Do I need a new chain and sprockets?

Being fairly new to biking and even newer to the 650, I've got a bit of a worry...
When picking up from lower revs (through traffic for example), I get a distinct knocking noise from the bottom end somewhere, best described as a "tock-tock" in time with the chain.
Is this normal or is it increasing wear in the drive sprocket and chain, as the engineer in me suspects it is?
If so, what should I be looking at in Beer Tokens for a new chain and sprockets?
Thanks in advance,
TR

Check the sprockets for wear. Are they hooked, especially the front? My old and new rear are below. Check the chain for stiff links and whether you can pull a full link off the rear sprocket. You can get a new set from £75 to £130. Depends on what your budget is.

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You can check the wear as dansin describes.

It may also just be the chain tension, they require periodic adjustment. This, and the amount of travel required will be in your handbook.

If too slack, then chain chatter will be common at low revs.

Tunnel Rat said:

Being fairly new to biking and even newer to the 650, I've got a bit of a worry...
When picking up from lower revs (through traffic for example), I get a distinct knocking noise from the bottom end somewhere, best described as a "tock-tock" in time with the chain.
Is this normal or is it increasing wear in the drive sprocket and chain, as the engineer in me suspects it is?
If so, what should I be looking at in Beer Tokens for a new chain and sprockets?
Thanks in advance,
TR

Click to expand...

With an F650 it's always advisable to wear earplugs, they tend to make a fair bit of noise.

As mentioned above, check the stiffness in the chain and also the slack. For ordinary 650s it should be 30-40mm halfway along the free run of the chain. On my Dakar this is 40-50 mm. Don't check midway between the sprockets, but halfway between the rear sprocket and roller (if you have one). Jam a rule against the swing arm, pull the chain down and check on one part of the link where it is, then push it up and see how far the same point has moved. If it's outside the range printed on the swingarm, you need to turn the adjusters (quarter turn clockwise each at most, after slacking off the Axle). If that's okay, try pulling the chain back on the sprocket. If you can see the gap between chain and sprocket it's wearing, if you can fit a pencil in the gap it's time to buy a new set. Look at the teeth on the sprockets, are they symmetrical with squared points, or are they shark fin like, with sharp points. If finned, probably time to replace.

Replace chain and sprockets at the same time. Don't go to BMW dealer or get an OEM chain as you need to remove the swing arm and pay far too much. I'd recommend DID chains but you are likely to pay somewhere around the £100 mark dependent on type plus you'll need a riveter, unless you get a spring link. If you are going to keep the bike for several years and do lots of miles, get a Double gold set, if not, get the grey set. If you are likely to do less than 5000 miles buy the cheapest set you can find regardless of make.

To change the lot, you'll need a big Torque wrench and 24 and 30mm sockets.

Thanks chaps.
There was a fair amount of slack in the chain, which I tensioned out as something of a priority. Did make things smoother although the tocking noise is still there. The rear sprocket seems in reasonable shape, the teeth still nice and symetrical.
Wonder if it's a case of TADTS that I'm just not familiar with.