Seized Drive Sprocket

[kahnowerh]

I could already feel the wind in my hair when...
Well, the chain jumped from the sprocket and got caught in the spokes.
I exclaimed things, fixed that problem (as far as I can tell) and was gifted with another.

It seems as though the drive sprocket is seized.
I could roll the bike (both with clutch in and clutch out) before my mishap.
Now the back tire's locked, regardless of clutch position.
I checked the clutch and everything looks okay.

I attempted to uncover the drive sprocket, but it seems some superhuman chinaman attached the thing, and I stripped the screw. (“—Also, Dude, ‘Chinaman’ is not the preferred nomenclature. Asian American, please.”)

So, maybe the question's a bit premature (as I can't get into where the sprocket is—yet), but I'm wondering if anyone has had the same problem or has any insight.

The weird thing, to me, is that it worked before the accident but now it doesn't.
And I'm not sure it's related to the chain jumping (but maybe when it seized the chain jumped? that doesn't make much sense to me)

Any help would be appreciated.

I've got a Dax F80.
It went together pretty smoothly for my first build...
But I think I'm going to replace all the butter-consistency bolts

 

[azbill]

sounds like the chain jumped off the drive sprocket
take the clutch cover off and check

 

[kahnowerh]

Ha... The advice I didn't want to hear last night.
I'm working on the patience thing...
Zen and the Art of Motorcycle Maintenance.

I'll let everyone know what's up after I get a bolt extractor some time late afternoon.

Until then, we can take bets...

I thought the chain had more slack previously, so I'm thinking maybe a sticky link got wedged in the small clearance area up there.

 

[Venice Motor Bikes]

sounds like the chain jumped off the drive sprocket
take the clutch cover off and check

I concur!! (It's a easy fix!)

 

[247Jude]

I had a simular incident when my chain was too loose, it folded under the sproket cover and wedged there, try rolling it backwards with force it may pull the chain loose, and save you a little time.

 

[kahnowerh]

Yep, I tried rolling it back and forth, with some force (increasing with my blood pressure).

I'm off to buy a new toy (bolt extractor) and I'll let ya'll know.

Thanks for the help.

 

[247Jude]

Not back and forth, just back with as much force as that when it locked. The chain is train reacked under the cover and wedged between the sproket and the cover bolt housing. ( More than likely anyhow). Ackually better to take the cover off and pry it free.

 

[Kevlarr]

(“—Also, Dude, ‘Chinaman’ is not the preferred nomenclature. Asian American, please.”)

The motors are made in China by (from every video I've seen) men so Asian American would NOT be the proper nomenclature.

 

[kahnowerh]

The motors are made in China by (from every video I've seen) men so Asian American would NOT be the proper nomenclature.

I had watched The Big Lebowski. If you're not familiar, I'd suggest you partake.
And, for some reason, Idiocracy gets better for me every time. I don't think that's supposed to happen.

Anyway, you are exactly correct, Jude.

(Sorry for the quality, cell phone.)


Anywho, my chain was far too long, I fiddled with it...
Ended up in the back streets deciding to shorten it. Told myself it was a bad idea to take off the master link only lit by streetlights (decent lighting, but not for small black-colored things).
I did it anyway. You know how that ends up.

I had to macgyver my way to a shorter chain. Luckily I had (almost) all of my tools and a poorly fitting chain-breaker (a parktools). I rigged it up to work, did some pounding, some finessing...
And now my chain actually stays on!

I'm loving my MB!
Just rode to school to pull a graphic design all-nighter...
But at least I didn't have to pedal (much).

 

[Nashville Kat]

If you have any more trouble with getting the screws off- like the sprocket cover-

although they are phillips head screws, a medium flathead screwdriver will fit on them- so get a good medium sized Craftsman flathead scrwedriver (or a whole set!) with the SQUARE SHANK- designed to get a crescent wrench on, and you can turn the screwdriver with the leverage of a wrench as well.

That chinaman will probably have not gone that far...

 

[Norman]

I've often wondered how they can make a machine screw where the head is almost as soft as lead
and the threads so brittle they are like glass? I wonder if the video with that Chinese guy with the hammer gently installing the seal would know?

 

[kahnowerh]

I didn't have a wide enough standard screw driver at the time. I did try, but the head was too wide for my puny screwdriver.

I've often wondered how they can make a machine screw where the head is almost as soft as lead and the threads so brittle they are like glass?

Mine were more the consistency of melted butter.
I was worried the extractor wouldn't take it out.
And then I leaned into it... and then harder... and then attempted to push the drill through the engine. Thankfully, the bolt cooperated.

 

[NEAT TIMES]

Someone Posted A Pic Of The Locked Chain And Sprocket. He Called It "cowboy Jam"!! Lol

 

[Bikeguy Joe]

WOW!!! You'd have to have a very very loose chain for that to happen.

 

[chrisme]

Someone Posted A Pic Of The Locked Chain And Sprocket. He Called It "cowboy Jam"!! Lol

I've had that happen to me. The sprocket on the wheel came loose, chain jumped off it, and jammed up in the spokes going about 35. Needless to say, it made a horrible mess of the wheel, but also jammed up the chain like that.

 

[jcchappy]

I was trying out a DIY spring loaded chain tensioner when I found out these things do this under deacceleration if the chain is loose. on the road when it happend miles from home. I figured out after the 3rd or 4th time you can stick a flathead screw driver between the sprocket and chain with the cover on and pop it loose. no worries now though no more spring loaded tensioner its just solid.

 

[kahnowerh]

I was trying out a DIY spring loaded chain tensioner when I found out these things do this under deacceleration if the chain is loose.

That's exactly how it happened. It was my first ride, and I didn't quite have the chain short enough.
But, knock on wood, i think i've found the butter zone.

 

[K.i.p]

Interesting assesment of the spring loaded tensioner. I'm a newbie but after giving it allot of thought I have to agree that it is a flawed concept. There should alway be a spring tensioner above the top (take up) chain feed as well. Something I thought of but have not seen here is a single spring loaded unit with a single lever long enough to hold a roller over the top chain and a roller under the the bottom chain. Under spring tension one end of the arm would always be pressing the top roller downward and pushing a roller at the other end (beyond the pivot) upwards against the bottom chain. Think of a teeter-tawter.

Of course the simplest engineering solution is a properly adjusted static roller, like the kit provides already.

 

[chrisme]

I made a spring loaded tensioner a while ago. I made it such that when I was starting or decelerating, and it pulled on the tensioner, it didn't go very loose. That way I didn't get all the chain jumping issues. Which is the reason I re-designed it... Mine was a horrible design and broke after a few hundred miles, but my idea wasn't flawed at all and worked great.

 

[K.i.p]

Sorry chrisme, I didn't mean to offend anybody. I apreciate your reminder that pre-load can be set on a spring, and I can see where that could be made to work provided the spring tension is dialed up pretty high. Point taken. Good call.