alto's carbon clincher shootout test

Discuss light weight issues concerning road bikes & parts.
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EmBe
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by EmBe

spartan wrote:https://knightcomposites.com/testing/

they have section on how the test rim failure. ironic part the youtube video is no longer available.

these clowns charge primo dollars for crap product. marketing. amazing cycling business

What:
Brakes are repeatedly applied and released to test the brake track durability and heat resistance.

How:
A rim is placed in the test rig and with a load of 100kg. It is then rotated constantly at 12.5kph, while the brakes are engaged and disengaged at a set pressure every 3 seconds. Rims should endure 3000 cycles of braking with no sign of failure to meet industry standards.

Why:
This tests how well the rim can withstand the heat generated from braking on the carbon track.

https://www.youtube.com/watch?v=T3Fu53u ... e=youtu.be
Video seems to be working fine now? What am I missing?

I have a pair of Knight Composites 35 Clinchers with almost 20K miles on them and lots of riding here in Southern Colorado and I've never had an issue with the wheels. I delaminated a pair of 303's descending on my local ride in 2014. I think any wheel company can have a bad day and soon enough, that day will come to Alto as well.

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ergott
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by ergott

TobinHatesYou wrote:There’s just as much friction in the 9lbs test with Alto’s rim vs the 7lbs test with the other rims.
I'd like this whole test to be independantly verified. There's no free lunch with material properties.

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TobinHatesYou
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by TobinHatesYou

ergott wrote:
TobinHatesYou wrote:There’s just as much friction in the 9lbs test with Alto’s rim vs the 7lbs test with the other rims.
I'd like this whole test to be independantly verified. There's no free lunch with material properties.
That's true, but they aren't claiming magic. Basically the claim seems to be their choice of resin and layup technique allows the entire rim to function as a heatsink rather than a localized portion around the braketrack. I'd like to see the test reproduced by someone else too. It would be easy enough to do. The question is why would Ryan Mason (formerly Mason Cycle Werks) and Spark Wheel Works have any reason to lie?

coachboyd
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by coachboyd

TobinHatesYou wrote:
I'd like to see the test reproduced by someone else too. It would be easy enough to do.
https://www.youtube.com/watch?v=lARQCMfGWzc
http://www.boydcycling.com The Handcrafted Revolution

dvq
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by dvq

coachboyd wrote:
TobinHatesYou wrote:
I'd like to see the test reproduced by someone else too. It would be easy enough to do.
https://www.youtube.com/watch?v=lARQCMfGWzc
Fire meet gasoline :D

TobinHatesYou
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by TobinHatesYou

coachboyd wrote:
TobinHatesYou wrote:
I'd like to see the test reproduced by someone else too. It would be easy enough to do.
https://www.youtube.com/watch?v=lARQCMfGWzc
Hi Boyd, could you reveal what the equivalent power was for the test and the wheel speed under braking? I see the scale of the y-axis on the left of the screencap, but is it's km/h or mph? Looks like around "15" either way and the max temp was around 290F?

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ergott
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by ergott

TobinHatesYou wrote:
That's true, but they aren't claiming magic. Basically the claim seems to be their choice of resin and layup technique allows the entire rim to function as a heatsink rather than a localized portion around the braketrack. I'd like to see the test reproduced by someone else too. It would be easy enough to do. The question is why would Ryan Mason (formerly Mason Cycle Werks) and Spark Wheel Works have any reason to lie?
Carbon is generally an insulator hence the issue with it as a brake surface material.

I can't think of any instance of carbon fiber being used as a heat sink when aluminium is generally considered far better.

Resins have gotten better over time, but not that much. Unless this resin is something completely groundbreaking and will be highly sought after far outside the bike industry. Usually developments like this are driven by far bigger industries.

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coachboyd
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by coachboyd

The test was done as a constant 15kph and the brake load was set at 3.5kg

Braking force, temperature, speed, and rim width were monitored the entire time.
The blue line is the braking force needed. You can see it rises, and then as the brake pads heat up they start to shed material. Once that happens the braking force decreases and the temperature follows suit.

By the end of the test we could actually measure the brake pad residue on the rim (the green line).
If you watch the video you can see at the end of the test there is a ton of brake pad residue on the floor. We lost about 65% of the brake pad life in 20 minutes. The same brake pads will last for me for about 5 months or so on the front wheel and I am going up and down Paris Mountain in Greenville, SC on most of my rides.

Image
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TobinHatesYou
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by TobinHatesYou

So not quite the same protocol used. In Spark/Alto's test, each of the wheels were spinning closer to 31-32km/h.

tonytourist
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by tonytourist

ALTO WHEELS ARE THE BEST BECAUSE TOBIN BOUGHT SOME!!
(Just run them tubeless so you get extra credit)

TobinHatesYou
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by TobinHatesYou

tonytourist wrote:ALTO WHEELS ARE THE BEST BECAUSE TOBIN BOUGHT SOME!!
(Just run them tubeless so you get extra credit)
I bought some and had a neutral experience with them. I even said I likely wouldn't buy them again. Your point?

And yes run them tubeless. Better yet, stop using rim brakes. These are all on my calling card.

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ergott
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by ergott

https://www.bikerumor.com/2017/12/14/en ... rake-test/

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ergott
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by ergott

Flrider wrote:!

Image
Still waiting for clarification on this. How could these rims be of a proprietary mold made in the USA, sent to Taiwan and manage to be exactly the same as the Pacenti rim?


Also waiting for an answer to my question about brake surface texture. Things are just not adding up and that should concern anyone relying on this test result.



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spartan
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by spartan

why even bother. your test is not realistic. constant speed should be closer to 35-40km/hr brake load set at 4-5kg.

if your confident send a pair of wheels to germany for testing by tour magazine. their alpine wheel test shreds majority of wheelsets they have tested :idea:
coachboyd wrote:The test was done as a constant 15kph and the brake load was set at 3.5kg

Braking force, temperature, speed, and rim width were monitored the entire time.
The blue line is the braking force needed. You can see it rises, and then as the brake pads heat up they start to shed material. Once that happens the braking force decreases and the temperature follows suit.

By the end of the test we could actually measure the brake pad residue on the rim (the green line).
If you watch the video you can see at the end of the test there is a ton of brake pad residue on the floor. We lost about 65% of the brake pad life in 20 minutes. The same brake pads will last for me for about 5 months or so on the front wheel and I am going up and down Paris Mountain in Greenville, SC on most of my rides.

Image
Current Rides:

2017 Giant TCR Advanced SL 0 DI2 9150

coachboyd
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by coachboyd

Most testing protocols are set between 12 and 16kph. It's not necessarily monitoring the speed, it's monitoring the braking force and temperature.

Kevin at Knight Composites has a lot of information about this and the ISO standards for testing. I need to look into the iso stuff more but I know those tests are run at 12.5 kph
http://www.boydcycling.com The Handcrafted Revolution

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