F800GS chain and battery

BMW is recalling bikes for new chain and sprockets now. I got a recall in my mailbox today

Are you serious?? Nice! So how do I go about getting my dealer to recognize this? I haven't received anything in the mail as of yet.

It is a Europe only thing.

Damn. Oh well I guess!

I know that this is off the subject on the thread, but the Front Axle recall started as a Europe. It took BMW almost 2 years to send an official recall notice for the North American bikes.

These are just my opinions and are not backed by any documentation. BMW recommends adjusting the chain on the F800GS to 35-45 mm while the bike is on the side stand. Due to the pivot point of the swing arm being aft to the counter shaft sprocket when the shock compresses the chain tightens. This is what I did. With the rear wheel still in place and the bike on a motorcycle jack I removed the shock and lowered the jack until there swing arm bottomed (compressed shock) and checked the chain tension. It was super tight so I loosened it a little. I put the shock back on and set the bike on the side stand again and took a measurement which I marked down in my book for future reference. That is where I have ran the chain tension for the last 15,000 miles with no ill effects to the chain of sprocket. To make sure the chain wouldn't jump off the sprocket I installed a chain guide/guard which keeps everything from slapping around.

I'm going to throw a big +1 about proper chain tension on this one. My opinion is that it is a huge factor as to whether or not your chain is going to snap or not. I too have always checked chain tension measurements while the bike is unladen and on its side stand (35-45mm). My stock chain has lasted me almost 6,000 miles now with no ill effects to the chain and sprocket.

If you set your chain tension with the bike on its center stand to 35-45mm, you'll noticed that it will be considerably tighter when you put the bike on its side stand. You must set the chain tension while the bike is on its side stand so that you don't over-tension the chain. A chain that is too tight will snap eventually.

That is what Toyota said for some of their problems as well.........

If somebody gets (seriously) hurt (which I hope won't happen) it will be interesting to see what a good lawyer could do to BMW showing them that the same chain was recalled in Europe but not in the US. I can hear BMW NA already "we have never been made aware of a problem anywhere".

Welcome to modern global communication.

Reiner

Hey, could be worse . . . . .

LINKY


Don't get me started!!!!

A large team could make BMW's Cost about 20% more in the USA, just like they already have in europe! Yeah! More profit for dealers and more work for service too, heck we could hire more employees on the publics buck

while we are at it, with the right entitlement, anti corporate atitude, maybe we could even get someone like Hugo Chavez for a president and show the rest of the world how fantastic letiges socialist countries can be

Ya, ve have vays of making you take it and like it! Ya, ve do!!!!

I just take the time to compress the suspension until the rear axle, the swing arm pivot, and the counter shaft are all in line with each other, this is the tightest spot in the wheel travel. I adjust the chain with just a small amount of tension at this point. Now put the bike on the center stand, or the side stand, which ever you prefer, and mark the bike some place as a reference. On my dirt bikes i would cut a small notch in the shock guard.
Cisco

Cisco:

If you have done this on the F800GS - have you ever then measured for the "resulting" tension when on the side stand?

Is it about 45mm?

Kkesp and cisco, I believe you are on the right track. This is also how I adjust chains, especially on the F8GS and other long travel suspension bikes. This is how I adjust customer bikes.

Specifically, long ago I set the chain for very light tension with the rear forks in line with the sproket, ie the point of maximum tension, then measured how much sag that equalled.

I set bikes on the center stand, or on a jack, for that sag, then have someone compress the rear to double check.

This really is important.

The side stand method is much to inexact. The suspension hight on the side stand is not repeatable.

For the side stand method to be accurate, a bunch of variables have to be solved. First preload has to be at the factory preload. Second the bike has to be unladen. This would include removing bags, bag frames, crash bars, and having the same amount of fuel in the fuel tank when the factory dreamed up this method.

Next the lean angle has to be the same as this affects how much weight is on the suspension verses the side stand and therefore how compressed the suspension will be. So find perfectly flat ground, remove any fat foot side stand mod, and make sure the side stand is not bent and it's bushings are new.

Also, there is a lot of stiction in the rear suspension. Are we supposed te set chain tension after compressing the rear suspension and allowing it to rebound, or shall we set sag after extending the rear suspension and allowing it to compress? The rear suspension will vary about half an inch from this alone.

Continueing, springs wear over time, and the ride height is also affected by the temperature of the spring and shock, and what if something is bent?

Lastly, some people have installed aftermarket shocks, springs, or even lowered suspensions. The factory specs and methodology for setting chain sag is truly meaningless for this, and inadequate even with stock suspension in my opinnion.

Set chain sag however you like, but varify it by compressing the rear suspension to the point of maximum tension.

More then a few chains, output shaft bearings, and wheel bearings would still be in this world if chain tension had been accurately set in my opinnion.

I'm not Cisco, but the few times I bothered to check, correctly tensioned chains varied from 35 to 55 mm of sag using the side stand method depending on the bike and how hard I pushed, another huge variable.

Ok Joel, I understand and agree with your concerns about using the side stand chain adjusting method. It didn't make sense to me when I read the procedure in the owners manual.

What in your experience is the correct chain free-play adjustment when the stock rear shock is fully extended on the center stand. I won't be removing the rear shock anytime soon to test this so this specification would be most helpful.

Thanks Joel!

I agree, the side-stand method is imprecise.... lots of variables.

On my F658GS (stock suspension & modest preload) the side stand puts the axle-swingarm pivot-countersprocket all pretty much in line. The tension is actually a bit less on the centerstand than on the side stand by maybe 1/4"

I'm sure the F800GS is different...

I wish the threads on the adjusters were a bit finer ... one flat seems to be about 5mm of slack so ... not a very fine adjustment and I'm never quite sure I have the sprockets running true. I may have to get one of those welding rod / laser alignment checkers....

I'm still partial to the "snail" adjusters

To be honest, I haven't measured on the side stand.

The only way to do this is to remove the rear shock. There is no other (practical) way to get the counter sprocket/swing arm pivot/ rear sprocket in alignment. Correct?

God Bless,
David

if you can get one other persons help, just have them sit on the bike, back seat if they are tall enough, preload all the way down if nessesary.

Have them bounce some. The tension is right when 99% of slack comes out of the chain but it never gets tight tight. Make sure the bike is in neutral.