Front and Rear sprocket Alignment

[M0C70R]

If my understanding is correct, the front and the rear sprocket should always be in a straight line or a single plane isnt it?

On my bike the swingarm looks to be left biased and so does the chain. However while riding I dont experience any kind of lateral pull. Do I need to get this corrected or am I damaging something in the long run?

For a slightly technical deduction, I measured the length from a central point on the chassis to the ends of both the arms of teh swingarm and the resulting lengths are not the same. The left arm has a slightly greater length than the right arm.

Would like to have your inputs please.

Thank you

 

[HippoDrone]

Your frame and swing arm may not be identical each side. To check wheel alignment you can use a straight plank or pole (eg scaffold type) and park the bike next to it with someone holding it upright with the front wheel straight ahead and the plank/pole butted up against the side of the rear tyre, then swap the plank/pole to the otherside of the bike and see if the gap from the straight edge to the front wheel is the same both sides. If that is correct then with the plank on the side the chain is, it should run parallel to the chain too!

 

[HippoDrone]

You may also be able to buy a wheel alignment laser but I don't know on availability or cost in India

 

[M0C70R]

@HippoDrone We dont have those tools here unfortunately. And this query isnt regarding wheel alignment. Its got more to do with the "cosmetic defect" so to speak. I say cosmetic because its not really affecting my handling or steering or stability. Rather, when you stand behind the bike and look at it, the wheel and the swingarm doesnt look right.

So frame and swingarm may not be identical on either side? I always thought the chassis is bilaterally symmetrical. Its not always the case?

In the image below, you can see that I drew a straight vertical line along the central axis of the motorcycle (ignore the rear fender, dont take it as reference). But you can notice the offset of the wheel and the arms of the swingarm. Axle adjustment is out of question here since the entire swingarm is offset from the center

 

[HippoDrone]

ahh I see what you mean. if you check the wheel alignment as I described above you'll be able to see if there is an issue or not. Are you the first owner?
You will find it quite common for the swingarm to have a larger gap on the chain side than it does on the brake side, this is so the chain can run past the tyre without hitting it.
As for the rear subframe, they can twist pretty easily if the bike has been dropped or hit by a vehicle but it doesn't necessarily mean the wheels/engine alignment has been affected.

 

[dandoolittle]

The front sprocket will be aligned unless you've put something between the sprockets at the bike!

The rear should stick to the wheel just fine unless you leave crap between (like above)

What you need to do is simply align the rear wheel by using the markers on the left/right just the same as adjusting/tightening the chain

 

[M0C70R]

@HippoDrone @dandoolittle

Thank you. I will do the rear wheel alignment and report back if anythings wrong.

 

[lupin]

Measure the distance from the edge of the swing arm to the wheel on both sides.

If that is the same the wheel is in the middle of the swing arm.

Look at the swing arm bushes / bearings for any movement.

If all that is good then look at the rear sub frame, as it could be that out of and not the wheel. A good indicator of this is if the seat is rubbing on the tank on one side.

 

[HippoDrone]

Measure the distance from the edge of the swing arm to the wheel on both sides.

If that is the same the wheel is in the middle of the swing arm.

Look at the swing arm bushes / bearings for any movement.

If all that is good then look at the rear sub frame, as it could be that out of and not the wheel. A good indicator of this is if the seat is rubbing on the tank on one side.

Am not sure this is helpful, you are suggesting that the swingarm should be equal on both sides which is not normal on most bikes.

 

[M0C70R]

If that is the same the wheel is in the middle of the swing arm.

The wheel is not the problem here. My issue is that the swingarm is not centered w.r.t. the frame possibly from the pivot joint. But this is not causing any technical issues, its just that when you look at it from behind the bike, it looks wrong. The front and rear sprockets dont line up. the Rear one is a bit offset towards the left

 

[M0C70R]

The length from the pivot bolt to the end of the swingarm is not the same on both sides. What do you guys make of that?