Chain

[simply]

Was driving home from work tonight came round round about and lost all drive. :wall: Coasted to the curb and got off and chain had jumped off. Put it back on and managed to ride home but its as floppy as anything....much more than the recommended amount. Checked the axel alignment and it hasnt moved from when i tightened the chain a few weeks back. So.............. any suggestions what else has happened, there doesnt appear to be any excessive wearon the chain or back sprocket. I dont want to just tighten the rear axel if there is obviuosly a bigger problem somewhere else. Havent really looked too much further at the bike as too late.

 

[greggs]

Simply - if the chain jumped off the sprocket, it is toooo looooose. It does not matter that you only tightened it a few weeks ago - do it again as it obviously needs doing.
Once adjusted, if the top of the sprocket is 12 and the bottom is 6 - grab some chain at the 9 0'clock position and try to pull it away from the teeth. If it comes more that halfway up the height of the teeth, it's knackered. Trade bike in and get one with a shaft drive !
cheers gregGS

 

[Greg Masters]

The 650GS uses a 520 chain. To check wear, put chain on full tension (temporarily overadjust rear wheel) and measure 20 links. When new this should be exactly 12½ inches. If it's stretched to more than 13 inches, buy a new chain.

You should also look at the sprockets. A worn chain rides further up the sprocket teeth and causes hooking and increased wear. Buy new sprockets too.

Fit a Scottoiler.

Check your chain tension regularly and more frequently as the chain gets older.

Greg

 

[simply]

Simply - if the chain jumped off the sprocket, it is toooo looooose. It does not matter that you only tightened it a few weeks ago - do it again as it obviously needs doing.
Once adjusted, if the top of the sprocket is 12 and the bottom is 6 - grab some chain at the 9 0'clock position and try to pull it away from the teeth. If it comes more that halfway up the height of the teeth, it's knackered. Trade bike in and get one with a shaft drive !
cheers gregGS

Thank you for stating that the chain was too loose i forgot i was a complete idiot!!!!!

I always check chain tension before i go out on my bike and before i left it was within its stated range, this is why i was suprised when it jumped off. I asked the question to see if there was any other explaination for the chain to jump off.

I your constructive advice about changing bike was very helpful really useful when trying to sort my bike out so i can get to work THANK YOU SO MUCH

 

[simply]

The 650GS uses a 520 chain. To check wear, put chain on full tension (temporarily overadjust rear wheel) and measure 20 links. When new this should be exactly 12½ inches. If it's stretched to more than 13 inches, buy a new chain.

You should also look at the sprockets. A worn chain rides further up the sprocket teeth and causes hooking and increased wear. Buy new sprockets too.

Fit a Scottoiler.

Check your chain tension regularly and more frequently as the chain gets older.

Greg

Thanks for the goodadvice have now retightened the chain and measured it and all are within the limits so will take it out later and see how it goes. Have order a scottoiler just waiting for it to arrive

 

[VAL. H.]

Thanks for the goodadvice have now retightened the chain and measured it and all are within the limits so will take it out later and see how it goes. Have order a scottoiler just waiting for it to arrive

Hi, reading your tread, you say you checked the tention of the chain when you first took the bike out that day.

If you are quite sure the tention was ok and when it came off, the rear wheel spindle was secure and had not slipped.

I suggest you take a close look at your swing arm pivot bearings. your looking for any sideways play. It is somtimes better to release one end of the rear shock from the bike as this can prevent you from being able to move the swing arm sidways because it's all under tention from the spring.

If this is your problem you need to stop riding the bike and get them sorted asap or they will take a perfectly good chain and sprockets with them. It would only take an hours riding to wreck the whole lot.

Somthing ells to consider is the rear wheel bearings, though this is usually more obvious when they start to break up.

Val. H.

 

[Imprest]

You've probably got this sorted by now however my chain suddenly went slack on my dakar. The cause was a missing lower chain pulley.
This is quite a common problem according to the f650 owner club.
Worth considering !