As I spin my 1973 750's tire while on the center stand, my chain goes tight, then slack, then tight, etc. Everything looks aligned. Could the chain have stretched in only one section of links? I'm perplexed. First time writing in. I always check here before and after I read my manuals. Enjoy Hobots stories and peoples follow-up retorts.
Drive chain tight, then slack
- Thread starter 7000
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Yes, Hobot is well known as a fiction writer. Perhaps some day when he has recovered from his crashes, he will once again actually ride his own Commando.
Your chain? Sounds like it is stretched out, shot, buy a new one, they are cheap. Likely at some point the tension was set too tight.
Your chain? Sounds like it is stretched out, shot, buy a new one, they are cheap. Likely at some point the tension was set too tight.
1up3down said:
I thougt we were going to ease up on the Hobot slammimg so why not give it a rest (I notice you are pretty new to this forum (Jan 2011) hopefully you will get bored and start behaving like an adult or leave. Sorry if this sounds harsh but if you are going to dish it out you are going to have to take some flak.)
To other forum members I try neverto get involved in personal spats. I hope you understand my view on this.
You may also check that either the back or front sprockets are running true which would explain the chain being tight and slack. A stretched chain will be streched all over, not in sections. If the sprockets are running true, they may be worn to the point the chain "climbs" on the teeth sometimes and cause the tightness.
Jean
Jean
7000 said:
HI 7000 my comment was not directed at your post I have no problems with what you posted it was one of the replies. Sorry for the misunderstanding
Shiny side up.........
Cheers Paul
OH yes chain sounds cream crackered. What you can do is take it off lay it on a smooth surface in a line then move up and down it to 'push the links together. Put a weight on one end and gently pull the other end towards you if it increases in length it is a goner.
7000, Go ahead and get a new chain but don't let that keep you from checking the sprockets. A couple of tight links will do this. It may just need a good soaking. Another good test is to see how much it bows when hold it out stretched on end. If it really dips down, it's really worn. I am not sure of the standard but is seem like 1" per 1' or so.Jeandr said:
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Relax on hobot target practice, part of my forced on me hobby to savor with thick skin and more tall tales yet to live, including some horrific insights on chain tension issues. hobot never capitalized as just a fictitious handle not a real name.
Chain wears pretty even all around, not stretching side plates, for very little difference in links tight to loose, until so damaged or rusted weakest links bind or break. Best and only realistic way to know if chain wear starting to injure teeth is to check the lift out of rear sprocket valleys. Chain tension has NO effect on this. The amount of lift detected is where the chain bears on teeth under speed and loads. I feel ok until ~1/3 lift then ease power loads till new chain.
As mentioned the source of uneven chain tension is off centering of cogs or the shafts or both. Be pensive, very pensive till source discovered and corrected. Worst tall tale on this was Ohio 1000 mile trip, noticed chain tension uneven and even had it come off, but on road and over loaded just set tightest not to tug with swing arm motion and road normal with traffic and friend. At rally found could not leave until DynoDave stole a rear bearing from a loaded bike because mine had decayed to wobble in its bore, accounting for the chain tension weirdness.
Another concern would be - one event where primary chain adjusted too tight for heated length and bent the main shaft in gear box &/or wore the sleeve shaft bushes badly quickly.
After drum bearings replaced still had fast chain and teeth wear and some tension variance, then discovered gear box issues for head smacking, can't just replace the obvious and expect problem solved.
I found its even possible to have everything wrong at once, off centered sprockets and shafts with too slack a chain with too stiff an O ring chain >>>
so it kinks can't swivel to fit in valley and chain rides the outside of teeth to jerked whole drive line to trash when shocks hit hard limit.
Chain wears pretty even all around, not stretching side plates, for very little difference in links tight to loose, until so damaged or rusted weakest links bind or break. Best and only realistic way to know if chain wear starting to injure teeth is to check the lift out of rear sprocket valleys. Chain tension has NO effect on this. The amount of lift detected is where the chain bears on teeth under speed and loads. I feel ok until ~1/3 lift then ease power loads till new chain.
