Oh Snap! Zero MX frame fails during Swiss race

Dailies -


Zero_MX_Frame_Failure_1.jpgA Zero MX suffered a catastrophic frame failure during a round of the
Swiss e-Moto electric MX series this weekend, it looks like the head tube snapped off
the frame rails. The bike’s rider, Tommy Heimburg, suffered a
concussion and a partially collapsed lung in the ensuing accident, but
plans to continue racing once he recovers. The damaged bike is being
shipped to Zero’s HQ in California, where they’ll examine it to
determine the cause of the failure. It’s not completely unprecedented
for a motorcycle frame to snap, but it usually indicates a manufacturing
flaw or previous damage. Having said that, the incident could seriously
hurt Zero’s reputation.

Zero_MX_Frame_Failure_2.jpgZero has come under some criticism, some of it from us, for specifying components that blur the line between motorcycle and mountain bike parts. They do this to achieve the lowest possible weight to maximize the limited performance currently available from electric powertrains, but often, the products end up feeling flimsy. Last May, Zero lost an electric supercross race to Quantya after Ryan Dudek’s X shed its spokes. In response, Zero released the MX, a beefed up version of the diminutive X intended for competition use. After this incident, a Quantya Track went on to win this race too.

Zero_MX_Frame_Failure_3.jpgThroughout the criticisms of its dinky componentry, Zero has been able to point at its aluminum frames as an example of its light-as-possible approach working flawlessly, saying their construction technique makes the frames both lighter and stronger than any equivalent items. The frame on the Zero MX (pictured) is constructed from aluminum with a wall thickness of just 80 thousandths of an inch and weighs just 13lbs. To strengthen it, Zero uses double pass welds in crucial areas, then heat treats the completed frame to restore the material to its pre-weld strength. Additionally, the MX frame is shot-peened and anodized and gussets are added around the head tube, all in the pursuit of strength and longevity.

Unless a manufacturing flaw or previous damage is found to be the cause of this failure, it could fundamentally question Zero’s approach to building its bikes. Even though this is an isolated incident, snapped frames are dramatic enough to grasp the public’s imagination, destroying consumer confidence, witness the Suzuki TL1000S, which saw sales plummet after on a handful of high profile frame cracks. Should Zero be unable to peg this incident on previous crash damage or a one-off screw up with its quality control, they’ll likely need to redesign, brace or otherwise alter the frame to restore confidence in their products. We’ll keep you updated.

via PlugBike

  • brettvegas

    I always thought the zero frame was a little goofy, the bats are perp. to the ground. it needs some angle to it. It screams ‘here are the batteries!.

    Hope nobody got hurt.


  • Emmet

    It’s also not completely unprecedented for a motorcycle frame to crack during a competition. I can’t tell you how many broken cars I saw at the last hillclimb I went to. These were stock SUVs and trucks that are meant to go offroading. If you push a machine to its limits you’ll find out what happens.

  • vic

    a frame that can survive moderate city/trail riding isn’t going to make it in a punishing enviroment like a motocross race .not a bad frame design just not adequate for the task
    i don’t think the guy behind zero checked with the experts before fielding this bike in an MX race.otherwise this should not have happened

  • http://www.amarokconsultants.com michael

    This incident highlights the simple point so often missed by e-bike start ups : the powertrain may be new, radical, even revolutionary, but the vehicle system has not changed. IT IS STILL A MOTORCYCLE. 120 years of R&D into chassis engineering didn’t suddenly become obsolete because we are no longer using piston engines.

    Zero and other start-ups had better wake up to the realities of modern state of the art frame construction or risk becoming the laughing stock of the industry.

    Along with the depressing E-Power “race” event at LeMans last week, this has been a very dismal spring the electric motorcycle year.


  • Bob

    Maybe Zero needs to sponsor a couple of bikes. At least to the point of supping new frames every race in exchange for the “raced” frame. Then they could put it back in the jig at HQ to find out what is really going on. If it check out good, they could just send it back as a replacement next time. It would be more work for the team, but they would probably co-operate in interest of getting the newest and hopefully the safest available. How hard could it be to strip down an E-bike and UPS the frame back? Assuming they already had the “new” replacement on hand. A lot could be learned in the real world.

