Chain Tension

**The Stranger:Me** · 23rd September 2005, 12:36

What torque setting for a rear axle nut on the blackbird please?

Last weekend I checked the chain tension on the Blackbird and set it as per the manual. I torqued the axle nut up to the specified torque (69 ft-lb) but thought it felt a little loose. I went out and purchased a nice new torque wrench and reset it. Yeah it was loose so I through the 25yr old torque wrench away.

Just check the chain tension again and it is bloody well loose again.

What did I do wrong?

**vifferman** · 23rd September 2005, 12:59

Originally Posted by CaN

What did I do wrong?

Too many wheelies? :spudwhat:

If everything is adjusted properly, and the axle nut is torqued up right, maybe there's something that's worn, allowing movement, like the swingarm bearings.

**Blackbird** · 23rd September 2005, 13:04

Are you sure it's your axle shifting? Sorry to introduce other variables but if your adjuster nuts are tight, I wouldn't have thought your axle would have shifted in the short term. I wonder if you're getting chain stretch due to a: Lack of chain lub or b: misalignment. I've got a Scottoiler on my 'bird and never have to adjust the chain between tyre changes. The other possibility is that your chain has stretched unevenly and just gives the illusion of having moved.

Geoff

**bugjuice** · 23rd September 2005, 13:07

for what it's worth, my rear axle is 96lb by the manual

**The Stranger:Me** · 23rd September 2005, 13:21

Ok the lack of lube should not be an issue, I am pretty careful here. It gets lubed at the end of each day with spectro chain wax.
As to misalignment, what do you mean?
The angle of the axle?
or alignment to the front sprocket?
I would have thought that the last one is pretty well set in stone by the design of the bike and I was careful of the first.

**vifferman** · 23rd September 2005, 13:21

Originally Posted by bugjuice

for what it's worth, my rear axle is 96lb by the manual

Rear axle? :spudwhat:

**Blackbird** · 23rd September 2005, 13:35

Misalignment of the drive train is a lot more common than you might think. The standard adjusters are NOT sufficiently accurate on most bikes. I'm not suggesting that is the reason but it's a possibility. Have attached a piece on alignment just for reference.

How old is your chain? The reason I ask is that when I bought my 'bird secondhand, the chain definitely had tight and loose spots. Easy to see with your bike on the centrestand and rotate the rear wheel slowly.

**bugjuice** · 23rd September 2005, 13:41

Originally Posted by vifferman

Rear axle? :spudwhat:

...... axle bolt thingy...
upyerbum

**loosebruce** · 23rd September 2005, 15:55

Could be just that your chain is poked, and needs replacing, poked chain tighten it up, then next thnig you know it's loose as again. Check and see how loosely it sits on the sprocket at the rear, if you can pull a fair bit of the chain up off the sprocket at the back, it's well poked.
Pffft torque wrench, if you can strip an axle nut and the thread on the axle you're doing well.
But the last thing you want is your chain to snap, makes a hua of a mess. Ask Speedmedic.

**vifferman** · 23rd September 2005, 16:03

Originally Posted by bugjuice

...... axle bolt thingy...
upyerbum

Muhahahahahaha!!!

Actual, the VifFerraRi does have an axle thingie (tech term) of sorts. It's a sort of spindle thingo (another tech term) similar to the axle stub on the front wheel of a car.
Or summat.
Or not.

The wheel's held on by four (4) bolts, which bolt into the rear hub. It's pretty kewl whipping the back wheel off, and not disturbing the chain, brake, etc.

Not quite as kewl as adjusting the chain: loosen the 17mm eccentric clamp bolt, whack the c-spanner on the eccentric, rotate slightly as required, tighten the 17mm bolt, done.
Must take...oooh.... all of 47 or so leisurely seconds.

**Blackbird** · 23rd September 2005, 16:56

Originally Posted by vifferman

The wheel's held on by four (4) bolts, which bolt into the rear hub. It's pretty kewl whipping the back wheel off, and not disturbing the chain, brake, etc.

You're a closet BMW owner, you are (snigger)

**The Stranger:Me** · 23rd September 2005, 17:15

Ok then, how many km should I expect from a chain?

You will note I said "should I expect", not what you would expect, just in case it is anything like your tyres.

The chain'o'meter on the adjuster is at 50%

How is the engine in GSX anyway?

**YamaHead** · 23rd September 2005, 17:24

I can get up to 8k miles out of a chain....but of course I lube & adjust religously. It also depends alot on how you ride

**Warr** · 23rd September 2005, 17:47

Originally Posted by Blackbird

Misalignment of the drive train is a lot more common than you might think. The standard adjusters are NOT sufficiently accurate on most bikes. I'm not suggesting that is the reason but it's a possibility. Have attached a piece on alignment just for reference.

How old is your chain? The reason I ask is that when I bought my 'bird secondhand, the chain definitely had tight and loose spots. Easy to see with your bike on the centrestand and rotate the rear wheel slowly.

I'm impressed Geoff !!
I've always wanted to own a laser torch/transmitter but apart from keeping up with my son, couldnt think of a reason to do so.
You have given me a reason to do so. (Apart from the small fact that I dont own a bike with a chain) ... But that could change...
Good idea there.