Lets talk sprockets and chains.

Had a great time riding this last week, no sooner than pulling into my drive way I tried to roll my 990 backwards to hose it off and I could hear my chain binding. A few days prior, I thought it may have been smoked while doing a 30 mph bump start. Anyhow, pulled it apart and the rear sprocket is smoked, front sprocket smoked, chain is K.I.A. 

Looking in my maintenance log (because I can't remember shit) It looks like the set only lasted 5K miles. I knowingly purchased what I can only assume is a Chinese sprocket set, and chain based on the fact it was only $95 for a 525 chain, 16t front, and 42t rear sprocket. I know people who ride fast, I have no illusions, I do not. I usually select the grade of parts I run based on what I think will suite the need.

Out of curiosity I've read what other 990s are getting out of chain sets and it's incredible, some as high as 20K miles! However, that seems possible if your commuting or something like that but if your riding in a place like District 37 I just don't see that happening. I asked around about hours/miles for sprockets and some of my friends average 5K out the Ironman ones that are supposed to be bullet proof. 

This leads me to my next point. In order to increase the longevity of a sprocket, you would have to harden the material or use a hardened material in general. So again, I intentionally reordered another cheap chain and sprocket set. Here is why, I would rather change sprockets than wear the output shaft. I think of it in terms of a engineered failure point. When the drive sprocket is harder than the material that output shaft is made of then I feel that there is potentially a more expensive failure. 

For example, I use to run stock spicer u-joints on my drive shafts because they were cheap and easier to fix than a ring and pinion, or a t-case out put shaft. Something is going to wear out, no way around it...

 

Note: I do regular chain maintenance. The bike is 2010 KTM990Adventure, has all the regular 990 engine type mods, cost wasn't the reason, and I do all my own wrenching. 

Thoughts, experience, anything, send it...

Interesting.  I'll have to inspect mine once I get it back ;)

I would also guess that the amount of weight your hauling plays a factor. For example, loaded up with cases, 2 up, 2 up with cases... 

Those variables have to have some type of impact on wear and tear. 

Wow, 5k isn't anything. I pulled the 530 the Tiger comes with at my 12k. Nothing wrong, just a little worn but even still a lot of guys questioned why I replaced it when most seem to be getting 15k out of a set. Just doing the 18k service now and during inspection I noticed I didn't get any locktite (or the correct torque) on my countershaft sprocket !!   No damage and obviously I had the chain aligned properly as it stayed on the bike but what a zinger! Really glad I do regular checks beacause this one could bite back hard.....chain derailment at 100+ could be problematic at best, fatal at worst.

 

Seriously though, 5k is weak even for a dirt bike. My XR still has her factory chain at 6000+ and it looks great and isn't even half worn by the indicator snails. As I said most Tiger wranglers seem to think at least 15k is normal and I load the crud out of mine as far as weight goes. At least 350 lbs at all times due to gear and what I'll pack at a minimum. The only reason that I would use an aftermarket chain is if it was somehow superior to the one Triumph sells. When I priced them Triumph was actually quite reasonable all things considered...200.00 for a DID 530 O-Ring chain with Sunstar sprockets fore and aft and the countershaft spacer was very competitive with others and you get Triumph's two-year warranty to boot. Yes, I could've probably saved some coin by ebaying them but a two year warranty has got to be worth something and having the peace of mind of all OE parts is handy when dealing with your Dealer and your Warranty. 

Now onto hardness as a factor......you've hit the nail on the head. I'll use my XR again as an example as it has a couple of interesting "features" shall we say.

     The Honda XR650L has been in production relatively unchanged since 1993 and is indeed based on an earlier foreign market only bike by the name of the NX650 Dominator. They've been around for a while in other words. The bike has two glaring weak points.....a weak subframe and a too thin countershaft sprocket resulting in notching of the countershaft output shaft. If you use the factory CS sprocket the wear is bad..if you use an aftermarket sprocket (such as JT) it will be worse. Since the CS shaft is part of the transmission it will require you to split cases when it strips. So we see a lot of XRs with sloppy CS sprockets, stripped CS shafts or horror of horrors WELDED sprockets. The solution of course was either a "kush" hub (expensive) or a new wider countershaft sprocket to help spread out the impact/load. At first guys were using the "R" models' CS shaft as it is a bit wider but the alignment wasn't perfect which caused unacceptable side wear. Fortunately Fritzcoinc over at the Asylum loves the XR and took it upon himself to design a new CS sprocket which addresses these concerns so now we have options besides "kush hubs" which are pricy and now unavailable.

     My point of all this was to demonstrate that there are a variety of factors at work here and as you noticed hardness IS a factor, sometimes to the detriment of some other part or system. I would carefully balance hardness against type of chain, type of terrain, weather and any other factors that were relevant. Should you maybe consider a Scottoiler? Would an X ring chain be better than O ring? Are JT sprockets really hard enough to eat a DID 525 in 3500 miles?(Hint-they ARE) These are questions that only you can answer. It all boils down to what you are willing to live with. 

