New Campagnolo brakes clearance

Discuss light weight issues concerning road bikes & parts.
xmashx
Posts: 42
Joined: Wed Mar 15, 2017 12:30 am

by xmashx

Alexandrumarian wrote:
Tue Jun 18, 2019 3:50 pm
By adjustment screw you mean the one for fine centering? I guess it makes sense now, you use that to send the arm as high as it goes. But then again, one needs to resort to the mounting bolt for fine tuning? That would kinda suck.
This is why I want to change the brakes. @Calnago mentioned in another thread the Chorus gave him extra 3mm of clearance. Well if 3mm in total is generally stated as safe enough. This means Chorus/Non-series can work pretty well without micro adjustments..

Alexandrumarian
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Location: Romania

by Alexandrumarian

Yeah, that is it, I just checked. Taking the screw out gives about 1mm extra space if not more. I guess one can open it with some 3 turns left, then center it from the bolt and then hope a couple turns are enough for fine tuning.

by Weenie


KarlC
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by KarlC

xmashx wrote:
Tue Jun 18, 2019 4:03 pm
Alexandrumarian wrote:
Tue Jun 18, 2019 3:50 pm
By adjustment screw you mean the one for fine centering? I guess it makes sense now, you use that to send the arm as high as it goes. But then again, one needs to resort to the mounting bolt for fine tuning? That would kinda suck.
This is why I want to change the brakes. @Calnago mentioned in another thread the Chorus gave him extra 3mm of clearance. Well if 3mm in total is generally stated as safe enough. This means Chorus/Non-series can work pretty well without micro adjustments..
@xmashx if you want the most clearance at the brakes on your F8 then you might want to try Pina MOST brakes as that what they where make for, also they are really cheep on ebay. I posted some photos for you of my F8 on your other thread, eather that or you can spend $$$ on EEbrakes.

viewtopic.php?f=113&t=157218

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AJS914
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by AJS914

I'm a little curious what moving the adjuster does to the geometry of the caliper. You are basically moving it to one side and then readjusting the whole caliper from the attachment bolt. When you do that, do both sides pull evenly to the rim?

I do think it's cool to know about this hack but there could be a bit of a downside as well. At minimum you lose your ability to use the centering adjustment feature.

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Calnago
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by Calnago

^Exactly... and I really do like that centering feature. It’s not an “adjustment” that’s intended to give you more clearance. If you have to start with it all the way out, then that essentially renders that feature useless.
I will have a closer look at that next time I have some time to tinker, because I am curious now. But even so, if it’s extra clearance you’re looking for from the new brakes, you should look elsewhere or get a frame with the mounting hole on the high side. Campy specifies what that distance needs to be in order to run 28’s comfortably. My Colnagos fall short of that distance but I run 25mm tubulars. I’ve already put the new calipers on my Koppenberg when they came out, and I went back to 25’s from the 27mm Vlanderens, but if I wanted to run the Vlanderens, then it would be back to the Chorus calipers. On the front fork of the Koppenberg there is buckets of clearance, regardless of the caliper used, up to 28mm easy. But the clearance you actually get is directly dependent upon the distance between the axle and the brake mount hole.

@xmashx: you mentioned I may have said somewhere that with the Chorus brakes you can squeeze an extra 3mm of clearance? Hmm, I don’t recall that, I think it might be more like 1-2mm of extra clearance, giving you a total of 3mm clearance, which would be fine. But they certainly don’t give an extra 3mm on top of whatever clearance you get from your normal skeletons.

@karlc: thanks for posting the pics. Definitely sparked my curiosity as I don’t know that I remember playing too much with the centering screw when I was checking the clearances. I will next time and report back.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
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xmashx
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Joined: Wed Mar 15, 2017 12:30 am

by xmashx

Calnago wrote:
Tue Jun 18, 2019 8:20 pm
@xmashx: you mentioned I may have said somewhere that with the Chorus brakes you can squeeze an extra 3mm of clearance? Hmm, I don’t recall that, I think it might be more like 1-2mm of extra clearance, giving you a total of 3mm clearance, which would be fine. But they certainly don’t give an extra 3mm on top of whatever clearance you get from your normal skeletons.
Ooooppsss! I just noticed that I didn't post my main reply and the draft was still open on my laptop. This could make the confusion as my another reply was after my dry-posting before.

