Front Sprocket Welded on

[whynot]

Just completed an oil change on my new transalp and noticed the front sprocket has been welded on.

I am about to take it in to get a new set as the chain in knackered.

Is this as bad as i think it is?

It looks in reasonable condition, sorry i didn't manage to get a photo.

What would be the best solution? Is it best to get it grinded off and re-welded? How long will it last in this condition?

or should i just get the chain and rear done and see how it lasts? Is it possible to just keep changing the chain and rear? if so how long would i expect the front sprocket to last?

Thanks in advance.

[btbloke]

If it's been welded on it probably means the splines have had it on the output shaft. It's a common last resort fix with the alp and the AT.If you change the rear sprocket and the chain it can be a bit of a false economy not to change the front but sometimes this is a bit of a dilemna as it is more work grinding off the welds and re-welding the new one back on.
If you are having it done by a professional let him have a look before you decide what to do,he may look at the sprocket and decide it has plenty of life left in it and recommend leaving it on.
Some pics may help you get a second or even 10th opinion before it goes in from people on here so I would suggest getting the camera out and let us have a look.What age etc is the alp? How many miles etc can explain why it has been done in the first place.

Just noticed your post in the introduction forum, is it the 2000 or the 2003? and if your off round europe I would get a new one on,makes sense to chain the whole caboodle.

[whynot]

Hi, thanks for the reply.
I will see if i can get some pics soon.

Its a 2000 650 with 40,000 miles on it.

[btbloke]

Might explain it, but 40k is not high,the previous owner may have used crap sprockets or there may have been an incident that damaged the splines.
Replace it with a pucker honda sprocket and you may find a minimal amount of welding will do the job. Also the honda one will see you round europe and last longer than some aftermarket ones so the job shouldn't have to be re-done for a long time to come.

[whynot]

here are a few pics, the sprocket looks ok to me but the weld isn't actually holding it and there is a few mm of play between it and the weld.

[paulc]

That is a crap bit of welding you have there,all it's doing is stoping the sprocket from coming off ,you can see that there is still movement of the sprocket on the shaft by the rust-dust when all he had to do was weld from the splines to the sprocket .
I dont know how you would get that off ,and you do cos the sprockets had it.
Lots of time and a Dremel?.................. hell of a lot of time!

[btbloke]

Yep,not good!
The sprocket has had it,very short teeth and I've never seen one welded all the way round with what looks like arc welding which hasn't actually caught the sprocket just lying next to where the retaining plate should be because it looks like it's missing. The bit it's attempting to weld to is the sprocket poking through the rubber of the sprocket it looks like anyway.

how are you for a dremel and lots of time?

[backlash]

Hello,
it appears from the pictures that the sprocket has been pushed further inwards probably onto an unworn part of the spline.The weld was just put on to keep it there.If that is the case then chances are it is out of alignment with your rear sprocket.All in all a very unsatisfactory situation.

Your choices are to replace the old shaft with a new one , or perhaps weld a new sprocket on closer to the original position checking that it is properly aligned with the rear .

I can see that it will be difficult to remove the sprocket especially if you decide to reuse the shaft by welding a new sprocket on.The only thing that comes to mind is for you to split the sprocket with an angle grinder working in from opposite sides first and then splitting the halves if necessary.Have never done so cannot comment on the difficulties involved.Then if that goes well,I think the next step would be to grind that terrible weld flush to the top of the splines.The carefully with a cutting disc in the grinder (or dremel) , open up the splines where they are filled with weld until you can get the new sprocket to slide on. Hopefully you can put a few welds on the new sprocket to keep it in its proper place then.

Perhaps what I have suggested is not feasible but I think I would try it that way.

[AIRWOLF]

Yes, the sprocket has had it. If the sprocket is free of the weld and is not spinning on the shaft it may not be as bad as it seem's (if you're lucky).

A small angle grinder will remove most of the weld, then a narrow bull-nose chisel and a dremel to clear the splines to allow the sprocket to slide off.

Then re-assess the situation.

[whynot]

Thanks for all the replies
Have decided to get a workshop to look at it as i don't have any welding/grinding gear with me at the moment. Hopefully it can be recovered.