Another chain question - XV250 this time! Much slower than a blackbird.

Just to continue the topic of bike chains...I recently replaced front
and rear sprockets, and chain, on a '99 XV250, aka the venerable Virago.

When I ride now, it makes a bad-sounding oscillating/whining/whirring
noise that wasn't there before, as if the axle is out of alignment.

Sure enough, it was out a bit the first time when I test rode it, but I
have checked and adjusted the back wheel to within an inch of its life,
and all seems correct and aligned, but the noise still happens.

I took it all apart again and checked everything again, all is on tight
and adjusted correctly. Again. And yes the chain is adjusted so it is
not too slack, and not too tight. And yes, I remembered to put the back
wheel back on.

However, while I was replacing the sprockets, I noticed that the old
original front sprocket has a rubber bit on each side of it, from the
factory. (the bike shop dude called them "cush drives").

The replacement front sprocket didn't have these bits of rubber but was
otherwise identical. Bike shop dude said they only come on the original
Yamaha parts, and he didn't offer to order one in, so I was sold a 3rd
party front sprocket that didn't have these cush drives on it. Could
this be the source of my strange noise woes, because it is missing the
rubber bits on the front sprocket and as a result the chain makes more
noise? (am clutching at straws here, otherwise I will take it to a
mechanic soon and humbly ask for it to be looked at by a "professional").

Has anyone replaced their XV250 chain and sprockets before and perhaps
has some relevant pointers about this?

PS my new chain works fine with a clip joining link, but I am sure that
has been said already in the other chain thread. Well, works fine except
for the noise, anyway.

Any well mannered, pertinent, relevant, helpful advice would be most
appreciated!

 

If the front sprocket is anything like the design of that on my bike you
won't be able to change the rubber over. ( I thought of doing that once)
Further could be dangerous if you could and didn't do it properly and it
subsequently caught up and locked up the drive.
It is a sound deadener and without detrimental impact it does not appear on
the many bikes that opt for aftermarket sprockets.
A tight spot in the chain can make an oscillating noise. Could also be a
brake disc problem which you might have caused when riding it the first time
when the wheel was out of alignment. Depending in how much you were out, the
disc may have been put under load as it turned in the caliper.... or you
might have bent the disc if you supported the wheel on it when changing the
sprocket?
??? suppose that a 250 V has a rear disc and not a drum?
Rockit

 

sounds like your chain is too tight dude. Slacken the chain a bit and
see if that makes a difference.

Like other posters have suggested, jack up the rear and turn the wheel
by hand to see if you can pick up the noise. Nothing? Start the bike,
engage 2nd gear and slowly release the clutch .. crank the throttle a
little bit..anything?

Let it run in 2nd for a few minutes crank the throttle just enough so
the bike doesnt stall.
SWITCH THE BIKE OFF. With the rear wheel stopped, touch the rear brake
drum, is it hot or too warm to touch? if yes, the brake is binding.
Adjust the rear brake.

Does the noise dissappear when you engage the brake lightly?

Are u sure the noise is coming from the rear?

 

Thank you for your suggestions everyone! Very helpful, however sadly I
will either need to buy a proper bike jack/lifter thingy (as I don't
have one), or take it to a bike shop to be looked at. Its a toss up
between ebay'ing my own jack or paying a workshop to do the honours at
this point. Oh well. Every time I do something like this I end up with
about 50 new tools.

I was lucky I was able to do the rear wheel at all originally, as the
Mrs had to hold it steady for me, on top of a car jack with about 2 x
20c coins of flat space, to balance the bike on at the time, while I
quickly changed the rear sprocket...a true OH&S nightmare.

 

Not yet! It has quietened down though as I found that some of it was
caused by one of the chain guards just back from the front sprocket
cover (just a thin metal sheet) being bent in too close to the chain, so
it was whipping it a bit in transit. (was only a millimetre or 2 off the
chain). The noise is still present though but not as bad...makes me half
wonder if I'm imagining it now!

All the bike shops in Canberra are, however, booked out until after I go
back to work, so I will just have to live with it till I get a bike jack
(in a few weeks I hope)...or until it falls apart, whichever comes first!