Thread: The Chain

Results 1 to 7 of 7
  1. Collapse Details
    The Chain
    #1
    Senior Member Gotted's Avatar
    Join Date
    Apr 2008
    Location
    Clarkston WA.
    Posts
    699
    Post
    Selecting the Right Chain
    Picking the right chain is the first step towards developing a reliable chain-drive system. Many people are surprised that finding the right chain is not difficult or expensive. Perhaps the most difficult part of purchasing chain is finding a supplier that carries the chain in sufficient lengths. While standard motorcycle chain with a tensile strength over 7200 lbs is sufficient for the task, most motorcycle shops are not in the practice of carrying chain that is long enough for motorcycle powered racing cars. “Most motorcycles require chain that is only 120 to 130 links long. Mini-sprints, micro sprints and modified midgets require over 130 lengths. We’ve started carrying large rolls of chain so that our customers can order whatever length of chain they require. This keeps them from trying to connect multiple lengths of chain to get what they need”, commented Fasse.

    Once you get beyond the question of length, you move into the age old debate between standard chain versus o-ring chain. Fasse commented, “At Speed Partz we supply both standard and o-ring chain, but almost all of our customers prefer standard chain. I believe if properly cared for, standard chain is the right choice. For one thing, it is significantly lighter and less expensive than o-ring chain.” There was a mass introduction of o-ring chain into the motorcycle industry in the mid eighties because of its relative ease of maintenance. O-ring chain uses tiny rubber seals between each plate to keep grease trapped inside the chains rollers, for longer life. Many people believe that the tiny seals used in o-ring chain create additional friction that keeps the chain from spinning as freely as a standard chain. However, there are manufacturers that claim as the greases in an o-ring chain thin out, they are capable of spinning as freely as non o-ring chain.

    Chain Wear
    Dyno testing has proven that a worn chain kills horsepower, in addition to placing the car at higher risk for a chain failure. The question becomes “how do I know when it is time to replace my chain?” Answering this question is heavily dependant on how well the chain has been cared for. Let’s digress for a minute for a better understanding of how a chain wears. Let’s begin our explanation in a perfect world with a new chain and sprockets. The sprocket on the engine (called the countershaft sprocket) is pulling chain off the top and feeding it on to the bottom of the rear sprocket causing the rear wheels of the car to rotate. As the rear sprocket rotates the next chain roller to be fed onto the bottom of the rear sprocket approaches the next groove in the sprocket and it drops straight into the groove. Since the distance between each link of the chain is the same, the chain will drop directly into the groove. The result is equal distribution of the pulling force across all links of the chain. This perfect world usually lasts less than one revolution of the wheel. In order for the chain to curve around the sprockets and then return to straight, the chain’s pins must rotate slightly inside the bushing of each link. Each rotation of the pin while the chain is under pulling tension results in some of the pins metal being worn away. Just how much metal is worn away depends on how well the chain’s pins are lubricated, the amount of tension on the chain and the condition of the rear sprocket. As the metal on each pin is worn away in different amounts for each link of the chain the pins loosen in the bushing allowing the distance between each link to change and making the chain appear to stretch. This means the pulling force is no longer uniformly distributed along the chain. Since the distance in between rollers changes the chain no longer fall directly into the sprocket groove, instead tending to ride up further on the sprocket teeth leading to increase sprocket wear and ultimately the possibility of the chain coming off.

    Determining when a chain has experienced signficant wear to rob horsepower or place the chain at significant risk for failure is not an exact science. Many people suggest that once a chain reaches an additional 3% of each original length, the chain should be replaced. Another sign of significant chain wear is the sprocket. Since a worn chain does not fall into the grooves of the sprocket as well as a new chain, the teeth on the sprocket deform leading to hooking or pointing. A worn, stretched chain puts uneven stresses on the motor and sprockets leading to additional friction and ultimately the loss of power. The bottom line on the dyno testing with a worn chain and a new chain—a worn chain can lead to a 5% loss of power.

