[BrianHull]

So I started out riding the bike to work this morning and about half way there the chain breaks! It flies off into the abyss and I have no acceleration. I pull over to the side of the highway and call the wife to bring the pickup truck. Like a trooper, she threw a few long 2x4's in the back of the bed and after a few tries we eventually get the 450 rolled up into the truck bed for towing. So after this I start to think about it and the broken chain wasn't that old, maybe 2-3 years tops. I recently replaced the back tire and perhaps had too much slack in it. Come to think of it I don't know the average chain life for motorcycles, but it seems to me they would typically last for several years minimum, probably longer if well maintained.

The other thing that seems odd is I was having trouble shifting gears right before the chain break. At the stop light I shifted it to neutral and it didn't want to go into 1st gear. Had to roll the bike a bit to finally get it to shift for take off. Before that it had revved up in 3rd or 4th gear acceleration like the clutch slipped a little. I relaxed the gas and it quickly catch itself again to normal. Do these oddities suggest a clutch issue? Perhaps one that would cause a chain break? I have had a few clutch incidences where it felt like slippage, but I would not think that would cause a chain break. I figured the clutch plates might be worn out and I would replace once I had a chance to get to it. Any ideas?

 

[longdistancerider]

Could be master link failure, badly worn sprockets allowing the chain to jump teeth, chain failure,, chain not adjusted properly, etc.
How are your sprockets, nice sharp points on the ends like this?

If so the the sprocket is dead, the one in the picture is a thousand miles past replacement.

 

[80cb400t]

Also if you see red dust like in that picture I'm fairly sure it comes from rust wearing off of your chain (not a good thing for a chain to do), solution is lube every two tanks (with chain saver dupont for example). The other possibility is rust between the hub and spacer, which means the spacer is probably worn out (or has rusted due to grease being dislodged)

Speculating about the transmission stuff, going from N to 1st sounds normal unless the bike has been crashed and the shift shaft bent, but it would be a pain to do every single time. I had a bike like that at a riding course to redo my skills test. I'd just be waiting in the practice line tapping and rolling it trying to get it into neutral (the opposite problem) before I gave up and kept it in gear or shut it off.

Clutch slipping could be oil (probably not if you're using rotella or a motorcycle oil), just plain old worn out, or potentially if your chain had too much slack for a while, you might have adjusted to slipping the clutch more to avoid jerking, which had worn out the clutch plates. Only way to find out for is measure them and the springs if it still does it after the new chain/sprockets

 

[BrianHull]

I don't think it is the rear sprocket. I looked at them and they seem good, not pointy, and no red rust. I'm going to say it was probably a improper chain adjustment. I don't know how good the last chain I bought was. Perhaps it was cheap metal or something. Does anyone have recommendations on a good name brand chain replacement before I start the web search?

 

[80cb400t]

I bought an EK one, RK and DID are the other name brands. When you get the wheel back together try pushing/pulling the sprocket towards and away from the wheel, that's how you can tell if the spacer/washer etc. have worn down and it's wobbling

 

[longdistancerider]

There's lots of cheap chains on eBay, even Amazon, that real shops won't sell. Things are usually cheap because of inferior materials first and poor manufacturing/cheap labor second. EK, RK and DID are known good brands.

 

[BrianHull]

Thanks for the recommendations. I will check those brands out.

The rear wheel sprocket is solid and has no movement. The front sprocket connected to the transmission is wobbly and moves noticeably. When push/ pull it moves about 1/16"-1/8" of an inch or so back and forth. Looks like it's key-wayed onto the splined tranny shaft and secured with two bolts. I'm not sure how much slop is allowed here but it definitely has some wiggle to it.

 

[longdistancerider]

Front sprocket should be loose like you describe. It's a designed floating sprocket to allow for slight misalignments of the chain as it rotates thru. The groove in the counter shaft that the retainer fits is sets the amount of play.

 

[BrianHull]

So I ordered a new DID chain a while back. Had a little trouble with linkage because it needed a special chain rivet tool. I bought a new chain rivet/press tool and I put the chain together off the bike and then realized I had a problem! Chain won't really go on the bike without taking apart the frame and perhaps the front sprocket:-?



