Brakeless fixie vs coaster brake

papercut said:

In the past, I've always countered the arguement made by
brakeless fixed gear riders (brakes are unnecessary on
fixie) that, at best, they have the stopping power of a
single coaster brake cruiser bike. And quite possibly
significantly worse for a number of reasons. However, I've
never actually put this to the test. Any thoughts to back
up or weaken the idea?

Those guys like to live on the edge. A brakeless fixie is
insufficient to stop you in an emergency - say if a car
pulls out of a side road. Don't do it. I can stop in about
40-50 metres from full speed on a velodrome, and that is
much too far.

Any rear wheel only brake (coaster or fixie) requires about
twice the distance to stop then a front wheel brake.

Why? Because the stopping force is determined by the
vertical force times the coefficient of friction. When you
are slowing down the center of gravity shifts forward and
hence there is less weight on the rear wheel. Draw some
force diagrams and you can figure it out....

Bruce

"papercut" <[email hidden]> wrote in message
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Quoted message said:

In the past, I've always countered the arguement made by
brakeless fixed gear riders (brakes are unnecessary on
fixie) that, at best, they have the stopping power of a
single coaster brake cruiser bike. And quite possibly
significantly worse for a number of reasons. However, I've
never actually put this to the test. Any thoughts to back
up or weaken the idea?

Quoted post said:

Originally posted by Papercut
In the past, I've always countered the arguement made by
brakeless fixed gear riders (brakes are unnecessary on
fixie) that, at best, they have the stopping power of a
single coaster brake cruiser bike. And quite possibly
significantly worse for a number of reasons. However, I've
never actually put this to the test. Any thoughts to back up
or weaken the idea?

Another problem with a fixed gear without a brake, is that the threads on the hub can't take the stopping force. I learned this the hard way. Thankfully they were crappy wheels on a crappy campus bike. 😄

-John

"j_erhardt" wrote...

Quoted message said:

Another problem with a fixed gear without a brake, is that
the threads on the hub can't take the stopping force. I
learned this the hard way.

What happened?

(papercut) said:

In the past, I've always countered the arguement made by
brakeless fixed gear riders (brakes are unnecessary on
fixie) that, at best, they have the stopping power of a
single coaster brake cruiser bike. And quite possibly
significantly worse for a number of reasons.

The maximum deceleration from a coaster braked bike is quite
a bit more than from a fixie of equivalent layout, for one
chief reason: When applying a coaster brake, much of the
rider's weight is shifted to the rearward pedal, and the
weight borne by the rear wheel is increased. Thus more
braking is available from the rear wheel before skidding.

With a fixie, not only is the rider's weight carried further
forward over the crank spindle, but there are dead spots at
the top and bottom of the pedal stroke in which the rider
can't apply much resistance against the bike's forward
motion. And this still presumes that the rider has both the
strength and the skill to make the most possible braking
from the available traction.

Chalo Colina

(papercut) said:

In the past, I've always countered the arguement made by
brakeless fixed gear riders (brakes are unnecessary on
fixie) that, at best, they have the stopping power of a
single coaster brake cruiser bike. And quite possibly
significantly worse for a number of reasons. However, I've
never actually put this to the test. Any thoughts to back
up or weaken the idea?

My commuter bike is my old track bike with a coaster brake
rear wheel. It works very well, I can certainly stop much
more quickly with this than I can with a fixed gear. I seem
to have better leverage in generating braking force than
with a fixie, and braking force is much more easily
modulated. However, it's nowhere near as good as a front
rim brake.

Coaster brake gives you almost every advantages fixies have AND they are safer.

Quoted post said:

Originally Posted by Loic Mercier [IMG]/img/forum/go_quote.gif[/IMG]

Coaster brake gives you almost every advantages fixies have AND they are safer.

Except for the continuous pedaling, or not being able to coast. For what it's worth.

For me, that's the whole reason for going out on a fixie ride. I don't know why other people ride fixies.

Loic Mercier said:

Coaster brake gives you almost every advantages fixies have AND they are safer.

Certainly slowing a bike without skidding a tire is better than slowing a bike by skidding tire. After all, sliding friction is less than static friction, no matter what fixie riders try to tell you.

Quoted post said:

Originally Posted by j_erhardt [IMG]/img/forum/go_quote.gif[/IMG]

Quote:
Originally posted by Papercut
In the past, I've always countered the arguement made by
brakeless fixed gear riders (brakes are unnecessary on
fixie) that, at best, they have the stopping power of a
single coaster brake cruiser bike. And quite possibly
significantly worse for a number of reasons. However, I've
never actually put this to the test. Any thoughts to back up
or weaken the idea? Another problem with a fixed gear without a brake, is that the threads on the hub can't take the stopping force. I learned this the hard way. Thankfully they were crappy wheels on a crappy campus bike. [IMG]/img/vbsmilies/smilies/biggrin.gif[/IMG]

-John

All of the acceleration and braking forces are transferred from the cog->hub->spokes->rim->tire->road to accelerate/decelerate the bike. The cog->hub transfer is via the threads the cog is screwed down onto. You're saying that these threads can strip and let the cog spin over them if too much force is applied, is that right? Couldn't this also happen during acceleration too?

It hadn't occurred to me that you could do that. Maybe just on the "crappy wheels" as you called them?