I was helping out a buddy

[jmorton10]

(that was my first mistake).  He has a RK with Baker trans & rear chain drive.

All we where supposed to be doing was replacing the rear tire & installing a new o-ring chain.

We took off the rear wheel, replaced & balanced the tire, reinstalled the wheel & replaced the chain (using the old chain to pull the new one through).

I left at that point.  Later he calls me & says now the bike won't move.  WTF, what do you mean it won't move??  He said it starts right up but if he kicks it into gear & lets out the clutch nothing happens.  He said he jacked up the rear wheel & spun it over & he said he could see the tranny sprocket go around when he spun the wheel.

Now, the bike was running fine before we took off the bald rear tire.  I guess I will be back over there looking at it tomorrow but does anybody have a suggestion as to what went wrong lol ??

~John

[Hossamania]

When he says the sprocket is turning, I'm assuming it's in gear? Bad clutch, broken primary chain (rare), spun splines on the sprocket, broken shifter not actually going into gear, broken tranny, broken compensator?

[jmorton10]

LOL it was running fine yesterday.

If the problem was in the primary (clutch etc) it wouldn't start.

Solid engine sprocket & Bandit clutch. It has to have something to do with changing the chain but I'm not sure what.

~John

[Hossamania]

Good point on starting, hadn't thought of that. Clutch could still be suspect.

[Scotty]

  That is a head scratcher. Let us know what you find as I am intrigued.

[kd]

If he threaded the chain on the rest of the way without you, he may have been a little offside with it and it climbed off the sprocket teeth and is on the inside hub. You don't say what year but the late model transmission sprocket on most chain conversions is about a 3/4" offset.  That's just about enough room for a chain to fall into.  That would have shown up as chain slack and needed adjustment though. It could however explain why it turns with the wheel when jacked up.  Did it make any noises?  Interesting problem.

[jmorton10]

I'm thinking that must be the problem Kirk.

How much of a PITA do you suppose it will be to get it back on the sprocket??

He's an idiot so I'll have to fix it lol.

~John

[Hossamania]

Don't hold back, how do you really feel?   

[jmorton10]

LOL, I love the guy to death. We have been buddies since grade school & if I need somebody to watch my back he is 100%.  I would do anything for him.

That being said, he can't fix anything. He breaks the stuff then I fix it.

~John

[misfitJason]

I'm going with the chain came off of the drive sprocket

[thumpr54]

That'll teach ya !   Sounds like my kinda luck.....

[kd]

Here is a comparison between a PBI 3/4" offset and a standard sprocket. (click on the pic to enlarge it) There's enough hub shoulder to support the chain at close to the same tension adjustment as if the chain was engaged in the sprocket.  With a new chain it may even be tighter that the old one if set at the same place.  It takes a few "HARD" miles to break in the better 530 0-ring chains.  A good 530 chain won't stretch and will hold that adjustment from then on.  If the transmission was in neutral when your buddy spun the rear wheel you can see that if the chain tension was tight enough the sprocket could turn too.  However, unless he has real loud exhaust, I would expect he would hear a whizzing sound as released the clutch and the transmission sprocket spun.  I guess tomorrow will tell.      If so, loosening the adjustment right off or pulling the axle should give enough slack to weasel it back on easily.  A piece of cake if you know anyone with Corvette engine experience.   

[hbkeith]

I'm going with the chain came off of the drive sprocket

   amazing if he was able to get chain tight riding on the offset and not the teeth

[Pirsch Fire Wagon]

We can all sympathise. We all know that one guy....

[Pete_Vit]

  Unfortunately that one guy is sometimes me 

[Billy]

Clutch hub splines stripped out maybe. I've seen it happen with no warning.

[jmorton10]

A piece of cake if you know anyone with Corvette engine experience.

lol good one Kirk.....

All fixed, the chain was off the tranny sprocket & it was kind of a PITA to get it right.
I would have liked to break the chain, but I didn't have a spare rivet master link. I pulled the rear wheel off (again lol) & even with the wheel off it was hard to tell if the chain was right. It slipped off the sprocket 3 times as I was getting ready to reinstall the wheel.

