Kawasaki KLR Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
117 Posts
Discussion Starter #1
So 2300 miles ago, I replaced a worn out rear sprocket with a new one from Rocky Mountain, primary drive brand. Now half the teeth are busted off, and the rest look ready to go too. WTF? Now I didn't change the chain out at the time, since it didn't seem to need it. And I'll readily admit that I ride aggressively commuting back and forth to work in heavy traffic. But still! Worn out between oil changes? When I install my new rear tire this week, I'll be putting on a new chain and both sprockets. Going with Sunstar sprockets this time, hopefully they last longer.
So is this the kind of life span I can expect with my style of riding or is it just what I get for going with cheap parts? Maybe it was just a fluke? What do you think?

Sent from my SM-G920V using Tapatalk
 

·
Registered
Joined
·
1,256 Posts
I think a good clear photo is needed. Maybe a couple rom different angles.

I also think Rocky Mountain would like to have that sprocket back and would most likely send you a new one.

I bought a new Shinko 270 rear tire from Motorcyclesuperstore.com and it lost about 11 center knobs in 500 miles. I asked how that could happen. They asked for a photo of some missing knobs and a drill bit through the tire and sent me a full credit. So, I am still buying things from them. Be polite and ask them how they think this could have happened and see what happens.
 

·
Premium Member
Joined
·
2,944 Posts
Most probable cause: bad chain. Order another set and replace both this time. The Primary Drive stuff from RMATV is decent according to all reports I've read.

2 cents,
Dave
 

·
Registered
Joined
·
91 Posts
I've never had an issue, if the old sprocket was worn, it's most likely that the chain was worn as well.

Sent from my Nexus 6 using Tapatalk
 

·
Administrator
Joined
·
3,564 Posts
How many miles on the chain?? I'm thinking the chain caused the excessive wear. Recommended to change the chain and sprockets together. Like to see what Rocky ATV would say about it. I've got about 8000 miles on a Primary Drive chain & sprocket set and they still look great.
 

·
Registered
Joined
·
529 Posts
I agree with the others here. A stretched chain can easily knock the teeth off a rear sprocket.

I don't know if you ride off road much, but I've crunched gravels between chain/sprocket and pooched gears that way. It stinks, but it's just part of the game.

A worn out cush drive with a bad bearing in a gear carrier could result in this as well.

Also, and not to be rude, but you really should be able to easily tell if a chain is stretched to the point of where it would wreck a gear. It would be clicking and popping trying to force-fit itself. If you didn't notice this, then definitely take pics of the gear and contact the seller. The world isn't perfect and there could be a batch of gears that didn't get machined properly. Sellers and manufacturers would love to know about this, but likely will never find out unless you help them.

Sprockets don't shed whole teeth when you wear them out. It's definitely not a premature wear issue, something is destroying the gear, or faulty manufacturing is at hand.

Last thing, are you positive the new rear gear was the correct pitch to match your preexisting chain?
 

·
Premium Member
Joined
·
1,585 Posts
Good point, Ribz.

Is a non 520 sprocket accidentally on?

I just came off a similar episode. Rock-twisted chain got replaced with a
used one. I didn't realize how used. On a 1200 mile round trip the chain was
getting HOT. Stops for gas and a shot of WD-40 on the chain made the stuff
kinda steam off !! Got to NY, the halfway point/ destination and the chain and
sprockets were shot in 600 miles. Reversing the sprockets and a new chain got
me home babying it. Spare front and a new rear sprocket are on now.

(The teeth were shark-finned but all were intact, and some flattening at the tips.)

Red,
I've been with D.I.D. chains and Sunstar sprockets 30 years.
A matched new driveset should last 20,000 miles on minimal care and hard riding.
30,000 for a clean, wet chain.
 
1 - 7 of 7 Posts
Top