MikeGSB01

Coming back from a ten-mile ride last week and after stopping at an intersection heard a noise behind me. I was shocked when it was my wife laying on top of the bike, her face plastered into the asphalt (thank god she was wearing her helmet), and saw the front tire separated from the bike. After ambulance, fire dept and ER visit for CT scan I began doing some research and find that front wheel separation is not unheard of, especially on ebikes with disk brakes, using quick disconnects. This bike has under 200 miles on it and now is destroyed (bent front forks, bent chain sprocket, smashed controller). Anyway over $8k in doctor bills, $1.5k bike shot, we are thankful that my wife was only going about 1 mph when the wheel was pulled fron the frame. What happened to the washers with the little hook? guess they don't go with quick disconnects. Now I check my QD every time I ride and use to never think about it, wife is still recovering from her bruises and hope she wants a new bike. Looking a thru axle vs quick disconnect to prevent this from every happening again.

shelbyfv

Yep, get a thru axle if she wants a new bike.

KerryIrons

Just to be clear, this was the WHEEL separated from the bike, not the tire. It appears your quick release was not sufficiently tightened. The standard guide is that your palm should have a noticeable dent in it from the pressure of closing the QR lever.

trailangel

Tire separation? Wheel separation? Which is it?... OH... I looked in my crystal ball and you didn't tighten the Quick Release (not Quick Disconnect)levers on the front wheel, and then gave it to your wife... and she put the front brake on and the "Wheel/Tire" came off the bike.

cb400bill

Thread moved from General to E-Bikes.

2old

As above, this isn't an e-bike problem, it's a bike problem and I'm surprised the "lawyer lips" didn't keep the wheel from "separating". FYI, there are bolt on skewers, some with specific inserts to make the wheel "theft-proof", that would prevent this problem.

MikeGSB01

correct I did not tighten or check the quick release on the wifes bike, but she had been riding it for 8 miles that day. Wheel (with the tire attached) separated from forks (not just the tire). I was shocked and come to find this is common with ebikes that have disc brakes and quick release vs thru axle. The engineering forces loosen the quick release and eventually pull the wheel from the forks. Go figure!

Leisesturm

Do you know how long it took for motor hubs to move from freewheels to cassettes? Thru axles? I snort in your general direction. If there are e-bikes with Thru axles you can't afford them. Tighten the Q/R skewer properly and ride safe.

Bald Paul

I almost hate to ask this, but how exactly did you tighten the QR on the wheel? Did you just turn the lever until it was snug, or did you flip the lever to tighten it? I ask because the only bikes I've seen with washers with the little hooks were low end, department store bikes where you tightened the axle with a nut. Is it possible that the QR wasn't tightened properly?
Glad your wife is okay.

mpetry912 

there is a lawsuit against Rad Power for a bike accident (I think the child was killed or badly injured) and the root cause is - was - the QR came loose, or was not sufficiently tightened.

I've been riding for a very long time - have never had a QR come loose. Yet I know two people who were new riders that had QRs come loose and went down much as your wife did.

I personally think that the QR mechanism is marginal for the braking forces that can be applied at the axle by disk brakes. Those forces are magnified when you're riding a 50 lb ebike. if that improperly tightened quick release comes loose at speed and the front wheel comes off it is a very bad crash !

it is a simple mechanism that is unforgiving of inattention or carelessness. Definitely not "idiot proof".

here are some videos that shows the correct way to tighten the quick release. This is a little detail that can save your wife a lot of trouble, injury etc. Make sure you understand how the quick release works and how to adjust it so that it is solidly "locked" over center.

Videos: safe bicycle quick release adjustmet - YouTube

Personally I prefer thru-axles for ebikes.

/markp

MikeGSB01

Actually, never attempted to tighten since we bought it two months ago. According to the engineers, this design tends to become loose as the disc brakes as used, eventually pulling the wheel out.

mpetry912 

Mike, don't put too much faith in what "the engineers" may have said. It's a lot like when you hear "Studies have shown...". Disregard everything after that.

While it's true that the quick release develops a clamping force that is marginal for a 50 lb ebike equipped with disk brakes, I would ​​put it to you another way:

when you start out on a bike ride, there are a whole bunch of reasons why you want your bike to be safe and reliable. So, much like pre-flighting an airplane before you fly it, you want to make sure the brakes are working, the tires are inflated, and the wheels are firmly attached to the frame and fork.

I'd suggest you get in the habit of doing a pre-ride check covering (at least) those items listed just above. This can take under a minute and it's a good habit to get in to as you become a more experienced rider.

/markp

MikeGSB01

You are correct.

Pop N Wood

Sorry for the painful life lesson. This really had nothing to do with the design of the bike and is entirely operator error. The front disc had little to do with it and it being an ebike had absolutely nothing to do with it. This happens on a pedal bikes with rim brakes.

The mods did you a favor moving it to the ebike section. If it stayed in the general cycling section the jackels would have descended.

Through axles are better with disc brakes because they keep the brake rotor better aligned than a QR.