Campagnolo Bora AC3 Braking Treatment

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jacobeh
Posts: 15
Joined: Wed Aug 17, 2016 12:56 pm

by jacobeh

Calnago, thanks for your thorough review! Now I'm glad I got a great Black Friday deal on the "old" 3Diamante version :)

jacobeh
Posts: 15
Joined: Wed Aug 17, 2016 12:56 pm

by jacobeh

@nismosr: I can't PM you back (not enough posts or some sort) but it was a pair of Ultra 50s bought on https://www.vanillabikes.com/ for ~1900€ - I believe it was a one set only kind of offer

Noctiluxx
Posts: 251
Joined: Tue Feb 07, 2017 7:17 pm
Location: Southern California

by Noctiluxx

My 2015 3Diamant brake surface Bora Ultra 50's were just replaced with the AC3 version, by Campy, due to faulty rear hub. Quick question. I just noticed my Campy skewers are at least double the weight of my Zipp NSW's. The Zipp skewers are 31 grams a piece while the Campy's are 63 grams each! I assume its safe to use the Zipp Skewers on the Campys? Both pair of wheels are shimano hub.
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robdv
Posts: 3
Joined: Fri Dec 29, 2017 6:52 pm

by robdv

I have a decision to make. I ordered a set of 2017 Bora One 35 clinchers but received a 2018 set with the AC3 finish – a superior deal were it not for the excessive braking noise and squealing that bothered me and annoyed fellow riders on my very first outing. The decision is whether to return the 2018 set for a refund (and buy a 2017 set from another source) or keep it.

It would be simplest to keep the 2018s if the AC3's noise and squealing can be made (subjectively) tolerable, by any and all methods. Campy's UK Rep Graeme suggests that exacting pad alignment should eliminate the squeal, and that overall noise should subside with wear after a few hundred kms. Is that the experience of AC3 owners here? Any other successful fixes?

My own attempt at improving the toe-in using a credit card and roughening the pads didn't help noticeably, but I'm more than willing to keep trying. If relevant, I'm ~80kg and ride in dry, hilly territory with 5-10% 1+km long descents fairly common and the occasional 10-15%. Thanks.

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Calnago
Posts: 5999
Joined: Sun Nov 07, 2010 9:14 pm

by Calnago

Toeing in the pads maybe a little more than you’re used to should eliminate the “squealing” entirely. I could never live with squealing, or howling. But as I noted in my post earlier, they are overall a little bit noisier just due to the inherently rougher surface I suppose. I was also wondering if that would subside a bit over time. If they did/do then all would be good I guess but if I had the choice between two brand new sets of Boras, one with the AC3 brake track and one with the 3D brake track, I would take the 3D. Nice soft sound. Great braking, etc.
However, if Graeme says that they should “calm down” a bit with wear I’d be inclined to believe him and just keep them. I don’t have enough wear on mine to be able to say if that’s the case or not. But no squealing. Couldn’t stand that.
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robdv
Posts: 3
Joined: Fri Dec 29, 2017 6:52 pm

by robdv

Calnago wrote: Toeing in the pads maybe a little more than you’re used to should eliminate the “squealing” entirely. I could never live with squealing, or howling. But as I noted in my post earlier, they are overall a little bit noisier just due to the inherently rougher surface I suppose. I was also wondering if that would subside a bit over time. If they did/do then all would be good I guess but if I had the choice between two brand new sets of Boras, one with the AC3 brake track and one with the 3D brake track, I would take the 3D. Nice soft sound. Great braking, etc.
However, if Graeme says that they should “calm down” a bit with wear I’d be inclined to believe him and just keep them. I don’t have enough wear on mine to be able to say if that’s the case or not. But no squealing. Couldn’t stand that.
Since you and Graeme were able to avoid the AC3 squeal, some additional fiddling might allow me to banish it as well (presuming personal and terrain differences don't override). Starting with brake pad positioning similar to yours might cut back on the trials and errors. Hope you can describe the setup, or the process you used to get there. Thanks.

Greg66
Posts: 243
Joined: Mon Sep 26, 2005 8:06 pm

by Greg66

I set my AC3 Bora Ones up with the raised number section of a CC between the rear third of the pad and the rim. No squealing. I get a sort of whooooossh sound when braking like air leaving something under pretty low pressure.

My pre 3Diament BU50s can be provoked into making a properly loud squreek noise under sudden braking. Loud enough to alarm pedestrians. I should probably check the toe in on them.

Campag red pads on both wheel sets.

robdv
Posts: 3
Joined: Fri Dec 29, 2017 6:52 pm

by robdv

Decided to keep the Bora One 35 2018 Clinchers. The 2017s are pretty much gone. Any left are priced considerably higher than what I paid for the 2018s.

Thanks for the input. Tightening the brakes and setting the pads more carefully got rid of the loud squeal. It's now what I would call a whine. Campy rep Graeme says that should fade with the miles. Improving my braking technique should help as well.

Interestingly, with the brakes properly tightened, I experimented by setting the front pads parallel (per Graeme) and rear pads toed (by raised CC thickness)... and... turns out they sounded pretty much the same. Reducing the rear toe to business card thickness (unfolded) didn't seem to affect the sound either. So I set both front and back pads to this same minimal toe and will see if it works as a happy medium.

mazador
Posts: 1
Joined: Mon Jan 29, 2018 9:25 am

by mazador

Do the 2018 Bora One's also have the "twill" carbon layup as well as moving to AC3? I currently have a sweet deal on my radar for a set of '17 Fulcrum Speed 40C (pretty much a 40mm Bora One - adds carbon front hub, slightly different G3 spacing are the significant differences). Would be missing out on AC3 (per this thread no biggie) and twill carbon. Haven't been able to find anything online about the latter other than marketing materials. Appreciated.

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