    Keeping the Chain On
    Here is one that it is probably wise not to touch. There are so many complexities to keeping a chain on that it would be impossible to give adequate treatment to all eventualities. We’ll take the high road on this one and cover a few of the basics. Most car builders agree that if a chain is properly aligned there is probably not a requirement for a chain tensioner at all. While I am not sure if this is fact or fiction, the point is that before assuming it is the chain tensioner, there are some other items to consider. All of these items center around alignment. The first item to check is the alignment of the front and rear sprockets. They need to be perfectly in-line. There are many ways to do this. The first test of alignment is a visual one. Get down on your hands and knees and sight from the rear sprocket to the front. This will get you in the ball park, if not there. If you feel additional alignment is required there are tools that can assist. A trip to the local hardware to purchase a laser alignment device might not be a bad idea. Others will opt for a string or steel rod. Whatever the method, it is important that the front and rear sprockets are perfectly aligned. A strong indication that your chain is out of alignment is how the sprocket teeth are wearing. If you find that one side of your sprocket teeth are shinier than the other, that is a good indication that your chain is not in alignment. Even if your chain is staying on, but is slightly out of alignment, you are increasing friction and robbing your car of power.

    Another point of alignment that people are less likely to think about is the height relationship of the front and rear sprocket. “The most common problem that we see here is that the engine has been mounted to high in the chassis. The front sprocket is up higher than the rear sprocket. The result is the chain basically runs downhill. As the suspension compresses under racing conditions, the distance between the front and rear sprockets shortens dramatically leading to excessive slack in the chain and ultimately causing the chain to be thrown or broken”, commented Fasse. Again the objective here is to have the middle of the front and rear sprockets level with each other when the car is sitting on level ground.

    Another common problem that is worth mentioning centers around how tight you keep your chain. While common sense would lead one to believe that a tighter chain is better than a looser one, this is not the case. A tight chain not only creates additional friction, but leads to increased chain wear. “We were as guilty of this as anyone. For a long-time we allowed very little slack in our chain. Mini-sprint pioneer, Gary Doemelt, looked at our car and told us your running that chain way to tight. He explained that we should be running around three inches of slack in our chain to allow the chain to roll more freely without binding up the car. He also introduced us to the block style chain tensioner that allows the chain to be run this loosely. Today that style of chain tensioner is one of our hottest sellers”, commented Fasse. In addition to allowing the chain to be run looser than traditional arm style chain tensioners, the block style chain tensioner is also significantly lighter and less expensive.

    Chain Care
    There is no question a well cared for chain can provide a competitive advantage—but more importantly should ensure that you finish the race. Keeping your chain oiled is extremely important to its operation and longevity. The pins that rotate inside the bushings of each link of your chain require constant lubrication. The prescense of lubrication prevents metal from being removed for the pins under normal operation. Even the cheapest non o-ring chain will last for a long time when properly lubricated. There are many very good lubricants on the market today. One of the most important things to remember is that chain lubricant needs at least twenty minutes to dry before you race. It is also a good idea to apply the chain lubricant from the inside surface of the chain. This gives it a better chance of penetrating. When applied to the outside surface of the chain, centrifugal force pulls the lubricant off the chain. When applied to the inside surface of the chain, centrifugal force pulls it through the chain. If you are really hard core, you might even want to go the route that many of the professional motorcycle road racing tuners go—gear lube. The gear lube is brushed on and allowed to dry overnight, so that all excess oil drips off. Be warned, this is a messy proposition.

    Dirt and grime are also enemies of the chain’s pins and bushings. In addition to causing the chain’s pins and bushings to wear more quickly, it creates additional power robbing friction. For this reason, periodic cleanings are a good idea. The best way to clean your chain is to remove it from the car and soak it in kerosene or diesel fuel. (It is not a good idea to soak your o-ring chain in solvents like kerosene or diesel fuel since they will destroy the rubber o-rings.) A wire brush is also helpful when cleaning your chain. After thoroughly soaking your chain in solvent, it is not a bad idea to also soak the chain in gear oil. This gives you the best chance of getting lubricant inside the hard to reach bushings.

