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PostPosted: Fri Dec 15, 2017 9:14 pm 
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Posts: 27
Unfortunately, I simply don't understand what was the intention behind that test and what conclusions are we suppose to draw.

I saw wheels explode at different temperature, I would assume higher is better since the wheel can handle that higher temperature.
I saw the alto wheel spinning faster with the force same force applied on the brake lever, I'm pretty sure its not a good thing!
I saw a temperature cooling time chart that make no sense at all since the initial max temperature is different for every wheels, so of course the cooling time to 120F will be different !?!

As far as I'm concerned, I find it more likely that somebody manipulate the alto wheel brake track with oily fingers then you guys come up with some magic resin.


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PostPosted: Fri Dec 15, 2017 9:54 pm 
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BobbySweeting wrote:
Can you please clarify what you mean when you say "the input force accelerating the wheel." When you're coasting down hill the input force is that of gravity (effected by mass and the slope of the ground), and the brake force is equal to it when you are at constant velocity.
We were talking about laboratory testing, weren't we? I mean if you have a 5 kW engine spinning your wheel and you are applying enough braking force to keep the wheel spinning at 12 km/h, that's quite different than if you had a 500 W engine spinning the wheel at that same speed. You can't really judge a test based on wheel speed alone.


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Posted: Fri Dec 15, 2017 9:54 pm 


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PostPosted: Fri Dec 15, 2017 11:29 pm 
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kavitator wrote:
When cornering at 30km/h there is little heat on brake track

"Killers" of carbon rims are steep and sharp corners - i dont think you will have more than 20km/h in that corners
The biggest carbon rim killer is constant brake dragging in between corners :wink:

I've tended to ride less well known mountain roads and at the fringes of riding season so there's hardly anyone else around. First time I rode around alta badia in august I was shocked at what I saw a lot of riders doing even on sensible gradients and easy roads. Just holding at 30 - 40kph even on long straights with perfect visibility. Brake track torture. :shock:


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PostPosted: Sat Dec 16, 2017 12:18 am 
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I’ve seen exploded carbon clinchers in many different scenarios. Steep straightish descents with bad road surfaces reducing rider confidence and steep twisty stuff. I agree that testing should be more aggressive than what is currently considered adequate by the industry. And while the Alto test goes to extremes, their test really isn’t as far off from what some people do in the real world as we think.


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PostPosted: Sat Dec 16, 2017 1:26 am 
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alto RESPECT for doing the unthinkable and calling out the industry on their non-existent safety standards.

interesting..

Bobby Sweeting December 15, 2017 at 5:14 pm
Your absolutely right! Trek has already purchased a CC52 front wheel from us. I’m not sure if they plan to keep their study internal or publish it, but either way I think that is a fantastic step in the right direction.

btw maybe if trek is impressed with alto's secret resin they will buy some :).

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PostPosted: Sat Dec 16, 2017 2:03 am 
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Spartan - Haha, you're right, I have no idea what they'll be doing with the rim. Getting acquired wouldn't be the worst thing in the world! Then I can retire from arguing about physics on the internet :P

Fiery - Sorry about that, I think there was a miscommunication. The calculation I showed was for a real rider on a descent. In the lab, we had to build out the motor with a torque meter, amp meter, and frequency modulator in order to ensure that the wheel stayed at 1200W input power throughout each test. It's definitely two very different calculations!


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PostPosted: Sat Dec 16, 2017 2:04 am 
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Location: Islip, NY
BobbySweeting wrote:
We launched this model at Interbike as a proprietary high pressure hookless system, and now Pacenti has launched a similar model. He hasn't done anything wrong because we have no patents on this particular design, it is just a similar system. Enve also makes a deep, hookless disc brake model that is very similar to this. There are only so many ways to do it so that the tire doesn't come off, haha.
You mean to tell Alto releases a rim at Interbike. Pacenti sees the design and get the exact profile into production within months??!! He has the ability to call a rim company up, send them the same profile specs (even assuming he sent your drawing to them), they tool up making the molds and he gets rims. In months. Wow.

Come one now. We're not getting the whole story.

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PostPosted: Sat Dec 16, 2017 3:12 am 
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Also, please answer this question.

WHY ARE YOUR 52MM CINCHERS ACTUALLY 50MM DEEP?


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PostPosted: Sat Dec 16, 2017 3:34 am 
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ergott wrote:
BobbySweeting wrote:
We launched this model at Interbike as a proprietary high pressure hookless system, and now Pacenti has launched a similar model. He hasn't done anything wrong because we have no patents on this particular design, it is just a similar system. Enve also makes a deep, hookless disc brake model that is very similar to this. There are only so many ways to do it so that the tire doesn't come off, haha.
You mean to tell Alto releases a rim at Interbike. Pacenti sees the design and get the exact profile into production within months??!! He has the ability to call a rim company up, send them the same profile specs (even assuming he sent your drawing to them), they tool up making the molds and he gets rims. In months. Wow.

Come one now. We're not getting the whole story.
You have connections in the wheel building world Ergott, why don't you drop a dime on Kirk Pacenti and see if he can shed any light on how the cross sections ended up being so similar, and what his development timeline was. There are cases of collaboration on rim designs, like how Derby helped design the Ibis carbon MTB rims, basing them on his previously designed own brand stuff. That isn't to say they are the same, but I guess I am saying that there could be some behind the scenes cooperation going on amongst small companies in order to share resources and defray costs.