So here it is:

Thanks for all the answers! I also finally found some other threads. The most important is this one: viewtopic.php?t=146083
So I put it for a reference here. However there was not much information regarding the newer models.
Calnago wrote: What they don’t say is that if you’re mounting them in the same hole as they came from (an existing frame), is that you will not have any more clearance than the prior Record/SR calipers. In fact, it will be slightly less (about a millimeter or slightly less). The brake shoes will end up mounting a bit higher in their slots, but that doesn’t help in the clearance department. A frame with a higher mounting bridge is the only way you’ll squeak more clearance with the new brakes. So, if it’s more clearance you need, in your existing frame, you won’t get it. Unless you move to the Chorus calipers. But if your ok with the clearance now, and just want the updated clean, non skeleton look, then go for it.
Right. Ok, I made a deeper research and inspection.
I have Dogma F8 and I want to continue to use it. As I'm switching from my carbon tubular wheels to alloys, I thought it might be a chance to try 25mm as 25mm tubular didn't fit (rubbing top of the brake on a valve area).
My current brakes are Super Record Dual Pivot 2015.

I previously forgot about rim width and didn't adjust brakes to more narrower rim as the alloy is (26mm vs 21.5mm on the outer size). So, on my new wheels I put the Conti GP 5000 25mm (regular version but the fact is I want to go tubeless if it's going to work!). My clearance verified by allen key between tire and brake on front is 2mm and <1.5mm on back (I couldn't insert the 1.5HEX). This was definitely too tight.

Then I squeezed rear brake pads closer to the rim (5mm of clearance due to different rims that I forgot!) and I could easily insert 1.5HEX but not 2mm on the back. I tried to use a micro adjustment bolt which is on the right side, and indeed it helped too, and I could easily insert 2 HEX but not 2.5.

So yeah, width of the rims and unscrewing the micro adjustment bolt helped me to get a bit over 2mm (I guess I could go from 2 to 2.5-3 for front in the same way). The only worrying issue was that brakes looked asymmetrical due to too much using of the micro adjustment. I guess this could be fixed by adjusting on the center bolt, right?

So, as on my current SR 2015 I have about 2-2.5mm of clearance between 25mm tire and brakes.
However, a clearance between tire and frame is 4+mm on front and 3.5-4mm on back (4HEX could pass but didn't want new scratches). So, I believe circa 4mm of clearance on both front and back between tire and frame is perfect!

As @Calnago and @KarlC already confirmed, the new R/SR don't help. But as I'm understanding Chorus Dual Pivot and Non Series Campagnolo Dual Pivot both would help in my case. Am I correct on it? With these brakes I could get the final clearance from 2-2.5mm to the 4-4.5mm (limited by frame itself)?

If so, I have just very simply questions:

1) Does it have to be Chorus 2015 or it can be also a newer Chorus 2x12?
2) What are real differences between the Non-Series and Chorus? I know they use different brake pads. Is my understanding correct that Non-series is 100% compatible with Shimano pads or I need convert them or change anything? I read also that the non-series have stiffer pads as they are thicker and it can improve performance. On the other side, some differences between center bolts and tension adjustment screw.
So, which one are preferable if budget is not a problem? I'm not really tech guy and didn't write hundrends of bikes. I can compare weight but not engineering ;) All I know is that Shimano pads are easier to get if this would be all difference.




@Calnago, but you were right. I remembered 3 mm, you stated about 1-2 mm. Is it clearance exactly the same for the non-series version?

xmashx
Posts: 42
Joined: Wed Mar 15, 2017 12:30 am

by xmashx

Calnago wrote:
Tue Jun 18, 2019 8:20 pm
Campy specifies what that distance needs to be in order to run 28’s comfortably. My Colnagos fall short of that distance but I run 25mm tubulars.
Could you please point to the papers? I just checked the user manual for skeleton brakes 2015 and found only specification about distance between brake pads and rim.

xmashx
Posts: 42
Joined: Wed Mar 15, 2017 12:30 am

by xmashx

Seems not much of interest in this thread.
I did some deep research and I believe Campagnolo have stated all necessary information in this technical manual: https://www.campagnolo.com/media/files/ ... _05_18.pdf

The most important parts regarding the thread from the manual:
- you can control your vertical clearance by using bundled washers between the lock-nut and the socker-head nut
- each of the 2mm washer (the bundled) gives 0.65mm more clearance
- there are listed specific distances (with some tolerance) for each group and front/rear combination between lock-nut and fork dropouts. Indeed, I believe the purpose of these is for clearance information and how to set it (pages 3-5).
- a minimum vertical clearance for the SR/R 12s both front and rear brakes is 4mm; there are no such detailed information about the clearance stated to other groupsets, only the distance between lock-nut and dropouts. As the distances are a bit different for other groupsets, I cause the clearance may vary too. However, I believe saying 4 mm is a minimum safe value sounds reasonable



So, my question to all you who have already tried it. Have you (@Calnago, @KarlC and others) compared all your options with using exactly the same amount of washers? I believe this could be simply not really taking into consideration and results in such different results like 11s vs 12s SR/R no difference or Chorus that didn't work for someone.