    Is the chain the Achilles heal of motorcycle powered racing cars? With proper alignment and care it really doesn’t have to be. The chain is actually one of the beautiful things about motorcycle powered racing cars since it reduces costs by eliminating expensive drive-trains.

    A properly cared for chain can provide a competitive advantage.
    Reply With Quote
     

  2. Collapse Details
    Re: The Chain
    #2
    Senior Member arrowhead's Avatar
    Join Date
    Jul 2008
    Location
    2 minutes from the sand in Florence
    Posts
    337
    Default
    Well said

    So what is the best lubricant to use other than gear oil?????? I can make a big enough mess without that.

    I prefer PJ1 Black Label in spray can

    I also use a 4" fan to cool my chain and it really seems to make a difference

    Dale
    Last edited by arrowhead; 05-04-2009 at 09:04 PM. Reason: spelling duh
    Reply With Quote
     

  3. Collapse Details
    Re: The Chain
    #3
    Default
    Quote Originally Posted by arrowhead View Post
    Well said

    So what is the best lubricant to use other than gear oil?????? I can make a big enough mess without that.

    I prefer PJ1 Black Label in spray can

    I also use a 4" fan to cool my chain and it really seems to make a difference

    Dale
    I thought it would be kinda cool to run a small sprocket on the chain that had a fan on it, that way the faster you went, the faster the fan cooled the chain, or if you could swing it, a fan mounted to the motor sprocket...
    www.SinisterSandSports.com
    918-521-3736
    Yes, i'm on facebook clicky clicky.................

    Reply With Quote
     

  4. Collapse Details
    Re: The Chain
    #4
    Senior Member arrowhead's Avatar
    Join Date
    Jul 2008
    Location
    2 minutes from the sand in Florence
    Posts
    337
    Default
    My fan is a 4" bilge blower from a boat that is turned on by a microswitch on the injector linkage so it only comes on when you get on the gas. After a fast run now my chain has never been hot to the touch...Before I installed the fan I was turning a 36 link chain blue
    Reply With Quote
     

  5. Collapse Details
    Re: The Chain
    #5
    Senior Member
    Join Date
    Feb 2006
    Location
    Winder Georgia
    Posts
    7,960
    Default
    It is amazing a 4 " bilge pump fan is cooling the chain from blueing to touch by hand... Id almost say miraculous..
    Reply With Quote
     

  6. Collapse Details
    Re: The Chain
    #6
    Senior Member arrowhead's Avatar
    Join Date
    Jul 2008
    Location
    2 minutes from the sand in Florence
    Posts
    337
    Default
    I have witnesses! 950 sand miles on the same chain

    There is a short piece of hose that blows directly on both sets of open chain
    Reply With Quote
     

  7. Collapse Details
    Re: The Chain
    #7
    Admin Gene's Avatar
    Join Date
    Dec 2005
    Location
    Soyo, Angola Africa
    Posts
    6,715
    Default
    Let's not forget the Honda transaxle that continues proving itself. That's impressive too.
    Reply With Quote
     

Similar Threads

  1. Which Chain do you run? (Turbo Hayabusa 530)
    By DuneMe in forum Driveline
    Replies: 21
    Last Post: 06-21-2010, 01:01 PM
  2. 530 chain maufacture for haybusa power minibuggy???
    By bngcustoms in forum MiniBuggy.net Lounge!
    Replies: 6
    Last Post: 12-23-2007, 10:30 AM
  3. Krause sidewinder chain
    By Bugpac in forum Driveline
    Replies: 7
    Last Post: 09-03-2007, 06:04 PM
  4. Chain at 16000 rpm
    By LEE1969GB in forum Driveline
    Replies: 13
    Last Post: 01-20-2007, 04:14 AM
  5. Chain driven trailing arm
    By LEE1969GB in forum Driveline
    Replies: 5
    Last Post: 01-18-2007, 06:04 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •