I hit a motorcyclist side on at about 30-35kmph. This is the state of the frame. It's a Deng Fu Chinese frame, so was curious to know if this is damage is what would have happened even to a branded frame, or is this an inherently weak frame?

It looks pretty nasty, but if you mean that you "T-boned" the motorcycle , I'm not too surprised. I've ruined a steel frame in that type of a wreck. It didn't look as bad, but both the top and down tubes were buckled, and the fork was bent.

BTW, how'd you fare?

I hope you're ok.

That look excessive based on the fact that it shattered in the middle of the top tube. I've t-boned stuff at greater speed and although I was bent and broken my bike was fine.

If the frame was going to fail I would expect to see a failure at the junctions between the top tube, down tube and head tube but not in the middle of a tube like that. Not at those speeds.

It looks as though that might be what happened at the down tube?

OP - glad you're well enough to post.

Geez, that poor bike....

At least it looks as if the wheels and bits survived.

How was the motorcycle?

Yes, T-boned is the expression I believe. We don't use that here though. The motorcyclist just turned from the left side of the road to the right to take a u. We drive on the left, and he was parked on the left. I was on the left slow lane, and didn't even have a chance to slow down. He just pulled out and turned in front of me. *******.

Lots of soft tissue injuries but no fractures.

Crazy thing is wife was involved in a hit and run 2 weekends ago to this day, and she had a head injury with concussion. CT was normal, but helmet was smashed. She is just recovering and now I'm down :-(

India is NOT a safe place to ride.

I think the frame was cheaply-built with inferior materials. I've been around for a awhile and though I was primarily a runner back in the seventies, I had a friend who purchased one of the first lightweight Schwinns made from thin aluminum predating chromoly. It could withstand normal road torsion but if it hit anything head on it would crumble like matchsticks. The kind of damage in your picture is unusual. I crashed my Cannondale at over 30mph., flipping in midair and hitting a stone wall which broke my leg. My frame survived save from a few scratches.

OP, sorry to hear about your crash and your wife's crash. Parts of California are not safe to ride either.

The wheels in your bike look OK, so the frame was probably defectively made or it had inferior carbon. Sorry about that.

Holy cow! ?

+1 - That looks like it was a nasty accident .... Good that the OP wasn't seriously hurt.

It looks excessive. The fact that the wheels look perfect is another clue. The downtube looks like is sheared very cleanly, which is usual for carbon. I would've expected the top tube to break closer to the fork.

I also would have expected the wheel to be the first damage but each crash is different. That frame is suspect without knowing more.

Front wheel is badly out of true. Fork looks OK though.

I T-Boned a Chevy Impala in the trunk area with a mid-70's Raleigh Super Course doing about 25 mph and just ruined the fork and the wheel. Frame looked fine.

If OP hadn't said otherwise, I would have guessed the motorcycle T-boned him just in front of his legs, not the other way around. I can't undestand impact that would break tubes and not tear up the fork crown-leg junction or fold up the wheels. Unless it was an unintentional crumple zone type effect.

Heck, in America, our bikes do that on their own ("asplode") when we dial up the wattage with our massive, overfed thighs.



Glad you're ok, though soft tissue injuries are no fun. I hope your wife is ok- serious concussions can be a big deal. Tell her not to push it. Her brain needs to heal before its confronted with difficult sensory input, etc. if you see personality changes in her, and/or if she has lingering emotional distress, get her in to talk to a psychologist. Makes a world of difference. OTOH if she's "just" having headaches and so on, then things should clear up for her.

Plastic bikes suck. I know all the CF boys will come out and say it ain't so but this kind of failure is crazy. A bike riding buddy of mine works in a Cervelo shop and tells me every week a bike comes in with significant failure from insignificant events. He is appalled, more at how the owner seems to think this is ok. I have a Merlin Titanium CF bike, the tubes are CF and the junctures are Ti. I had a persistent rattling and with a careful inspection found the waterbottle cage cage bolts had torn out of the carbon fiber. Had it repaired and same thing occurred within a couple months. Now I'm wondering when this down tube defect will spread and catastrophically fail on me.
I have an Italian steel frame, Columbus Double butted, that I have been riding for 4 decades, several major crashes, many simple falls and it is still going strong with no problems.
I repeat, plastic bikes suck.

Yeah I've been riding a plastic bike for the past 5 years and it broke and I died 3 years ago

I see two types of carbon frames. Example of first is the old style Colnago. It is lugged and made from thicker carbon. Well it may not be as light but it withstands all kinds of crashes and still very nice ride. The other are modern frames with paper thin walls. They might be ok when the load is strictly the type from normal riding but anything else and they break.

I ride an aluminum bike with a carbon fork. Neither has failed, but I've not been in a wreck with it. The question here is how many people that have been in the same kind of accident have experienced the same kind of damage? Is that type of damage only experienced with no-name Chinese frames, or do people on Cannondales, Treks, Specialized, etc. also have that happen? I'd probably disregard the anecdotes from anyone who hasn't experienced the same type of accident. On the other hand, if your bike folded into pieces like that while you were going 15 on a flat and hit a shallow pothole, I'd say it's definitely the frame.

Yeah, plastic sucks. Just a week ago I got T-boned in the seat/chain stay and the plastic seat stay snapped in 3 places. I'm typing this on St. Peter's iPad.

If I was riding steel, I'm sure the SUV would have been towed away, and I would have just brushed off its paint leavings and have been on my merry way.

How on earth are you able to abut those two events. Do you think that t-boning anytihng at THIRTY mph is an insignificant event?

On top of that, the OP is riding an open mold bike of dubious origin. Don't let that slow you down though.

Hard to say from looking at the results of a single crash whether the frame was weak or not. Crash forces are rather chaotic and seemingly similar crashes can have drastically different effects depending on exactly where and in what direction the peak forces occur.

The only crash I've had that damaged one of my bike frames was a T-bone type collision with a medium-sized dog (black lab) on a steel bike (531 DB). Both the top and down tubes buckled although no other components were damaged and the wheels remained true. It didn't come apart like the OP's frame, but it wasn't salvageable either.

Oh do they now.

We don't know the specifics of the OP's crash and likely neither does he, since was flying through the air and all.. That (cheap, generic) top tube might have taken a direct 90-degree hit from something. To generalize from this wreck to "plastic sucks!" is blatantly opportunistic at best.

If you were riding a Scwhinn Varsity, most definitely.