In my case, I only have a single washer on front and rear. And I never thought about amout of washers while installing brakes!
In summary I believe that I should be really fine with 25mm clinchers.
- frame has clearance about 4mm on each sides which is acceptable
- front: current 2mm + 0.67mm (1 extra washer) + 0.5mm (squizzing brake pads: 25mm -> 21.5mm external rim's width) + 0.5mm (microadjustement bolt) + 1-2mm (swapping from SR to Chorus/Non-Series) = 4.5-5.5 mm
- rear: current 1.5mm + 0.67mm (1 extra washer) + 0.5mm (squizzing brake pads: 25mm -> 21.5mm external rim's width) + 0.5mm (microadjustement bolt) + 1-2mm (swapping from SR to Chorus/Non-Series) = 4-5 mm

This sounds very promising (and optimistic). Even if one of the tuning option would fail there are still plenty of other options to try.

Now the only problem is, should I go with Chorus 11s or 12s or Non-Series? If the only real difference is brak pad compatibility (Shimano are cheaper and easier to get) + weight (pros for Chorus) which way would you go?

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Calnago
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by Calnago

Ah, sorry... I remember you asked for that link but I forgot to post it. But yes, that’s where most of the info is.
And I did get a chance to play with this in excruciating detail again... even got back the wheelset with Vlanderens (27mm tubulars) to test with.
I compared standard mount versions of Super Record calipers, the ones that went with 11sp and the most current for 12sp, although aside from the graphics they are not groupset dependent.
I took a bunch of pics but my Flickr account (where I host pics) has been acting up and not working properly lately, so I haven’t posted anything.
But my conclusion remains pretty much the same except I may have said that the newest version has even slightly less clearance. That’s not quite right, as I think with everything adjusted exactly the same, there is an insignificant, if any difference, between available clearance between the two. I used two washers in both cases. Same rim, same tire. Same ultimate adjustment of pad distance from rim. I did this with both the centering screw where I want it in order for it to be a functional feature, and also with it completely turned out so that it’s function was nil and you had to center everything with only the main mounting bolt. Playing with that screw will not get you any extra meaningful clearance, all else being equal. And even if it did, that is one of my favorite features, and not one I would be willing to give up... being able to really fine tune the centering so that both pads touch the rim at exactly the same time, nice and smooth.
The only way you will get more clearance with the new brakes versus the old. is if the mounting hole on your frame is higher. Otherwise you’re simply positioning the pad holders at slightly different heights in the slots, but that does not give you any greater clearance above the tire.
So, if it’s ultimate clearance you’re after, I’d go for either the current Chorus calipers or the non-series calipers. The Chorus will get you a little bit more than Record or SuperRecord, but not scads more.
Did you mention which frame and wheelset you’re putting this on? The internal rim width will make a difference if you’re using clinchers, and tires can make a differnce too, with Continental 4000sii’s sitting the tallest of any 25mm clincher I’ve come across. The newer Conti 5000’s sit more similarly to other 25mm tires from most accounts I’ve heard. I’ve only installed one set of those so far but didn’t spend much time really comparing them to anything. Just wrestled with getting them on the rim, which is pretty common these days it seems, especially with the tubeless specific offerings.
Oh, regarding that 4mm clearance, that is what manufacturers are supposed to abide by... minimum 4mm of clearance from tire to any part of the frame. However, from a practical standpoint on the road, I’ve found through experimenting that 2mm gets me enough clearance that “chatter” from road debris going between the tire and fork crown or rear brake bridge is enough to make me happy. Less than that is a no go. My guide is if I can easily pass a 1.5mm Allan key through the entire passage like a wand over the tire and under the brake caliper/fork crown/rear brake bridge then I’m ok. 2mm strong and I’m golden.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

xmashx
Posts: 42
Joined: Wed Mar 15, 2017 12:30 am

by xmashx

Just a quick update.

I finally switched the wheels, added 1 extra spacer for a rear brake and adjust both brakes and brand new brakepads for a new (and narrower rims). I didn't use the microadjustment (used only for a disgned purpose).
Results for a SR 2015 Dual Pivot with 1 spacer in front and 2 spacers in back, attached to Dogma F8 with Conti GP5000TL:
- front: 4mm allen key plays easily
- rear: 3mm allen key pass between tire and brake without problem but not that easy as for the front

In my visual opinion the 3mm of clearance is perfect. Seems like all I needed was 1 extra spacer. I will do some rides in next days and hope all problems are gone and there is no need to spend extra $$$ for the Chorus :)

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Calnago
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by Calnago

Good to know and sounds like clearance is just fine with the 5000’s in 25mm. If you’ve got 3mm with the “wand” test between the rear brake bridge and the tire and the fork crown and the tire then you’re golden. You probably wouldn’t have been so lucky with the 4000sii’s in the 25mm.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

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