R1200S and explosions from the exhaust

Fenring · 07-14-2007, 06:11 AM

I'm not sure if any of you noticed this on your bikes, but I hear A LOT of explosions coming from my R1200S' exhaust while downshifting and engine-breaking. I mentioned this to my dealer and he says it's normal and that I shouldn't engine-break so much beacuse the R1200S has good and strong front brakes. I guess that's a sound advice

, but it's difficult to change my riding style now and it really anoyes me while riding, because I try to keep a low profile, and it would be preferable not to destroy the cat just right away.

So, is this really normal, and can this situtation be somehow remedied with after market exhaust cans or something?

At this very moment I have a "Motorrad Testbuch 2007" (Motorrad Magazin Sonderausgabe) in front of me and they claim that, by their account, R1200S is "Bester Supersportler Zweizylinder", but it's a German magazine and, as they say, everyone praises their own race horse.

Anyway, there are pluses and minuses for every tested bike, and under a minus for R1200S it says "verschluckt sich beim Gasaufziehen", so I guess I'm screwed on the exhaust issue, or what?

Tirebiter · 07-14-2007, 06:43 AM

I am a strong advocate for using brakes as the primary method for slowing down and agree with your dealer for a couple of reasons: first off, your brakes are much more powerful than the engine for this job (and with infinitely more control on the front wheel where it belongs). Second: brake pads are cheap compared to engines, transmissions and clutches if used for the same purpose....why add to the wear and tear of these components if a better tool for the job is available??

Besides, if you are truly looking to keep a low profile, engine braking, regardless of the exhaust system in place, always seems to attract more attention than not.

my $0.02...

Brock

signit98 · 07-14-2007, 07:21 AM

...I don't see how it would make a difference... that IS one of the reasons why I am riding twins.... the control you have over the bike with the engine (i.e. torque in both directions)... plus, when you close the throttle, it's UNAVOIDABLE that the engine brakes...??? am I missing something here or what...?

Funny though, my bike only pops when I have a slightly more open exhaust on it... not with the factory end..

Fenring, that is a very good magazine and they have been known to bash German products as well... not to worry. Though they seem to be a little biased here... but "verschluckt sich beim Gasaufziehen" means that it has issues when you open the throttle, nit the other way around!?

...that is something you can fix with a PCIII or equivalent device...

Steve Carlton · 07-14-2007, 07:35 AM

I think your dealer is full of *****. Mine doesn't backfire at all, just a little burble. And I don't see any problem with using engine braking, either.

ckcarr · ckcarr's Garage

Agree

I think that is one of the strengths of a twin.

These bikes are tuned so uniform, perhaps you are more sensitive to it. I'll have to listen to mine today.

MaineRoads · 07-14-2007, 07:46 AM

My prev. K1200s and current R1200s both burbled under decel. Put on a more free flowing exhaust, the louder the burble. Why were slipper clutches developed if engine braking was bad?

signit98 · 07-14-2007, 07:50 AM

...Slipper clutches are for the slightly more "extreme" or inexperienced riders... it's not the engine braking that's "bad" but the after effects... slipper clutches were developed to minimize the rear end stepping out on you in a corner when you are shifting down under hard engine braking (or, in my opinion - being that I have quite a bit of experience with riding twins - wrong choice of gear!)

...if you are not used to that, it can be a nasty surprise...

Tirebiter · 07-14-2007, 07:59 AM

Quote:

Originally posted by signit98
...I don't see how it would make a difference... that IS one of the reasons why I am riding twins.... the control you have over the bike with the engine (i.e. torque in both directions)... plus, when you close the throttle, it's UNAVOIDABLE that the engine brakes...??? am I missing something here or what...?

I could be wrong, but my read on the post was that Fenring was downshifting with the express purpose to slow the bike down using the engine in lieu of the brakes. Modulating speed with the engine as you describe is a completely different deal and perfectly suited to our bikes.

Brock

Steve Carlton · 07-14-2007, 08:06 AM

I downshift with a blip of the throttle all the time to slow down. Not always, but when I feel like it. Often do it when I want that lower gear anyway after I've slowed down. I don't advocate downshifting and slipping the clutch a lot to speed up the engine and slow down the bike.

signit98 · 07-14-2007, 08:14 AM

...maybe I am just misunderstanding him, Brock... that's one of the drawbacks of the written word.

...but no engine has sufficient braking power to solemnly rely on it exclusively!?!? (being redundant here...)

..that would be downright dangerous! Other than that, my style of riding is such that I have my corner entry speed where I want it and I am off the brakes when I hit the turn... the rest I do with the throttle... even on the track I try to apply that principle (I am not trying to win races anymore).

That way I have a nice security blanket and still a lot of fun...

MaineRoads · 07-14-2007, 08:16 AM

Shifting down in a corner under hard engine braking; bad idea.

Bob Hancock · 07-14-2007, 09:35 AM

Quote:

Originally posted by Steve Carlton
I think your dealer is full of *****. Mine doesn't backfire at all, just a little burble. And I don't see any problem with using engine braking, either.

+1. The tranny is there to keep you in the correct gear for the situation...going up or down. Use it. As far as the noise....it's supposed to do that. Ignore it...wear earplugs....whatever. Now if there really is an explosion....like a grenade or a cherry bomb....then there is a problem so please send pics of the insides of the cans. I'm curious if the route from pipe to air is as circuitous as that of the R11S.

Fenring · 07-14-2007, 01:15 PM

Now don't worry folks. I use engine braking often, but not in extremis.
And recently I discovered there's a nifty lever on the right hand side and when you pull it the bike starts to slow down. No kidding, try it.

2 signit98: You are correct sir! My german is so bad that I had it upside down. It turns out that "verschluckt sich beim Gasaufziehen" would actually mean that the bike has slow throttle response.

In fact I apologize for alarming you all. It is possible that I overstated the issue. There are often burbles and pops coming out of the exhaust while reducing throttle. Sometimes even a loud bang happends. I will talk to my dealer about this again, just to make sure that it's nothing seriuos. I'm probably just not used to it popping like that, because my previous ride made no such rude sounds. I am concerned though, that I don't damage anything (other than my brain, for which it is too late).

signit98 · 07-14-2007, 01:34 PM

...Steve, the rear end on those things keeps stepping (even if you finish your shifting before the corner) because it takes the motor a little to catch up with the rest of the bike..

Our donkey is not so prone to do that because it's:
a) a little on the "porky" side of bikes and
B) ...the incredible telelever prevents the rear from lifting to much... until you REALLY push it!

Fenring... no worries, that's what I get from having been born and raised in Germany... I can still read it

markjenn · 07-14-2007, 04:03 PM

I don't think there is a binary right/wrong answer for engine braking.

I always leave the bike in gear until I come to a stop, but I don't go down through the gearbox revving the beejesus out of the motor in each gear for routine stops. Just leave it in the higher gear, use the brakes, leave the clutch out, and as I approach the stop, pull the clutch and shift down to 1st.

But out in the twisties, I'll do typically blip/shift down through each gear to get setup at in the right exit gear for the corner exit.

It depends on the situation. The bike will speak to you and tell you what is normal aggressive riding and what is unnecessary wear/tear if you listen to it. If what you're doing is obviously making a lot of excess noise/racket, I woudln't just keep doing it with a "old dog can't learn new tricks" ratiionale.

I don't own a R1200S, but if a stock bike is truly backfiring on downshifts, that doesn't sound right. A little lean misfire burble maybe, but not a true backfire. But if you've modified intake, exhaust, etc., all bets are off. My guess is that you've got something wrong.

- Mark