04 RT Riding on wet surface.

[stpete]

To those who have 04 RT's. I've owned it for several months now and never got caught in the rain yet. Question I have: since it has fully linked brakes, how does it handle on the corners when streets are wet. In the past with regular breaks I would use only rear ones to prevent front slipping away but now I have no choice with linked ones, when I apply foot brake, rear and front activate as with hand lever. It goes for wet and gravel roads as well.

[co_g30]

To those who have 04 RT's. I've owned it for several months now and never got caught in the rain yet. Question I have: since it has fully linked brakes, how does it handle on the corners when streets are wet. In the past with regular breaks I would use only rear ones to prevent front slipping away but now I have no choice with linked ones, when I apply foot brake, rear and front activate as with hand lever. It goes for wet and gravel roads as well.


well, assuming you've got good thread on your tires, you just have to be "smooth", no jerking on the brakes in my experience. I tend to start slowing down earlier for curves. My metzler 880s do fine on curves in hard rain.

ymmv and the msf would not approve but I tend to not use all four fingers on my front brake lever because of how strong the brakes are. I rarely use the rear brake pedal except to signal I am slowing.

my only problem with rain is reduced visibility since your helmet visor becomes covered in rain drops. A small wiper blade on my left hand's glove's finger blade helps with that.

otherwise, no big deal riding in rain. Unless you're in the mountains in Colorado, then you have to monitor for ice and snow at times. Like yesterday. Temps in the low 50s but got snowed on at Berthoud Pass.

on gravel roads, it gets a big iffy, I tend to do gentle slow application of the front brakes with two fingers max. It's better to go slow and use engine braking in that kind of terrain in my opinion.

Good luck and have fun with your RT, they're great bikes.

[rinty]

RT:

On my non ABS oiler RS, I do my braking before the corners in wet weather; I don't want to upset the bike. If I had an ABS bike, I would still not brake in wet corners; you don't know if there's diesel fuel or oil patches waiting to bite you. I never use the rear brake after the first part of any corner, even if it's dry.

I just slow down the pace a bit when it rains and try to be as smooth as possible.

Rinty

[ultracyclist]

Are you saying that one should not use trail braking techniques in rain if the bike has linked braking systems?

[OfficerImpersonator]

:lurk

[lionlady]

Okay. My '04 R1150R Rockster has "partially linked" brakes. Squeezing the front lever gives some rear braking also. Using the brake pedal gets rear brake only.

Interesting that the different models of the same year have different systems.

P

[r11rs94]

To those who have 04 RT's. I've owned it for several months now and never got caught in the rain yet. Question I have: since it has fully linked brakes, how does it handle on the corners when streets are wet. In the past with regular breaks I would use only rear ones to prevent front slipping away but now I have no choice with linked ones, when I apply foot brake, rear and front activate as with hand lever. It goes for wet and gravel roads as well.

I've been caught in the rain more than I want to remember. Almost always when traveling on the highway. I have never had any breaking proplems that I can remember and did make one panic stop, when the car in from of me had stopped and had no break lights. I was glad for the abs at that time. So ride away, adjust the shield to just where it helps keep you shield clear and enjoy. oh and make sure you have good rain gear. :thumb

[rinty]

Are you saying that one should not use trail braking in rain if the bike has linked braking systems.....Ultracyclist

My understanding of trail braking is an application of back brake only, for certain riding situations, including cornering. In a bike with a linked system, the front brake is always applied to a certain degree, and the result would not be "pure" trail braking.

Regardless, the application of linked brakes is going to result in an additional load on the front wheel, with a resulting increased potential for the front end to kick out on a slippery surface, while cornering.

My practice in wet conditions has always been to try to brake, if at all, before the corner entry, and then to ride through the corner with constant throttle or slightly increasing throttle. By adding power to the rear wheel, you decrease the load on the front, and decrease the chance that it will slide out. I have never ridden a bike equipped with linked brakes in wet corners, but I would still avoid braking such a bike in these conditions while leaned over, for the above reasons.

A review of a number of internet sites, including Keith Code's and Kevin Schwantz's, suggests that wet braking be done very smoothly and while the bike is upright, before entering corners.

Just my opinion, and hopefully Dave Hough can weigh in here on this worthwhile topic.

Rinty

[OfficerImpersonator]

ABS prevents the front wheel from slipping relative to the rear wheel, and vice versa.

It has no effect whatsoever on on the lateral centrifugal forces caused by the turn itself.