  • BL

    wes, weren’t you just saying a couple weeks ago how the KTM e-bikes had ‘spindly frames’ ??

    vic, the failure was on a competition designed frame as mentioned in the article….not one made for tooling around the city or trail

    Emmet, you compare a competition MX bike to a stock SUV?

    dang right michael.

    it doesn’t even look like it was much for terrain…an E-bike race on a grasstrack …not so extreme

    that all said, shit happens….i’m sure they’ll learn something from it.

  • eduba

    Welding AL is tricky. There’s lots of opportunity for mistakes to enter during the fab process. First the shear strength range for the wire (for 6061-T6 at least) is between 11.5-ksi to 20-ksi.

    Plus, in my experience finding certified AL welders can be a challenge, and when you do find them, they prefer to weld using softer wire because the higher strength stuff likes to crack.

    I’m assuming they also stress relieved the weldment too before re-heat treating it…so more processing = more opportunities for an error.

    Given the location of failure and they typical loads, I’d guess it started with a small manufacturing defect and fatigued into a larger failure…the proverbial “zipper” effect. After the start of the weld failed, that reduced the area, increase the stress, cracked a bit more, etc., etc.

    The key is Zero’s response. Everybody makes mistakes. What will define the company’s character is how they respond. I’d suggest open and full disclosure including specifics on how this won’t happen again (…I was in QA also…)

  • AceCAfeClipOns

    Maybe the future isn’t here yet. Maybe we need to wait a little bit until electric bikes deserve beeing called motorcycles. I think I would stick at petrol engines and proper cycles as long as the industry allows me to. And each time I read something about electric bikes it makes me guess the same things: Is the industry on a hurry to make this err “things” standard? Isn’t this going to be new BetaMax? Are electric motorbikes really going to save the environment? Are we soon going to need mandatory nuclear energy for fueling all our vehicles? Does the future sucks that much or is it just my imagination?

  • brettvegas


    Well, I can’t say that I have not built anything that hasn’t failed.
    Aluminum is unforgiving, most gas bikes use huge castings.
    “diluting” the load.

    The headtube junction on any motorcycle is the weak link.
    I’d guess the bike had some miles on it, fategue(sp) and yeald are basicly the same with 6000 or 7000 series aluminum, stress the weldment often enough(~500,000 to one million), it pretty much has to fail. Look at any big3 MX alloy frame and you see massively built castings around the head tube.


    Um, I bought two bikes in the last week, 750 guzzi, and a neat little 75cc dirbi. I figure burn gas now, at least untill the eggheads(dumbshits) figure out that “lithium-oxy” batt. If they figure that shit out, we will all happily shove the gas bikes in the ditch. Twice the energy-to-mass ratio of gasoline keeps my hopes up, a little…

    The li-ion bikes are crippled, like a 1903 pump engine.


  • VetteWrecker

    Man, I don’t know anything about the engineering behind this failure so I won’t comment on that. I do know that Zero just just withdrew some good will from the brand account. Even worse, the haters are going to use this as another example of how electric bikes are a joke. I wish Zero luck sorting this issue, and I hope they take the criticism (in the article and comments) to heart.


    Anybody knows the weight of a new,250cc MX,Alu.or steel frame,just to compare,thanks.

  • Kerry

    this is what happens when you get a bunch of bicycle guys who try to build a motorcycle. You see a lot of this kind of frame failure in down hill bicycle racing (it isn’t common in general, but among frame failure the head snapping off is at the top). I have had the opportunity to spend time with zero products and a lot of it looks like bicycle spec, not motorcycle spec. I know they are trying to save weight but really, at some point you have to stop building bicycles and start building a motorcycle.

  • Scott


    hope the rider is OK

  • http://www.dgy.com JT

    Remember David Pingree 9 or 10 years ago? His KTM frame came apart at the neck… It can happen!