SIGH, Hawk 250 chain adjustment issue. Six attempts and I give up.

[HawkTwoFifty]

Originally Posted by Boatguy

I’m sure my bike is different than yours, but if I were in your shoes, I would just account for this situation with the initial chain adjustment.

If every time you tighten those axle bolts, the chain tightens, I would start with a more loose chain setting to account for that. That way when you tighten them up, it will be correct.

Thanks, I guess this will be my last resort if I cant figure what else is wrong. If I go this route, is it ok to run two master links in a chain, or perhaps one master link and a half link when adding additional links back to the chain?


Also, I did some reading elsewhere online since posting this, and found two interesting things regarding this issue. I read discussions of other dirt bikes (non-Hawk 250 bikes) where people experienced this same issue where chain slack was removed from the chain once tightening the axle bolt. A saw posts mentioning that the location of the axle nut could cause this. After watching videos online of Hawk users working on their bikes, I see that their axle nut is installed from the left side of the bike, with the nut being on the right side. I was installing my axle nut from the right side, and having the nut on the left side. I never thought this would make any difference, but maybe the tightening forces of the nut being on the opposite side is causing this. I will give it a try, but am not very confident this will make any difference.


Another interesting thing I read was where people were placing a shop rag between the sprocket and chain and then spinning the wheel until the rag is fed (wedged) tightly into the sprocket which provides enough tension to reduce slack from happening while tightening the axle bolt.



I really hope this solves the issue...

[zscr]

I think you should check everything on the ground before torquing the nut down, if you are lifting the bike without using the swingarm(making the rear suspension hang) the chain will tighten a little more once you get it in the ground.

[HawkTwoFifty]

Originally Posted by zscr

I think you should check everything on the ground before torquing the nut down, if you are lifting the bike without using the swingarm(making the rear suspension hang) the chain will tighten a little more once you get it in the ground.

Thanks. I am adjusting the slack to be on the high side before tightening the axle bolt to compensate for any differences once lowered. Even if a leave a ton of slack, tightening the axle bolt removes every bit of slack from the chain. If only there was a locking nutt in the chain adjustment that would prevent the axle from sliding rearward while tightening the axle bolt, I'd be golden the first time. But the swingarm axle chain adjustment sliders just automatically move rearward while tightening the axle bolt and ends up removing every bit of slack I set. Its seriously wearing me out!

[Mudflap]

Have you tried grabbing onto the chain, both top and bottom about midway between the sprockets and squeeze hard while you tighten the axle nut?



Also make sure the chain isn't overly tight (10mm to 20mm play) when the countershaft, swing arm bolt, and rear axle are in a straight line. That is the tightest point.

[HawkTwoFifty]

Originally Posted by Mudflap

Have you tried grabbing onto the chain, both top and bottom about midway between the sprockets and squeeze hard while you tighten the axle nut?



Also make sure the chain isn't overly tight (10mm to 20mm play) when the countershaft, swing arm bolt, and rear axle are in a straight line. That is the tightest point.

Thank you for that idea!! I cant believe I didnt think of that myself already.

[zero_dgz]

Originally Posted by zscr

I think you should check everything on the ground before torquing the nut down, if you are lifting the bike without using the swingarm(making the rear suspension hang) the chain will tighten a little more once you get it in the ground.

This is correct, for the future reference of anyone reading this. Chain slack is generally set on all bikes, not just the Hawk, with the rear wheel on the ground and the bike on its side stand. As the rear suspension compresses and the rear tire and swingarm move up relative to the frame, the chain is effectively tightened. This is why there needs to be slack in it in the first place. In the case of a dual sport bike with a long suspension travel the difference will be a lot.



If you set your slack with the rear wheel dangling in the air you will find that it is then too tight once you set the wheel back on the ground. Trying to compensate for this by setting the chain really lose before putting everything back together and the wheel back on the ground will be a frustrating process. Just adjust it with the wheel on the ground in the first place.


This will also help prevent it from walking away on you while you tighten the axle nut. (Hold both ends of the axle with a wrench: its head with one wrench, and tighten the nut with the other.)

[Boatguy]

Originally Posted by zero_dgz

This is correct, for the future reference of anyone reading this. Chain slack is generally set on all bikes, not just the Hawk, with the rear wheel on the ground and the bike on its side stand. As the rear suspension compresses and the rear tire and swingarm move up relative to the frame, the chain is effectively tightened. This is why there needs to be slack in it in the first place. In the case of a dual sport bike with a long suspension travel the difference will be a lot.



If you set your slack with the rear wheel dangling in the air you will find that it is then too tight once you set the wheel back on the ground. Trying to compensate for this by setting the chain really lose before putting everything back together and the wheel back on the ground will be a frustrating process. Just adjust it with the wheel on the ground in the first place.


This will also help prevent it from walking away on you while you tighten the axle nut. (Hold both ends of the axle with a wrench: its head with one wrench, and tighten the nut with the other.)

Explains why I never had a problem. I have never taken the bike off the ground to adjust the chain. Ever.

[Thumper]

Originally Posted by zero_dgz

This is correct, for the future reference of anyone reading this. Chain slack is generally set on all bikes, not just the Hawk, with the rear wheel on the ground and the bike on its side stand. As the rear suspension compresses and the rear tire and swingarm move up relative to the frame, the chain is effectively tightened. This is why there needs to be slack in it in the first place. In the case of a dual sport bike with a long suspension travel the difference will be a lot.

Absolutely true. The chain tensions as the weight of the bike compresses the swingarm as you lower it into the ground. The arc of the swingarm changes the distance between the front sprocket and rear axel, and it is maximum when it is straight out. Lifting it off the ground shortens that distance. On my dual sports, the chain typically tensions as I sit on the bike and the swingarm gets more straight. Have someone sit on the bike if you want to check on this after setting the chain tension. A small amount is tolerable, but you don't want to put massive torque on the drive shaft that the front sprocket is mounted on if it still gets too tight.

As you wisely suggest, zero, the chain can be adjusted with the rear tire on the ground to mostly avoid this tensioning.

Also, I snug (not tight) the rear axel bolt to increase the friction somewhat before making the final adjustment on the bolts that push back the axel. They can overcome significant tension on the rear axel bolt easily, and it helps stabilize this process.