My understanding of the physics involved is that the ABS will help retard wheel stoppage in one dimension (forward travel) but will have no impact on lateral movement (wheel "coming out from under the bike"), so it will slightly improve, but not appreciably reduce, the increased risk of sliding if brakes are applied during a turn on wet or slippery pavement.

Thus, if at all possible, I attempt to accomplish all necessary braking before entering the turn. I never know if I'm going to encounter a big greasy patch of diesel or some other slippery substance combining with wet roads to create a skating rink at some point after I've committed to the turn.

Obviously, speed plays a critical role. You can get away with a lot more at slower speeds. If the caution sign recommends 25 mph for the curve ahead, I'm certainly going no faster than 25 entering the curve on wet pavement, all other variables being equal.

[bikerfish1100]

My understanding of trail braking is an application of back brake only, for certain riding situations, including cornering. In a bike with a linked system, the front brake is always applied to a certain degree, and the result would not be "pure" trail braking.

Regardless, the application of linked brakes is going to result in an additional load on the front wheel, with a resulting increased potential for the front end to kick out on a slippery surface, while cornering.

My practice in wet conditions has always been to try to brake, if at all, before the corner entry, and then to ride through the corner with constant throttle or slightly increasing throttle. By adding power to the rear wheel, you decrease the load on the front, and decrease the chance that it will slide out. I have never ridden a bike equipped with linked brakes in wet corners, but I would still avoid braking such a bike in these conditions while leaned over, for the above reasons.

A review of a number of internet sites, including Keith Code's and Kevin Schwantz's, suggests that wet braking be done very smoothly and while the bike is upright, before entering corners.

Just my opinion, and hopefully Dave Hough can weigh in here on this worthwhile topic.

Rinty

actually, trail braking is application of front brakes while in the corner. http://www.sportrider.com/ride/RSS/146_0306_motorcycle_trail_braking/index.html

other than that, i'd say your thnking is pretty accurate about the "what to do".

041150RT: In general, the advice you've been getting is: don't worry so much. Just smooth all your inputs, turn down the volume control (throttle), use brakes (if necessary) before you get your lean going, and relax (ease up your grip, relax your shoulders and arms, etc).

[bobh41]

After Googling this interesting topic it becomes clear that trail braking is a pretty tricky technique used by the fastest car and bike racers. You may have used this technique without realizing it, but you may also have crashed because of it. Here are a couple of interesting references:
http://motorcyclebloggers.com/tech-talk-articles/brakes-101/trail-braking/

http://www.safespeed.org.uk/braking.html

[deilenberger]

After Googling this interesting topic it becomes clear that trail braking is a pretty tricky technique used by the fastest car and bike racers. You may have used this technique without realizing it, but you may also have crashed because of it. Here are a couple of interesting references:
http://motorcyclebloggers.com/tech-talk-articles/brakes-101/trail-braking/

http://www.safespeed.org.uk/braking.htmlInteresting links - the 2nd one explains what is being called "trail braking" in an automobile. While the physics are similar - the results can be different. In an automobile - worst case is plowing off to the outside of the curve. On a bike - a lowside is more likely if over braked in a curve.

I believe what most people understand "trail braking" to be on a bike is the application of the rear brake - gently - at the beginning of a curve in order to get the suspension settled and help a bit with turn-in (probably by some weight transfer to the front wheel due to the braking.) No matter what brake you use - the weight transfer will take place - that's basic physics, but the idea of using just the rear brake is that you aren't taking up any of your available traction on the front tire by using it for braking (as well as cornering traction.) I'd admit to doing it at very low speed sharp corners - it helps the bike turn in IMHO.

Back to the original posters question..

- On an RT - you have fully linked brakes. Using the rear brake also applies the front brake, and I believe in exactly the same ratio as using the front lever alone.

- As other mentioned - braking BEFORE the corner is what should be happening, when your bike is upright with maximum traction available for braking. Once you start cornering - you're sharing traction between cornering forces, engine forces (on the rear wheel) and any braking force you apply. If you exceed the 100% traction limit - the tire will start to slip on the road, which can lead to a lowside.

- Modern tires - in good condition - have amazing wet traction, especially if you wait for 30 minutes or so of rain before riding (to let the accumulated road munge wash off.) I've heard numbers of > 75% of dry traction, and based on my experience - I believe these numbers.

