Ciamillo Brakes - Warning!

[flybywire]

Just recently rode down some more proper steep descents that needed proper braking power. Think like 10%-15% grade down to an immediate very tight hairpin/switchback turn. My confidence in the front brake is pretty good now, the front slows you down quite a bit, and quite nicely, but the rear is something I will still need to tune up because it just isn't trimming enough speed for my liking. And the flex due to the design of the rear brake is still concerning. I'm thinking something like a nylon washer and/or some carbon-safe lubricant could allow you to tighten the brake assembly a little more to reduce flexing.

[cloud9blue]

i like fancy carbon parts as much as everyone here, but is it really worth it to save some grams for something as critical as brakes, especially when the reliability of these designs are kind of unknown.

[expatscot]

Are there any UK distributors for Ciamillo? I'm running the old CNC Planet X calipers, which have been pretty decent, if slightly underpowered vs dual pivot Shimano.

[MichaelB]

Just recently rode down some more proper steep descents that needed proper braking power. Think like 10%-15% grade down to an immediate very tight hairpin/switchback turn. My confidence in the front brake is pretty good now, the front slows you down quite a bit, and quite nicely, but the rear is something I will still need to tune up because it just isn't trimming enough speed for my liking. And the flex due to the design of the rear brake is still concerning. I'm thinking something like a nylon washer and/or some carbon-safe lubricant could allow you to tighten the brake assembly a little more to reduce flexing.

I read the above as "They are OK, and I am getting more confident that they'll work OK, but need lots of fiddling to be acceptable"

[PatrickJGrant]

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[glepore]

FWIW, I'd be more comfortable with one of the ee clones than these. They are a bad design from the start. I don't think anyone did FEA on these, or the issues would be obvious. THM is a good carbon brake. Plates like this? A workaround.

[Coolcat]

FWIW, I'd be more comfortable with one of the ee clones than these.

Can you post a link to EE clones?

[Butcher]

Grow up? Never.

[glepore]

FWIW, I'd be more comfortable with one of the ee clones than these.

Can you post a link to EE clones?

https://www.aliexpress.com/item/1005001 ... 3416%22%7D
Several different sellers. They are the long reach brompton style, no idea whether they'd work on a normal road bike.

[eurostar]

Just seen a few bad reviews on aliexpress regarding spring failures on these things. Not super surprising given that its barely strong enough to overcome the cable friction needed to spring the brake open.
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Maybe someone on here can source replacement springs or make their own.
Interesting too is just how many of these have sold already. Some sellers have sold 30+ sets.

Links please?

[WorkonSunday]

This seller is advertising a slightly wider version (and heavier 158.7g vs 140g) that fit 28 rims and 32c tires.

https://www.aliexpress.com/item/1005003 ... GXSl0&mp=1

Clicked through and saw that it's still the 140g version. Where did you see that it's 158g?

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further down there is a description of style B and Style c (aluminium version).

i notice style b has ZTTO logo on it (ZTTO is one of the bigger cassette manufacturer in china).

with regards to 140 vs 158.7g, i think it'st just difference between with pads and without pads.

mine just arrived (London as well). i ordered the style b with brown pads.

they arrived at 70g front and 69g rear.

they only supplied one pair of pads, oh well, not that im bothered.

[Beancouter]

Article on Bikeradar about the Nat hill cilimb champs yesterday.

It quotes Andy Nichols custom Orbea riding lekkis …. Look like Ali clones to me…..



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[Superlite]

Can anyone confirm what type of brake pads the Aliexpress version uses? Need to order a set.

Thanks.

[flybywire]

Can anyone confirm what type of brake pads the Aliexpress version uses? Need to order a set.

Thanks.

Honestly, I just stuck my koolstop shimano/sram style pads in mine and it works, but its a very tight fit, and ideally I would have trimmed some of the back of the brake pads to properly slide them in. You could also just use a different brake shoe. Something tells me that the shoes it comes with want some form of campagnolo pad...

On the other hand, I've still been riding my bike with these brakes and they work great so far. No cracking, no failing. I've tightened up the rear brake cable tension a bit more, and now the rear brake works decently too. No problems stopping at all whatsoever. I must also mention, I only weigh about 61kg, so that definitely plays a big role. I honestly wouldn't buy these brakes if I weighed over 80kg, as the 130-200g weight savings are not going to help you if the inertia of your body and bike flying down a descent can't be counteracted with proper braking force in the case that one of the brakes cracks.

[jpeterson1012]

I'm going to sidetrack and avoid the whole discussion of fake/real/ted/Chinese and circle back to OP's first post regarding failures.

If you've ever used any ciamillo brakes, regardless of model, in the past, you're probably somewhat familiar with how the brake shoes aka pad holders work/mount to the caliper.

If not, here's a summary: Each arm of the caliper has an elongated (slotted) crater shape on the side that faces the brake track (said crater also has an elongated hole that the shoe-mounting bolt goes through). Each brake shoe has a corresponding dome-shape that mates with the curvature of the arm's elongated crater. The domes are also hollow, and behind/under each dome is a nut that has one curved side which the bolt screws into. When the parts are assembled, the dome fits into the crater, but can pivot like a bone in a socket. The nut in the dome can then be pivoted to match the angle of the screw, which then binds the whole assembly together to prevent it from moving. This allows the brake shoes to be toed/tilted appropriately. I've drawn up a simple diagram to demonstrate this.


Now observe OP's failures. Each failure occurs on the same component (the aluminum piece which has the elongated crater), and at the exact same spot (the end/tip). The explanation for this failure is very simple: over-torque.

When you press a dome and a crater together, it's naturally going to want to make the crater bigger. It's like driving a wedge into a crack. It's going to exert forces outward when you tighten the bolt, and in the case of lekki8's, it's going to splay the two sides of the slotted crater apart, causing it to fail at its weakest point, which happens to be the end/tip where OP's failures occurred.


I'm not going to definitively place the blame on either party (perhaps OP over-torqued the bolts, or perhaps ted just didn't leave enough material there to begin with), but the solution is equally simple - less torque. Ted's manual says 6Nm on the pad holder bolts. You don't need 6Nm on those bolts. Where is your pad holder going? It's literally being mashed into a rim everytime you apply the brakes. What I recommend is: blue loctite the bolt, a very thin layer of grit paste on the mating surface (aka the dome/crater) mostly to prevent the pieces from seizing over time, and apply 3-3.5Nm of torque. Also, don't toe your brakes, you don't need to on high-quality calipers, all it does is introduce extra stress and twisting forces when you brake. Instead, set them parallel.

questions:
1. are you an engineer, did you FEA this? no and no, I used common sense and my brain to analyze what happened.
2. Does this apply to the chinese brakes as well? if they are truly using the same design/design principles, yes.