New chain and sprocket - Still tight spots on chain

[allpassDenmark]

Hi guys!

I'm having a really annoying problem with my 92' 600 kat.

I've recently replaced the chain and sprockets, with new DID 530 endless chain, and good quality sprockets. But I still can't adjust the slack correct.
The slack varies a good 10mm. I've checked the following:

Axle is straight? Check!
sprocket is centerede on axle? Check!
Sprocket aligned? Check!
Checked chain thorougly? Check!
Checked wheel bearing, spacers and rubber shock absorber. Check!
checked everything again? Check!
Screamed at the chain and sprockets? Check...

Does anyone have a good idea as to what it could be?

Thanks

Allpass

[cintidude04]

What do you mean by the slack varies?
Is it too loose by 10mm?
Can you not get proper 1"+/- of slack by adjusting the rear axle back with the adjusters?
You may need to remove a couple links.

[KatanaGSX92]

Assuming that you have a brand new chain and sprockets, if you're saying that when you rotate the rear wheel by hand while the bike is in neutral, that the bottom half of the chain (measured half way between the front and rear sprockets) varies in tightness by 10 mm, then perhaps the shaft where the front sprocket is attatched is either bent or the bearings on the shaft are bad...

[JayBell]

are you sure you are doing the measurement correctly?



it should be noted that chain slack measurement is always done with the rear wheel on the ground supporting the bike, never on the centerstand or not under any suspension load.

[mammut89]

1. how much do you weigh ?
2. do you ride with passengers ?
3. do you have a topbox ?

the 20-30mm adjustment wont work if youre bottoming out your suspension in the rear basically.

[KatanaGSX92]

I think he's saying that even with a new chain, there are still tight spots, which shouldn't be the case and that, on top of the normal slack, that slack varies by 10mm at different parts of the chain.

[allpassDenmark]

KatanaGSX92: exactly (I see that I maybe was a bit unclear in my initial description of the problem). I'm doing the adjustment while having the bike on centerstand, with no weight on rear wheel, and adjusting the slack to 30mm on the tightest spot on the chain, as described in Haynes manual for gsx600f. I don't see how it could affect the current problem, if i adjusted while having the rear wheel on the ground.

The problem occurs when i turn the rear wheel and measure the slack on different positions. The slack then goes up and down, as if a sprocket was mounted excentric on one of the axles. But that doesn't seem to be the problem; the rear axle is straight, and undamages, and I'm pretty sure the driveshaft is straight. I'm gonna check that again to be sure.
I might just have to take it to the mechanic, and let him have a look.
Ultimately the conclusion might be, that there's a manufacturing problem with either the chain or the sprockets.

Allpass

[Badfaerie]

Having it on the center stand takes it off the rear suspension, which changes everything about how the rear section fits, that's why it matters. (Others can give you the detailed and technical description of why this is if you want.) If you adjust your slack while on the center stand, as soon as you take if off, your chain will be too tight and cause extreme wear on your sprockets.

Try adjusting it off the center stand and check your slack with both wheel on the ground, rolling it forward a bit to double check it.

[wickeded]

By different spots do you mean you are measuring in different locations or is it the same location but a different link of the chain by rotating the tire?

I might be wrong but the measurements will be different in different spots, more slack in the center between sprockets and less slack if you measure closer to the them.

[allpassDenmark]

Thanks for the replies.

I'm aware that the whole geometry of the swingarm changes as the shock absorber is compressed under the weight of the bike. What I meant, was that I don't see how it would affect the current problem, where the chain slack varies, not just when on centerstand, but when rolling as well.

Allpass

wickeded: I measure the slack the same place every time

[allpassDenmark]

Update.

I had a mechanic look at it, and the conclusion was that the transmission axle, on which the front sprocket is attached, was askew by around 0,5mm., which is actually alot!

Is it worth the while to replace the axle and bearings, with the axle costing around 175$, and all the other costs such as bearings, gaskets and fluid? I can get a used engine in Denmark for around 750$, and I was thinking of getting an gsxr750 or gsxr1100 engine anyway.

I imagine either solution is alot of work, and with the bike still in working condition, the question that remains, is if I should just live with a slightly loser chain, in order to account for the tight spots? The only problem right now, is that it eats through chains and sprockets a bit faster than normally..