Braking in the wet

[TOTO]

I know there are threads about that and I've read them, just sharing my experience here...

Today I was on my way back from uni and it had just started the rain, maybe 5 mins ago, decided to go to the bakery but on the intersection I locked up the rear wheel and it gave me a scare coz I wasnt pressing on the back brake hard and it was totally unexpected. Skidded for maybe half a metre.

Anyway afterwords I decided that it would be a good idea to go to an empty carpark and practice braking in the wet.

Went to the empty carpark 2 hours ago and started practicing stopping - front brake only , back brake only, 2 brakes at the same time. It was not as slipery as when It just started to rain , actually I can Say that I had more grip when it was soking wet that when it just started raining.

My special mission was to see at what stage does the back wheel lock, so I was playing mainly with the back brake. I tried at different speeds: 10, 20, 30, 40, and 50Km/h Tried two methods of pushing the brake too: one is constant push all the way doun and the other I tried was "pumping action" - pressing and releasing the brake.

Tried braking on 2 different surfaces too, one was just the normal type of road, the smooth one , not the rough one, and also one which was more like smooth couble stones(dont know the name exactly, but the carpark I did it is the carpark of the North Shore Event Centre)

Here are the things I found:

1. Half wet surface is most likely to lock the back wheel than fully soakeing wet surface.

2. Pumping the Back brake seemed to help me not locking the back, not sure if its always like that but this is what I observed.

3. If you lock the back brake at loower speed you slide less than if you lock the wheeel at higher speed

4. Locking the back wheel standing straight is more managable than if you are a bit on an angle.

5. If you lock the back wheel and you are holding the front hard and keeping it straight, even if the back slides like a russian gymnast on ice skates it will eventually come back , even if still locked till the end (I'm sure ppl can disagree here )

6. The tires still have about 80% traction compared to dry road so leaning over in a corner is a matter of confidence, where as in the first 15 min of rain I'd say you have maximum 60% (estimation)

7. people walking their dogs are quite entertained watching a biker skidding around in the carpark

8. Doing the wet weather excersisses boosted my confidence, now I have some Idea about what to expect.


So there you go. These are my observation from todays wet practice.
If you have any coments, sugestions for other wet weather excersises, or thing you've found out about wet weather BRAKING in particular I'll be glad to hear them.

TOTO

[FJRider]

We dont worry about the rain down here. We get it twice a year, no prob's

[MickDastardly]

Jeez wish i had done a bit of wet weather practice, I have totally no confidence in the wet I ride like Im pushing a trolley, still didnt stop me from going for a slide to work this morning

cheers for sharing your tips!

[rphenix]

I know there are threads about that and I've read them, just sharing my experience here...

6. The tires still have about 80% traction compared to dry road so leaning over in a corner is a matter of confidence, where as in the first 15 min of rain I'd say you have maximum 60% (estimation)

TOTO

I'll sort of agree with this one... Your tyres will probably let you lean over way more than you might first think till you build your confidence but I don't know about 80% traction I think when its first starts to rain i.e. not enough to clean the crap of the seal you can loose quite a bit!

One trick I learnt ages ago is if I want to keep my normal speed up in the wet I tend to lean my body of the side more and keep the bike a little more upright you seem to get around the corner just as easily and it feels "safer" of course this can make recovery a little harder if you mis-calculate as you have to shift your weight back again but it certainly works for me.

[Ixion]

1. Yes. The first bit of wetness is very slippery because of shit (rubber, oil, dust) mixing with the water. This (a) more slippery than plain water and (b) the sipes in your tyre can't easily pump it away. After a bit the shit gets flushed away .
2."pumping" has a mixed press, Basically it just helps avoid too heavy an application, and thus lockup. But on the other hand you lose a lot of braking time, because , in effect you are only breaking half the time. There is a more sophisticated approach called pulse or cadence breaking which in theory overcomes this. On a rear wheel I'm not convinced it's worth bothering. In theory ther eis also a risk of a high side by locking and then releasing the wheel.
3. But a low speed slide gives you less time to sort yourself out,
4. Yes. A locked rear is no big deal if you are upright and straight, just release the pressure a bit. Try to avoid braking at all if you are not. Obviously sometimes the real world intervenes. almost all modern road bikes, IMHO have back brakes which are far too powerful. There is no justification for a disk brake on a road bike, except maybe a heavy crusier.
5. No disagreement here. It will indeed straighten out. But don't hold the bars hard- firmly yes, but don't fight the bike. Just concentrate on keeping upright and straight, and if the rear fishtails a bit, let it.
6. Um. Yes. But be very careful here. Overall, traction is not all that much reduced in the wet, with GOOD modern tyres . However there are some still out there where wet grip is MUCH less than dry. The other dangerous thing is that in the wet there is a far greater variability of traction. This corner may be 80% of dry. But the next one could be down to 50%. and white lines and manhole covers can be down to 10%.
7. Next time get someone to pass a hat around
8. Well done. Fore prepared is well prepared.

[Unit:Me]

Must go and try this on the 14, can anyone point me to a carpark big enough?

[C_A]

cool. practice is always good.
I rode home yesterday in rather dismal conditions. had pretty low visibility.

I was more concerned about stading water on the motorway, having never really encountered it before. I've ridden a few times in heavy rain but never really come across more than patches about half a metre in diameter that were easily avoidable. going along the wellington motorway there was almost two lanes covered in parts.
what's the safest thing to do if you start aquaplaning at highways speeds?

