Hah, same thing on some roads here in Poland
But it's keeping to be better and better every year.

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A light bike does replace good fitness.

Another test right there. If you can't use cross tires, just make sure they supply enough normal ones, and just check what happens if you ride on a flat tire. When will the testing begin?

The impression I have is that the biggest weakness of using carbon as a material to build wheels is its toughness (i.e., absorption of energy in an impact). This weakness can cause ruptures and buckling of the material at points of high stress such as near the spoke holes or near the braking track. A lot of manufacturers have sorted this out by adding more fiber to these areas, causing a general increase in rim weight over the last few years.

So... For a light weight rim, I feel that toughness is an area of concern that could be tested and lends itself well to real world experimentation. This can also be easily compared to theoretical models. For example, while I was playing around with building titanium rims I had a materials scientist use a criteria of 50 km/hr impact with a 2 inch obstacle (80 kg rider) as the dynamic loading requirements. This should not cause any permanent deformation or weakening of the overall structure (other assumptions made such as 24 spokes, typical dimensions, blah, blah, blah were made).

Where am I going with this? I'd like to see wheel manufacturers actually perform these impact tests to determine toughness, which would be an indicator of real world use and durability.

Construct a 2 inch pothole and a 2 inch curb. Ride into them at increasing speeds multiple times, noting any damage. Compare to similar carbon wheels and traditional aluminum rim, wire spoke wheels.

That's what I would love to see.

John Swanson

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www.bikephysics.com
www.lanternart.com

I like the John Swanson pothole test and Paris Roubaix. Those are about the only ones that would impress me, though the TSA test would be valuable too.

Debris from rockfalls has been what has taken out almost all of my carbon wheels so gravel roads with 22-23mm tires have to be included too, and the bigger gravel too - no cheating with fine gravel/hardpacked dirt which is better than a lot of paved roads.

A lot of trials/miles are needed too. You can hit rocks a couple dozen times with no problem but when it hits just right it's one and done.

Now that I think about it they should be sending the wheels to me because I think I've broken more carbon rims than anyone on here, and I don't think it's my massive 62kg physique doing the damage.

[quote="ScienceIsCoolse a criteria of 50 km/hr impact with a 2 inch obstacle (80 kg rider) as the dynamic loading requirements. This should not cause any permanent deformation or weakening of the overall structure ([/quote]

well we where tested as the best at UCI test

10 km/h 100 kg frontal on 2 differant location
and fixed location

result must no spoke detached and sharp edges
but wheels are destoyed due to larger impact energy
so.................

How about floating ashore from the center of the Atlantic with it as a life buoy? ( I know it's not possible judging from the densities of the composite components... but it just so happens that ZG's Ted Ciamillo is doing his subhuman project, so it will be timely for LEW to try something like the human buoyancy project)

Mmm I don't really like John's test; too rigidly rooted in inductive scientific process for me. This should a test of what you won't often see in a laboratory, say, hammering a nail into the wall with the rim... then riding into The Dog That Broke It.

Oh, and since you are testing the wheelset, couldn't you test the yellow spoke of champions at the same time. Maybe people would be less hesitant to choose this option if they knew it was tested?

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"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.

just ride flanders that will sort em out.
tikka

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So how do you score the results of testing the yellow spoke of champions? Based on how many people laugh at you?

So, when will the testing begin?

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"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.

Well I think John's test is more for testing how much a wheel can survive while still being rideable while the UCI test is a safety test ?
The pothole test is interesting.

Yeah, the UCI test is a safety test and actually isn't very hard on a wheel.

Testing will start when I get the test wheelset. That's likely to be a month or so away, as LEW is filling customer orders.

Actually he'll have it within 10 days...

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Lee Vaccaro
VP of Corporate Development
702-205-5766 direct
702-743-5508 office
www.lewracing.com
www.lewaerospace.com

Uh...The UCI test is actually made to completely destroy the wheel by hitting a fixed wheel with a 3000lb. square edged sled moving at about 30 mph. To pass no part of the wheel is allowed to eject beyond the plane of the outside of the axle caps. It is said to try to mimick what would happen if a rider hit a curb at speed.

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Ride hard, have fun...

I have to admit I was rather sceptical about all this and had my thoughts drifting towards a direction that LEW was implying that their wheels were really strong by just announcing some testing, so when nothing really happend I was ready to call BS.

For anyone thinking the same right now, AFAIK, the testing is not taking place right now for a reason that LEW is not resposible of. (this sentence doesn't really sound like English, does it?)

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"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.