Very cool - carbon vs Alu destruction testing video

[lostrack]

In the Santa cruz lab...

If you're not yet on pinkbike I highly recommend it

http://m.pinkbike.com/news/santa-cruz-bicycles-test-lab.html

 

[amigafan2003]

And this is why I shrug off any concerns that people express when they see my little geared motor sitting in my carbon fibre front fork 8)

 

[MadRhino]

I can confirm that the V 10 is a stiff ride that can take repeated abuse. The V 10 frame is half inch thick CF. One should not consider this test a validation for all CF frames out there, especially those that are 10 yrs old.

 

[corkscrew]

I'll believe that there are carbon builds out there that are tough. The way carbon breaks is enough for me to not want any structural bike parts made out of it. Rather than bending it merely breaks.

http://www.bustedcarbon.com/

 

[amberwolf]

I do question their JRA-collision testing methodology, though, as I do not think the forces would be solely forward thru the BB as their machine puts them, but rather also thru the toptube via the seatpost from the rider's weight (until the rider begins to leverage off the seat), and thu the stem via the handlebars.

If they had a bike loaded up the way I do mine, then the forces along the frame would probably be more like what they are testing for, but I think that the average rider in such a collision would not transfer force thru the frame in the way they are testing.

 

[MadRhino]

Well, this test simulates a front landing crash, that is the most frequent cause of MTB frame failure. Also, this is the Santa Cruz Nomad, that is their lighter weight All Mountain frame. The V 10, their DH racer, has more than twice the CF thickness as the Nomad, and the destruction tests are so good that they had to upgrade their testing equipment to bring it to failure point. The V 10 is the only Downhill racing frame ever, to have a lifetime replacement crash guarantee.

 

[amberwolf]

Well, this test simulates a front landing crash, that is the most frequent cause of MTB frame failure.

Ok, well, that's not what the article said about the way the test setup was made--it calls it the JRA (just riding along) test which to me implies riding along a normal path, and then a massive collision like maybe a huge pothole or parked car or rock or huge crack in the ground or something.

I guess it depends on your biking experience and ride style for what it actually means, though, so for an on-road biker like me, it'd be quite a different test.

But still, even with a downhill crash, wouldn't there be even *more* force from the rider pushing on the handlebars as he goes flying over them in such a crash, compared to a similar road crash, given the likely much greater speed of the downhill crash?

The machine shown above emulates a massive and catastrophic frontal impact, picture casing a rather large gap with your front wheel. The front of the bike is held stationary with enormous steel fork tubes, and the bottom bracket is forced forward until failure. The test lab has aptly named this the JRA Ultimate test. JRA refers to the well known adage 'just riding along', and Ultimate denotes the test's destructive nature.

 

[MadRhino]

You are right, this test simulates a frontal impact, yet that is what happens in a front landing crash. The difference is that being downhill, the rider usually flies instantly and end up face planting with the bike flipping over him. If he is lucky enough to have his feet free, he will be saved from the bike pulling him by the pedal clips to fold his back and sink his head even deeper in the mud, or scraping his face longer on the rock garden. I know from experience. The fork is broken most of the time, and if the frame fails it will be either at the bottom of the steer tube or the middle of the top tube.

I believe that a front hit on the flat, would apply more weight from the rider to the frame, for his body mass would not leave the bike as quickly. No experience of a front crash on the flat, yet. :wink:

 

[amberwolf]

I see your point. :schock: