Thought I'd share this..... As this thread is getting a tad stale...

[BolinJrsPit Crew]

Not that what I have to say is gonna spice things up, just thought I'd share this.

My son and I are getting ready to head out for a ride. His bike always seems due for service, pisses me off, anyways so I'm changing his oil cleaning his filter checking for loose bolts yada yada yada!!

I go to lube our chains and I notice that his chain would get tighter at a particular point. I had just put on a new aluminum sprocket on the rear and my first instinct was to think, "sprocket must be out of round". I spun it again looking over the whole final drive looking for something goofy. Nothing!! So we head out thinking I'll buy a new sprocket when get back.

We were riding in some local foothills, nothing special just some high speed stuff. He says I look like Caselli when I'm over the handlebars and my rear end is swapping around. I tell him " Whatever!!" but on the inside I'm a little giddy. I know he's full of shit.

To be honest I truly love to watch my kid ride. He's got a style that I love. Probably because he's my kid but whatever.

So I'm behind him, and on a decent about 60 mph. Something comes shooting from his back wheel. Suddenly I'm caught up with him.

He stops, throws his hands in the air as if "wtf" and gives me the stink eye.

I get off and take a look.

That's when it hits me, "transmission shaft was bent". Damn. Why didn't I think of that at the house.

His chain snapped in two. That's what flew off his bike. His tranny was locked up and he couldn't be more disappointed in his old man.

How many of you figured out shit just a tad too late???

[crazybrother]

Not that it matters, but what bike does he have? And how many hours/miles on it? I did see one shaft bent, the tale tale sign was a countershaft seal that kept on leaking, even after changing it out three times... And yes, the chain would act like a link was getting stuck and tight.

Bummer, anyway ?

Time to take it to Paul... (A.S. Racing).

[Jim Dettman]

<<How many of you figured out shit just a tad too late???>>

 

Always tough when something like that happens and some times things are simply hard to spot.  As they say "live and learn" and I'm sure it will never happen to you again.

 

<< His bike always seems due for service, pisses me off, anyways so I'm changing his oil cleaning his filter checking for loose bolts yada yada yada!!>>

 

  I hope he's taking part in some of that.  I've always felt a good rider should be able to work on his own bike to a large extent.   Maybe not to the point of being able to split the cases, but they should be able to pick up a wrench and do most of the basic stuff.  This makes them more familiar with the bike, where things can go wrong, and aware of high wear items that need attention.   While their primary job is to ride, part of the job is being in-tune with the bike from a mechanical standpoint as well.

 

 By the way, besides a leaky counter shaft seal, one of the things you need to watch out for is an over tight chain.  Anytime you change chain length, you really should go through the little exercise of disconecting the rear shock, aligning the center lines of the front and rear sprockets, and then figure out what the adjustment should be to give you 2% deflection on the chain.   You hook the rear shock back up, sit the bike down, and then know what you should have in terms of slack for a properly adjusted chain.  Many mechanics make a go/no go block up so it can be checked easily.  This should even be done on a brand new bike as you'd be surprised how often manuals are wrong.

 

Jim.

[CRF DOC]

Probably not a bent countershaft to start with...probably the countershaft bearing was failing and allowing the countershaft to wobble as it was rotating.

 

Hopefully the internal damage won't be too bad. Just look at it as an opportunity to build a badass 250 engine.

Edited September 20, 2013 by CRF DOC

[BolinJrsPit Crew]

Not that it matters, but what bike does he have? And how many hours/miles on it? I did see one shaft bent, the tale tale sign was a countershaft seal that kept on leaking, even after changing it out three times... And yes, the chain would act like a link was getting stuck and tight.

Bummer, anyway ?

Time to take it to Paul... (A.S. Racing).

 

CRF250R.... No leak, don't remember seeing any countershaft gear wobble. I mean it don't matter now.... I'm just glad he didn't get hurt.

[BolinJrsPit Crew]

<<How many of you figured out shit just a tad too late???>>

 

Always tough when something like that happens and some times things are simply hard to spot.  As they say "live and learn" and I'm sure it will never happen to you again.

 

<< His bike always seems due for service, pisses me off, anyways so I'm changing his oil cleaning his filter checking for loose bolts yada yada yada!!>>

 

  I hope he's taking part in some of that.  I've always felt a good rider should be able to work on his own bike to a large extent.   Maybe not to the point of being able to split the cases, but they should be able to pick up a wrench and do most of the basic stuff.  This makes them more familiar with the bike, where things can go wrong, and aware of high wear items that need attention.   While their primary job is to ride, part of the job is being in-tune with the bike from a mechanical standpoint as well.

 

 By the way, besides a leaky counter shaft seal, one of the things you need to watch out for is an over tight chain.  Anytime you change chain length, you really should go through the little exercise of disconecting the rear shock, aligning the center lines of the front and rear sprockets, and then figure out what the adjustment should be to give you 2% deflection on the chain.   You hook the rear shock back up, sit the bike down, and then know what you should have in terms of slack for a properly adjusted chain.  Many mechanics make a go/no go block up so it can be checked easily.  This should even be done on a brand new bike as you'd be surprised how often manuals are wrong.

 

Jim.

Yeah he takes part. He changes oil, cleans his filters, pulls the wheel etc. he helps... As long as we have time otherwise, he is spectating. Awfully damn slow...lol.

 

Chain adjustments were always fine, if anything they run a little loose between adjustments.

[BolinJrsPit Crew]

Probably not a bent countershaft to start with...probably the countershaft bearing was failing and allowing the countershaft to wobble as it was rotating.

 

Hopefully the internal damage won't be too bad. Just look at it as an opportunity to build a badass 250 engine.

That makes sense. I bet he don't have a 100 hours on those bearings. Replaced all bearings a little over a year ago. I've done the crank twice within that time but that was due to an aftermarket bearing prematurely failing. All OEM since.

Anything mechanical will fail... that, we can all count on.

Would love to build a badass engine just don't have time. Is this Paul BTW?

[CRF DOC]

Yessir... ?

Damn...strange for OEM bearings to let go in 100 hours. The shaft may have had a slight wobble adding to the stress on that bearing.

[MasterT2000]

That makes sense. I bet he don't have a 100 hours on those bearings. Replaced all bearings a little over a year ago. I've done the crank twice within that time but that was due to an aftermarket bearing prematurely failing. All OEM since.

Anything mechanical will fail... that, we can all count on.

Would love to build a badass engine just don't have time. Is this Paul BTW?

We don't mention the "P" word here....... CRF DOC is an anomaly, an enigma, a mystery wrapped in a riddle. He most likely only exists within the machine mainframe.

[CRF DOC]

We don't mention the "P" word here....... CRF DOC is an anomaly, an enigma, a mystery wrapped in a riddle. He most likely only exists within the machine mainframe.

In the Construct to be totally accurate... ?