Quoted message said:The Berk said:Obviously I would assume they could if you clamp down fast enough.
Quoted message said:I ask because I bruised some rib bones this week when I stomped the
front brake and *surprise* I found out later my front rim has a
bubble bend in it from (I guess) a pot hole at some recent time.
....
http://www.sheldonbrown.com/brandt/over-the-bars.html
Quoted message said:it would have been funny if it hadn't hurt so much at the time
As someone else noted, most recumbents are immune to this
flipping-over-forward problem under hard braking. In my opinion this is
another reason that recumbents may be safer for general use--in that
during a panic stop, the brakes can be applied with wild abandon and
while the bike may slide out and drop the rider sideways, at least it's
not going to flip them over onto their head.... Usually (with any type
of cable-operated brakes) neither wheel will lock up. The LWB recumbent
I have has 160mm BB5 (cable) disk brakes and can't lock either wheel on
clean pavement at all. The RANS Fusion I own isn't that much longer or
lower than a normal upright bicycle; it has 200mm BB7's and won't lock
up or flip over forward either, from a normal riding position, and that
bike basically only has one riding position (standing on the pedals
requires serious effort for anything more than a few moments, and the
pedals are so far forward of the seat that you cannot scoot backwards
off the seat at all). Both these bikes carry about 66% of the weight on
the rear tire normally; that may not be ideal for racing but it seems to
improve safety.
Of course you always get people who claim they can stop an upright bike
perfectly fine,,, but this sounds kinda like when anti-lock brakes first
became common on cars and some people argued that they "didn't need it".
....Which is true in the absolute, you don't /need/ it, but you can't
stop as quickly without it, or with as good of control. Over time the
advantages of not losing directional control in a panic stop became
pretty obvious in repeated studies, and if you brake hard enough to lift
the rear wheel of an upright bike off the ground, then you've pretty
much lost control.
Also if you enter the words {bicycle over bars crash} in Google, you get
back a huge number of results--you still see a lot of people telling
"over-the-bars" stories, which was what safety bikes were supposed to
solve compared to the earlier penny-farthings. If you enter the
words("recumbent bicycle" over bars crash} you get very few, and most of
those aren't discussing such a recumbent crash at all. Much of the
upright-bike results seem to be off-road/MTB stories however, which I
don't consider a "typical" riding situation in terms of safety. When
you're riding off-road you do all sorts of stupid stuff, it's what MTB's
are for. The flipping-forward problem I only consider to be important
with on-road use bicycles.
I don't know that this translates into shorter stopping distances
however. It'd be interesting to compare two bicycles with hydraulic disk
brakes (and speedometers)- an upright MTB and a LWB recumbent--and do a
three-way comparison to see which one can stop quickest from a given
speed. The recumbent, with the rider in the normal (only) riding
position, and the MTB in the normal riding position, and also the MTB
with the rider low, arms locked and scooted backwards off the saddle.
The reason I say "hydraulic brakes" is that the power of cable-operated
disks varies with the cable lengths. The braking power front-to-rear on
an upright bike is a bit disappointing, but the difference on a longer
recumbent can be huge (does anyplace make thicker brake cable & jacket,
that will work with normal brakes? I'd try it...). I'd love to see
results of this kind of testing, but can't be much help as I won't
likely be putting hydraulics on either of my bikes anytime soon.
.....If you *prepare* yourself for braking you can lay on the front brake
of an upright--but that is the exact problem; many people who suffer
these crashes during on-road use are unaware they will have to stop
until it's too late.
Quoted message said:
Don't laugh. I wouldn't be so ready to tell all that I used bicycle
brakes in such a clumsy manner. Skilled motorcyclists do nose-down
wheelies at high speed, often crossing the finish line on only the
front wheel. That takes a bit of extra skill. A motorcyclist crashed
fatally yesterday in East Palo Alto doing that.
This is called a reverse wheelie, or a "stoppie":
http://www.dirtrodders.com/stoppie.html
Interesting on this page, that the article notes that the front brake
(of a motorcycle) needs to be applied smoothly, or else the front wheel
will simply slide. (I don't have a motorcycle, so I can't play these
sorts of games)
I am informed that it's bad for the fork seals.
There's classic photos on the stuntlife website of one kid attempting a
stoppie--likely not the first time--and his forks crumpling at the
triple clamps and the bike falling onto him (Stuntlife's motto seems to
be something like "Keeping high school overpopulation in check, one
motorcycle rider at a time"😉.
~