That is some really great info. I was shocked when I looked back and saw that I only had 5K on the set, but not so much when I asked a friend what he was getting on his 500 EXC. Although, my friend represents what I consider to be an outlier because he's just one of those guys who rides all the time, always fast, and it's 99% gnarly dirt. 

I agree the loads (weight, HP etc.) are a major factor, I really think it is mostly due to the environment that you are riding in. If you are commuting in the dry, sure 12k should be easy. If you are commuting all year in a place like the Pacific North West where it rains a lot and the sprockets are constantly covered in grit who knows? Now if you are riding in sand, dirt, mud etc. the chain and sprockets are subjected to the harshest conditions I would accept 5000 miles as reasonable.

My2c

RPM 

I'm with you on this one. I was thinking lately about bike builds and stuff and I came up with this idea.

I personally ride fairly conservatively, some days, weeks, what ever it's all fire roads and pavement. Some times it's all dirt. But I realized that it's the place where you do your riding.

I had my suspension redone last year by Konflict; yes they have really effective marketing, I day dreams of fully getting it on my 990, I like most big bike guys have some sick idea that these huge bikes are still rally capable beneath all the cool gadgets, but most of all; the desert was beating the hell out my bike. Without even riding it hard, the terrain is so rough that it breaks your stuff. 

Living and riding in a place like Ridgecrest will destroy your stuff. That's why all the local 29 year olds look like they're 40+. 

I guess my old sprocket set wasn't that bad, It looks like they were made by JT. Not Chinese, but Japanese. 

Best thing you can do, especially on a big bike, is invest in the best chain and sprockets you can buy.

I've had good reults with Renthal and Supersprox.

 

 

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I just checked out some of the Renthal Chains, price seems pretty good. 525 R4 SRS @ $150-$180 for the 120 link chain. 

 

Does the 990 have a cush hub? If so, more durable drive components aren't going to add stress to the output shaft.

On 3/6/2017 at 9:36 PM, 556baller said:

I guess my old sprocket set wasn't that bad, It looks like they were made by JT. Not Chinese, but Japanese. 

JT is probably the best steel budget sprocket for the money. Sunstar steel are a bit more, but better steel, probably the #1 oe supplier out there. But, the best I've used are the Ironman stainless sprockets, now called Dirt Tricks Zirconium I believe: http://dirttricks.com/product-category/sprockets/

http://dirttricks.com/shop/sprockets/se-rear-sprockets/ktm-zirconium-rear-sprocket/#

1 hour ago, Bryan Bosch said:

Does the 990 have a cush hub? If so, more durable drive components aren't going to add stress to the output shaft.

Yes, it's running a cush. 

3 minutes ago, 556baller said:

Yes, it's running a cush. 

Figured. That's a lot of torque for the street w/o. I typically do sunstar front, dirt tricks rear, and a quality D.I.D o or x ring chain. But, arguably more important is proper hub alignment and chain tension.

 

 

1 hour ago, Bryan Bosch said:

JT is probably the best steel budget sprocket for the money. Sunstar steel are a bit more, but better steel, probably the #1 oe supplier out there. But, the best I've used are the Ironman stainless sprockets, now called Dirt Tricks Zirconium I believe: http://dirttricks.com/product-category/sprockets/

http://dirttricks.com/shop/sprockets/se-rear-sprockets/ktm-zirconium-rear-sprocket/#

I'm pretty curious, I may throw one on to see what it's like. I wonder if it's like one of those things where you don't know until you know...

Very much a known quantity. If maintained correctly, they will pile on the miles. Made in the USA and with a 2 year warranty. Of course, I'd read its terms and conditions, but in my experience good stuff.

The whole chain and sprockets thing is all new to me this summer.  I've been flogging miles on the 1200GSA for the last couple years and my Africa Twin is forcing me to start studying chains and sprockets.  I'm going to be needing new ones in just a couple months. 

I've got >24,000km on my current chain sprockets on my 990.  This is a 16/42 setup, OEM ktm sprockets with a chain from the local dealer.

Chain still seems great, sprockets only showing slight "wave" profile.  I keep the chain adjusted and sometimes lubed...it only gets dusty miles.

I have a new set of JT sprockets and an RK X-ring 525 chain on the bench ready to go on.  Call it a preventative.  We have a 7000km run down the CDR and back to Canada this summer and I have found in the past when a chain starts to go, it goes fast.  I didn't want to be half way through an EPIC ride and have chain issues.  

I just replaced the 525 chain on my Vstrom because it was going tight in one section.  It wasn't stiff, just rode high on the rear sprocket as if it stretched in the one section?  The sprockets didn't look too bad, but didn't like that feel.  I went to a 530 because that is what my old SV1k ran and it seemed the right size for a liter twin.  So an SV 17t front sprocket from PBI, a 42t JT steel rear for a GSXR1k, and a DID X-ring 530 chain went on for a much smoother ride.  That should last a while.  :thumbsup:

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