Trials style riding on Hawk video + chain issue

[Ichrisbot]

Tried some more easy trials riding and a bunch of longer and more techincal hill climbs today. Unfortunately camera problems started cropping up so I couldn't catch any of the climbs and failed attempts on video lol.

Also kept throwing the chain off the rear sprocket on a certain climb when hitting a very specific bump on the way. First time it happened, I noticed the chain guard was bent in and rubbing against the chain, so I fixed that, then I completely removed the guard after the second time, and then a third time it happened and I'm still not sure why.

This photo shows the part of the frame that the front half of the plastic chain guard attaches to. After the last time, with no chain guard installed, I noticed it bent all the way over.



I don't think anything hit the chain or that part of the frame, all I can think is that the chain bent it down after it came off the sprocket. After each time I fixed it, I checked the chain tension and it appears to be fine. Sprocket also appears to be in great shape as well, no signs of wear yet.

Outside of that one particular climb, the chain never had any issues anywhere else. It was a spot right after a big bump where I would feather the clutch and rev up before the next steep section. As soon as I'd dump the clutch, off it went. Any ideas?

[SeerAtlas]

have someone hold the bike vertical, get behind it and have them ride forward a few feet now look very closely at how the chain sits on the rear sprocket. the sprocket should lie dead center of the chain. if off to one side or the other, realign the rear wheel until it does, doesnt matter what the swing arm marks say.

next have some one heavy sit on the bike try to squash the suspension in the rear all the way. stand on the side and watch for where the chain is tightest as he/she pushes through the full range of motion both compression And lifting the tail ,then adjust your chain tension at that tightest point.
if the foregoing doesn't alleviate your chain problem, u got a bad chain or a bad sprocket.

if they aren't the problem go out and get yourself a live chicken.

You are going to need to perform a ritual sacrifice to the mystic {and inscrutable} Chongqing industrial motorcycle dragon god . ask Spud or Weld for further details.

[Ichrisbot]

I'll try that soon, I adjusted the tension a while ago and made sure the marks were lined up on both sides of the swing arm, didn't think to check if they were actually accurate or not lol.

[Adjuster]

The marks on my swing arm are way off.




/

[pete]

just check the chain gets tighter as the arm compresses...
unlike the silly pit bike I had... the chain got loser..had to put guide plates
on the rear sprocket to keep it on...
A total chinese geometry stuff up...
Looks like it should be OK going by what I can see in the pic...



..

[humanbeing]

Originally Posted by SeerAtlas

... go out and get yourself a live chicken.
You are going to need to perform a ritual sacrifice to the mystic {and inscrutable} Chongqing industrial motorcycle dragon god...

NOT the talking 1 as http://www.ettoday.net/news/20121127/132639.htm

NO-o-oo...(Mandarin:不要 Bùyào) & Hurts(Hokkien 足疼 tsiok thiànn)

[Ichrisbot]

Thanks for the help, I put the bike up on a stand this morning and sure enough the alignment was slightly off.

Another thing I found, I compressed the rear spring and adjusted the chain tightness, it was a little bit on the loose side but not much. One interesting thing I noticed, and I remember reading a post here about it, but the knobbies on the left side of the rear tire are dangerously close to the chain, and I noticed some definite wear on those knobs from the chain. Any slop or left/right play in the chain could have also contributed to kicking the chain off the sprocket.

Anyways, worked great at the track today, up until I crashed it really hard and broke a few parts lol.

[SlowJunk]

Originally Posted by Ichrisbot

Thanks for the help, I put the bike up on a stand this morning and sure enough the alignment was slightly off.

Another thing I found, I compressed the rear spring and adjusted the chain tightness, it was a little bit on the loose side but not much. One interesting thing I noticed, and I remember reading a post here about it, but the knobbies on the left side of the rear tire are dangerously close to the chain, and I noticed some definite wear on those knobs from the chain. Any slop or left/right play in the chain could have also contributed to kicking the chain off the sprocket.

Anyways, worked great at the track today, up until I crashed it really hard and broke a few parts lol.

On a stock setup Hawk, if the alignment is spot-on some of the left side lugs on the knobbies may hit the chain when the suspension unloads from compression. Check the knobby groups that a lowest down on the left sidewall (I think there are 4 or six groups). If there are any cuts in the lead knob or if it is sheared then your chain has been hitting the lug.

[Ichrisbot]

Yep, those ones on the far left have definitely been shaved down. Seems a little close for my taste, but it's been running great since fixing alignment. It's actually an ingenious design, the Chinese engineers just let the machine clearances work themselves out lol.

[SpudRider]