Countershaft issue

[Paul_E_D]

Use the macro setting on your camera for close ups.

Wow, you're lucky that thing held for even one event. Someone hacked that job. You're only choice there is tap threads and use a bolt and springwasher.

[FTMS]

Where was the original bolt that held it in place go?

Was it in the center of the shaft where you want the new bolt to go?

[slammp]

why don't you tap the center hole on the counter shaft and bolt the sprocket on. You could add stainless washers in front and behind to shim the sprocket in either direction. My rc51 has a tapped shaft (no pun intended)

[Pittenger5]

Where was the original bolt that held it in place go?

Was it in the center of the shaft where you want the new bolt to go?

why don't you tap the center hole on the counter shaft and bolt the sprocket on. You could add stainless washers in front and behind to shim the sprocket in either direction. My rc51 has a tapped shaft (no pun intended)

Thats what Im trying to do, but its hardened steel and I cant drill it at all.

[slammp]

Fill the hole with 2 part metal epoxy and let it cure. Drill out the epoxy and tap into that.

[Pittenger5]

Fill the hole with 2 part metal epoxy and let it cure. Drill out the epoxy and tap into that.

Is that gonna hold though? That was my first thought

[slammp]

Unknown, but they hold up the tunnel ceiling (most of the time). The only other option I see is a weld shop to fill it with real steel. See if anyone on here has a portable weld set up that could do it on bike for you.

[FTMS]

You are one lucky son of a bitch that a bolt stayed in there since there are no threads in there. One possibility is to have a stud welded to the end of the shaft so that you could then put a nut and washer on the end to hold the sprocket on. Threading the end is the besting thing but that is not going to be easy since the shaft is harden. Filling the hole with an epoxy and taping the epoxy mite be a possibility also.

[Tricky Mike]

Bad idea.

Buy some new parts to that bike. Do yo want to die by just doing a temporary fix?

If you can't keep your bike in proper maintenance, don't ride it because it could kill you. This is not car where you have four tires so what if one blows out you still have three more type scenarios.

Enough said.

+1 Richie. I'm glad we had this talk.

[Pittenger5]

+1 Richie. I'm glad we had this talk.

Haha, lemme guess. You can fix it in 3 minutes right?

[Mad Max]

If the inner bore of the CS isn't too messed up (ie smooth surface finish, round, ect.) I would have a machine shop make a custom fastener. You want a smooth, steel stud that is about .0007" - .0010" oversized for that hole and has threads on the end that stick out. You want to be able to tighten a nut down onto the stud over a large outer diameter, small inner diameter, thick washer. The washer will bottom out on the shoulder of the stud which you want to be proud of the CS by the smallest amount possible (.005", let's say)

This interference fit means that you will (ideally) press the stud into the shaft which makes it very difficult because now you have to split the cases and take it apart (i.e. a huge PITA)

The easier and less picky way to do it is to heat CS (might want to remove the seal, or plan on replacing it) and cool the stud. Gently hammer it into the CS using some type of a chemical locking assembly glue in there for kicks. Don't get the CS too hot because it will loose its temper (AND GET VERY MAD!! ) horrible joke, I'm sorry.

If the amount of play that the sprocket has on the shaft is significant you want to take it up with spacer, but you do not want that nut to be tightening down onto the sprocket itself. The sprocket should have just a little bit of slop.

If you think this would work then I can give more details.

How deep is the hole?
It looks like there is something brass colored at bottom, what is it?

[Mad Max]

What kinda bike is it?

Also, I agree with others that tapping the hole and using a bolt is the best bet. My idea was counting on you not being able to thread the hole.

From my knowledge, threaded holes are usually tapped before hardening and then the threads are cleaned up afterwards with a run through. The only machining that is usually done after a hardening process is precision grinding or super machining for supercritical dimensions (e.g. bearing surfaces). Depending on the type of steel and the hardness, taping may or may not be a routine job.

[richw]

1st pull up a parts diagram on an oem parts diagram website

I am suspiscious that a
LONG Bolt went inside and got threads deep in the inner hole.

2nd there is a small chance that the shaft has moved inward.

The spacer may be supposed to be internal for the oil seal to run on


The shaft is formed soft then heat treated hard... you ain't threading sh*t

[Paul_E_D]

mad max is on it.

[Awesome]

What's the spacing distance? I bet Tricky could toss that sprocket on a lathe and take off enough around the shaft to get a nice flush fit with the original circlip. Or go R7's route and let it be a little offset....though it only has 2 tires and if you don't buy new parts it'll kill you.

[obsolete]

What's the spacing distance? I bet Tricky could toss that sprocket on a lathe and take off enough around the shaft to get a nice flush fit with the original circlip. Or go R7's route and let it be a little offset....though it only has 2 tires and if you don't buy new parts it'll kill you.

How bout welding the sprocket and the spacer together then turn it down so you don't lose strength on the sprocket? ...or would welding on it lose it's temper.

[DuncanMoto]

Wirelessly posted (BlackBerry9000/4.6.0.297 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.1.20.0)

Give me the bike and go buy a new one. There's no need for you to have to deal with these problems.

[Pittenger5]

Wirelessly posted (BlackBerry9000/4.6.0.297 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102 UP.Link/6.3.1.20.0)

Give me the bike and go buy a new one. There's no need for you to have to deal with these problems.

Ted, I couldnt in good conscience give you a bike that could kill you at any moment due to shoddy repairs because Im too cheap to buy new parts.


Ill probably just fill it with some of that epoxy shit and drill that out. It takes a LOT of effort to get the sprocket off with the chain on, and I can see how it didnt come off, even with no bolt on it. So I think drilling and tapping the epoxy will be enough (hopefully). Either that or I will drop the bike off at Tricky Mikes and tell him to send me the bill. Which is what I plan on doing anyway.

[Kurlon]

The pics I've seen of stock RMZ's don't show much of a recess/hole present, so I'm fairly confident the hole/threads were added after the fact by the bike's prior owner.

Also, KTMs use the same sprocket retaining setup, the bolt does bottom against the shaft, but they also have you use a cupped 'spring' washer so that the sprocket presses against the countershaft seal constantly. If you let that washer flatten out, instant oil leak.

[Pittenger5]

The pics I've seen of stock RMZ's don't show much of a recess/hole present.

I dunno man, this is a stock picture, and you can def see a decent sized hole there.
http://www.canim.net/motors/resimler...4_1024x768.jpg

[Kurlon]

Yup, that pic shows a good one. I was going from pics on SMJ and don't remember much of one back when you were first chasing sprockets?

[gregp]

I dunno man, this is a stock picture, and you can def see a decent sized hole there.
http://www.canim.net/motors/resimler...4_1024x768.jpg

And there is no bolt intended to go there.

"on the RMZ the countershaft has been spaced out to allow the chain clearance of the rear wheel"

You're doing it wrong.

[Pittenger5]

You're doing it wrong.

How is I supposed to did it then?

And there is VERY little clearance to space out the rear sprocket at all. I doubt that would do much of anything, so Im gonna stick with the countershaft sprocket spacing

[gregp]

Run the right size tire/wheel.

[Pittenger5]

Run the right size tire/wheel.

Dirt tire might not stick well on the track though.