I had 3-4 extra 530 masters but they are all the clip type & I didn't want to throw that in even temporarily.

~John

[smoserx1]

 

[kd]

A piece of cake if you know anyone with Corvette engine experience.

lol good one Kirk.....

All fixed, the chain was off the tranny sprocket & it was kind of a PITA to get it right.
I would have liked to break the chain, but I didn't have a spare rivet master link. I pulled the rear wheel off (again lol) & even with the wheel off it was hard to tell if the chain was right. It slipped off the sprocket 3 times as I was getting ready to reinstall the wheel.

I had 3-4 extra 530 masters but they are all the clip type & I didn't want to throw that in even temporarily.

~John

We all had faith you would figure it out and there was a good reason I called for someone with Corvette in chassis engine experience.  There may have been a requirement to have the patience (that it actually took) to get it back in place. 

[jmorton10]

I called for someone with Corvette in chassis engine experience.

Well I had plenty of that when I was working as a flat-rate mechanic in the 70's (my first job out of high school.) Vette's where really pieces of s*** back in those days & half the guys I worked with completely refused to work on them.  I made good $ working on them so they started rooting all the vette repairs to me.

I do wish I still owned the 1958 vette I had back in those days. This is me in my mothers driveway in 1970 HaHa 

~John

[Hossamania]

Glad to hear it was inexpensive and (relatively) easy to fix. Notice how I went right to the catastrophic failures? Just a little build up for you to make the simple fix a relief...

[jmorton10]

Notice how I went right to the catastrophic failures? Just a little build up for you to make the simple fix a relief...

LOL, when it is something of mine I always think of the catastrophic things it could be.

Of course part of the problem is that through the years I have had just about anything that could go wrong happen to me at one time or another.  I had the flywheels scissor in a 117" motor with less than 2000 miles on it trashing the whole motor, I blew 3rd gear out of three 6 speed trannies before I put in a Grudgebox, I welded up cracks in a set of wild stroker Shovel cases before I replaced them with Delkrons etc.etc.etc. HaHa 

~John

[kd]

So I bought a set of 3 piece C&C full aluminum disc bolt together rims from Rick's Wheels in Baden Baden Germany for my hotrod RGU.  It was a crappy day today and not too hot so I was swapping them out from the 2011 knuckle style OEM wheels. I installed a fresh 57 tooth rear sprocket on the rear wheel and I cleaned the chain so it could be re-lubed and would have a fresh start.  I was remembering this thread so just before I put the wheel into the fender I got down with a flashlight and a mirror to inspect the transmission sprocket for wear.  GUESS WHAT I SAW.    The flipping chain had come off the transmission sprocket just like the one in this thread.    I wiped off the sprocket from behind, inspected the gear for wear and it looked minty (except there was no damn chain on it  ).  It was easier to inspect that way too.    It was also a lot easier to put back on without the wheel in the way like you had.  Just sayin.    Lesson learned was ALWAYS take 30 seconds to check that chain before installing the wheel.  I may not have if not for this thread.  I never had it happen before and now I expect I never will again cuz I'll be checking it first.   

BTW, this is the second year on that 530 O-ring chain and when it was cleaned up it felt as tight as when new.  I purposely bought the best I could and it looks like it's paying off.  (Just like it payed off reading this thread so thanks for posting it John.    )

[Tacocaster]

Exactly KD!
This forum and the larger majority of the members heron are an incredible resource - even when you don't have a current problem underway, there's something to learn.

[jmorton10]

Well I definitely learned something too. I must have had the wheels off of every bike I have owned 50 times & have never once had the chain slip off like that (& of course it had to happen when I am doing a freebie job for a friend lol).  It is certainly easier to put the chain back on correctly with the rear wheel off & I will definitely make darn sure it is on correctly before reinstalling any rear wheel from now on !!

I know one thing, just like Kirk I am super impressed with these new o-ring chains.....

~John