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PostPosted: Sat Dec 16, 2017 4:41 pm 
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Posts: 1045
interesting they are using filament winding process to eliminate human error control resin application. topkey is a top end taiwan producer.


"GatorRacer: We worked on the resin here in Sarasota for about 3 months, simply studying it as a thermoset post-curing and testing its various properties: heat transfer, brittleness, ultimate yield, shear strain, etc. It is a process of experimenting with additives within a high-temp aerospace grade resin in order to manipulate the properties to be ideal for our application. There are three additives in our resin that are not proprietary to us, but I believe we may be the only manufacturer within the cycling industry to be using them. We've decided to keep the intricate details as a trade secret, for obvious reasons.

The resin isn't used in pre-preg, as we're filament winding the brake track on these rims and not laying them up by hand. The fibers are dipped in a resin bath prior to winding, and this is done by machine at the Topkey facility in Taichung. "

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PostPosted: Sat Dec 16, 2017 7:46 pm 
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I really believe that the industry, if they so choose, could make carbon rims (or some other wonder material) that withstands heat well enough to endure the rigors of the most demanding races, and perhaps even the rigors of the novice overweight rider fearful of descents, .. IF they really wanted to. But what would that mean for the industry as a whole. It would mean the whole disc experiment on road bikes could come to an abrupt end, period. It would be next to impossible to see any advantages to discs. All the pitfalls of braking on the rim would be eliminated, and all the pitfalls of running discs in the peloton (and there are many) would be avoidable. No need for wider dropout spacing. No new chainline issues. No need to beef up frames to accommodate the added stresses of discs. And aside from changing the resins and layups and maybe materials on the wheels, no need to change anything else like lacing patterns, quick release to thru axles, etc. No significant weight addition. Hmmm.... seems too good to be true. We already have hydraulic levers now and all that would be needed is hydraulic rim calipers, Magura has them as an example. And it would be very very good for us, the end users. But very "meh" for the manufacturers. Where's the money!? The money is in new frames for all (obsoleting the old), reduced costs of production (by virtue of having one braking technology for both mountain and road), new groupsets for all those new frames, etc., etc.,... the list goes on. $$$$

If all they did was come up with a brake track that could withstand heat and look cool, because lets face it, the look is a big part of why people buy carbon clinchers, then that would all be well and good for the consumer as all they'd need to do is go buy a new set of wheels. And if they wanted the light smooth action of hydraulics then by all means, get a new group too, but you wouldn't be forced to do so.

Now, if Altos has truly come up with a brake track so revolutionary that it not only stands up to and conducts heat well without falling apart, but brakes well and is not so brittle as to crack over time or when it hits a slight pothole, then more power to them. All they have to do is convince the major manufacturers that they can make more money adopting this technology versus continuing on the path of redefining the road bike market as we've known it for so long. Good luck with that.

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Last edited by Calnago on Sat Dec 16, 2017 8:04 pm, edited 1 time in total.

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PostPosted: Sat Dec 16, 2017 7:57 pm 
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Posts: 48
they made successful advert with little cost. I just thought they did experiment in a wrong way like using wrong brake pads, deliberately. so they could make terrifying pictures. so far, their intention seems working. at least for me. cause I never heard of alto before.


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PostPosted: Sat Dec 16, 2017 8:08 pm 
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ohhyeok90 wrote:
they made successful advert with little cost. I just thought they did experiment in a wrong way like using wrong brake pads, deliberately. so they could make terrifying pictures. so far, their intention seems working. at least for me. cause I never heard of alto before.
I am in ohhyeok's camp.

I did an armchair thought experiment: it does not seem like an overly daunting task to get the math right for an experiment with real-world forces involved, or even in slight excess. The owner of Alto wheels acknowledged that this experiment is extreme. Why? Because a close-to-real-world experiment will just show all the wheels surviving the test. It's not shocking. The cycling media won't pick it up.

I also feel sorry for the other wheel manufacturers. It's the holiday season, where their employees get a bit of a break. It's the shopping and gift season where more merchandise is pushed. It says something that the results of this unrealistic test was released precisely in the midst of this season.

It may very well be the case that the resin is slightly superior under real-world conditions, but to me, that is overshadowed by the intentions behind the test.


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PostPosted: Sat Dec 16, 2017 9:12 pm 
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I tend to believe the test. It is however a rather dramatic marketing video which breeds distrust. The jist is they are saying the thermal conductivity of their braking track is better than their competitors. I would be totally convinced if they would just give the conductivity measurements for their rims vs the competitors.


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PostPosted: Sat Dec 16, 2017 9:48 pm 
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When you want to show your product as significantly better in some aspect, why not to come up with the test that really shows it? If they'd perform a less drastic test maybe all rims would survive it and that wouldn't be interesting. If the test isn't totally out of touch with some edge case scenario (like 120kg heavy man dragging the brakes like crazy down some 20+km Alpine descent) I don't see big problem with it.

The biggest problem is that they shouldn't use the braking force as the target variable, but rotational speed instead. When braking you care about the speed. The force you need to apply will be different for each rim.
Another problem are pads. They should use the recommended ones and perhaps perform another reference test with the same pads for all rims.


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Posted: Sat Dec 16, 2017 9:48 pm 


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