chain damage??

[tosh23]

f650gs twin (59) 6000mls
Before a ride out today I adjusted the chain, checked it on the centre stand, checked it on the side stand, checked it with me on it and checked it with the wife on as well, everything looked ok..
I rode 1 mile to get petrol, after the fill up I checked it again with the wife on the back and again all ok...
Rode 25 miles to seaways cafe, once off the bike I checked it again and it was tight, so tight that it has worn away the rear sprocket teeth to the tune of about 2000 miles of normal riding..
I found a workshop just around the corner and adjusted it again, this time everything is how it should be after a 50 mile jolly..

So now im worried about the output bearings and knowing the poor bearings from BMW what would any of you suggest....
PS On some bikes the front sprocket wears faster than the rear, is this the case on a 650 twin ?...Cheers guys ..Tosh

 

[Micky]

Let it develop

 

[tosh23]

Micky, when it comes to your advice I know it's sound, so I will do just that...cheers mate...Tosh

 

[v8legend]

f650gs twin (59) 6000mls
Before a ride out today I adjusted the chain, Rode 25 miles to seaways cafe, once off the bike I checked it again and it was tight, so tight that it has worn away the rear sprocket teeth to the tune of about 2000 miles of normal riding....Cheers guys ..Tosh

Chains can't adjust themselves tight? They can develop tight spots, and they can go dry. Was it correctly lubed? Was it correctly adjusted? These bikes aren't like sports bikes/tourers, they have a lot more slack in them. I can't see how you've use up 40mm of slack so quickly. It sounds like the shop has adjusted it correctly, as you haven't had to adjust it since.

Also, if the chain was so tight that it wore the sprockets in 20 or so miles, you'd feel it whilst riding.

Lastly, you checked it a lot of times before riding, and again a few miles later. Do you think maybe, that you're subconciously aware of a developing problem?

Despite the widely reported chain problems, even the dodgy chains didn't need frequent adjusting. They were failing. My bike has only done 15,000 miles. The chain rarely needs any adjustment. Most adjustment actually takes place when changing the tyres!

 

[tosh23]

I knew that the chain needed adjusting because it was clanging against the swing arm when I throttled off, Every Time I adjust a chain be it on my other bikes in the past or indeed the wife's bike I always check it every time I stop for the whole of that day or 6 or 7 times, I would say over 100 miles in total..Only then am I happy that the chain is adjusted correctly, call it belt and braces if you like I also laser the alignment and check that twice before the initial ride and again on the last check..This routine has seen me well in the past and this is the first time I have had a problem...
On the ride I noticed that there was no noise on throttle down so I knew it wasn't too slack but like you say, a nagging feeling in my brain wont go away unless i'm 100% happy, hence all the checks over the initial 100 miles..
Again like you I don't understand how the chain became so tight, the rear spindle was torqued to 64 foot pounds and the locking nuts on the adjustment screws were check twice before the ride..
I am going to monitor it closely over the next 500 miles, I am also going to clean the chain and sprockets today and completely lube everything up again..
With the bike being a 59 plate the chain should be of better quality than the chocolate ones from the 08 bikes,
So if needed I will change the drive system completely I just hope the output bearings are OK. Lucky it was only 25 miles maximum so I might of go away with it....Here's hoping....Tosh

 

[Greggers]

Think how many times the output shaft bearing will have rotated in 25 miles...

Yes, you might be lucky, but how did you quantify 2000 miles worth of wear on the sprocket - is it hooked?? If your chain wasn't worn (some say stretched) in the first place then it shouldn't be worn as such.

As has been said I can't see how the chain would tighten itself - if anything it would loosen as the tension on the chain would pull the axle forward..

I changed my OE rear at 8000 miles as I assumed at that mileage it would be shagged. However it was almost perfect despite a hooked front and a badly worn chain - that might be the one long-life component in the drivetrain lol..

G

 

[mark71]

Chances are first you will know about the worn output bearings is the oil leak unless they get noisy but if your really concerned take the front sprocket off and give hem a check.

As another said you checked it so many times, it's almost like you don't trust yourself.

I don't think you will of done that much damage in 20 miles though.

I may be wrong but if it's not noisy and there's no oil leaking leave it alone!!

Regards

Mark

 

[tosh23]

well here is the front sprocket

After 6000 miles it looks ok
Here is the rear

Looks like an alignment issue because on side of the drive side teeth are worn, whether it was like that before the incident I will never know..
Anyhoo the sprocket teeth on both look ok, maybe a little worn but after 6000 miles that is what I would expect to see...I have cleaned up the sprockets and cleaned the chain ( its sitting in a bath of 10/40 at the mo)..
I have looked around the oil seal of the output shaft and no oil is present...Touch wood..
Ther is one HUGE problem though...
I have read a few times of people really struggling to remove the front sprocket off the shaft...I tried a little bit but I knew just from the look of it this is going to be a right xxxxxxxx

Rust all around the splines and the spline itself rusty...
ANYONE WITH ANY IDEAS..heat is not an option because of the seal behind it..
I suppose the front sprocket in its condition will last 10,000 miles, so if I spray it with penetration oil every week .........Im up sh*t creak with this one..

 

[Dean]

f650gs twin (59) 6000mls
Before a ride out today I adjusted the chain, checked it on the centre stand, checked it on the side stand, checked it with me on it and checked it with the wife on as well, everything looked ok..
I rode 1 mile to get petrol, after the fill up I checked it again with the wife on the back and again all ok...
Rode 25 miles to seaways cafe, once off the bike I checked it again and it was tight, so tight that it has worn away the rear sprocket teeth to the tune of about 2000 miles of normal riding..
I found a workshop just around the corner and adjusted it again, this time everything is how it should be after a 50 mile jolly..

