tsappenfield

I'm not a triathlete, but I am a time trialer My question concerns the braking technique you should use in a race where there is a turn around. Assuming a dry road, I wait to brake to the last possible moment. What about the technique for braking. Do I brake only with the front brakes, or both brakes simultaneously? I have been using the latter method, but I'm now wondering if the former method would be better. This thinking is based on articles I've recently read on braking on a road bike where apparently as much as 95% of braking is done with the front brake only. Supposedly it's a much more efficient way to brake. But would this be true for a time trial turn around?
Tsapp

FBinNY 

I'm a committed 2 brake man. I realize that in a maximum Gs stop all the braking force is generated at the front wheel, and the rear is unweighted, contributing nothing.

But, shy of that there is some rear wheel braking, however slight. Also with the rear brake applied the rear wheel will lock when it's unweighted enough. That makes it a telltale, announcing that I'm at the threshold of total unweighting, so I can modulate the front to prevent an endo.

BTW, your goal shouldn't be a full stop, you only want to scrub off enough speed to make the turn. In your shoes, I'd stress learning how to Kate the turn at the highest possible speed. That saves time slowing, and more important, time bringing the bike back to speed.

FlashBazbo

Even if you assume the front brake provides the majority of braking power . . . (and I think 95% is a vast overstatement) . . . the rear still contributes additional power. If you want to stop/slow as quickly as possible and under control, using both brakes is the way to do that.

Lots of studies have been done for motorcycle racing where, for decades, racers bragged of using ONLY the front brake. Every study indicates that using both brakes is better -- and by a significant margin.

ridelikeaturtle

Coming from years of motorcycling and cycling (road and mtb), but none racing... all things being equal (and I'm thinking the size of the area you have to do the turn is very important here), if it were me I'd be using mostly the front brake, and wanting to maintain as high a "cornering speed" as possible (like in MotoGP lol), to maintain momentum.

Using the rear brake would be sparingly, and just to stabilize the bike so you can maintain a high level of control, so you can put the power down as fast as possible once the turn is complete.

FBinNY 

Both MC and bicycles can be brought to a point where 100% of the braking power is off the front brake. You see it when folks stunt and do front wheel wheelies balancing on the front wheel with the rear off the ground.

At that point the rear brake no longer matters, but before that it can be brought to where it ALMOST doesn't matter, (before it lifts) leaving some margin for error, especially since most people aren't stunt riders. So, I used 95% as a point of reference, but it can be anywhere shy of 100% depending on the rider's skill in balancing braking force.

As I mentioned, in an emergency maximum effort stop, the rear brake doesn't help, but using it helps by providing feedback and an early warning of impending tip. So we agree on the principles involved, and can skip debating the finer points.

FlashBazbo

Agreed on the theory. But I was trying to avoid sounding like an idiot. Doing a stoppie while moving around a curve on a TT bike is probably not realistic for any humans outside the realm of accident.

FBinNY 

I agree completely. Braking on curves problematic in the best of conditions, executing a hard turn while braking is especially difficult and borders on stunt riding.

In my youth, I was able to punch the front brake, lift and swing the rear wheel around and recover to start out in a new direction successfully a decent percentage of the time, but it wasn't anything I'd count on. (plus that was then and this is now).

So, for the OP or anyone operating a bicycle at higher speeds or more critical maneuvers, the key is to scrub off the required speed before turning and entering the turn free rolling, then possibly applying some power as you exit.

tsappenfield

So I'm leaning even more strongly to the front brake method. I'm hoping some more members will chime in on this post.
Tsapp

ZIPP2001

I've done well over 200 time trails over the years and have always used the front brake only if the time trails has a turn around section. To that point I did for many years only have a front brake on my tt bike years after I had stopped doing time trials. The best thing would to be practice your braking technic in a non race environment and find what's best for you. Everyone has a different level of comfort and I know some very good time trial racers that are a little heaver on the rear brake at turn. It's the same as some riders can stay in the aero bars on some very technical courses and some can't, it's your comfort level.

