Panic braking or chain lock up?

**switchMode** · 30th October 2013, 08:54

Chain looks loose while he's sliding, you'd think it would pull tight if it got caught..

**carbonhed** · 30th October 2013, 14:00

TBH he doesn't look at all freaked out by what's happening so I don't think he panic braked... OTOH he rides funny... meh... on balance I'd give him a mechanical.

**switchMode** · 30th October 2013, 14:47

TBH he didn't even seem to react until it was way too late, maybe he just has glacial reaction times?

**tigertim20** · 30th October 2013, 17:16

Originally Posted by switchMode

Chain looks loose while he's sliding, you'd think it would pull tight if it got caught..

not necessarily, if part of the top run jammed between the sprocket nuts and the swingarm, its possible the chain would simply hang on the bottom run.

**switchMode** · 30th October 2013, 17:19

Originally Posted by tigertim20

not necessarily, if part of the top run jammed between the sprocket nuts and the swingarm, its possible the chain would simply hang on the bottom run.

It would have to jam up pretty tight to not wrap the bottom with the top since its all off the sprocket anyway (if it was caught on anything rotating it would wrap the bottom before the top and wrap the top of the chain down right?), and if that happened how did they just pick it up and walk it off the road? Did it uncatch during the crash? Magic?

I say unlikely.

**george formby** · 30th October 2013, 17:48

Well i just watched that with my new fangled youtube frame by frame software, tapping the pause/play button quickly. Coming into the turn he has a finger over the front brake & the balls of his feet high & back on the pegs. I did not see his leg move forward for a bite on the rear brake, may not have been necessary admittedly but it did not look covered to me.
If his chain was fooked, most probably, then braking may have caused a link to piggy back over the front sprocket causing a lock up. Chain most probably shagged from bad wheelies & the best thing about the bike would be the paint job. Show pony.
So, rider error or rider laziness. Same ting.

**Robbo** · 30th October 2013, 18:02

This appears to be a classic case for "Mythbusters"

**george formby** · 30th October 2013, 18:08

Originally Posted by Robbo

This appears to be a classic case for "Mythbusters"

More like CSI, shirley? The whole, "t'was not me" thing screams fuckwititis.

**tigertim20** · 30th October 2013, 19:23

Originally Posted by switchMode

It would have to jam up pretty tight to not wrap the bottom with the top since its all off the sprocket anyway (if it was caught on anything rotating it would wrap the bottom before the top and wrap the top of the chain down right?), and if that happened how did they just pick it up and walk it off the road? Did it uncatch during the crash? Magic?

I say unlikely.

I mentioned earlier that after watching the vid, Im of the view that it was rear-brake induced. I was simply answering a question by pointing out that it was possible. but yes, IF (and its a big if) the chain getting caught was the cause, it could easily have been jarred loose from the impact of the crash.

**switchMode** · 30th October 2013, 21:05

Originally Posted by george formby

If his chain was fooked, most probably, then braking may have caused a link to piggy back over the front sprocket causing a lock up.

I don't really understand how this would happen if his chain was off the rear sprocket before the crash? Surely the chain would be either pulled right by the front sprocket or the chain would just be rolling around the swingarm. See pic, I just don't see where the chain could jam on the rear wheel that wouldn't cause the chain to snap up just before the crash. Excuse shitty arrows.

**Transalper** · 31st October 2013, 20:00

Couldn't resist a look, was going to go with the chain lock but I see the wheel start turning again after the initial skid before the highside.
I think he braked while banking a little, maybe add clipping the edge of the road marker causing the skid, then released the brake too late causing the wheel to regain traction when freed while stepped out to far = formula for highside. You can see the wheel rolling again as the bike stands up but I would not expect a jammed chain to release again, at least the couple I've seen pop off and jam stayed jammed to the end.
I also know from experience that under a nice gentle and constant rear braking scenario that crossing to a different surface (old seal to new seal) that thing can lock up real easy without changing the pedal pressure as the friction level between road and tyre change.. just like bumping a road marker I imagine.

**EJK** · 31st October 2013, 21:41

Who needs NZ police serious crash investigation unit when you have Kiwibiker?

**SVboy** · 1st November 2013, 09:19

No-one seems to be pointing out that our "experienced" rider seems to be lacking in basic maintainance skills, which most likely contributed to his crash.