Only mod I regret doing on my Hawk 250....
 

Chain/sprockets upgrade.
I didn't have any real issues with this bike before hand, few hiccups here and there but never anything this long.

Ever since I changed the chain I've had issues. When I first installed it I checked the slack and it was within specs, went out for the first ride and the chain masterlink snapped, got it back home and got a new link, got the chain back on without adjusting anything and it was way too tight, obviously had moved when riding, so I went ahead and bought a whole new chain and adjusted back to specs, went riding around the farm and checked it again, and everytime it moves now, I've repeated this process 3-4 times and no matter what the chain re-adjusts itself after riding for a bit. I had it adjusted to exactly 25MM of slack and now it's about 30-31MM of slack. A bit on the loose side. Should I just ride with it or try to get it back to 25?

(20-30mm being the goal?)

How do you pros get your chain adjust properly on the first try? or do you just keep adjusting, riding, adjusting, riding, etc until finding the sweet spot?


So after looking up 30mm it's actually 1.1inch-ish, I'm right over 1inch, so I should be perfect for the more loose side of the specs, question is do I want it on the loose side of things?

Really dumb question, but is your axle nut correctly torqued?



The chain pins can't be wearing that fast (this is the actual 'stretch') so I wonder if your axle is creeping. Lock nuts snug?

The only time I've ever had a chain get out of adjustment that fast is when the back wheel isn't straight. When you adjust that chain you have to make sure the back wheel is straight. On the Hawk its harder to do that I believe because there are no hash marks on the swing arm to assist in alignment. But there are a few ways to do this. you can take measurements on the adjusters, or measure the distance from the swing arm to the rim at the side of the wheel closest to the motor. You can do some measuring and put yourself some hash marks on the swing arm to help you with adjustments in the future.

Since I have so many bikes and they're all different, I made myself a Rear Wheel Alignment Stick Of Doom (tm) out of three pieces of aluminum flat stock: First is just a straight piece about 30" long. Then I have two "pointers" made out of the same flat stock but with the ends cut off at 45 degree angles. One is riveted square at a 90 degree angle at the end of the long piece, and the other is mobile and I just clip it to the long straight piece with a binder clip. This has always been perfectly accurate for me, and even beats the fancy Motion Pro chain alignment tool both on cost and ease of use.



What you do is, you slide the mobile piece up or down the length until both pointers can be exactly centered on the swingarm pivot bolt and the rear axle. Then you compare this to the other side, and diddle with it until both sides are the same, from center-to-center. What the actual measurement is between the two doesn't matter one whit; what matters is that they're both the same. And that the amount of slack in the chain is roughly correct, of course.


I have a wide array of bikes from cheap Chinese junk (why I'm here) to metric cruisers, sport bikes, brand name dual sports, standards, and more. Even among the ones that have factory supplied alignment marks on the swingarms, none of them are particularly accurate or agree with each other on the left vs. right sides. I just use my stupid alignment stick and I've never had a problem since.

You're setting your chain slack way too tight if you are setting it with the rear suspension at full droop (fully extended). It should be about 38mm of slack at full droop, and that is 38mm at the tightest point of the chain.

The actual specification is a bit ridiculous and hard to achieve without either using ratchet straps or unbolting the rear shock and manually setting the swing arm at the right angle.

The actual slack spec is 15mm at the tightest point of the chain when the counter-shaft (shaft the sprocket is on) swing arm pivot, and rear axle are all in perfect alignment. This is where the chain is at it's tightest through the whole arc of it's travel.

I set my bike to this spec once, marked the point of the chain I set the slack to, and then measured again with my rear suspension at full droop. and ended up with the 38mm number.

That explains the first time when I snapped the master link, I've been adjusting it with the bike on the ground since, though.

Thanks, I think this is the problem, one side has 3 1/4 threads showing, other side has 2 threads showing. Back to adjusting this damn thing for the 5th-6th time now....

35 ft lbs? I hope that's correct. I read 65 at first and tried to do that and stripped out the stock nut lol. Been doing 35 since after finding it when googling correct ft lbs.

That is the CSC TT250 torque spec and the one I have used on my Hawk since I first bought one. Never been an issue.

Yeah I'm pretty sure it was one of your posts I found that led me to that conclusion LOL

I have a random question - when I got the bike my dumbass put premium fuel with Ethanol in it - I've ran it out of the bike since and filled it with premium with no ethanol - do I need to switch the fuel selector over and run the reserve out too? I think it's had that ethanol fuel in it this whole time? Not sure if that's truly a "separate" tank or how a reserve works tbh.

The reserve works in a fairly simple method. The standard Run position draws fuel through a tube that sticks up in the tank a couple of inches. Once the fuel is at the top of the tube it is "out" of fuel even though there is still fuel in the tank. The reserve pulls from the actual bottom of the tank.

I normally just run mine in reserve since my fuel gauge works and I have a good feel for how much fuel my bike has left on the last bar of the fuel gauge. The whole idea of the reserve valve was from the days when bikes didn't have fuel gauges, so you could ride around and once you had to switch to reserve you knew it was time to hit up a fuel station.

The misalignment is a good catch. I usually measure the adjuster threads as I don't trust the stamped swingarm marks at all (definitely a friday afternoon job on my TT250...)



Always do to one side what you do to the other, keeps it simple.

I didn't even notice there were swingarm marks? Maybe that's a TT250 thing lol, or maybe my hawk is just too dirty.

It was a lot easier than I expected lol, just tightened one side a half a turn and loosened the other side a half a turn. Chain tightened a bit but still seems within specs, can't ride her to confirm it's gonna stay put though, it started raining. :(

my hawk has marks on the right side of swing arm but none on the left. I measured threads on the tensioner to adjust mine, I hope that is okay. I am still learning.

This is covered in the General Discussion section. This post, the first video, fast forward 9 minutes and 5 seconds in.


https://www.chinariders.net/showthread.php?t=32615