[Cache Wraith]

1. Yes. The first bit of wetness is very slippery because of shit (rubber, oil, dust) mixing with the water. This (a) more slippery than plain water and (b) the sipes in your tyre can't easily pump it away. After a bit the shit gets flushed away .

Fully agree. The most dangerous time in terms of slippery surface is the first rain after a dry spell. Particularly if it is light rain. All the recently deposited oil, diesel, coolant just rises to the surface. This goes equally for cages too. Avoid the road if at all possible until a decent rain clears it.

[Trudes]

I was told that you should lightly apply the brakes occasionally in the wet to help to keep them a bit drier, so when you need to use them they won't need to scrub off a surface of water first and they don't work so you apply more brake but then they dry and grab suddenly. not sure if that was understandable... or correct, just what I was told.

[TOTO]

Fully agree. The most dangerous time in terms of slippery surface is the first rain after a dry spell. Particularly if it is light rain. All the recently deposited oil, diesel, coolant just rises to the surface. This goes equally for cages too. Avoid the road if at all possible until a decent rain clears it.

I agree too, today before my practice , when I had my first skid , the road felt like GLASS , I was soooo nervoius

[johnnyflash]

Jeez wish i had done a bit of wet weather practice, I have totally no confidence in the wet I ride like Im pushing a trolley, still didnt stop me from going for a slide to work this morning

cheers for sharing your tips!

Having no confidence probably makes you a smart rider :-) it means you will take precautions, and you can still have confidence in your ability, just not Over Confidence, which will kill you :-)

There is no such thing in the wet of trying to predict exactly what amount of grip you might have, our roads a a changing scene from one minute to the next, depending on what passed over it and what they left behind, as well as rain sun seal debri etc.
the smart scenario is to treat every meter of seal as different, scan the road all the time, looking for shiny/greasy bits helps access the grip, but many traps you wont see, when oil / deisel / paint / gets heated byt the sun and mixes with water its darn near invisable at 4 meters, from my experience there is no 100 % g/teed grip in any situation, remember most road tyres are a balance of tred/compound for all riding situations, not specialist tyres for specialist conditions for the race track.
Only thing that works is to follow the basic rules, brake while upright, read the corner correctly, take good lines that allow a margin for a little movement, and of course practice....
stopping in all sorts of situations, dry, drizzle, rain, flood.
Always look at the point where you want to end up particulaly when emergency brake/evasion. Because as sure as hell you will get caught out by bad surfaces/grip/situations at the worst possible time..

[Ixion]

cool. practice is always good.
I rode home yesterday in rather dismal conditions. had pretty low visibility.

I was more concerned about stading water on the motorway, having never really encountered it before. I've ridden a few times in heavy rain but never really come across more than patches about half a metre in diameter that were easily avoidable. going along the wellington motorway there was almost two lanes covered in parts.
what's the safest thing to do if you start aquaplaning at highways speeds?

True aquaplaning, a wedge of water building up under the tyre, so it ries on a wave, is very rare on a motorcycle, because of the rounded profile of the tyre.

However significantly deep water can cause drag which can affect handling, and running water will tend to pull the front wheel. And the effect of a wheel dropping into a rut or hole full of water can be very unpredictable.

and I guess with modern crusiers having tyres almost as wide and flat as a car, they may start to suffer the same way as a car.

If it did occur , I guess the approach would be the same as a car. Upright straight, gently decelerate, all smooth.

[Ixion]

I was told that you should lightly apply the brakes occasionally in the wet to help to keep them a bit drier, so when you need to use them they won't need to scrub off a surface of water first and they don't work so you apply more brake but then they dry and grab suddenly. not sure if that was understandable... or correct, just what I was told.

This really only applies to dosk brakes. Water accumulates on the rotors. Some folk like to VERY GENTLY apply the brake every so often to wipe the water off. I've never really seen the point, because how long will it take to get wet again?

But, it does raise a VERY important point. In rain, the rotor gets a film of water on it. When you first apply the brake, for a very small time, it will not be very effective, because the water holds the pads off the rotor. It is only a fraction of a second, but it can seem a long time when that truck is looming up. A classic novice mistake is to panic, "oh shit my brakes aren't working" and squeeze harder. Much harder. then the water is dispelled the brake grips fully, and you can imagine what happens next. Get used to braking with a steady measured squeeze, even if for a moment it doesn't seem to do much.

[TOTO]

was just thinking , maybe a good idea to stop somewhere for a coffee while the road is completely wet instead of riding trough the first minutes of it...may as well.

[Movistar]

cool. practice is always good.
I rode home yesterday in rather dismal conditions. had pretty low visibility.

I was more concerned about stading water on the motorway, having never really encountered it before. I've ridden a few times in heavy rain but never really come across more than patches about half a metre in diameter that were easily avoidable. going along the wellington motorway there was almost two lanes covered in parts.
what's the safest thing to do if you start aquaplaning at highways speeds?

Probably the best thing to do is SLOW DOWN so you don't aquaplane!!!

But if it's too late for that, don't brake, don't accelerate, just stay as upright as possible and maintain a firm but not tight grip on the handle bars.

It's a scary situation to be in and to be honest once you've done these things a bit of luck will go along way...

Well done for at least getting out there and practising and experimenting, you can learn so much by doing this but remember the best and safest way to brake is using both front and rear brakes, I would highly recommend you practice this next time.