Slack front sprocket on drive spline

**DragonflyDH90** · 6th November 2005, 11:08

Hi ,
Have been just replacing my front sprocket and chain, and when removing the sprocket noticed that there is a lot of slack on the spline, it is the first time I have replaced a sprocket on this bike so cant say if its normal or not.

The bike is a GSX250 Across and the sprocket is held on by an E Clip and groove

, which makes it quite slack on the shaft but its the backlash I'm concerned with looking at the splined drive the spline doesnt have semetrical (spl) shoulders, it looks like it supposed to be like this but not sure.

The bike is a project so havnt ridden it yet, so cant make a comment on what it feels or sounds like, just concerned with the slack, would have thought it would have been a tighter fit (ohh eer

)

Could it be that it has the wrong front sprocket? Ill check this shortly...

If this isnt normal what do you think the best option for a fix is, I hope the splines not buggered but it looks fairly normal apart from the unusual shoulders on it but like I said it looks like they were machined that way not worn.

**Pixie** · 6th November 2005, 11:16

Is the slack due to wear on the spline or the sprocket?
You should be able to determine this if you can see a wear pattern on the parts.
Either way, if the slack isn't too great throughly degrease the spline and sprocket and apply Loctite 609 bearing retainer to take up the clearance.

**DragonflyDH90** · 6th November 2005, 11:51

Ill post a couple of pics when my batteries are charged, but at this stage there doesnt seem to be a lot of wear on the sprocket and spline, all looks to be fairly normal.
Ill post the pics soon.

**DragonflyDH90** · 6th November 2005, 20:23

Here are a few pics, see what ya think...

http://i21.photobucket.com/albums/b2...0/P1010800.jpg
Drive Spline

http://i21.photobucket.com/albums/b2...0/P1010803.jpg
Front Sprocket

http://i21.photobucket.com/albums/b2...0/P1010805.jpg
Front Sprocket

http://i21.photobucket.com/albums/b2...0/P1010807.jpg
Rear Sprocket

Im probably being paranoid, the more I look at it and the more I move it on the spline drive the less concerned I get.

**erik** · 6th November 2005, 20:57

Sorry to say it, but it looks worn to me.
Take a look at the attached photo of the sprocket, I've circled bits on the sprocket where the edges look like they've been beaten and kind of pushed out to form sharp-ish lips. I'd say the odd shaped shoulders on the spline are also due to wear.
It looks like it's the right sprocket though:
http://www.jtsprockets.com/61.0.html...tnr=JTF1439,13

**DragonflyDH90** · 6th November 2005, 21:13

Ah well, guess its time for some new sprockets and chain.
Ill do a bit more cleaning on the spline and see if they are wear marks or its machined like that.

**Motu** · 6th November 2005, 21:16

That's a very badly worn mainshaft spline,damn near half worn away! Bad news is it's a total engine strip and the shaft is not cheap new,and possibly hard to find 2nd hand.

**DragonflyDH90** · 6th November 2005, 21:39

Damn, I know where there is a couple of spare donks for the bike but didnt want to have to fork out for one, might be cheaper than replacing the maindrive spline though.