in unnoticeable-to-anything-but-a-supercomputer efficiency. Couple this with a better fitting jersey and the removal of your ponytail and moustache for added benefit.

airwise
Posts: 1049
Joined: Tue Jul 27, 2010 8:31 pm

by airwise

jsinclair wrote:
Epic-o wrote:
jsinclair wrote:I'm not pro-disc or anything, but anyone that thinks the aero penalty incurred is going to be even noticeable is kidding themselves. Wearing just one shoe cover would most likely more than compensate. All this aero talk is ridiculous.


Have you got any data to back up this or you are just talking without knowledge?


Only a couple of years of Aeronautical Engineering at university, which i moved out of into architecture, so no i don't have the degree.

Of course i don't have the data, but neither does anybody else which is precisely my point.

You hear someone like Phil White of Cervelo say things like "It doesn't look good" (referring to disc brakes in the tunnel) but then fail to back it up with any sort of proof. So essentially his statement is worthless hyperbole, as is basically everything else their marketing dept comes up with. Ill bet the moment they release an S6 with discs, that quote will be long forgotten, and they will be calling it the fastest frame in the world again.


By moving to discs you are able to clean up the fork crown area, and move the callipers and such down into an area that is probably pretty disturbed anyway due to the hub and spokes. So looking at just the front there is maybe a small loss in efficiency, but its too hard to tell without hard data. As for the back, the placement of the disc there would already be in such disturbed airflow that after accounting for the removal and clean up of the top of the seat stays, could even result in a small gain in aerodynamics. Now if you were to fully internalise cables with the hydraulic discs, as opposed to a conventional cabled setup, then there is a further gain to discs. So overall, with the small loss at the front, and the potentially small gain at the rear, the overall difference would likely be quite small, especially when compared to the overall drag of a pedalling human being atop a bicycle (not just the idealised bicycle).


Then take one shoe, quite outboard and in its own, probably mostly undisturbed airflow. Cover it up/smooth it out and you might make some nice cheap gains in unnoticeable-to-anything-but-a-supercomputer efficiency. Couple this with a better fitting jersey and the removal of your ponytail and moustache for added benefit.


:thumbup: :thumbup:

Epic-o
Posts: 621
Joined: Tue Nov 20, 2007 7:18 pm

by Epic-o

jsinclair wrote:You hear someone like Phil White of Cervelo say things like "It doesn't look good" (referring to disc brakes in the tunnel) but then fail to back it up with any sort of proof. So essentially his statement is worthless hyperbole, as is basically everything else their marketing dept comes up with. Ill bet the moment they release an S6 with discs, that quote will be long forgotten, and they will be calling it the fastest frame in the world again.


By moving to discs you are able to clean up the fork crown area, and move the callipers and such down into an area that is probably pretty disturbed anyway due to the hub and spokes. So looking at just the front there is maybe a small loss in efficiency, but its too hard to tell without hard data. As for the back, the placement of the disc there would already be in such disturbed airflow that after accounting for the removal and clean up of the top of the seat stays, could even result in a small gain in aerodynamics. Now if you were to fully internalise cables with the hydraulic discs, as opposed to a conventional cabled setup, then there is a further gain to discs. So overall, with the small loss at the front, and the potentially small gain at the rear, the overall difference would likely be quite small, especially when compared to the overall drag of a pedalling human being atop a bicycle (not just the idealised bicycle).


The marketing department can say anything but we are intelligent clients that can discern between the truth and the lie. The fastest way to mount a brake is integrating them in the chainstay and the fork crown and make them hydraulic. You can't save any drag from that setup

I don't know if Damon Rinard's claim (not Phil White) is completely true or if the drag increase is less but you can see easily that a disc brake can't be any faster, there is not cleaner setup that the one I have mentioned. A disc at the front is a similar performance loss to changing from toroidal rims to standard box rims...you change completely the flow that passes through rim's leading edge, downtube, legs, etc. Adding elements in the front end of the bike is very detrimental

jsinclair
Posts: 396
Joined: Sat Aug 27, 2011 3:26 am
Location: Sydney, Australia

by jsinclair

Totally agree with you on those points. My original issue was that even though there will undoubtedly be a net loss in efficiency, when it's view as a percentage of the total system, it's still going to be way too low for anybody to start harping on about.

I too would prefer integrated hydraulic rim brakes, but I think we both know that the likelyhood of manufacturers investing r&d into that is pretty low when they can just adopt a simple disc mounting standard and leave Shimano, avid, SRAM to deal with the mess of road brake design. Couple that with the fact that we look at things from the perspective of weight weenies, with very specific wants/needs. Manufacturers are not going to take any notice of us when choosing their business strategy for the coming years. as much as I don't like it, discs kind of make sense when you are designing for the other 95%.

dyki
Posts: 27
Joined: Mon Jul 17, 2006 10:28 pm
Location: London

by dyki

I don't really quite get the disc brakes on the road bikes. I've never had any problems with rear brakes - even in the wet, do we need more braking power there? I seem not to have any problems locking my rear wheel in any kinds of situations...

Is UCI looking into safety of the riders taking part in crashes? How many crashes have been caused by overreacting riders braking too much/suddenly/not needing any braking in the first place? Surely heated up disc could burn one more than a heated up rim? How about cutting through helmets and parts of the bodies - when are we going to see chopped of fingers in the crashes at races? In my opinion discs for MTB and CX are fine as they mainly involve high separation between the riders (except for the start).

by Weenie


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