So now im worried about the output bearings and knowing the poor bearings from BMW what would any of you suggest....
PS On some bikes the front sprocket wears faster than the rear, is this the case on a 650 twin ?...Cheers guys ..Tosh

Thats spooky Tosh and a big worry hope it gets sorted OK

I changed when I could to the gold DID joby being most impressed when I fitted my wire wheels end of autumn fitted new bearings BTB but also new DiD and sprockets front and rear.

compared to the standard looks chocolate , I'm confident the scot oiler (you can just see the little fella's Tube on the rear sprocket) keeps the adjustment good for longer

 

[Sooty09]

Dont worry too much about bearing damage. The rear sprocket runs on a bearing which has much less capacity than the gearbox output bearing, so would probably fail first.
I find it difficult to set the chain tension, the adjusting screw needed to be a finer thread. Im also not confident the adjusting marks are the same both sides. I have not had the chain move once adjusted and all the nuts tightened up. I dont use torque settings and use a socket and cut down tommy bar for the main wheel nut.
38000m now 2nd chain original rear sprocket.
If your sprocket is seized to the shaft use a wall paper stripper steam generator to spray onto cloth wrapped round the sprocket, it needs a few minutes to heat through before it can be pulled off.

 

[tosh23]

I think maybe I know what happened, When I used the laser alignment tool on the rear sprocket, due to its small amount of side wall surface and the amount of old chain lube,grit, and thousands of miles of crap the build up along the sprocket face/chain wall it gave an inaccurate reading, what I should of done was clean the sprocket with brake cleaner to create a smooth clean metal surface that the tool could sit on flush and true.
Thus making the wheel alignment way out and marking the right hand side of the rear sprocket teeth..
But it still baffles me how the chain that was checked 4 times,Once with my weight, twice with the wife and I then after 25 miles ,it tightens up ?

 

[Greggers]

The most reliable way to make sure you're aligned is using a pair of internal calipers to measure the difference between the casting on the back of the swingarm and the sliding collar that the adjuster bears on ..

Don't forget that quite often tightening the axle nut will upset the adjustment - IME it will tighten it - you might need to allow for that when judging the slack...

Good news is that your sprockets look fine.

Removing the gearbox sprocket can be a real arse. I ended up buying a 3kg slide hammer/puller from MachineMart (it cost me £53.00) and it took over an hour of hard graft and banging to finally get it off... When you do manage to get it off, be sure to be generous with either copper grease or moly paste to ensure it doesn't stick again.

 

[Dave Ett]

Every Time I adjust a chain be it on my other bikes in the past or indeed the wife's bike I always check it every time I stop for the whole of that day or 6 or 7 times, I would say over 100 miles in total..

I also laser the alignment and check that twice before the initial ride and again on the last check..

Blimey.

You are one seriously paranoid mechanic / rider!

In the 200,00 miles I've been riding and maintaining my own bikes, I'll check the chain weekly (daily if touring) and adjust it once when necessary. It's obvious if I've cocked up the adjustment soon as I ride off!

There isn't a 'perfect' adjustment for a chain, just a grey area - hence the 35-45mm adjustment allowed on the F8GS.

I have an FJ1100 with 100,000 miles on it, so I reckon I do have some experience in chain adjustment...

 

[tosh23]

There is a very good reason why you should ALWAYS keep your bike clean..
On the rear sprocket there is a "step" between the side face and the teeth. I didnt see it because of all the crud and crap...
So the alignment was WAY OUT...
I went for a ride with the wife today and it seems fine, Once again the chain has been checked half a dozen times during the ride and it has remained the same....
On a very lucky note..
Whilst the rear weel was out I checked the wheel bearings and the non sprocket side is slightly crunchy, So it looks like the races are pitted or worn...How lucky am I..I need a new set of wheel bearings and im over the moon......Tosh

PS, I would just like to say thankyou to everyone for your comments and ideas, Its nice to know friends are always on the other end of the pc screen.

 

[tosh23]

In regard to the front sprocket, I'm going to spray it with penetrating oil for a few weeks while I save up for a 3 leg bearing puller, That should do it, if not then I will be screaming on here...Once again cheers guys for all your help...Tosh

 

[rce]

One acronym...

OCD ?

 

[Sooty09]

I had trouble centralising the three legged puller, two legs set into the bottom of the tooth while one was on a tip. I found it easier with a bit of old chain wrapped round the sprocket, the legs grip the links easier (needs a high quality extractor with thin arm tips). I made a small threaded insert with a centralising dimple to fit into the drive shaft end to try stop the puller slipping off, I was applying so much force it stripped the thread on my extractor.
I do not think a slide hammer is a very good idea, the sideways forces are going through the gearbox bearing in a direction they are not designed for.

 

[ricfrench]

In regard to the front sprocket, I'm going to spray it with penetrating oil for a few weeks while I save up for a 3 leg bearing puller, That should do it, if not then I will be screaming on here...Once again cheers guys for all your help...Tosh

Seriously why do you need to save up or even spend so much money on a gear puller

http://www.google.co.uk/products/ca...a=X&ei=dw52T8X6Fsis8gO4ufXBDQ&ved=0CE8Q8wIwAg

 

[tosh23]

One acronym...

OCD ?

By checking the chain all I do is check the tightness, and all that takes is a slight lift with my right boot, it takes about 2 seconds when im getting off the bike, OCD ? yep. Its not that I dont trust myself, I think along the lines of measure twice and cut once. Besides it costs nothing but a few seconds and lets me sleep at night..Im a cockney what more can I say..Tosh

 

[tosh23]

" I was applying so much force it stripped the thread on my extractor."

Thats why I need to save a little, when I but a tool I buy the best I can afford, I think of it as.....A tool is for life, not just for Christmas.