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On every new kawi in the past years, the lower chain roller disintegrates after just a couple rides.
The new 2019/2020 450 has the worst roller with it only holding up about one to three rides, yet the japanese engineers refuse to do anything about it.
You would think that would be a simple fix.....
Ever tried that brace that was linked on the previous page?
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There's no way to gather accurate data about those failures, but I have a good hunch most people ripping the chain guide brackets off of the swing arm are running those aftermarket polymer guides like yours.
Most of those polymer guides are probably made from UHMW, Delrin, Acetyl, or HDPE.
They flex a lot more than a stamped aluminum guide from any Japanese OEM.
The flex between the mounting tabs is probably a source of your trouble. Those tabs are much stronger if stressed together as a unit.
What I am saying is that you need a metal bracket between the bolts on the front and back to stiffen up the assembly.
The engineers who developed that designed it as a complete system with the stock metal chain guide.
Any non-Honda OEM:
"Should this be replaced or updated? Yes. Will it be easy to do and cost effective? Yes. Will it enhance the value of our vehicles? Yes. Will it reduce warranty claims and/or invite more return business? Yes. Is this change fully within our operational parameters to make for the next model year? Yes. Do we have all the necessary tooling and resources to go forward? Yes.
Is Honda doing it? No.
OK, let's wait until they do it."
Honda:
"Are any of those other twits doing it? No. OK, let's wait until they do."
I’ve never had any problem with chain guides on KXs for 35 years
- I ordered a new (used in good condition) yzf swingarm off ebay, should be here in a few days.
- Upon receiving the swingarm, I'll start taking some measurements and see what I can come up with to strengthen this area. I'm going to avoid welding anything extra to the swingarm for reasons I've outlined in previous posts, so any additional pieces will be bolt on. I'll likely be using the ktm braces linked on the first page of this thread as inspiration because like CW said, the polymer chain guides could very well be allowing the mounts to flex independent of each other and actually be doing more harm than good over time.
- With any luck I'll be able to come up with something reasonable and be able to machine up a prototype. It will depend on how complex it gets since I don't have CNC access, but I can get at a manual mill so hopefully that will be sufficient. If it comes out well and is user friendly maybe we can organize a group buy and have them machined at an actual shop, we would probably need at least 10-15 people willing to buy in to make the cost worth it though because low quantity runs are outstandably expensive.
As things progress I'll update this thread.
Alignment is easy. Clamp a straight edge to one or both sides of your sprocket, have it long enough and rigid enough to reach your counter sprocket. Not using the marks on the swing arm align your rear wheel using your gauge. Once that rear wheel is dead on, just use your sprocket as a reference for the new guide placement.
I have various straight edge stock for alignment, 1/4 thick 1 1/4 wide cold rolled steel bar works good. Aluminum extrusions are really straight as well.
Another tip, if you have an extra hub around, mount it with a sprocket to the swing arm, align to front sprocket. Then take the swing arm off and take to the welder with your new fancy pants bracket. Being able to bench weld that bracket would be great, could get a damn good eye / gauge view on that bracket to sprocket alignment instead of working off the floor or stand.
Pit Row
Cool story Bro..... try again
Did a sprocket bolt or two come loose causing the chain to come off breaking the mount?
Did the rear axle or chain adjusters loosen on one side causing the chain to come off breaking the mount?
Did you just short a jump or ? and hit a large rock causing it to break?
Could an improperly adjusted chain cause too much stress over time, causing the break?
I too have been riding 30+ years and never broke one. I don't know that I've actually seen one in person, just on the web. Plenty of broken bones though!
There has to be a source to the break. There is no way this just broke on it's own from riding.
If that was the case, we'd hear way more about that happening.
In my opinion, if everything is tightened properly and adjusted properly, this doesn't happen unless someone crashes or hits something with quite a bit of force.
These don't rip themselves off for no reason. Something unusual is causing it.
Post a reply to: Japanese manufacturers, can we have an honest conversation about your chain guide mounting please?