Wobble when engine braking

[kml.krk]

Recently I noticed that my rear end behaves strangely when I brake with engine.
It feels very similar to rear wheel lock, but not as severe.
It happens mostly when I change gear to first and release clutch quite fast (not very fast though)

When I brake hard with rear brake everything is normal and there is no wobble so I think that wheel alignment is not an issue.

Bike is 2004 with 2800 miles on it... (shhhh, don't tell anyone  )

What may be the cause? What should I check?
thanks in advance
KML

[centuryghost]

It happens mostly when I change gear to first and release clutch quite fast

There you go. Release a little easier.

[kml.krk]

^^^^^
dude, it's totally not what I had in mind.

I said I don't release clutch very fast, which means I use engine to slow down moderately.
Besides I don't think it was happening before.

One more thing: this absolutely should not be happening so don't tell me not to use engine for braking (because this is what you pretty much just said)

anyone else could say something that makes more sense?

[centuryghost]

Yeah, you didn't say that you release very fast, you said quite fast!

Also, there's nothing there in my post that says to not use engine braking, I do it all the time. When I release my clutch "quite fast" when coming to a stop, my rear will buck and wobble and slide a little bit.

You're a little touchy this morning, huh?

[dgyver]

Recently I noticed that my rear end behaves strangely when I brake with engine.
It feels very similar to rear wheel lock, but not as severe.
It happens mostly when I change gear to first and release clutch quite fast (not very fast though)

When I brake hard with rear brake everything is normal and there is no wobble so I think that wheel alignment is not an issue.
...

Sounds normal... like the start of wheel lock up, especially in first gear which you would be going slower. Normally you have better control with the rear brake as it is less aggressive and does not unload the rear suspension. Unloading the rear suspension will make the rear light and the wheel feel squirrelly. Feather the clutch to engine brake effectively takes some practice and experience. Since the GS does not have a slipper clutch, rear wheel locks are more prone to happen.

[Gary856]

Whenever I'm rough with shifting and clutch work the bike gets unsettled momentarily. That's normal, especially when down shifting to first, so I'm still not clear about the problem description from the OP on what is not normal. Like centuryghost said, just be smoother with the clutch was what I thought when I read that.

What road speed and engine rpm do you down shift to first?

[kml.krk]

[...]You're a little touchy this morning, huh?[...]

Sorry centuryghost.
I guess I am lil' touchy. I did not even realize how much my calculus final exam (that went really wrong yesterday) affected me.

Thanks for answers, I will be more gentle with the clutch.
I was just worried that some rear end component may be coming loose, because I used to engine brake quite hard before and I never noticed that wobbly feeling 

[centuryghost]

It's all good  

The only other thing I can think of would be not enough chain slack  

Oh, another thing - I noticed it more when my rear tire was ready for a replacement.

[ohgood]

you know, i don't engine brake in 1st much. sure, sometimes i will just to slide the rear a little (being a jerk) but it's not a very nice, settling feeling with the rear pulling that much to a stop. it feels much better using the front brake to balance the bike, slow considerably, and then slightly drag the rear to keep things sorted the last few feet of a stop.

as far as engine braking, brake pads are cheeeeeeeeap man. think of all the things that take the stress vs a couple of 3 minute parts to replace. just something to consider.

engine braking is great on bikes in moderation. it helps settle things, helps maintain a nice rpm for immediate repsonse if/when throttle is opened, all the other fun stuff.

maybe try (like post a reply after you do) much easier engine braking in 1st and see if the odd feeling is still there ?

try dragging ONLY the rear brake in a similar stopping fashion and see if it's still present ?

then try the same decelleartion with ONLY the front brake.

now, we're not talking balls-to-the-wall decel, just a normal stop. might help isolate where the problem is, if there really is a mechanical problem.

good luck !

[tt_four]

If it is wobbling for a reason, and not just the tire trying to break traction, the main places to start would be chain tension, tire tread, and all the bolts holding on your chainring. I'd also pull off the side cover to make sure the front cog is on right.

any chance your chain/gears are worn? when those wear they mostly wear on one side because your chain is usually pulling in one direction. If it's getting worn you might not notice when giving it gas, but you would notice if it pulled hard in the other direction since that side of the teeth aren't worn. That's more of a problem on bicycles considering how thin the chains are, but it still applies.

[kml.krk]

not a chance that gears are worn.
rear is stock, front was changed to 15T about a 1000 miles ago. Bike has 2800 miles total...
I lube the chain regularly.

I will check if the bolts are tightened properly just to make sure everything is fine.
I am planning to ride through the winter this year so I need the bike to be in excellent shape, especially suspension/handling wise.

Chain slack is adjusted as per manual, I believe that is 1inch.

PS. I will not be riding when there is snow/ice on the roads. It would be very irresponsible considering my experience 

[mister]

Engine brake in 1st!?

The only reason to let the clutch out in 1st while coming to a stop is to Check that the bike is actually in 1st. While nearly stopped, let the clutch out Just Enough for the engine compression to kick in letting you know it's in 1st, then pull the clutch back in. ALL your slowing down should be done Before going into 1st.

I find the GS has what I describe as a Double Click when going into 1st. So I don't need to semi-release the clutch as a Check it's actually in 1st.

Michael

[jeremy_nash]

Engine brake in 1st!?

The only reason to let the clutch out in 1st while coming to a stop is to Check that the bike is actually in 1st. While nearly stopped, let the clutch out Just Enough for the engine compression to kick in letting you know it's in 1st, then pull the clutch back in. ALL your slowing down should be done Before going into 1st.

I find the GS has what I describe as a Double Click when going into 1st. So I don't need to semi-release the clutch as a Check it's actually in 1st.

Michael

I agree, and a possible reason for it doing it now, and not this past summer is you generally wont build much heat in your tires in december, so you dont have as much traction

[CliffHanger]

Engine brake in 1st!?

The only reason to let the clutch out in 1st while coming to a stop is to Check that the bike is actually in 1st. While nearly stopped, let the clutch out Just Enough for the engine compression to kick in letting you know it's in 1st, then pull the clutch back in. ALL your slowing down should be done Before going into 1st.

I find the GS has what I describe as a Double Click when going into 1st. So I don't need to semi-release the clutch as a Check it's actually in 1st.

Michael

I agree with mister.  In the Canadian MSF we were taught to use engine braking while shifting down each gear sequentially (maybe two gears on close transmission ratios).
1) you are always ready (gear/rev) to respond to traffic changes
2) less chance for rear wheel lock up.
This assumes normal riding patterns and only when there are no cars behind us (no brake lights for the clueless cagers)

In an emergency stop it should be front and rear brakes evenly applied while dropping into first to prevent stalling when the situation is resolved. (hopefully)
Relying on first gear for engine braking from, say 70km/h (50mph), seems like a dodgy proposition to me.

CliffHanger

[drewbytes]

You shouldn't be engine braking in 1st. Sure do all the other gears if you like down to 2nd, and just about or as you come to a halt slip it into 1st so you're ready to take off.