You can crash into a bend if the bend includes a guard rail or other obstruction. Whether the expression is used when no guard rail or obstruction is present is unknown to me. And it's not clear from the photos and video whether the bend in question has/had a guard rail/obstruction.
To crash into a bend is an expression used in British English and Australian English (as well as in current Englishes derived from BrE, such as in Hong Kong, Thailand, Bhutan). It is not used in American English. Also note, when talking about driving in general, bend is characteristically British English (eg, driving through a bend), whereas curve (or turn) is used in American English.
From the above photo, from a Hong Kong government site showing an
Example of traffic sign and road marking arrangement at long steep cycle downramp towards a bend
it's easy to see how one can crash into a bend when the bend includes physical features that one can crash into, including the guard rail. If the guard rail wasn't there, one could easily crash into the tree which is along the bend.
For instance, an article about a fatal accident in a neighborhood in Australia all but equates smashing into the bend with crashing into a tree at the site of the bend:
Police are piecing together how a 56-year-old driver from Maryborough failed to negotiate a bend heading towards Buderim village and crashed into a tree... A neighbour known as "Jill" said it was not the first time she had witnessed a car smashing into the bend heading uphill along Lindsay Rd.
In 30 years she has lived in her home, Jill has had a car burst into her front yard and saw a motorcycle crash into the bend.
The photograph accompanying the article does not show a guard rail.
Whether or not the phrase can be used when there is no "physical feature" other than the bend (ie, AmE curve) itself is not known to me. But many dangerous bends have a guard rail into which one can crash.
The preposition into (definition 2):
Expressing movement or action with the result that someone or something makes physical contact with something else:
'he crashed into a parked car'
See also More Example Sentences, which feature cars crashing into walls, kitchens and homes.
This race car has crashed into a bend. (This is the opening frame of a video posted on youtube.) The accompanying text, describing an event filmed live in Thailand, starts:
Just some extracts from Toyota Motorsport event at Sapan Hin, Phuket, on Sunday 9 October, just seconds after a racing car crashed into a bend, but driver got out OK and went off in ambulance...
Results for "crash(ed) into a/the bend" are meager/meagre on search engines. Yet, several of them are in a context of a bend that includes or implies a guard rail or other obstruction one can crash into.
No 1 At the gran prix
It's fun seeing a car crash into a bend - I've learnt that I'm a sadist
No 2 From old Nintendo Grand Prix Auto Race game
So once you have started the race, you will notice that it can be quite a challenge to master the controls...If you crash into a bend or run over the curbs, it will cause damage to your vehicle...
See the accompanying youtube video of the dated game, showing bends into which a race car can crash.
No 3 MOH Qualifying - Respect the Mountains.... (BrE)
on the way down to the super steep “double black” – dropping in, my arms are killing – probably 15 minutes into the race now – so struggling to exert enough force to brake, and with bodies strewn left, bodies strewn right, I am sent slightly off line and crash into a bend. Hot damn – people pass me.
It's possible that in the above description of a mountain bike course that there is no guard rail to crash into. The same can be said for the following usage:
No 4 around taiwan on 2 wheels 02 – the full monty (5) (BrE)
from shipai 石牌 , it was a fingers-and-hands-numbing-brake-holding 20km downhill to lunch point 坪林. we had to constantly remind ourselves that if we got distracted for even 1 second, we’d crash into the bend or worse, string our cycling mates along.
No 5 4th JK Tyre Indo Bhutan Friendship Rally (race car circuit, Bhutan)
...Then car number 23 rolled over and had an accident and another crashed into a bend.
The rally (race) is in Bhutan, whose English is traditionally British English. There are many photos that accompany the article thread.
No 6 Car seat decisions (UK?, not US)
When I was driving home a week ago- car in front of me doing about 40mph and crashed into a bend. Driver was injured and I had to dial 999 for her,...
(999 is the emergency phone number used in the UK and elsewhere, but not in the USA).
No 7 Dims not very good (the UK)
It wasn't too bad on the dual carriageway but once off it I couldn't actually drive without my full beams being on for fear I'd actually crash into a bend.
No 8 Signs of the Times* (Ireland)
...A growing issue in County Cork is missing road signs which leave dangerous areas unmarked for visitors passing through...or worse, some one could crash into a bend because there are no signs to warn you its there.
No 9 most crashed into a bend on (Thailand)
Meng Xiang started out with his defense ,hard block Buddha palm ,although early after the jump dismantled the strength ,but still feel his arms like is one hundred thousand jins giant impact ,hot stabbing pain my heart ,body is bumped to fly almost 50 meters ,a knocked down several hapless passers-by ,most crashed into a bend on the corner ,before it stopped .
This is a blog entry from a website in Thailand (where traditionally Britsh English is taught). Its usage of a space before a comma (,) or period (.) is not in accord with standard UK and US usage.