quote:
Originally posted by 1sttruck:
If there's one thing you can't skimp on with high-horsepower bikes- it's the chain. And for the Hayabusa- it isn't cheap. I typically find myself replacing the chain and sprockets once a year- or about every 10,000 miles. On high horsepower bikes, the teeth of the chain get literally bent- not in dramatic way- but when you set the old against new, you can clearly see it."
Maybe he's talking about the sprocket, but he did say chain.
You do not trust anything I'm offering, yet you refer us to a message board offering by a fellow who didn't even proof read his material.
Of course he's talking about a sprocket, as we all know (well... maybe we all know)that a chain has no teeth. What the guy was explaining was the difference in new and used sprocket tooth profiles. Which, btw...were deformed due to CHAIN ELONGATION!
When a chain enters a sprocket, the tooth working face meets up with the roller. A slight chordal action takes place with a slight rise and fall of the reel entering the chain wheel.
Once the reel has undergone it's chordal action, it proceeds to the valley that is in between two teeth. Without the rollers in place on the chain, this action would indeed wear the working faces of the teeth. However, the roller provides a means to take away the friction between sprocket and the outside of the roller, and places the friction to the inside diameter of the roler and the bushing, which is lubricated to minimize wear from this action. The pin also rotates against the inside diameter of the bushing at this point, and is also protected from frictional wear by lubrication.
Once the reel is in place in the valley, it remains at complete rest during it's travel, while the corrosponding reels are also at rest in the valleys before and after, because the pitch of the chain is exactly the same as the distance between the center of the tooth valleys.
When the chain exits the sprocket, the roller protects the working faces of the teeth as it did at entry.
Since a roller moving along the surface of the working face does not create any friction at all, (similar to a tire roling on a road) there is no continued wear from the entry and exit of the chain.
Since the friction that IS created is within the chain, and is theoretically protected by lubricant, wear, which is completely seen on the chain components, is kept to a minimum.
ONLY when the pitch of the chain changes, is there a problem with the sprockets seeing any sort of undue stress.
Since the pitch of the worn chain is now slightly longer than the distance between the tooth valleys, the chain rollers will tend to "climb" the working faces of the teeth, and never can actually seat themselves into the valley, as the new pitch chain could.
With increased elongation of the chain, this climbing of the working faces becomes more and more pronounced. As there is less and less material on a sprocket tooth as you go outward, the "meat" of the tooth is less and less able to keep from deforming, due to the elongated chain trying to mesh.
The result is "hooked" or pointed teeth.
The brute force of a bike has NOTHING to do with the deforming of the sprocket teeth.
This fact will be argued as incorrect by many, simply because they are using logic and conventional wisdom in their arguments, and not chain dynamics and engineering absolutes.
In other words, people only "think" that their monster HP bike is what deformed their sprocket.
The fact is that a higher HP/torque bike can indeed accelerate the elongation of a chain, especially a chain that is undersized, or being inadequately lubricated. This accelerated elongation of the chains pitch is what starts to deform the teeth of the sprockets, and not the pull force of the chain.
Quality driver sprockets will often times be case hardened, creating a hard outer surface (that helps protect from extraious contaminants like road grit and sand) yet have a soft inner core that helps to absorb shock load. This is a very important factor when considering using a driver (front or "countershaft") sprocket, as they often will have fewer teeth than proper engineering standards dictate.
The driven (rear) sprocket does not really need to be a super hard item, as it has many more teeth in play, and has the load distributed amoung multiple teeth, reducing the load on each individual tooth.
Yes, wear that cannot be accounted for can occur from the sprockets seeing dirt and grime, or from trail/road hazzards. But, this type of wear is never seen as a typical thing amoung the teeth. In other words, this type of wear will only be seen at the teeth that saw the dirt or hazzard, and not a continued deformation that is exactly the same on each tooth. Only an elongated chain, OR a maladjustment can do this.
More often than not, a person who experiences an almost immediate wear problem will have an adjustment problem, assuming they are providing sufficient lubrication.
I have had customers complain that their sprockets started deforming right away after mounting up brand new stuff. What I will most often find is that the chain was adjusted with insufficent sag. The sprockets may well be perfectly aligned, BUT the tension placed on the chain was a slight bit too much. The result is that when the bike sees a bump, the swingarm changes position, and the chain is forced into a taught postition, which in turn places undue stress on the working faces of the teeth, as the chain is trying to enter the sprocket.
This compressed condition is exactly why we need to have proper tension placed on the chain with it in it's tightest position.
Problem is, that tightest postion MUST be accomplished by either compressing the shock and keeping it in that condition by a cargo strap or weighting the bike. Or by removing the shock completely and then strapping the swingarm in it's tightest postion.
(a straight line from front sprocket-through swingarm-to rear sprocket)
This mounting procedure is missed by many people.
I even see bikes on showroom floors with chains too tight. I know for a fact that guy who buys the bike, and does nothing but ride it away, is going to have problems. Most folks will immediately complain that the OEM chain and sprockets are junk, when in fact, the reason they saw a problem almost immediately is due to the ineptness of the mechanic (or so called mechanic) that assembled the bike.
satterfli,
Yes, it is advantageous to use an automatic oiler like the Scott. However, they tend to make big messes. Another problem that Scott oilers have is that they sling the lubricant directly in the plane of the sprocket and back to the chain. The sprocket meets the chain at the INNER sideplates. Whne the oil meets that chain at this area, it can indeed get to the roler/bushing area and the rings themselves. WHich is all that is needed on a ring chain, as the pin/bushing area is protected by internal lubricant.
BUT, using a Scott oiler while having a standard non-ring chain mounted can be a problem when you use a higher end roler chain.
High end roller non-ring chains tend to now have the bushings mfg'ed as a one piece item, as opposed to the conventional formed bushing.
(a plate that is bent into a circle making a bushing)
A solid bushing can only get lubricant introduced from each end. It has no slot in it latteraly as does a formed bushing chains.
The bushing will also often slightly protrude past the inner plate side.
This condition makes it very hard for the oil to be introduced into the bushing opening, which is on the opposite side of the inner plate where the lubricant goes when it leaves the oiler.
But trust me...I am providing this little pearl of information for the benefit of others. I can see you are a kid with a bad attitude, even resorting to name calling, so I am pretty much done with you, pal.
Like I said, if you care to learn something, I will be glad to help. You want to continue name caling and being a bad clown, then be my guest.
Enjoy your ignorance.
Just a couple of links that may help us to understand the real deal on this issue:
http://www.didchain.com/install.htm
http://www.dansmc.com/rearchain.htm
Usually, when the chain is worn out so are the front and rear sprockets. This is because a chain does not "stretch" as it wears. It becomes elongated due to wear in the joints. This changes the pitch, which in turn wears out the sprockets.
Folks have asked me to provide proof of what I'm telling you, and is probaly waranted because it is me that is asserting these facts. However, perhaps it's fair for me to ask those who disagree to also provide a bit of proof that I'm incorrect.
Explain to us how a sprocket wears without the chain elongating, and being perfectly adjusted and sufficiently lubriacated.