tsappenfield

After Zipp2001's reply, I'm convinced that going front brake only and spending more time practicing my turn around technique is the way to go. I'm still learning how to race this event and have been improving my times every year for the past four years. I was 12th in the 5k and 10k TT races this past season at the National Senior Games. It seems like fixing all of my technique mistakes might get me a top 10 finish in the 2019 games, at least that's my goal. I'm pretty sure that I have been braking way too soon coming into the turn around and using primarily the rear brake. Not good! If I'm going to brake at the last possible moment and therefore brake hard, I want to know the proper technique.
Tsapp

seypat

Why don't you just go some place like a school parking lot/bus loop where you can experiment and find what works best for you? Getting in the right gear before you exit the turn around might be more important than what brake you use.

_ForceD_

I like FBinNY's method of shedding the speed before you begin the turn so that you can perform the turn without using any brakes while turning. However, a factor that I didn't really see mentioned, but does bare consideration is: How wide of an area do you have to execute the turn?
Since you're a TT'er and not a triathlete you're likely executing the turn without any other bikes present (not always the case in a tri). In the TT, presumably you are free to take any line you want. If you have both lanes of a two-lane road you can make a wider turn...which IMO is more controlled. Granted you're covering a little more distance, but since you have more control, and shedding the speed before you begin the turn and not being on the brakes in the turn, you should be able to apply some amount of power through the turn. You also maintain more momentum and coming out of the turn you can get up to speed quicker.

Dan

rubiksoval

Why is it an issue to use both brakes? Both hands are on the hoods? You're talking like an additional cm of additional hand movement?

Brake late (so both brakes), and be done braking before entering the turn.

You'll gain or lose more time by taking a bad line through the turn than you will by trying to figure out which brake to use. So I'd focus on entrances/exits, setting your body up to minimize the turn radius (butt hanging off the outer back of the saddle) and then straightening the bike back up and pedaling hard as soon as you start exiting.

Lastly, just practice turn-arounds. It's a skill that can be improved, like most everything else.

tsappenfield

Practicing is only good if your practicing the correct technique(s). Coming into a turn around, any time trialer has a lot to think about such as how much speed to carry into the turn, the line to take, when to brake, how to brake, what gear to down shift into, when or if to get out of the aero bars, etc. Out on the aero bars and with your finger on the bar end shifter on the drive side aerobar, you're about a foot away from the brake levers. Since the front brake lever is on the non-drive side and the shifter for the rear derailleur is on the drive side aero bar, it seems reasonable to me that after all has been said here, to brake with the front brake only unless I realize that I can't get the bike down to a perfect speed to execute the turn and get back up to speed without going off course. I'm really looking for the best technique(s) to shave off some seconds in this critical part of a time trial race.
Tsapp

FBinNY 

It's possible to overthink things, or to lose significant time by making a mistake chasing hat last fractional second.

The total turn around time is only seconds, and basic good technique can get it down to only a very few. After that another shaved second is unlikely to be serious. It might be advantageous to focus in finding the maximum speed you can carry in to the turn. That means less time lost to scrubbing it off, less time in the turn and less time and effort accelerating back to speed after.

Depending on the space available, the fastest total time might be achieved by finding the widest loop that fits and carrying maximum speed through.

So, back to practice. Mark off a box representing the space available at the turn around, get a stopwatch, and practice using the braking techniques discussed here, find the maximum speed you can carry, then drill it like crazy until it's completely automatic.

Doge

I have spent a lot of time on this (for my kid and team, not me) for TTs and Team TTs - which are just fun and tricky as you can change positions.

As with many things it comes at a cost. Fastest is brake at the last moment, and accelerate out.

Obviously, don't over brake or under brake. The cost is it takes more energy. You may have traffic.
The line you take is more important, but you didn't ask that.

FlashBazbo

This.

And this is why even the pros tend to do turn-arounds with BOTH hands on the brake hoods. On the extensions, you have less braking and STEERING control in the turn -- and speed / control in the turn is what it's all about. Braking well only matters if it lets you carry maximum speed through the turn.

Work on braking, turning, gear selection skills. They all matter. Along with, "when do I switch from the extensions?"