Brake physics, front vs. front+rear???

Hi, something that I have been arguing about with people (especially bicycle newbies) for DECADES now, and I am pretty sure about it, but not 100%, so I am happy to hear your well-founded opinions:

In case you want to do a sudden full braking (on dry flat pavement), will it make any (which) difference if you
A) brake solely with a really good front brake (for example a disc brake), carried out in the perfect way, i.e. really hard and with your rear wheel taking off a bit, but without flipping you over the bars
or
B) also using an additional rear brake (not sure what the "perfect way" would be, if your rear wheel takes off it makes no difference anyway! So that would mean you may not brake as hard on your front wheel as in A?)

Happy to hear what you think

Your rear wheel doesn't take off right away when you start applying the 'perfect braking' method with only the front brake. So until that time, the rear brake is of use.

Looking past that, the 'perfect braking' method is not a viable braking method. Especially because when you need to brake really hard (in an emergency), you don't have the time and state of mind to use the 'perfect braking' method. So two brakes is still the safest/best way to slow down in any real world scenario.

also, the rear one has a massive effect if and when the front one fails

I was riding with just a front brake for a long time, and I had this incident some years ago where the brake cable snapped right on a big crossing, luckily I was going not that fast and the car next to me that was taking a turn realized early enough that I cannot slow down, it was actually a nightmare situation, especially considering that the car could also have been a lorry or something.
The next day I was wondering what to do, because the frame had no possibility of adding a rear brake (track frame with carved-out rear bridge).
So, I decided to simply fit a disc fork, build a front wheel with disc hub and rim brake compatible rim, and ended up with two front brakes (left lever = hydraulic disc brake, right lever = classic rim brake), but I actually never ever use the right lever, which is solely there in case the disc brake fails.
In my case, there is no other way of adding a second brake anyway, but this unusual setup was often the starting point for discussions as described in #1

Rear brake is also good on slippery stuff.

For sick skids

You're on LFGSS now. Calm down with that crazy talk....

In good conditions, rear brake doesn't do much. In wet, icy, slippery conditions, it is quite easy to cause a front wheel skid which is generally terminal. Recovering from a rear wheel skid is straightforward - some people even do it deliberately, for fun.

Brake cables also snap, especially if they live outside, are old, galvanised, unloved, etc.

loc'd out fuckin golfaz pullin' sique skidzz

Depends on the centre of gravity of the bike and rider. Since most of the weight of the unit is the rider. Riding position and reaction when braking is critical.

A rear brake is also really nice for descending very steep slopes (fun in the forest...)

I know that rear brakes are fantastic on wet or steep terrain, but my comparison refers explicitely to the difference between front vs. front+rear on dry flat pavement

When I did my motorbike test the emergency stop was slowly gripping the front brake lever, rather than jamming it on, and following with the rear brake.

That’s how i stop on my bike as well. Unless if you’re doing a stoppy. Then it’s front brake all the way.

But like if your rear wheel doesn’t leave the ground it’s only going to help slow you down if you brake.

The one the drives me mad is when new riders insist that the front brake is bad as it’s only going to throw you over the bars. Only if you’re lucky

The front brake will only throw you over is when the centre on gravity is shifted heavily forward. This would happen either down hill (very steep) or the rider is off the saddle and leaning forward .. like longest skid competition.

or if you're riding a Klein Mantra

or jumping off a wall and landing in to shingle front wheel first

If you're braking from high speed or while descending, using both brakes rather than just one brake will prevent heat build up, and reduce the negative torque causing deformation in the front sidewalls.

Are you riding this fixed or freewheel?

75% front
25% rear

freewheel

Get an appropriate frame and bingo bango you’ll soon find the best way of braking.

End thread

You'll have that perfect braking one time of many, in all other circumstances you'll be better off with both brakes.