As mentioned the source of uneven chain tension is off centering of cogs or the shafts or both. Be pensive, very pensive till source discovered and corrected. Worst tall tale on this was Ohio 1000 mile trip, noticed chain tension uneven and even had it come off, but on road and over loaded just set tightest not to tug with swing arm motion and road normal with traffic and friend. At rally found could not leave until DynoDave stole a rear bearing from a loaded bike because mine had decayed to wobble in its bore, accounting for the chain tension weirdness.
Another concern would be - one event where primary chain adjusted too tight for heated length and bent the main shaft in gear box &/or wore the sleeve shaft bushes badly quickly.
After drum bearings replaced still had fast chain and teeth wear and some tension variance, then discovered gear box issues for head smacking, can't just replace the obvious and expect problem solved.
I found its even possible to have everything wrong at once, off centered sprockets and shafts with too slack a chain with too stiff an O ring chain >>>
so it kinks can't swivel to fit in valley and chain rides the outside of teeth to jerked whole drive line to trash when shocks hit hard limit.
Hobot, I don't know what you just said, but I enjoyed reading it. I will definitly look into the sprocket alignment issue, but I'll go ahead and get a new chain anyway. I've had this bike since 1992, and for all I know it has the original chain.
Thank you, everybody, for the replies.
Thank you, everybody, for the replies.
I replaced my center stand this weekend. It was twisted beyond repair, and had extra bracing welded on, rather poorly. It looks like it may have come apart sometime in the past. Also, my primary chaincase has a chunk missing, where the sprocket is. I read on this forum about somebody's experience with a center stand coming off on the road, causing similar damage. Let me guess...Hobot's right, and I have bad damage to repair?
rvich
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I would probably run the bike with the drive chain off, put it in gear and get down there were I could watch that counter shaft sprocket to see if it is running on a bent shaft. It would probably be good to do a good inspection of the primary as well since the primary chain could be experiencing the same thing.
As for the center stand...are you going to scrap it? Somebody cut the extension off the left side of mine and if I had another I would weld it back on!
Russ
As for the center stand...are you going to scrap it? Somebody cut the extension off the left side of mine and if I had another I would weld it back on!
Russ
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Can never go wrong with a new chain, just may do the same tight/loose tension if the stuff it runs on is skewie. If clutch basket wobbles there's a clue, but only real way to tell is get shafts out and roll them together or direct measure for run off.
What I've found in mine is they don't just get a bend as if put in vise and pounded on, no sir that'd be too easy to straighten, they turn into candy cane spirals that need to be un-screwed by many multiple impacts and checks betweens.
I think me bad drum bearing wobbling and beating axle may had something to do with the axle breaking on return home at 90 mph. So I may be a bit more pensive on chain tension variation. Also used up some gear box sprockets and couple of drums worth of teeth - before finding gear shafts likely involved.
What I've found in mine is they don't just get a bend as if put in vise and pounded on, no sir that'd be too easy to straighten, they turn into candy cane spirals that need to be un-screwed by many multiple impacts and checks betweens.
I think me bad drum bearing wobbling and beating axle may had something to do with the axle breaking on return home at 90 mph. So I may be a bit more pensive on chain tension variation. Also used up some gear box sprockets and couple of drums worth of teeth - before finding gear shafts likely involved.
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Had a similar problem on my MKIIa with the chain going tight then loose as the wheel rotated causing the chains to wear rapidly. After a critical look at the rear sprocket and axle set up with the two peice QD style axles I decided there too many parts and that we never really had much of a chance getting the set up right with the short axle and the long axle trying to work against each other. as well as the axles breaking under hard use. My soloution was to make a full length axle out of 4140 Cr Mo steel and making a spacer of similar dimentions to the stub axle, With a good nut on each side of the swing arm when tightened it pulls the whole assembly together rather than the two peice style pulling things apart. This mod in conjunction with an o ring chain has extended chain life considerably.
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