I think I've wrecked a new cam chain :(

[erik]

Crap! I think I've stuffed a new cam chain!

The cam chain came as a continuous chain that had to be split. I didn't think to grind the head of the pin off before pushing it through to split the chain (it's the first time I've tried changing a cam chain). Now the plates have burrs where the rivetted end of the pin pushed through them (see attached photo). The burrs make the link bind.

As far as I can tell, I can't file or peen the burrs down as the finish would probably be too rough for the chain. Plus the fact that the burrs are there means the holes will have deformed a bit.

The only way to salvage the new chain, as far as I can tell, would be if I could get some new intermediate plates and another joiner link (which consists of the two side plates and two pins). But I don't know if you can get individual plates.

Anyone have any suggestions?

I'm hoping to get out to Mt Eden Motorcycles tomorrow evening, have to see if Ricky can trade/sell me some exhaust shims and will also ask him about the chain and order a new one if I have to.

[WINJA]

Crap! I think I've stuffed a new cam chain!



Anyone have any suggestions?

USE THE CHAIN IN AN ARMED ROBERRY AND USE THE CASH TO BUY A GOOD BIKE

[DingDong]

My advice... dont do anything, take it to the shop and wear the cost of your error:eyepoke:

[erik]

USE THE CHAIN IN AN ARMED ROBERRY AND USE THE CASH TO BUY A GOOD BIKE

I'll keep that in mind. I get my full licence in january and if I haven't saved up enough cash...

[erik]

My advice... dont do anything, take it to the shop and wear the cost of your error:eyepoke:

But if I did that, I wouldn't learn how to change a cam chain.
Plus, even if I have to buy another chain, I'll still be saving money on paying a mechanic to do it (assuming I get it right next time...).

[Sniper]

Learning bears its costs. If you don't have a manual, I would suggest not going to do something important.

Take it to a mechanic matey.

[DingDong]

But if I did that, I wouldn't learn how to change a cam chain.
Plus, even if I have to buy another chain, I'll still be saving money on paying a mechanic to do it (assuming I get it right next time...).

Agreed... but study up first (get a manual or someone to guide you) it can be a very costly lesson if your chain fails at 100kph, and Winja will reply "TOLD YOU SO!"

[DEATH_INC.]

Don't worry about it, they're usually tight after you re-rivet them,and you can't remove material before pushing 'em out or you don't have anything to rivet over when you put it back together.

[erik]

Don't worry about it, they're usually tight after you re-rivet them,and you can't remove material before pushing 'em out or you don't have anything to rivet over when you put it back together.

So you reckon just ignore the burrs and rivet it back together?

[T.W.R]

So you reckon just ignore the burrs and rivet it back together?

file the burrs then use the new joiner supplied, compress the rivets properly with the chain rivet tool.

the inner plates take the lateral pressure of the chain, the outer plates take the torsional pressure. so when the joiner link is fitted & the rivets are compressed the link will be fine.

[DEATH_INC.]

So you reckon just ignore the burrs and rivet it back together?

Yep,unless it came with the joiner.

[erik]

Thanks for the advice, Death and T.W.R.
It's nice to know the burrs aren't a major problem

After actually trying it, I found I could carefully flatten the burrs by beating them with the wrong end of a nail punch.

Joining the new chain to the old to thread it through was a bit tricky at first trying to hold the pin in position and press it in place with the chain tool.
I dunno how you guys do it, but I had to make a guide to hold the pin in place (part of a bolt with a hole in it that the pin and chain tool pin could fit in - basically a tube, but I didn't have any tube the right size).

I was sold a joiner link with the chain, so when I removed the second pin from the new chain, I ground the head off. It worked well, the plates didn't get damaged at all.

So right now the new chain is in the bike with the joiner link in place but the pins haven't been riveted yet. I think I'll experiment a bit riveting the old chain before I attack the new one. The rivet tool in that came with the chain has a rounded end (slightly flatter than it originally was after I tried it on a pin in an old final drive chain). It's different to the method I've seen described of punching a cross and a centre punch, so I don't think I trust it. The manufacturer's method of riveting the links seems to be to squish two edges of the pin a bit and I'm trying to make up a rivet tool that will do that for the chain tool. I'll see how it goes on the old chain first.

Interestingly, the old chain showed no signs of burrs after pushing the rivet through. I don't know if there is any difference in the hardness of the steel used in the chains, but I did find that the riveted part of the pin on the new chain was 2.9mm across whereas the riveted part on the old chain was only 2.8mm across (pin diameter is 2.7mm in both cases).

The pin from the old chain had quite noticeable grooves in it from wear. I'll measure the old chain later to see how much it's streched across a number of links (gotta go and find what it should be).

[Wasp]

just a few quick Qs

what is a cam chain and what does it do?

my mechanic said i need to replace the cam chain(s) and tensioners, how much is this going to cost to buy the chain and tensioner? how long would it take if i got him to do it?

[Kwaka-Kid]

VT250 = more expensive because long camchain running around the twin.. cost? dunno.

Erik: Yeah just however man, i have joined heaps of camchain with just a hammer and nail/whatever form of punch is within arms length Its amazing how well they just hold together. And fully agree with death dont worry about the burrs, its amazing how not-rocket-surgeory it is, but at the same time, a critical piece in the workings of that revvy beast.

[T.W.R]

Thanks for the advice, Death and T.W.R.
It's nice to know the burrs aren't a major problem


So right now the new chain is in the bike with the joiner link in place but the pins haven't been riveted yet. I think I'll experiment a bit riveting the old chain before I attack the new one. The rivet tool in that came with the chain has a rounded end (slightly flatter than it originally was after I tried it on a pin in an old final drive chain). It's different to the method I've seen described of punching a cross and a centre punch, so I don't think I trust it. The manufacturer's method of riveting the links seems to be to squish two edges of the pin a bit and I'm trying to make up a rivet tool that will do that for the chain tool. I'll see how it goes on the old chain first.

glad to hear you didn't strike any hassles with the rest of the job. I wouldn't have slipped the joiner into the chain though before i was ready to finish the job, just needs someone to play with it & the joiner could say bye bye down into the sump! lacing the chain ends together with a piece of wire may have been safer.
the punch in the kit relys on compression spreading, and the technique you describe actually fractures the rivet end to achieve the spread. the factories obviously use a fully automated system of machines to do the work, but the rivet spreading is done by a 2 or 4 dogged compression punch.

the tool has a sprung loaded system to hold the chain in place so you shouldn't have to much trouble completing the job.