It looks like the sprocket needs removed to fit a riveted chain on. Wanted to check if I was opening a can of worms or if there is anything I should know about removing the sprocket before I put the chain on this way? Think I have have everything else clear and ready to access the chain area. Also while I have the swing arm off is there any thing I should check on before reassembly? Everything seems to be working fine other then a chain breaking. Open to suggestions on maintenance while I have the rear apart though.

 

[jd50i]

How is the alignment between the front and rear sprocket? Any reason you didn't use a master link?

 

[BrianHull]

I have not checked alignment between sprockets. Far as I know it's fine.. What's the best method for checking this?

By master link, I assume your talking about the clip on c-shaped linkage. When I bought the DID chain it came with a rivet type link. I did some research and found the rivets are stronger and break less. Seem like a good idea to go rivet since I had a chain break on me.

 

[76TWIN]

Um what? Why would you need to remove the sprockets and swing arm in order to install the chain?
Just break the chain and then use a master link to reconnect it.

 

[BrianHull]

I did try to remove the link but it seems like the rivet is really on there. I'm afraid I'll ruin the linkage or possibly the chain if I over do it. Which I want to good rivet chain connection and was able to get to it better off the bike. I already had the rear tire removed for alignment. Seems easier at this point to thread the riveted chain through the frame. I'm not sure if the sprocket needs to come off but it seems like it might to get the chain around the surrounding housing. Also, I just like taking things apart!

 

[jd50i]

I have not checked alignment between sprockets. Far as I know it's fine.. What's the best method for checking this?

By master link, I assume your talking about the clip on c-shaped linkage. When I bought the DID chain it came with a rivet type link. I did some research and found the rivets are stronger and break less. Seem like a good idea to go rivet since I had a chain break on me.

If you have a laser line level you can shine the laser from the rear pointing forward. Run the laser along the edge of both sprockets and see if they are aligned. You can also use a string or a straightedge if you have room.

I'd go find the chain to see how it failed.

 

[76TWIN]

I would still suggest using a master link for the chain. That way you can remove it easily later when it needs to be replaced and won't have to take out the swing arm and sprockets.
These chains are designed to use master links.

https://www.ebay.com/itm/D-I-D-530N...236513&hash=item3fa4f9230d:g:JIoAAOSwjXNbRlTf

 

[longdistancerider]

The normal way of doing the chain is to rivet it once the chain is in place since the swing arm prevents installation of a completed chain. I've only used the clip type master link and have never had a problem with them.
I'd inspect the swing arm bushing assembly for wear and change the zert fittings over to ones that work with a conventional grease gun. Clean out all of the old grease, the old zerts are probably gummed and plugged up.

 

[JamesPal]

There are continuous chains without master links. And there are chains that have a master link. Our bikes delivered from the factory with continuous drive chains. There is a reason for that, which is they are more reliable. I have always replaced the continuous chain with a master link and never lost one. With that being said I always ride with a spare master link in the bike's tool kit. I have the ability (tools) to reinstall the chain on the side of the road. I think it is important the master link is properly installed, the chain tensioned correctly and the sprockets aligned. If you are running the correct rear wheel, all you should need to do to align the sprockets is to make sure the wheel is straight in the swing arm. There are little marks along the axle slot on the face of the swing arm. Just make sure they are the same number from the end. If you are willing to do the work to install a continuous chain, them my hat is off to you. You will be better off.

 

[dtsmjr8dan]

In almost 57 years on bikes, I've only ever had one master link fail. And it was a well used link on a well used chain.
I'd say that's a pretty good record for using master link chains.
Since that time, I've been more diligent with maintenance (benefit of experience and listening to those who know more...lol)

 

[BrianHull]

The internet seems to say continuous chains are stronger, but perhaps not necessary for normal street uses. I did use the marks around the rear tire axle to align the tire and rear sprocket. I also used calipers to measure the tensioner bolt spacing on each side of the rear wheel. Installing the continuous chain by removing the rear wheel, swing arm, and front sprocket wasn't that bad. Nothing scary, just loosening bolts. It allowed me the opportunity to check the swing arm and front sprocket. With it all disassembled, I was able to clean the areas before putting everything back together. I ended up with 19-21 mm of chain movement after everything was done. Now it's time to clean up the shop and wait for a dry day and see how it all works.

 

[longdistancerider]

The CM/CB 400 series was originally a clip type master mink from the factory, not continuous or a rivet master link.
The chain freeplay should be measured with the bike on the ground, not on the center stand or rear wheel off the ground.