- Rain riding - in general - is all about smooth (at least for me..) It becomes a zen like game to see just HOW smooth I can operate the bike. That means planning ahead for everything. I started riding back in the era of "never use the front brake, you'll "wash out" or "go over the bars".. and it took a while to overcome that bad learning. A week or so of rain riding a few years ago showed me that rain riding CAN be enjoyable, can be done safely and is actually not a bad thing (it sure beats any day sitting behind a desk at work..)

- If you haven't taken one - the Experienced Rider Course (or whatever it's called now) from the MSF is well worth taking. You'll learn lots - even if you've been riding for decades. I try to take one every 3-4 years.. as a refresher and to remind me just how good a modern bike can handle unexpected events..

Best,

[rinty]

It's worthwhile reviewing the basic cornering physics from time to time. :)

I too am amazed at the wet cornering traction available with current tires.

Rinty

[OfficerImpersonator]

On an RT - you have fully linked brakes. Using the rear brake also applies the front brake, and I believe in exactly the same ratio as using the front lever alone.


On my '02 RT, the rear pedal definitely has a bias towards the rear brake, and the front lever definitely has a bias towards the front brake. The are definitely not the same front/rear ratio. I certainly prefer this arrangement, so I hope it doesn't indicate something out of adjustment or needing service.

When descending wet pavement, on a steep grade at slow speed (I'm especially thinking of our streets here in downtown Seattle), I can easily get the rear ABS to activate by attempting to lock my rear wheel. If it's really slick, I'll be unable to completely stop the bike with the rear brake pedal alone as the ABS system does its thing. To ensure a stop on wet pavement and a steep grade, the use of the front brake is mandatory.

[rinty]

I think it was a senior Honda executive that one of the major magazines quoted as saying that in a few years all the new bikes will have linked brakes.

I would hope that BMW's system would allow the rider to turn the system off, in full or in part, to suit the rider's preference.

For example, many riders might want to have no front brake operation with actuation of the rear pedal, so that they can rear brake (trail brake) into corners, among other scenarios.

Rinty

[deilenberger]

I think it was a senior Honda executive that one of the major magazines quoted as saying that in a few years all the new bikes will have linked brakes.

I would hope that BMW's system would allow the rider to turn the system off, in full or in part, to suit the rider's preference.

For example, many riders might want to have no front brake operation with actuation of the rear pedal, so that they can rear brake (trail brake) into corners, among other scenarios.

RintyTurning it off - nope, can't see that happening. The current BMW design - at least on the Roadster, and I believe GS, possibly the RT - has linking between the front and rear, and the rear can be operated independently, as you suggest.

As noted above - there was a LONG discussion on trail braking - where it may not be exactly what most people assume it is.. dunno exactly what we'd call what we're doing, but apparently the actual definition doesn't limit one to JUST the rear brake.

[rinty]

...nope, can't see that happening.......deilenberger

I don't see it happening either, for liability reasons.

...it may not be exactly what most people assume it is.....deilenberger

I agree that the term is an imprecise one: there is the technical definition and then there is colloquial usage......:scratch

Rinty

[knary]

I ride in the rain many months of the year. Just as in dry conditions, the front brake provides the vast majority of your braking power. If the rain isn't the first for a long time, you've still got most of the traction you'd have in dry conditions. It's a lot harder for an experience rider (read: someone that knows better than to GRAB the front lever) to wash out the front wheel than you'd think.

[Andy VH]

I do not believe in the practice of "trail braking" for rain riding conditions. For that matter, I rarely if ever use true "trail braking" techniques for any braking at speed as I prefer to get my braking completed before the turn so I can maximize traction for cornering seperate from traction for braking.

I have done tens of thousands of miles of rain riding with no problems at all, on both my 76 R100RS and 94 R1100RS (with ABS).

Also, by the definitions I am aware of, true "trail braking" is the technique of using braking (not just rear brake, but front or maybe both brakes) to help a bike "turn into" the corner. That in itself is a misnomer term, as a cycle is never "turned" into a corner but rather leaned into a corner by various methods, the most common of which is countersteering (lets not get into that thread right now). Anyway, the application of true trail braking in a lean/turn in effect "quickens the steering" geometry by compression of the suspension during gradual and feathered application of the brakes with simultaneous blending in of throttle application. It is not about using the rear brake only when entering a turn. Also, it is a technique best left to real experienced and trained riders.

Since the real issue in rain riding is traction and stability, I stress getting your braking done well in advance of a turn or leaning condition, which then helps maximize traction for leaning. Also, smooooooth application of the throttle (while in a lean) also helps to stabilize the bike and maintain traction at both the front and rear tire.